Genetic characteristics of Human Immunodeficiency Virus-1, and deter-minants of late presentation for care and Diabetes mellitus amongst newly diagnosed Human Immunodeficiency Virus positive patients in the Eastern Cape, South Africa.
- Authors: Sogbanmu, Olufunso Oladipo
- Date: 2019
- Subjects: HIV infections
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/${Handle} , vital:40495
- Description: Phylogenies may help to characterize transmission pairs, enhance contact tracing and outbreak investigations, track the origin and spread of epidemics over place and time, and to identify patterns of onward Human Immunodeficiency-Virus (HIV) transmission among risk groups. If the pattern and evolution of HIV drug resistance can be mapped, this may influence the development of guidelines in the clinical management of HIV especially with issues relating to prevalence of primary drug resistance and its impact on outcomes of present antiretroviral treatment (ART) regimen in use and the ability to trace and track the development of drug resistant strains. The roll-out of the test and treat Programme for newly diagnosed HIV infected pa-tient, seeks to identify HIV infected individuals early and to prevent morbidity and mortality associated with the late presentation for HIV care. The determination of the magnitude of ‘late presentation’ and or ‘presentation with advanced HIV disease’ can be used in very diverse settings and for many purposes. It provides a unified way to define the problem, thereby targeting appropriate interventions to prevent the detrimental outcomes associated with late presentation to care. The subtle relationship between HIV and diabetes mellitus (DM) may also help in formulating better preventive programs to aid the control of non-communicable diseases such as DM. This cross-sectional study includes a purposive selection of 335 HIV positive patients attending the voluntary counselling and Testing (VCT) and HIV Counselling and Testing (HCT) centres and outpatient departments at Cecilia Makiwane Hospital and the HCT sites at the Buffalo District municipality community health centres, Eastern Cape Province, South Africa. Late or delayed presentation of HIV infection was defined as CD4 cell count beneath 350 cells/μL and/or patients presenting with an AIDS-defining event at the first follow-up regardless of the CD4 cell count. Chapter 1 provides the general introduction had an overview of the introduction to the study, the statement of the research problem, hypothesis, the aim and the objectives. xx Chapter 2 looked in-depth at the HIV, case definition, the latest epidemiology of HIV, the HIV genome, the life cycle of HIV, its diagnosis, the classes of antiretroviral drugs, development of drug resistance. Chapter 3 highlighted the prevalence of Transmitted Drug Resistance (TDR) with focus on the protease gene. RNA was extracted from blood samples of 72 newly diagnosed HIV-1 patients attending some HIV testing and counselling clinics from August 2016 to July 2017. Protease fragments were amplified with specific primers by RT-PCR followed by nested PCR. The amplified products were sequenced using the ABI 360 sequencer, edited with Geneious version 9.1.5 and translated into amino acid with BioEdit software. Drug related resistance mutation (DRMs) analysis was performed on all the protease sequences in accordance with the 2009 WHO list of surveillance drug resistance mutations by submitting the edited sequences to Stanford HIV drug interpretation programme and the international AIDS society-USA guidelines for query of drug resistance associated mutations while phylogenetic analysis was performed using MEGA 6 to allocate all viral sequences into subtypes. In the study, a total of 52/72 (71.1%) reliable HIV-1 protease sequences were obtained in which subtyping and drug resistance mutations were performed. Two (3.8%) major Protease resistance associated mutation (V82A/L and L90M) were observed while another polymorphism like L10F, T74S, Q58E, L10I/V and M46V were also identified. Phylogenetic analyses delineated all the sequences as HIV-1 subtype C. Chapter 4 describes the prevalence and the determinants of late presentation amongst newly diagnosed HIV positive individuals in the Eastern Cape. It indicates the extent of the prevalence of patients presenting to care and at what HIV stage they were assessing health care services since the inception of the ‘test and treat’ strategy. It is a cross-sectional study where a total of 335 newly diagnosed patients were recruited consecutively be-tween August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established Aids- xxi defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis. The study showed that 60% of patients were late presenters, with 35% presenting with advanced disease. The major determinants identified were being male and low level of education. This led to recommendations directed at ensuring programmes that targets men in identifying their HIV status and assess care at early stage to prevents the morbidity and mortality associated with delayed presentation. Also, it was recommended that effort should be made to improve access to education and also include HIV related topics into the educational curriculum. Chapter 5 aimed to describe the prevalence and determinants of DM amongst newly diagnosed HIV positive individuals. This is a cross-sectional study which recruited 335 patients between August 2016 and September 2017. Definition for diabetes mellitus was made based on the SEDMSA 2015 guideline of HBA1C of above 6.5%. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of abnormal glycated haemoglobin. Findings showed the prevalence of DM at about 6% amongst newly diagnosed HIV positive individuals. This is similar to findings in other study within the country, but a bit lower than what was obtained in the developed countries. The role of older age (above 40 years) as predisposing factor to development of diabetes in newly diagnosed HIV positive individual was well noted and taken. This ensures that screening for DM should be targeted at elderly HIV positive individuals. The grey area of the appropriate mode of diagnostic test to use to diagnose HIV is still debatable, however, a combination of HBA1c and fasting blood sugar (FBS) may improve the diagnosis of DM in this population group. In chapter 6, the general conclusions, recommendations and future perspectives of the study are reflected.
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- Date Issued: 2019
Genetic detection of some tick-borne bacterial and protozoan pathogens in ticks collected in Raymond Mhlaba local municipality, Eastern Cape Province, South Africa
- Authors: Nqoro, Ayabulela
- Date: 2019
- Subjects: Tick-borne diseases Ticks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17084 , vital:40846
- Description: Ticks and tick-borne diseases are becoming a major life threatening concern to wildlife, domesticated animals and human health. Besides causing skin damage, ticks infestations have become a growing burden in food security, economic losses and transmitting multides of pathogens. Little data and knowledge is available regarding the occurrence of etiologic agents of tick-borne diseases in the Eastern Cape of South Africa, hence the study was conducted and aimed at screening for genetic material of Anaplasma, Rickettisia, Ehrlichia, Borrelia, Babesia and Theileria species in ticks collected in Raymond Mhlaba District at Eastern Cape, South Africa. Ticks were collected from domesticated animals in Raymond Mhlaba Municipality, and were morphologically identified and processed for DNA extraction. Ticks were chopped into bits and DNA was extracted from the samples with commercial DNA extraction kit. The extracted DNA samples was used to molecularly identify the tick as well as assess the presence of tickborne pathogens belonging to Rickettsia, Babesia, Borrelia, Anaplasma and Erhlichia, and Theileria spp. by PCR using specific primer pairs published in literature. Positive amplicons were sequenced in a commercial sequencing facility. The obtained chromatograms were edited with Geneious bioinformatics software and were subjected to BLASTn and phylogenetic analyses using MEGA7 version for evolutionary relationships with curated reference sequences in GenBank. Nine hundred and sixty two tick samples were collected from domestic animals. Collected tick samples belonged to three genera, which were the Amblyomma, Rhipicephalus and Haemophalis in decreasing order of their abundance. Screening of tick DNA samples by PCR did not show presence of Babesia, Borrelia, Anaplasma and Erhlichia. 13 Positive PCR products were observed for Rickettsia and Theileria spp.. The positive amplicons were purified, sequenced and analysed for speciation of Theileria and Rickettsia. The presence of Rickettsia was detected in 60/994 (6%) from the three genera of ticks. Phylogenetic analyses shows that the sequences obtained are phylogenetically related to members of Spotted fever group Rickettsiae. Genetic material of Theileria spp. was detected from 10/994 ticks with an overall infection of 1% obtained in Rhipicephalus genera. Analyses shows that the sequences obtained are phylogenetically related to T. orientalis complex. The finding from this study therefore expands the knowledge on recent emergence of Theileria and Rickettsia spp. in Raymond Mhlaba Municipality in Eastern Cape, South Africa
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- Date Issued: 2019
Genetic diversity, resistance profile of hiv and risk assessment of mother-to-child transmission in pregnant women on antiretroviral therapy in the Eastern Cape, South Africa
- Authors: Adeniyi, Oladele Vincent
- Date: 2019
- Subjects: Antiretroviral agents , HIV infections -- Treatment -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15120 , vital:40183
- Description: Despite the initiation of life-long ART in HIV-infected pregnant women, the rate and determinants of infant HIV transmission are not known, especially in the poor resource settings of the Eastern Cape, South Africa. Maternal anti-retroviral therapy (ART) is crucial for elimination of mother-to-child transmission (MTCT) of HIV. However, the inevitable risks of emergence of HIV drug resistance poses significant threat to achieving this goal of HIV-free generation and keeping mothers alive. Also, it is unclear if women with high viral load at delivery have acquired clinically relevant mutations, which could confer resistance to the ART, thus, further increasing the risks of motherto-child transmission of HIV-drug resistance strains. In addition to the gaps identified in the prevention of mother-to-child transmission (PMTCT) context, the understanding of regional epidemics is crucial to the broader epidemiological profiling of HIV infections in the country. Despite the rapid influx of foreign nationals to South African and Eastern Cape Province, there has not been any molecular epidemiological studies profiling the HIV diversity in the Eastern Cape.
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- Date Issued: 2019
Geological and geophysical assessment of groundwater vulnerability to contamination in selected general landfill sites in the Eastern Cape Province, South Africa
- Authors: Mepaiyeda, Seyi
- Date: 2019
- Subjects: Groundwater -- Pollution Sanitary landfills
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: http://hdl.handle.net/10353/12227 , vital:39217
- Description: Increasing expansion, population and urbanization have resulted in high volume of waste generated daily in South Africa. Most municipalities in the Eastern Cape are experiencing challenges in effective waste disposal, thus resulting in pollution of the air, soil and groundwater by the percolation of harmful contaminants into the environment from landfill leachate. Groundwater resources are limited in South Africa due to itssemi-arid nature. Also, there islimited information available, not only about where it occurs but how to manage it so that its quality does not depreciate to unacceptable levels. A combination of these factors coupled with a gap between waste policy and its subsequent implementation may be disastrous to South Africa. This research examines the impact of landfill sites on groundwater resources at three selected sites in the Eastern Cape Province using an integrated geological and geophysical approach. The methodology adopted include: an exhaustive literature review on waste management policies and practices in South Africa and Eastern Cape specifically. It also involved remote sensing for the study of geomorphology and structural interpretations of lineaments. Field excursions, analysis of physico-chemical and geochemical properties of groundwater obtained from monitoring boreholes and leachate pond in the vicinity of the landfill sites was also carried out. Combined induced polarization (IP) and electrical resistivity measurements for geophysical assessment of groundwater vulnerability and petrographical analysis was alos adopted. Data analysis and interpretation of the obtained results showed that the selected landfill sites are generally characterized by a 4-layer Earth structure with an average depth to top of the bedrock between 15 m - 30 m. Plant-rock association observed from the aerial photo-interpretation showed groundwater potential around the locality of the landfill sites with a dendritic to poorly drained x patterns and moderate to high topography. Structural controls such as the presence of lineaments and a fractured bedrock beneath, which are excellent pathways for the migration of leachate, particularly at the Berlin and King Williams Town landfill sites were observed. Analysis of physico-chemical and geochemical properties of water samples showed contamination of the groundwater by heavy metals and some of the physico-chemical properties were above the generally acceptable limits (WHO). These include high electrical conductivity (EC) and total dissolved solid (TDS) values observed in the groundwater samples from the King Williams Town landfill which indicated a downward transfer of leachate into the groundwater. The difference in EC and TDS values for boreholes BH2 and BH1 (9892 µS/cm, 4939 mg/L and 6988 µS/cm, 3497 mg/L respectively), showed that concentration of contaminants increased towards the centre of the landfill. Interpretation of the obtained results from the Berlin landfill showed the presence of heavy metals in groundwater samples in high concentrations. This indicated the dumping of toxic and hazardous waste substances on the landfill, contrary to the landfill design and classification. This could have harmful effect on plants and animals. Integrated geophysical assessment showed the presence of leachate plumes on pseudosections across the landfill sites. This was further corroborated on the chargeability pseudosections. Resistivity and IP pseudosections from the Berlin landfill showed a 4-layered Earth structure and anomalous zones of resistivity (≤ 112 Ώ-m) and low chargeability (≤1.25 ms) in the top layers. This is indicative of percolating leachate plume in the unsaturated zone. Contaminants ranging from unsaturated waste with high ion content to dense aqueous phase liquid contaminants, characterized by low resistivity (34 Ώm to 80 Ώ-m) and low chargeability values (0.05 ms to 5.75 ms) were identified across the Alice landfill. Results from the King Williams Town Landfill revealed plume contamination to a depth of about 75 m, well within the aquiferous zone. xi It is suggested that waste disposal practices should be improved by proper waste inspection and classification at landfills prior to disposal, use of lining and cap material to prevent leaching of contaminants into the groundwater below and the construction of waste cells and containment structures. This will go a long way in mitigating groundwater contamination due to landfilling at the study areas
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- Date Issued: 2019
Germination potential of seeds harvested at the Worcester Veld Reserve
- Authors: Swart, Rudi
- Date: 2019
- Subjects: Ecological disturbances -- South Africa -- Karoo , Environmental degradation -- South Africa -- Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43923 , vital:37084
- Description: The rangelands of the Succulent Karoo and Nama Karoo biomes are in various states of degradation. The injudicious stocking of overly high numbers of domestic livestock is considered to be the anthropogenic cause of this degradation. The palatable plants of these rangelands have been greatly reduced in number or extirpated from some areas. In order to return palatable plants to degraded rangelands and improve rangeland productivity, many restoration projects have been attempted that involve reseeding. The sowing of seeds into degraded rangelands, or other disturbed areas, has often provided disappointing germination results. This study will attempt to determine what some of the main aspects are that affect Karoo seed germination, both positively and negatively. The specific objectives of the study are to determine the causes of pre-sowing seed mortality, the effect of drying on seed germination, the effect of planting depth on seed germination and the effect of storage time on seed germination. The seeds of four palatable Karoo plant species harvested at the Worcester Veld Reserve were selected to be subjected to germination trails and viability testing. This study uses germination trials under controlled light and temperature conditions, as well as 2, 3, 5-triphenyl tetrazolium chloride tests to determine whether the four species of Karoo seeds harvested at the Worcester Veld Reserve for rangeland reseeding projects are viable and germinable. The practice of drying seeds after harvesting is tested to determine the effect of drying on seed germination. The germination of seed was also tested over 17 intervals of 3 weeks to determine the effect of storage time on seed germinability. Germination trials were also conducted in a nursery to determine whether there was a difference in seedling emergence between seeds planted at 10 mm depth compared to seeds planted on the surface with a partial covering of sand. The seed viability of all four species studied was found to be below 50%. Drying only significantly improved the germination of Osteospermum sinuatum seeds. The seeds of O. sinuatum and Eriocephalus africanus germinated reasonably well throughout the 17 time intervals, while the seeds of Chaetobromus involucratus and Gorteria integrifolia germinated poorly during the first six months after harvesting, after which v germination improved markedly. Seedling emergence of all four species studied was significantly higher when planted at the substrate surface, compared to seeds planted at 10 mm depth. The findings of this study show that while the viability of the seeds harvested for rangeland reseeding projects are quite low, the appropriate pre-treatment, seed age and planting depth will allow a significant increase in germination. This increase in germination should provide a greater chance of establishing palatable plants in rangeland reseeding projects.
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- Date Issued: 2019
Governance mapping: a framework for assessing the adaptive capacity of marine resource governance to environmental change
- Authors: Dutra, Leo X C , Sporne, Ilva , Haward, Marcus , Aswani, Shankar , Cochrane, Kevern L , Frusher, Stewart , Gasalla, Maria A , Gianesella, Sônia M F , Grant, Tanith , Hobday, Alistair J , Jennings, Sarah M , Plagányi, Éva , Pecl, Gretta T , Salim, Shyam S , Sauer, Warwick H H , Taboada, Manuela B , Van Putten, Ingrid E
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145336 , vital:38429 , DOI: 10.1016/j.marpol.2018.12.011
- Description: Marine social-ecological systems are influenced by the way humans interact with their environment, and external forces, which change and re-shape the environment. In many regions, exploitation of marine resources and climate change are two of the primary drivers shifting the abundance and distribution of marine living resources, with negative effects on marine-dependent communities. Governance systems determine ‘who’ makes decisions, ‘what’ are their powers and responsibilities, and ‘how’ they are exercised. Understanding the connections between the actors comprising governance systems and influences between governance and the environment is therefore critical to support successful transitions to novel forms of governance required to deal with environmental changes. The paper provides an analytical framework with a practical example from Vanuatu, for mapping and assessment of the governance system providing for management of coral reef fish resources. The framework enables a rapid analysis of governance systems to identify factors that can encourage, or hinder, the adaptation of communities to changes in abundance or availability of marine resources.
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- Date Issued: 2019
Governing pregnancy in South Africa: political and health debate, policy and procedures
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
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- Date Issued: 2019
Government support and sustainable small, medium enterprises (SMEs) in the ocean economy: a case of Eastern Cape
- Authors: Zilimbola, Mlungiseleli
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape , Marine resources -- Economic aspects Shipping -- Economic aspects Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/44291 , vital:37149
- Description: In the past few years, South Africa has started to follow other developing countries, such as Japan and Greece, in pursuit of oceans economy. The presidency launched operation phakisa in Port Elizabeth in 2016 with the hope that it would contribute greatly to job creation and economic development in South Africa. It has been noted that oceans economy is a wide concept and covers a number of activities/sectors in the oceans. This study will focus on different economic is a wide concept and covers a number of activities, such as transport, fishing, bunkering and many other economic activities. This study seeks to investigate the strategic role of SMEs in the oceans economy. In accordance with the report drafted by the small enterprise development agency (seda) in 2016, which was commissioned by the department of trade and industry , the report show that SMMEs are struggling because of access to finance and markets, poor infrastructure, labour laws, crime, skills shortages.
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- Date Issued: 2019
Grabcuts for image segmentation: a comparative study of clustering techniques
- Authors: Manzi, Nozuko Zuleika
- Date: 2019
- Subjects: Algorithms , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14494 , vital:39995
- Description: Image segmentation is the partitioning of a digital image into small segments such as pixels or sets of pixels. It is significant as it allows for the visualization of structures of interest, removing unnecessary information. In addition, image segmentation is used in many fields like, for instance healthcare for image surgery, construction, etc. as it enables structure analysis. Segmentation of images can be computationally expensive especially when a large dataset is used, thus the importance of fast and effective segmentation algorithms is realised. This method is used to locate objects and boundaries (i.e. foreground and background) in images. The aim of this study is to provide a comparison of clustering techniques that would allow the Grabcuts for image segmentation algorithm to be effective and inexpensive. The Grabcuts based method, which is an extension of the graph cut based method, has been instrumental in solving many problems in computer vision i.e. image restoration, image segmentation, object recognition, tracking and analysis. According to Ramirez,et.al [47], the Grabcuts approach is an iterative and minimal user interaction algorithm as it chooses a segmentation by iteratively revising the foreground and background pixels assignments. The method uses min-cut/ max-flow algorithm to segment digital images proposed by Boykov and Jolly [9]. The input of this approach is a digital image with a selected v region of interest (ROI). The ROI is selected using a rectangular bounding box. The pixels inside the bounding box are assigned to the foreground, while the others are assigned to the background. In this study, the Grabcuts for image segmentation algorithm designed by [48] with a Gaussian Mixture Model (GMM) based on the Kmeans and Kmedoids clustering techniques are developed and compared. In addition, the algorithms developed are allowed to run on the Central Processing Unit (CPU) under two scenarios. Scenario 1 involves allowing the Kmeans and Kmedoids clustering techniques to the Squared Euclidean distance measures to calculate the similarities and dissimilarities in pixels in an image. In scenario 2, the Kmeans and Kmedoids clustering techniques will use the City Block distance measure to calculate similarities as well as dissimilarities between pixels in a given image. The same images from the Berkeley Segmentation Dataset and Benchmark 500 were used as input to the algorithms and the number of clusters, K, was varied from 2 to 5. It was observed that the Kmeans clustering technique outperformed the Kmedoids clustering technique under the two scenarios for all the test images with K varied from 2 to 5, in terms of runtime required. In addition, the Kmeans clustering technique obtained more compact and separate clusters under scenario 1, than its counterpart. On the other hand, the Kmedoids obtained more compact and separate clusters than the Kmeans clustering technique under scenario 2. The silhouette validity index favoured the smallest number of clusters for both clustering techniques as it suggested the optimal number of clusters for the Kmeans and Kmedoids clustering techniques under the two scenarios was 2. Although the Kmeans required less computation time than vi its counterpart, the generation of foreground and background took longer for the GMM based on Kmeans than it did for the GMM based on Kmedoids clustering technique. Furthermore, the Grabcuts for image segmentation algorithm with a GMM based on the Kmedoids clustering technique was computationally less expensive than the Grabcuts for image segmentation algorithm with a GMM based on the Kmeans clustering technique. This was observed to be true under both scenario 1 and 2. The Grabcuts for image with the GMM based on the Kmeans clustering techniques obtained slightly better segmentation results when the visual quality is concerned, than its counterpart under the two scenarios considered. On the other hand, the BFscores showed that the Grabcuts for image segmentation algorithm with the GMM based on Kmedoids produces images with higher BF-scores than its counterpart when K was varied from 2 to 5 for most of the test images. In addition, most of the images obtained the majority of their best segmentation results when K=2. This was observed to be true under scenario 1 as well as scenario 2. Therefore, the Kmedoids clustering technique under scenario 2 with K=2 would be the best option for the segmentation of difficult images in BSDS500. This is due to its ability to generate GMMs and segment difficult images more efficiently (i.e. time complexity, higher BF-scores, more under segmented rather than over segmented images, inter alia.) while producing comparable visual segmentation results to those obtained by the Grabcuts for image segmentation: GMM-Kmeans.
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- Date Issued: 2019
Grasses as suitable targets for classical weed biological control
- Authors: Sutton, Guy F , Day, Michael D , den Breeyen, Alana , Goolsby, J A , Cristofaro, M , McConnachie, Andrew J , Paterson, Iain D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417984 , vital:71499 , xlink:href="https://doi.org/10.1007/s10526-019-09968-8"
- Description: Grasses are amongst the most abundant and environmentally damaging invasive weeds worldwide. Biological control is frequently employed as a sustainable and cost-effective management strategy for many weeds. However, grasses have not been actively pursued as targets for classical weed biological control due to a perceived lack of sufficiently specialised and damaging natural enemies to use as biological control agents. There are also concerns that the risk posed to economically important crop/pasture species and closely-related native species is too great to consider implementing biological control for invasive grasses. In this paper, we review the literature and demonstrate that grasses can possess suitably host-specific and damaging natural enemies to warrant consideration as potential biological control agents. The risk of grass biological control is no greater than for other weedy taxa if practitioners follow appropriately rigorous risk assessments protocols.
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- Date Issued: 2019
Green entrepreneurship model utilising the system dynamics approach: A review
- Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450677 , vital:74973 , xlink:href="https://ieeexplore.ieee.org/abstract/document/8978804"
- Description: Green entrepreneurship as a concept is still in its infancy stages around the globe. In order to assess the Green entrepreneurship ecosystem, the researchers adopted a systems dynamic approach to determine key variables that will enable the development of the system. A theoretical review was conducted through a literature review of which n=44 sources met the criteria that the researchers set for ecosystem or variables. Through review of data, the researchers discovered that ecosystem of green entrepreneurship needs to be viewed from meso, macro and micro level with key variables such as green entrepreneurial motives, start-up factors, green support mechanisms, performance and monitoring tools as well as barriers to environmental entrepreneurship. A virtual abstract simulation of system dynamics approach from the systematic review is also formulated in the current paper. Brief summary of findings are classified and explained. Recommendations for future research are also made towards the end of the research paper.
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- Date Issued: 2019
Green ship recycling as an alternative maritime industry for South Africa
- Authors: Nkalitshana, Malwande
- Date: 2019
- Subjects: Ships -- Recycling -- Environmental aspects , Ships -- Recycling -- South Africa Ships -- Scrapping
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/41852 , vital:36603
- Description: Ship recycling is a process of partially or completely dismantling of a vessel for various reasons with an intention of recovering some or all the material of it, for re-use and reprocessing. During economic recession, ship owners sell or send their old vessels for scraping to the ship recycling facilities to get some money out of its materials. Vessels are also dismantled normally when they reach a certain age where their usefulness at sea has deteriorated. Ship recycling offers socio-economic and environmental benefits and can assist with developing the port infrastructure, shipping building and repairs. Green Ship recycling can also create employment and business opportunities. Furthermore, ships are made up of almost 90% of recyclable material and with that, recycling of ships can contribute on the preservation and sustainable use of natural resources. In terms of global participation in the ship recycling sector, Asian countries are dominating, and they account for more than 80%. The remaining 20% is accounted by other countries excluding those within the African continent, South Africa in particular. Despite the long-term benefits associated with this sector, South Africa’s participation is very minimal nor absent at all, though it has its triple challenges that could be minimized by this sector. In mitigating the health, safety and health issues that associated with this industry, South African has legal instruments which protect the safety and health conditions of workers, and furthermore it is a signatory into international organizations that regulates ship recycling industry. For it to participate in this sector, a collaborative and partnership between government institutions, academic and research institutions and private sector needs to be established. Through these collaborations and innovative research on green ship recycling, South Africa stands an increasing chance of realization of the objectives of its economic policy; National Development Plan. In addition to these collaborations, South Africa should rectify Hong Kong convention and domesticate it through formulating pieces of legislations that would regulate green ship recycling practices. Transnet as state owned company responsible for ports in South Africa, upon these collaborations and deliberations, should allocate a site for this industry within the port environment. Furthermore, through ship recycling, South Africa could attain its Objectives of growing the economy and increased job creation as envisaged in Operation Phakisa.
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- Date Issued: 2019
Green skills for agriculture A method for focusing demand analysis and prioritisation
- Authors: Rosenberg, Eureta
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436026 , vital:73221 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: This chapter is the second of the occupational demand studies that share insights about a methodology for determining green skills demand with a laminated approach and value chain anal-ysis. Based on research into skills for Climate Smart Agriculture (Cobban and Visser, 2017), it provides insight into the history and features of agriculture in South Africa that shape current skills needs. Drawing on one component of Cobban and Visser’s study, and employing a critical revision of the ‘climate smart’ framing, it shares findings about what green skills are needed for more sustainable poultry farming in which occupations to contextualise the discussion on methodology. This chapter contrasts the layered, in-depth green skills studies with approaches aiming for broader coverage and representivity, and illustrates the use of multi-criterion ‘hotspotting’ to prioritise among skills needs at strategic leverage points for social-ecological trans-formation. The case of the agricultural study illustrates the val-ue of smaller scale, in-depth studies that provide the occupa-tion level insights to inform skills planning and investment that is needed if agriculture is to sustain itself and all those it could – and should – benefit.
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- Date Issued: 2019
Green skills research in South Africa
- Authors: Rosenberg, Eureta , Ramsarup, Preesha , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436040 , vital:73222 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: This book brings the diverse contributions offered in the different sections of this book together into a pathway for new policy development research, new forms of critical skills research and ongoing engagement with education and training system development. The chapter first provides a meta-reflection on the different types of green skills research that are needed to, in combination, make a stronger impact on the national system of skills research and planning. Secondly, the chapter makes a strong argument for aligning green skills research to the Sustainable Development Goals, and their critical and contextual articulation at national level, with emphasis on working with the cross-cutting Sustainable Development Goal (SDG) 4, Target 4.7 that motivates for governments to include a focus on education and sustainable development across the lifelong learning system in order to enable and support learning and skills for enabling the other SDGs to be realised in practice. Lastly, the chapter considers the shift in the way that work is considered when political economy meets political ecology, and we argue that work transforms towards not only a productive focus, or a social focus, but also an ontologically grounded regenerative focus, much needed at the start of the twenty-first century.
- Full Text:
- Date Issued: 2019
Green skills research: Implications for systems, policy, work and learning
- Authors: Lotz-Sisitka, Heila , Ramsarup, Presha
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392875 , vital:68808 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: This chapter brings the diverse contributions offered in the different sections of this book together into a pathway for new policy development research, new forms of critical skills research and ongoing engagement with education and training system development. The chapter first provides a meta-reflection on the different types of green skills research that are needed to, in combination, make a stronger impact on the national system of skills research and planning. Secondly, the chapter makes a strong argument for aligning green skills research to the Sustainable Development Goals, and their critical and contextual articulation at national level, with emphasis on working with the cross-cutting Sustainable Development Goal (SDG) 4, Target 4.7 that motivates for governments to include a focus on education and sustainable development across the lifelong learning system in order to enable and support learning and skills for enabling the other SDGs to be realised in practice. Lastly, the chapter considers the shift in the way that work is considered when political economy meets political ecology, and we argue that work transforms towards not only a productive focus, or a social focus, but also an ontologically grounded regenerative focus, much needed at the start of the twenty-first century.
- Full Text:
- Date Issued: 2019
Green skills supply: Research from providers’ vantage point (s)
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436051 , vital:73223 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: This chapter emerges from a need to consider the dynamics of supply side research for green skills from a providers’ vantage point. The chapter starts with the argument that environment and sustainability skills are cross institutional, cross sectoral and also inter- and transdisciplinary. The chapter notes that there are a wide variety and diversity of supply side studies that can offer perspective on the many dynamics of green skills supply and provisioning. Four cases have been selected and brought into view to illuminate the influence of context and history on designing curricula and the importance of reflexive curriculum review studies, whole institution approaches and transformative, transgressive forms of learning that move beyond the boundaries of single institutions. These studies are also brought into view to indicate the scope and depth of contextual, systemic and engaged research that is required to develop transformative orientations and perspectives on green skills supply, taking skills system supply beyond the traditional training needs analysis. The chapter argues that this is an important dimension of green skills research, if conceptualised within just transitions and transformations to sustainability.
- Full Text:
- Date Issued: 2019
Green skills supply: Research from providers’ vantage point(s)
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392895 , vital:68810 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: This chapter emerges from a need to consider the dynamics of supply side research for green skills from a providers’ vantage point. The chapter starts with the argument that environment and sustainability skills are cross institutional, cross sectoral and also inter- and transdisciplinary. The chapter notes that there are a wide variety and diversity of supply side studies that can offer perspective on the many dynamics of green skills supply and provisioning. Four cases have been selected and brought into view to illuminate the influence of context and history on designing curricula and the importance of reflexive curriculum review studies, whole institution approaches and transformative, transgressive forms of learning that move beyond the boundaries of single institutions. These studies are also brought into view to indicate the scope and depth of contextual, systemic and engaged research that is required to develop transformative orientations and perspectives on green skills supply, taking skills system supply beyond the traditional training needs analysis. The chapter argues that this is an important dimension of green skills research, if conceptualised within just transitions and transformations to sustainability.
- Full Text:
- Date Issued: 2019
Green synthesis of zinc oxide nanoparticles using Solanum torvum (L) leaf extract and evaluation of the toxicological profile of the ZnO nanoparticles–hydrogel composite in Wistar albino rats
- Authors: Ezealisiji, Kenneth E , Siwe-Noundou, Xavier , Maduelosi, Blessing , Nwachukwu, Nkemakolam , Krause, Rui W M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194015 , vital:45416 , xlink:href="https://doi.org/10.1007/s40089-018-0263-1"
- Description: Current study reports a simple and one-pot synthesis of zinc oxide nanoparticles (ZnONPs) using an aqueous extract of Solanum torvum and evaluation of its toxicological profile (0.5% w/w and 1.0% w/w) in Wistar albino rats with respect to the biochemical index. The nanoparticles were characterized using ultraviolet–visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction technique. Dynamic light scattering (DLS) and zeta potential of synthesized nanoparticles were analyzed to know the average size and stability of particles. Synthesized nanoparticles were stable, discreet, and mostly spherical, and size of particles was within the nanometre range. Biochemical markers of hepatic and renal functions were measured. Zinc oxide nanoparticles significantly decreased serum uric acid level (p less than 0.001) in a dose-dependent manner, while the serum alkaline phosphatase level was increased at the two test doses. The level of alanine transaminase was increased after exposure for 28 days (p less than 0.05). This study concludes that biogenic zinc oxide nanoparticles-infused hydrogel applied dermatologically could affect hepatic and renal performance in rats, and there was an observed cumulative toxicological effect with time of exposure.
- Full Text:
- Date Issued: 2019
Ground thermal regimes in Western Dronning Maud Land, Antarctica in 2016
- Authors: Masebe, Consliah Tebogo
- Date: 2019
- Subjects: Climatic changes -- Antarctica , Frozen ground -- Research -- Antarctica , Frozen ground -- Thermal properties -- Antarctica , Queen Maud Land , Earth temperature -- Antarctica , Soil temperature -- Antarctica -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95581 , vital:31173
- Description: Research shows that the climate of Antarctica is changing and, it is vital that the change is monitored to understand how it will affect global ecosystems. Since the International Polar Year (IPY) 2007-2008, research in permafrost studies has grown. However, there are still existing gaps that impede complete understanding of Antarctic cold environments and landscape processes. Permafrost has been noted as one of the major controlling factors of the terrestrial ecosystem dynamics in Antarctica. However, the understanding of Antarctic permafrost, when compared to other cryospheric components, is limited, especially its thermal and physical properties, evolution, as well as links to pedogenesis, hydrology, geomorphic dynamics, and responses to global change. This project provided an understanding and insight to over-arching research that evaluates the state and status of permafrost and the active layer in Dronning Maud Land (DML) through examining short-term variations on ground thermal regimes. The main focus is on understanding the influence of synoptic, diurnal and seasonal events on the active layer in 2016. Analysis of available data shows that ground thermal regimes are influenced by variations in air temperature, pressure, wind speed and to some extent, relative humidity. Subsequently, ground thermal regimes also depend on soil physical characteristics including sediment particle size and bulk density. Furthermore, sediment particle size and bulk density have been found to have a great influence on thermal propagation rates as well as active layer depth; the higher the bulk density, the higher the thermal propagation rate and the lower the bulk density, the lower the thermal propagation rate. Conversely, a large proportion of bigger sediment particle size in soil corresponds with a higher thermal propagation rate and a large proportion of smaller sediment particle size in soil corresponds with a lower thermal propagation rate. Also, ground thermal regimes vary according to seasons. Ground temperatures are more variable in summer, while air temperatures are more variable in winter. The variability according to different seasons shows that the active layer responds to seasonal climatic variations. Additionally, the active layer also responds to synoptic and diurnal weather events.
- Full Text:
- Date Issued: 2019
Growing up with a parent who has a mental illness: exploring the development of resilience
- Authors: Hannie, Robyn
- Date: 2019
- Subjects: Psychology, Applied , Developmental psychology Mentally ill -- Family relationships Parenting -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/42320 , vital:36645
- Description: Mental illnesses are one of the world’s greatest health challenges and fall amongst the top ten contributing factors to disability. However, mental health has been one of the least prioritised health issues. Mental illness has major implications on the economy of the country, health services as well as on the quality of patients’ lives, their relatives and society. According to research studies, parental pathology has been identified as an adversarial life experience. Despite the risks associated with growing up with a parent who has a mental illness, some individuals still function well. Current understanding of resilience is that it is a dynamic bidirectional process that is influenced, developed or constructed by individuals in relation to their environment. The understanding of resilience in this context is crucial to foster the development of resilience in young people in similar contexts. This study aimed to explore and describe the experiences and development of resilience in individuals raised by a parent who has a mental illness. It attempted to do so by conducting seven face-to-face individual interviews. Qualitative methods and specifically thematic analysis was utilised to explore participants’ development of resilience in the context of parental mental illness. The findings are represented by four broad themes: challenges of growing up with a parent who has a mental illness, social support, mental health literacy and coping strategies that helped to develop resilience.
- Full Text:
- Date Issued: 2019