A Cost-Efficient Energy Management Model for ICT4D Platforms in Low Resource Communities
- Authors: Mbotoloshi, Dumisani
- Date: 2018
- Subjects: Information technology Communication in community development|
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/14538 , vital:39999
- Description: A couple of Information and Communication Technology (ICT) researches have been conducted in the rural communities of South Africa (SA). This has encouraged the development of ICT services such as e-government, e-commerce, e-judiciary, e-health, e-agriculture and many others. Proper ICT implementation has led to societal development, economic empowerment and sustainable communities. However, this is achieved after intensive planning and stakeholders‟ involvement. It is clear that ICTs require energy to function. Most significantly is the fact that a bulk of ICTs in low resource communities (LRC) are mainly donations and less consideration if any is made on their energy consumption. LRC are regions with minimum access to energy, clean water, educational facilities, health facilities, government facilities, technology etc. There have been debates on whether in LRC ICTs are consuming energy. Most ICTs have been deployed without much consideration on the required energy consumption. On the other hand, less research has been done on the sustainability of ICTs, especially considering that all ICT devices and related platforms rely on the availability of energy. There are a lot of possible low cost energy solutions that are available, which could be used to support ICTs in LRC. However, there are so many ICT services, devices and platforms that are lying idle and not been fully utilized in such areas due to the energy related issues. In most cases, ICT solutions in LRC are introduced mainly with Computer Science and Information Systems researchers, without including other key stakeholders like energy experts. The research presents a Cost Effecient Energy Management Model that could be used to assist ICT for Development (ICT4D) platforms or projects in LRC. Both qualitative and quantitative research methods were used within the Siyakhula Living Lab (SLL) in Eastern Cape (EC) Province of SA. Design Science theory is considered for the designing of the model. The SLL is an ICT project which is undertaken within the Dwesa, Bulembu and Alice rural communities. In this dissertation, Dwesa rural community is the chosen case. The surrounding schools in the communities have been used as the ICT point of contact. Interviews, questionnaires, literature v review, action research, focus group, experiments, formulas and evaluation were the specific methods used to conduct this research. Results show that ICTs deployed in the SLLs are mainly donations which consume much energy. The main source of energy use within the SLLs is electricity. From the three schools that were selected where ICTs have been deployed it was found that the electricity bill has increased enormously. This has caused some schools not to open the computer laboratories, which are supposed to be used by the community members. It was also found that there is no energy management plan or solution in place for the SLL resources. The findings show that ICTs within the SLL are been affected by energy related subjects, though the community has been willing to pay for electricity. The Cost Efficient Energy Management Model is proposed at the end of the dissertation. The model is targeted for ICT service providers and has five (5) main pillars i.e stakeholders‟ engagement, energy and ICT infrastructure, new business models, monitoring and evaluation, and finally awareness and training. The dissertation identified all the ICT resources and services at three selected schools within the SLL and drew up the energy consumption for each school. All schools indicated that there has been an increase in the electricity bill after the introduction of the SLL project. There was a clear indication that no energy expert was involved in the establishment of the SLLs. The dissertation indicates that there is a need for renewable source of energy for ICTs to improve service delivery in LRC. ICT service providers should consider energy subjects when planning for development of such solutions in LRC. This research focuses on designing a low cost ICT energy model to inform on ICTs energy consumption in LRC. It further outlines the possible ICT energy solutions that could be used to benefit targeted communities.
- Full Text:
- Date Issued: 2018
A derivation of the the black-scholes equation using martingales
- Authors: Nyarko , Ebenezer Narh
- Date: 2018
- Subjects: Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14572 , vital:40016
- Description: This work focuses on the application of stochastic differential equations, with martingales, in finance. The emphasis is on the derivation of the Black-Scholes model for the valuation of options. A theoretical framework in stochastic analysis, together with Itô calculus (Kiyoshi Itô), is explored. The Girsanov Theorem is applied in order to transform a modelled stochastic equation based, on predetermined stock and bond prices, into equivalent martingale measures. A replication strategy is then adopted to solve the two equations analytically, by finding the natural logarithm of the expectation of the solution to the stochastic models. We finally compute the resulting solution based on a standard, normal distribution to get the desired outcome of the Black-Scholes model.
- Full Text:
- Date Issued: 2018
An analysis on the use of web-based ontology to support ubiquitous learning in South African secondary schools
- Authors: Bamigboye, Oluwatosin Omotoyosi
- Date: 2018
- Subjects: Internet in education World Wide Web Ontology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12859 , vital:39385
- Description: There is certainly a need to upgrade our educational system and this can be done through technology-enhanced learning. Technology-enhanced learning can be achieved by developing a web-based ontology e-learning platform, which allows learning to take place ubiquitously. In achieving this task, this research is focusing on analyzing the use of web-based ontology to support the design and implementation of a ubiquitous learning system in South Africa. The implemented web-based ontology e-learning system was deployed and tested. The system testing was done on two variables (Information retrieval and Scalability) of localhost and client system, with the following testing metrics: time is taken for information retrieval, request time to process the request, transfer rate, time localhost receives request, time to respond, roundtrip time for request and network usage. The metrics testing was achieved using apache benchmarking console and gnuplot application to generate the data captured and performance graph, while Wireshark was also used to test/analyze round trip time and network usage through the deployed system. The results of the findings in this study show that the relationship between student and learning content becomes explicit when using ontology technology in searching, organizing, gathering and development content. Results obtained from information retrieval show that the transfer rate of information on localhost for 100 request @ current level of 5 is 37169.89kb/s, while on the client’s system, the transfer rate was 48494.36kb/s which was due to multiple request on the client’s side. Results obtained on scalability shows the round trip time which was (time to respond-time to request). The longest roundtrip was 8 seconds as a result of network being congested with multiple packets request from various sources trying to access the localhost at the same time while the fastest was 1 seconds. The implications of this results show that web-based ontology e-learning system has a positive input to teaching and learning processes in schools for content retrieval and network usage. The system furthermore shows the relationship adopted by learners and teachers, and also the match needs that arise in between. The contribution of this study adds to the existing discoveries on the use of web-based and knowledge-based ontology.
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- Date Issued: 2018
An evaluation of the impact of the biogas digesters project at Melani village, Eastern Cape, South Africa
- Authors: Mthimunye , Thabiso Vincent
- Date: 2018
- Subjects: Biogas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14561 , vital:40014
- Description: A study was conducted in Melani rural community of Raymond Mhlaba district in Eastern Cape, with the aim of identifying types of energy sources and households energy utilization. Melani village (32°43’29” S, 27°07’35” E) is 13 km away from Alice, the closest town and its household population is about 350. The survey was conducted with 50% of the randomly chosen households using semi-structured questionnaires and some onset CTA-A hobo current transducers were installed in three households to measure electricity used for either cooking, heating or lighting. The survey shows that electricity (supplied by Eskom) is the main source of energy for cooking, lighting and heating, while paraffin and candles are also used for lighting. The data collected using the data acquisition system has also shown that each household consumes an average of 140 kWh of electricity per month. Assuming this amount of energy being used throughout the year, on average the households consume 1680 kWh of electricity per year. The research concludes that there is a need to promote sustainable energy resources and technologies such as the use of biogas digesters as an alternative source of energy since the households has on average 20 of cattle, 10 of goats, 10 sheep and 4 donkeys. The research has also shown that the economic analysis of the biogas project is financially feasible. The Net present value was high and positive showing the feasibility of the investment on the project. The payback period was implying that the project pays itself off within the service life or within a set payback limit, which must be shorter than the technical service period of 5 years. The research has further shown that the emission factor for carbon dioxide for every 1MWh of electrical energy saved is 1.07 kg and consequently a corresponding volume of avoidance water is 1.40 KL. This can be mentioned that this monthly cost saving in the electrical energy consumption can go a long way in improving the social and economic welfare of the people. More so, it also vi plays a key role in the reduction of the global warming potential and the amount of air pollutant in the atmosphere. The avoidance water also contributed greatly in reducing the total volume of water used in the cooling towers of the coal power generation plant.
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- Date Issued: 2018
Analysis of the security and reliability of packet transmission in Wireless Mesh Networks (WMNs) : a case study of Malicious Packet drop attack
- Authors: Adeniji, Victor Oluwatobiloba
- Date: 2018
- Subjects: Wireless communication systems Mobile communication systems
- Language: English
- Type: Thesis , Masters , Computer Science
- Identifier: http://hdl.handle.net/10353/17450 , vital:40969
- Description: Wireless Mesh Networks (WMNs) are known for possessing good attributes such as low up-front cost, easy network maintenance, and reliable service coverage. This has largely made them to be adopted in various areas such as; school campus networks, community networking, pervasive healthcare, office and home automation, emergency rescue operations and ubiquitous wireless networks. The routing nodes are equipped with self-organized and self-configuring capabilities. The routing mechanisms of WMNs depend on the collaboration of all participating nodes for reliable network performance. However, it has been noted that most routing algorithms proposed for WMNs in the last few years are designed with the assumption that all the participating nodes will collaboratively be involved in relaying the data packets originated from a source to a multi-hop destination. Such design approach exposes WMNs to vulnerability such as malicious packet drop attack. Therefore, it is imperative to design and implement secure and reliable packet routing mechanisms to mitigate this type of attack. While there are works that have attempted to implement secure routing approach, the findings in this research unearthed that further research works are required to improve the existing secure routing in order to provide more secure and reliable packet transmission in WMNs, in the event of denial of service (DoS) attacks such black hole malicious pack drop attack. This study further presents an analysis of the impact of the black hole malicious packet drop attack with other influential factors in WMNs. In the study, NS-3 simulator was used with AODV as the routing protocol. The results show that the packet delivery ratio and throughput of WMN under attack decreases sharply as compared to WMN free from attack.
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- Date Issued: 2018
Anthropogenic effects on sustainability of fish biodiversity in Tyume River, Eastern Cape, South Africa
- Authors: Kinya, Jane Njeri
- Date: 2018
- Subjects: Fishes--Behavior Fishes--Physiology Biotic communities
- Language: English
- Type: Thesis , Doctoral , Zoology
- Identifier: http://hdl.handle.net/10353/11740 , vital:39102
- Description: To determine the anthropogenic effects on the sustainability of fish biodiversity in Tyhume River, a mixture of ecological, economic and institutional parameters were used. To measure ecological parameters, 10 study sites were selected to represent varying intensities of anthropogenic effects on habitat, to represent typical river zones, and to correspond with historical survey sites for trend analysis. In these study sites, habitat characteristics that represent geomorphology (habitat quantity), water quality and ‘alien’ (non–native) fishes were used to determine anthropogenic effects on habitat and fish assemblage. The measured geomorphology characteristics included current velocity, wetted width and depth. The water quality characteristics used were temperature, pH and conductivity. To determine the effects of native and non-native on indigenous fish species in situ, electro fishing was used in riffles, small pools and runs; as well, in situ seine-netting was done in pools. The riches of river fish species was measured, using numbers abundance and longitudinal distribution indices. It was established that only 11percent of the Tyhume River habitat was relatively near natural, while 89percent exhibited anthropogenic habitat modification. Three major sources ofanthropogenic modification on habitat were identified. The major contributor of anthropogenic effects was Binfield Park Dam which accounted for 43percent of modification. The second source of anthropogenic effects on habitat was Alice urban area where storm water runoff accounted for 28percent of modification. Agricultural and livestock grazing, the third anthropogenic effect, accounted for 18percent of modification. The Eastern Cape Rocky, Sandelia bainsii Castelnau, 1861 and Border Barb, Barbus trevelyani Günther, 1868, exhibited reduced distribution. B. trevelyani longitudinal distribution was less than 25 km along the river continuum, with sporadic presence in the sandy foothills. S. bainsii was not found in the Lowland Zone, while previously this species extended from the mountainous zone to the confluence of the Tyhume and Keiskamma Rivers in the Lowland Zone. These indices supported the homogenization theory, as reflected by increased dissimilarity for two indigenous fish species, S. bainsii and B. trevelyani, among study sites. S. bainsii was previously distributed from source to confluence, while B. trevelyani recorded a 50percent decline at the study site below the Binfield Park Dam. To assign economic value to ecosystem services and assess post Rio-institutional parameters two hypothetical scenarios were developed from the ecological survey; one depicting current conditions and another depicting improved ecosystem services. Using a structured interview questionnaire, five ecosystem services in need of restoration were described to respondents. Applying the contingent valuation method respondents were asked a dichotomous choice question on willingness to pay (WTP). Results of the economic study from 209 personal interviews revealed, individuals were willing to pay an additional R 32.00 on their monthly water bill or R 384.00 annually. Generalizing this to 2 829 households living in the Alice and Ntselamanzi urban areas, a total value of R 1 086 336 would be realized annually. This was equivalent to the Nkonkobe Municipality annual budget for storm water management in Alice urban area. Costs/benefits revealed a positive net present value (NPV) = 1, which, in line with economic theory, meant gainers were able to compensate losers The institutional part of the economic survey sought to determine the effects of post Rio Earth Summit institutional measures on sustainable management of Tyhume River fish assemblage. A desk review of Rio Declaration and three South African statutes were used namely; Constitution Act 108 of 1996 (South African Constitution 1996); the National Environmental Management Biodiversity Act No. 10 of 2004 (NEMBA 2004), the National Environmental Management Act (NEMA) No. 107 of 1998 (NEMA 1998), and the National Water Act No. 36 of 1998 (NWA 1998). The Institutional and Analytic Development (IAD) Framework, coupled with requirements for sustainability of Multiple Use Resource Domains were used for the analysis. De Jure, the statutes had internationalization of environmental costs through “polluter pays principle”, while sustainable use was the overarching goal. De facto, the community participation, a requisite of post Rio measures, was low; however 89percent of community respondents were willing to join an environmental conservation group. This, coupled with the fact that 77percent of those interviewed supported the establishment of a Tyhume River Restoration Fund, provided scope for a broad based community participation framework This study contributes to sustainable use of Tyhume River and other lotic systems by generating information on the link between anthropogenic effects on fish biodiversity, economic value of ecosystems services and institutional mechanisms.
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- Date Issued: 2018
Appraisal of wastewater final effluents and river water as reservoirs of cholera and non-cholera causing vibrio species : case study of the Amatole and OR Tambo District Municipalities
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
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- Date Issued: 2018
Assessing the implementation and effects of the Fetsa Tlala Food Initiative Programme in achieving its vision of eradicating household level food insecurity in Lukhanji Local Municipality, Eastern Cape Province, South Africa
- Authors: Njara, L I
- Date: 2018
- Subjects: Poverty -- South Africa -- Eastern Cape Food security -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10476 , vital:35484
- Description: Declining agrarian activities in significant parts of the country, even in the subsistence sector, has meant that access to food is increasingly a function of household cash income, hence low-income households experience inadequate access to food. Over 12 million people in South Africa are vulnerable to food insecurity. Since 2013, substantial efforts and large sums of money have been devoted to poverty reduction through government’s Fetsa Tlala Food Production Initiative. Fetsa Tlala was conceptualised as an integrated government framework that seeks to promote food and nutrition security and to address the structural causes of food insecurity, which continue to perpetuate inequality and social exclusion. The main objective of this study is to assess the implementation and effects of Fetsa Tlala. The specific objectives include: to measure the direct and indirect benefits of Fetsa Tlala; to assess the cost-effectiveness of the programme; to evaluate the model of the programme using a social systems approach; and to assess the implementation approach of Fetsa Tlala. A cross-sectional study was carried on a sample of 70 households and four Fetsa Tlala projects in the Eastern Cape. Households were selected using the simple random sampling procedure. Structured and semi-structured interviews using questionnaires were conducted. The research objectives were analysed using both qualitative and quantitative approaches. Among the quantitative approaches used was a micro simulation exercise, which was performed to help understand the cost-effectiveness of the programme. The results show that the business model of the programme is not built with sustainability in mind and the systems approach was ignored when designing the programme. Furthermore, the cost of the programme outweighs its benefits. This study recommends that the programme should take into account human development and build a needs-based approach going forward. Further recommendations are that the government should target relevant partners, and prioritise agricultural insurance, infrastructure and agro-processing.
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- Date Issued: 2018
Assessing the income derived from agricultural hawking in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa
- Authors: Seteni, Vuyo
- Date: 2018
- Subjects: Street vendors -- South Africa -- Eastern Cape Street vendors -- South Africa -- Eastern Cape -- Economic conditions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10167 , vital:35364
- Description: The hawking business has grown profusely in Buffalo City Metropolitan Municipality, to such an extent that street hawkers are found on every street corner of the Metro. The literature suggests that street hawking holds great potential for employment creation for the unskilled population who cannot find employment opportunities in the formal sector. In light of the proliferation of street hawking in BCMM, the study aimed at assessing the performance of agricultural hawkers in the municipality by means of looking at hawkers’ strategies, determining their sales and net income, and ascertaining their level of ‘job satisfaction’. The sample was selected from the population of hawkers in three major towns of BCMM, namely Mdantsane, East London and King William’s Town. A sum of 200 respondents were selected in the study through interval based probability sampling. The study made use of a cross tabulation of the hawkers’ income according to the three main towns. The results revealed that that agricultural hawking contributes to poverty alleviation in Buffalo City Metropolitan Municipality, as the majority of hawkers earn enough to live above the poverty line. A correlation matrix was used to ascertain the strength and direction of association between hawkers’ monthly income and selected independent variables. The study also used an ordered probit model to determine which specific variables affect hawkers’ monthly income generated from fruit and vegetable sales. The results from the model suggest that business training is significantly and positively related to increasing monthly income, as are age, years of experience, and membership of a hawkers’ association. The study recommends that Buffalo City Metropolitan Municipality build new markets and improve the infrastructure of existing markets, and also provide proper sanitation and clean water to avoid unhygienic situations in street hawkers’ markets.
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- Date Issued: 2018
Assessment of the human health implications of climate variability in East London, Eastern Cape, South Africa
- Authors: Orimoloye, Israel Ropo https://orcid.org/0000-0001-5058-2799
- Date: 2018
- Subjects: Climatic changes http://id.loc.gov/authorities/subjects/sh85027037
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19715 , vital:43171
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03 percent and 0.9 percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period. , Thesis (PhD) (Geography) -- University of Fort Hare, 2018
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- Date Issued: 2018
Assessment of the human health implications of climate variability in East London, Eastern Cape, South Africa
- Authors: Orimoloye, Israel Ropo
- Date: 2018
- Subjects: Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Geography
- Identifier: http://hdl.handle.net/10353/10113 , vital:35346
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03percent and 0.9percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period.
- Full Text:
- Date Issued: 2018
Assessment of the impact of land use practices on vegetation , soil and carbon-nitrogen sequestration potential in Mopane rangelands of Central Northern Namibia
- Authors: Kahumba, Absalom
- Date: 2018
- Subjects: Rural development Land use Land tenure
- Language: English
- Type: Thesis , Doctoral , Pasture Science
- Identifier: http://hdl.handle.net/10353/11718 , vital:39100
- Description: This study was conducted in Ogongo district, situated in Omusati Region of the central northern Namibia. The objectives of this study were to assess the impact of land use practices on 1) vegetation distribution and status; 2) soil properties; 3) carbon-nitrogen sequestration potential, and 4) investigate the indigenous pastoralists’ knowledge and perceptions on livestock production, rangeland degradation and its indicators in three villages (Omaandi, Epukunoyana and Oshitutuma) in Mopane savannah rangelands of central northern Namibia. For vegetation and soil assessment, three grazing land management systems (communal, game reserve and cattle ranch) were identified adjacent to each other. In each grazing system, three sites (for game reserve and cattle ranch, these were camps) were selected. In each site, three belt transects of 50 m x 5 m2 were marked to record vegetation and soil data as well as to collect vegetation samples for analysis. Grass species composition was recorded using step point methods from 250 points per belt transect. A total of five 0.25 m2 quadrats were randomly laid within each 250 m2 belt transect to record the herbaceous plant density, tuft diameter, tuft distance and biomass. All woody plants in the belt transect (250 m2) were measured and recorded for species plant height and canopy diameters. Three soil samples per belt transect were collected at the time of forage sampling down to a depth of 20 cm using a soil auger. Soil and plant samples were analysed for macro and micro minerals, total organic carbon, total nitrogen, carbon-nitrogen ratios, and carbon and nitrogen isotopes. For bulk density, soil samples were collected using soil core samplers. In the social study, a total of 90 households were randomly selected from three villages and a total of 48 elders were purposefully selected based on the age, time spent in the village and livestock ownership. A combination of structured and semi-structured questionnaires were used to gather household information, while a structured questionnaire and open ended discussion were used to interview elders on the constraints of livestock production, rangeland degradation related issues and their consequences on livelihood. Field vegetation and soil data were analyzed using a General Linear Model (GLM) in SAS (2007), whereas the social data were analyzed using SPSS version 21 (2014). A total of 23 grass species were identified in all three land management systems, of which 48% were perennials and the remaining 52% were annuals. Aristida meridionalis dominated the game reserve and the ranch, whereas Eragrostis trichophora was dominant in all land management systems. Forbs occurred commonly in the game reserve and the ranch, but were dominant in the communal areas. The abundance of A. meridionalis responded significantly (P < 0.001) to land management systems with the game reserve showing remarkably greater abundance than the ranch. In summer, the abundance of E. trichophora was high (P < 0.001) in the game reserve followed by the communal and ranch sites, whereas in winter, the species had still greater abundance in the game reserve followed by the ranch. In summer, the mean grass density was greatest (P < 0.001) in the game reserve and least in the communal lands, but vice versa for the tuft distance. In summer, the average distance between tufts showed great variations (P < 0.001) with the communal areas having greater values than the ranch and game reserve. In winter, both the game reserve and the ranch showed records of similar grass tuft density and distance between tufts, whereas these values were nil for communal areas, because, there were no grasses recorded. Herbaceous plant dry matter was significantly greater (P < 0.05) in the game reserve followed by the ranch and the least in the communal areas. Results on biomass showed remarkably higher values (P < 0.001) in summer than winter in all land management systems. The total woody plant density was significantly higher (P < 0.001) in the ranch (542 TE ha-1) than the game reserve (449 TE ha-1) and communal area (324 TE ha-1). However, percentage of canopy cover did not differ significantly (P > 0.05) between the three land management systems. Woody plant density of height classes were significantly different (P < 0.05) between three land management systems. The abundance of seedlings, saplings and young shrubs were significantly greater (P < 0.05) in the ranch than the game reserve and communal area. The mature trees had a significantly greater density (P < 0.05) in the game reserve than the ranch and communal area. Soil analysis results showed that Magnesium (Mg), Potassium (K), Manganese (Mn) and Copper (Cu) had similar (P > 0.05) concentrations in soils obtained from all land management systems in both seasons. Soil Calcium (Ca) levels showed differences between land management systems in winter only being greater (P < 0.001) in the game reserve than the ranch and the communal lands. Soil Phosphorus (P) and Iron (Fe) also showed variations between land management systems in winter being significantly greater (P < 0.001) in the ranch than the other land management systems. The concentration of soil K differed between the two seasons in soils collected from the ranch and the communal lands, being greater (P < 0.001) in winter than summer seasons. Soil Zinc (Zn) also showed differences between land management systems in summer being greater (P < 0.001) in the game reserve than in the ranch and communal land. Seasonal variations were observed in soil P level of samples collected from the ranch being greater (P < 0.001) in winter than summer season. The concentration of soil Zn was higher (P < 0.001) in the soil collected from the game reserve and the ranch in summer than winter season. Woody forage analysis results showed that browse samples harvested from the ranch had greater (P < 0.001) Nitrogen (N) level than the other land management systems in both seasons. The browse samples harvested from the game reserve had greater (P < 0.001) Ca level than the other land management systems in winter season only. The level of P showed variations (P < 0.05) between land management systems in samples harvested during winter only being greater (P < 0.001) in samples from the ranch than the other land management systems. Similarly, browse harvested during winter showed significant differences (P < 0.05) in K levels being lowest in samples collected from game reserves, where the Ca level was greatest. Browse samples collected from the communal land and the ranch had the lowest Mg levels in summer and winter seasons, respectively. In all management systems, browse harvested during summer had greater (P < 0.001) N and P levels than those harvested in winter, and the reverse holds true for K and Ca levels. Browse samples harvested during winter had greater (P < 0.001) Mn levels in samples from the communal area and game reserve than the ranch, but in summer, the game reserve had higher Mn level than the other two sites. Browse samples harvested during winter only showed differences (P < 0.05) in Cu and Zn levels being greatest (P < 0.001) in samples collected from ranch and game reserves. In all management systems, browse samples harvested during winter had greater (P < 0.001) Fe, Mn, Zn and Cu (except for the game reserve and communal land) levels than those harvested in summer. Herbaceous analysis results showed that samples harvested in summer from the game reserve and ranch had greater (P < 0.001) TOC levels than the communal area, but in winter, samples from the game reserve and ranch had similar TOC levels, except for communal areas that had no herbaceous vegetation. Herbaceous samples harvested in winter from the ranch had greater (P < 0.001) TN levels than the game reserve, and that made the C:N ratio higher (P < 0.001) in the game reserve. Woody foliar samples harvested in winter from the game reserve and communal lands had greater (P < 0.001) TOC than the ranch. Values on C:N ratio showed that in winter, the communal and ranch had greater (P < 0.001) C:N than the game reserve, but in summer, the ranch had higher (P < 0.001) C:N than the game reserve and communal area. The vegetation TOC (kg ha-1) showed the order of the game reserve > ranch > communal area and the trend was similar in both seasons. In summer, the game reserve had the greatest (P < 0.001) TN (kg ha-1) followed by the ranch and the lowest in the communal area, but in winter the game reserve and ranch had similar and higher (P < 0.001) TN (kg ha-1) than the communal areas. In summer, both the game reserve and ranch recorded greater (P < 0.001) herbaceous δ13C and lowest δ15N than the communal area, but in winter, the game reserve had higher (P < 0.001) δ13C than the ranch, though both the game reserve and ranch had similar (P > 0.001) δ15N values. In summer, both the communal and ranch had slightly higher (P < 0.001) woody foliar δ13C than the game reserve, but in winter the ranch had greater (P < 0.001) δ13C than game reserve and communal areas. Woody foliar samples harvested from the ranch showed variations (P < 0.05) in δ15N between seasons being higher (P < 0.001) in summer than winter. The TOC was greatest in summer, in soils collected from the game reserve followed by the ranch and least in the communal land, but in winter, the lowest TOC was recorded in soils collected from the ranch. The soil C:N ratio varied between land management systems in soils collected during summer only being greater (P < 0.001) in the game and ranch than the communal area. The soil TOC (kg ha-1) and TN (kg ha-1) did not show (P > 0.05) differences between land management systems. Soil δ13C level was remarkably (P < 0.05) affected by land management systems, but did not interact with seasons. In both seasons, the communal land had slightly higher (P < 0.001) δ13C level than the other two land management systems. In both seasons, δ15N levels showed great differences (P < 0.001) between land management systems, with highest soil δ15N levels observed in the communal area than the ranch and game reserve. Results on social survey showed that the majority of the interviewed households in Omaandi (63percent), Oshitutuma (53percent) and Epukunoyana (50percent) were female headed families and the remaining were male headed. The mean population of goats and cattle were significantly higher (P < 0.05) in Omaandi and Epukunoyana than in Oshitutuma village, respectively. In this study, household respondents in all villages indicated that all livestock species were primarily kept for wealth status and provision of meat for consumption. Respondents in all villages also indicated that lack of grazing lands and shortage of feed were the primary constraints of livestock production followed by water scarcity and recurring droughts. Elder respondents in all villages perceived overgrazing and climate change as the primary cause of rangeland degradation. Elder interviewees in Omaandi and Oshitutuma villages regarded low grass cover and dominance of poor quality grass (Epukunoyana only) as the primary vegetation indicators of rangeland degradation. The animal related indicators such as stunted animal body as a result of mineral deficiency, high livestock mortality, emaciated body and animals traveling long distance for grazing and water (Oshitutuma only) were regarded in all villages as the primary livestock related indicators of rangeland degradation. Elders from Epukunoyana village ranked low rainfall, high soil and atmospheric temperatures as the primary climate related indicators of rangeland degradation, although in Omaandi and Oshitutuma, high soil and atmospheric temperatures were considered as the primary climate related indicators of rangeland degradation. Based on the findings, this study concludes that land management systems had great influences on the distribution and production of herbaceous and woody vegetation in summer and winter seasons. This study also observed that land management systems interacted strongly with season to influence most vegetation and soil variables. Lastly, based on the study findings, the study concludes that all three communal rangelands are degraded and degradation led to a gradual declining trend in the livestock population over the past 10 to 20 years in the communal areas as a result of feed shortage.
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- Date Issued: 2018
Bayesian spatial modelling of tuberculosis and its effects on socio-economic and demographic factors in South Africa : a case study of the Eastern Cape Province
- Authors: Obaromi, Abiodun Davies
- Date: 2018
- Subjects: Tuberculosis -- South Africa -- Eastern Cape Tuberculosis -- Epidemiology -- Statistics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9648 , vital:34813
- Description: This dissertation is concerned with evolving and extending statistical models in the area of Bayesian spatial modelling, an increasingly important field of spatial epidemiology with particular interest towards application to Tuberculosis data in the Eastern Cape province of South Africa. In spatial epidemiology, the diseases to be examined usually occur within a map that needs spatial statistical methods that are appropriate, to model the observed data in the presence of some covariates and also cater for the variation of the disease. In this thesis, the Bayesian models were developed in such a way that they allowed several factors classified as fixed and random effects, to be included in the models and using the Bayesian approach. The basic model used in disease mapping is the Besag, York and Mollie model, which incorporates two random effects; one which is spatially structured and the other random effect which is spatially unstructured. The effects (fixed and random) were the covariate effects, socio-economic and demographic variability and the spatial variability respectively, which were all investigated in seven different hierarchical/multilevel Bayesian models. These factors showed varying and substantial effects in the posterior relative risk estimation of the disease. We assumed a negative binomial and generalized Poisson distributions to the response variable or relative risk estimate, 𝑦𝑖 ,to capture the over-dispersion phenomenon that is common and inherent with Poisson density for counts data. Spatial and non-spatial models were developed to model over-dispersion with all the distributions; Poisson, negative binomial and generalized Poisson. Negative binomial and generalized Poisson showed varying properties from comparisons with DIC values and parameter estimates to standard errors, which made either of them fit depending on the choice of model selection. It was found that a lower DIC value could be insufficient to determine a best fit model, if other models present estimates with lower variances even at higher DIC values. The generalized Poisson, a two parameter distribution like the negative binomial, which also has the ability to capture both under-dispersion and over-dispersion, was found to perform better in the results than the negative binomial on the basis of a lower variance and with more exact parameter estimates. A new weighted prior distribution, the “Besag2” ICAR model for the structured spatial random effects, which is an extension of the traditional ICAR prior model with two hyperparameters, was also developed and compared with some existing prior models; BYM and ICAR, to measure for spatial dependency in the regions. This new prior distribution was found to show a better fit, when compared to the basic ICAR prior usually assumed for the spatial random effect in the BYM model. This newly parameterized prior distribution in the Besag, York and Mollie model also led to improved parameter control, as the hyperparameters can be seen independently from each other. The result also showed that the new model performed well, both presenting good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performed at least equally well and better than the existing models, and the new formulation also gave parameters that are interpretable and have a clearer meaning. To interpolate scattered or regularly distributed data, there are imprecise or exact methods, but there are some of these methods that could be used for interpolating data in a regular grid and others in an irregular grid. Linear and biharmonic spline methods were implemented in MATLAB, to compare for smoothing in the distribution patterns of tuberculosis in the province. This smoothing spline is a method of fitting a smooth curve to a set of noisy observations using a spline function. This new method is rarely used in disease mapping applications, but it has a superior advantage to be assessed at subjective locations rather than only on a rectangular grid as seen in most traditional GIS methods of geospatial analyses. The proposed new models and methods in this thesis were found to be flexible and robust, since they can be reduced or extended according to the nature of the data. Nevertheless, great care must be considered in the choice of prior densities. The approaches developed in this dissertation helped to broaden the scope for spatial analysis and disease mapping applications in epidemiology and public health studies.
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- Date Issued: 2018
Calibration and validation of satellite data (images) over inland water bodies and the effect caused by the adjacency towards them
- Authors: Faniso, Zimbini
- Date: 2018
- Subjects: Hydrology Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10350 , vital:35400
- Description: Remote sensing of inland water quality is a particularly challenging satellite Earth observation (EO) application. This arises because inland water bodies are small and optically complex targets that are generally dark compared to surrounding land. Inland water bodies are source supplies of water for both living and non-living organisms, that include human beings hence they need an observation. The spatial distribution of water changes over time and that leads to issues in different sectors like agricultural sector, environmental services and ecological issues. Signal reaching the satellite is usually dominated by light scattered in the atmosphere. Aerosols are strongly variable atmospheric constituents and play a major role in generating this unwanted signal which must be quantified and removed before any conclusions about water state and condition. In order to see how the aerosols affected the water state the light scattered in the atmosphere will be observed through electromagnetic spectrum bands in the atmosphere. This study will analyse the visible and near infrared wavebands of the electromagnetic spectrum as well as where it will be easy to distinguish the atmospheric noise types. A field campaign has been executed at Roodeplaat dam near Pretoria relating to Calibration and Validation (CalVal) of the recently launched Sentinel 2 and Sentinel 3 satellites. In situ measurements were taken at Roodeplaat dam simultaneously with the satellite overpass. Atmospheric Radiative Transfer Modelling (RTM) is required to analyse the satellite surface measurement data that is in the form of radiant quantities. Aerosol models for radiative transfer have been evaluated and refined to improve retrieval accuracy of water-leaving radiance at Roodeplaat dam. A retrieval algorithm for water-leaving radiance (Lw) and remote-sensing reflectance has been developed to analyse the sensitivity of the retrieval to aerosol optical properties, sensitivities, as well as proposals for enhanced retrieval methods, are presented.
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- Date Issued: 2018
Chemical transformation and phytochemical studies of bioactive constituents from extract of callistemon citrinus (curtis) skeels
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
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- Date Issued: 2018
Classification of Distinct Fuzzy Subgroups of the Dihedral Group Dp nq for p and q distinct primes and n ∈ N
- Authors: Nxala, Baphumelele Ellen
- Date: 2018
- Subjects: Fuzzy mathematics Fuzzy sets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14516 , vital:39997
- Description: In this dissertation, we classify distinct fuzzy subgroups of the dihedral group Dpnq, for p and q distinct primes and n ∈ N, under a natural equivalence relation of fuzzy subgroups and a fuzzy isomorphism. We aim to present formulae for the number of maximal chains and the number of distinct fuzzy subgroups of this group. Our study will include some theory on non-abelian groups since the classification of distinct fuzzy subgroups of this group relies on the crisp characterization of maximal chains. We give the definition of a natural equivalence relation introduced by Murali and Makamba in [67] which we will use in this study. Based on this definition, we introduce two counting techniques that we will use to compute the number of distinct fuzzy subgroups of Dpnq. In this dissertation, we use the criss-cut counting technique as our primary method of enumeration, and the cross-cut method serves as a means of verifying results we obtain from our primary method. To classify distinct fuzzy subgroups of this group, we begin by investigating the dihedral groups Dpnq, for p and q distinct primes and specific values of n = 2 and 3 to observe a trend. We classify the flags of these groups using the characterization of flags introduced in [93]. From this characterization, we then present formulae for the number of distinct fuzzy subgroups attributed to the flags of Dp 2q and Dp 3q . To generalise results for Dpnq, for p and q distinct primes and n ∈ N, we characterize the flags of this group and classify them as either cyclic, mdcyclic for 1 ≤ m ≤ n, or b-cyclic. Finally, we establish a general formula for the number of distinct fuzzy subgroups obtainable from these flags. We conclude by comparing results obtained from using our general formula to those obtained by other researchers for the same group. Based on the results from this study, we give an outline of future research work
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- Date Issued: 2018
Correlations between the occurence of virulent helicobacter pylori strains and chronic disease conditions in dyspeptic patients hospitalized in Chris Hani Baragwanath Hospital, Gauteng Province, South Africa
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
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- Date Issued: 2018
Design and development of a context sensitive rural development software application for eService provisioning
- Authors: Masikisiki, Lizo
- Date: 2018
- Subjects: Rural development Electronic commerce Computer networks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15332 , vital:40366
- Description: After more than a decade since South Africa realized the importance of Information and Communication Technology (ICT) and the role it can play to deliver services, the country is still confronted by a number of challenges challenges that hinder the implementation of a fully-fledged ICT-based system in a form of electronic government to better deliver services and information. While rural development remains as one of the country’s greatest concerns, ICT is among approaches and perspectives that are recognized for not only accelerating rural development but also for providing the country’s economic growth. This research was set to investigate approaches to implement ICT solutions for rural development and service provisioning in the context of electronic government. The research focused more on the technical skills to implement such ICT systems for the benefit of rural development and e-government stakeholders that have an interest in design and development of an integrated and interoperable solution to accelerate service delivery, especially in rural communities. A mixed methods approach was used throughout the research accompanied by an evolutionary prototyping to development the desired prototype. A study was then conducted to gain an understanding of the state and the needs of rural communities to date. The results of the study yielded a number of urbanized service providers that rural dwellers need to timeously visit to consume services. Scenarios to design and develop the intended prototypes were then drawn from these results. The overall implementation of the prototypes produced an integrated platform that allows multiple disparate systems to communicate, share and use information. The qualities of the prototype are what this research recommends to relevant to stakeholders in order to implement an integrated and interoperable e-government system that elevates rural development programs and service delivery.
- Full Text:
- Date Issued: 2018
Distribution of virulence determinants in Plesiomonas shigelloides and Vibrio species isolated from selected hospital wastewater effluents in the Eastern Cape Province, South Africa
- Authors: Mashudu, Mavhungu
- Date: 2018
- Subjects: Vibrio
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14505 , vital:39996
- Description: Plesiomonas shigelloides and some Vibrio species are amongst the bacteria species classified into the emerging pathogenic bacteria grouping, and they portend increasing virulence and high resistance to some of the most potent antimicrobial agents used as most important and critical lines of defence against pathogenic infectious agents. Hospital wastewater has attracted significant attention as a pool for the regurgitation of pathogens into the environment which eventually becomes a problem to public health. It has been variously reported that hospital wastewater critically serves also as a puddle for microbial genetic interaction with outcomes including the development of resistance to antimicrobial agents among other pathogenic traits. And, in the same vein, exchanges and gene recombination may have been leading to the emergence of virulence determinants not previously known owing to the capacity of hospital wastewater to encompass a vast diversity of pathogenic bacteria and antimicrobial agents at the same material time. Hence, this research aimed at the evaluation of the prevalence of virulence and antibiotic resistance in Plesiomonas shigelloides and some human pathogenic Vibrio species isolated from selected hospital wastewater in the Eastern Cape Province of South Africa. Wastewater samples were collected at two weeks intervals throughout three months sampling duration from hospital wastewater facility in the Eastern Cape Province. The wastewater samples were from the secondary hospital and, tertiary hospital along with Limbede community wastewater facilities based in the Eastern Cape Province of South Africa. The wastewater samples were aseptically screened for the presence of presumptive Plesiomonas shigelloides and selected Vibrio species using the culture-based method. The identity of the presumptive Plesiomonas shigelloides and Vibrio species (Vibrio cholerae, V. fluvialis, V. parahaemolyticus, and V. vulnificus) isolates were confirmed using species specific primers. After that, the presence 14 of virulence determinants and the antimicrobial susceptibility profiles of the positive strains as well as the antimicrobial resistance factors were all determined. The distribution of the presumptive isolates was as follows; 322 Plesiomans shigelloides and 378 Vibrio species respectively. However, upon molecular confirmation studies, 85 out of 322; 26% of the total presumptive isolates, were confirmed as positive for Plesiomans shigelloides and, on the other hand, from the 378 presumptive Vibrio species, 71% (270) was as positive to Vibrio genus, and upon speciation of the positive isolates; 27% (73) was confirmed as Vibrio cholerae, 9% (24) as Vibrio parahaemolyticus, 4% (12) as Vibrio vulnificus and 3% (8) as Vibrio fluvialis. The remaining 57% (153) which was unaccounted for may belong to other Vibrio species not included in this studies. Various virulence determinants were shown to be present in the Vibrio species identified and the degree varied in line with the species. P. shigelloides showed high levels of resistance to impregnated antibiotics (18 different types). The antibiogram characteristics showed P. shigelloides to possess 100% resistance to Ciprofloxacin, Nalidixic acid, Trimethoprim, Ampicillin, Penicillin, Tetracycline, Doxycycline, Erythromycin, and Cephalothin. These findings are of crucial importance to public health and the science of infectology as it gives insight into the role of the hospital wastewater as a puddle for the recombination of antibiotic resistance determinants and virulence emergence in bacteria. On the strength of the finding of this research, it is essential to indicate that there is a need for an immediate review of hospital wastewater disposal process. Some form of treatment or pretreatment of the hospital wastewater is required before discharge into municipal wastewater treatment facilities. And, perhaps, continuous monitoring of hospital wastewater to reduce the risk posed to public health.
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- Date Issued: 2018
Dynamic Mathematical Modeling in Chemical Reaction Networks
- Authors: Gurajena, Simba
- Date: 2018
- Subjects: Chemical reaction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11961 , vital:39122
- Description: Many students are familiar with the idea of ecological, financial modeling and modeling in other fields, but modeling in engineering fields is still an area to be looked at. In this discussion the researcher will deal with chemical reaction networks. This will cover areas in chemical reaction, interaction diagrams and the associated models. The discussion will also cover dynamic behaviour of reaction networks. The law of mass action and examples of simple networks will be dealt with. Differential equation models of biochemical and genetic systems are invariantly nonlinear, and as such numerical simulation is used to solve such models. The use of numerical simulation packages will be discussed and separation of timescale and model reduction will form part of the discussion.
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- Date Issued: 2018