Parents and personnel’s partnership in early childhood education provisioning in the East London Education District
- Authors: Mudziwapasi, Lilymore https://orcid.org/0000-0002-7978-8499
- Date: 2022-02
- Subjects: Education, Preschool -- Parent participation , Education, Preschool
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21700 , vital:51743
- Description: Early childhood development is fundamental to human development and success in later life. Several stakeholders influence that development. Developmental policies are advocating for formal education provision at that early childhood age. Therefore, relationships and interactions of these stakeholders are of paramount importance in ensuring effective early childhood education provisioning – especially between parents and practitioners. Yet it has been reported that sharing of information concerning children’s educational development is not happening between parents and ECD practitioners. ECD centres are said to face many problems such as poor teaching and learning which may result in weak childhood educational development. Some of these challenges can be addressed through enhancing the partnership between parents and the ECD practitioners. The purpose of this study was therefore to explore the parents and practitioners’ partnership in early childhood education provisioning in ECD centres in the East London district. This study used the mixed method approach in the sampling, data collection and data analysis processes. The study focused on the partnership between parents and ECD practitioners, on how they work together, their views, how they communicate, on decision making and the strategies to enhance the partnership of parents and practitioners. Research questions in this study required both qualitative and quantitative data and analysis techniques. Quantitative data was collected from the ECD practitioners and principals by using questionnaires and qualitative data was collected through interviews with the parents. Quantitative data was analysed using SPSS and qualitative data was analysed using the thematic approach. The findings indicated that both parents and practitioners are working together in supporting learning and development. Parents are said to provide resources for use at the centre. Parents and practitioners are using different modes of communication for the learning and development of the children, including technology-based WhatsApp and emails. Practitioners are said to include parents in some decision making. The results indicated that even though some parents are working together with practitioners, while other parents are still showing ignorance and lack of knowledge on how they can partner for the educational development of the children. , Thesis (PhD) -- Faculty of Education, 2022
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Adsorption of antibiotic-resistant bacteria and their cell-free deoxyribonucleic acid harbouring resistance genes in drinking water with metal oxides
- Authors: Tobechukwu, Anthony Eric
- Date: 2022
- Subjects: Metallic oxides , DNA -- Synthesis , Drinking water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27787 , vital:69494
- Description: Access to cleaner water is essential to human health. The incidence of Antibiotic Resistant Bacteria ARB in drinking water and subsequent proliferation of Antibiotic Resistance Genes ARGs in drinking water is a concern for public health. The free DNA cassette harboring antibiotic resistance gene in drinking water has been linked with impaired public health. The ARGs allows bacteria to develop resistance towards antibiotics while ARB render antibiotics ineffective. Existing drinking water treatment technologies eg adsorption, ozonation and chlorination, have shown different levels of potency in the removal of conventional water pollutant. These technologies, which operating principles is based on oxidation or mass transfer, have been explored to gained an insight into their efficiency in the removal of ARB ARGs in water treatment. In general, methods that functions by mass transfer of the ARB ARGs is more effectively than bacteria oxidation. Consequently, adsorption technology was chosen using common metal oxide adsorbents. The adsorbents ZnOAg CeO2 and Al2O3 were synthesized via the self propagation combustion method. This method was selected because of the purity of the final product and the energy requirement. One of the challenges in the removal of ARB in drinking water is the release of ARGs. To address this concern, five different ZnOAg heterostructures were synthesized for the removal of Enterococci faecium. ZnOAg was chosen because of the bactericidal and bacteriostatic characteristics. The study revealed that the concentration of the precursors influences the microstructures of the adsorbents; however, it did not significantly affect the adsorption efficiency. The maximum adsorption capacity q34.11 CFUg was obtained for Ag1Zn3.5. The kinetic studies revealed that Ag1Zn1 and Ag1Zn2 adsorbents agreed to the pseudofirst-order kinetic equation and adsorbents Ag2Zn1 Ag3.5Zn1 and Ag1Zn3.5 agreed to the pseudo-second-order kinetic equation. Initial tap-water pH range was beneficial for the adsorption and the pH of the treated tap-water was within the WHO tap water recommendation 6.5 – 8.5 whereas the effect of ionic strength, anionic and cationic interference was insignificant in the adsorption of MDREF onto the different heterostructure. Interestingly the MDREF could retain its cell membrane integrity and resistance genes, suggesting that surface adsorption was the primary mechanism for the removal. Cerium IV oxide CeO2 was selected because of high adsorption towards phosphate, backbone base for DNA. To prevent the problem of antibiotic resistance, we have synthesized a CeO2 adsorbent that exhibit highly positive character in a wide pH range, via the simple self-propagation combustion protocol, for the removal of free DNA harboring antibiotic resistance genes. Molecular characterization of the extracted genes showed that the sizes for E. coli and inherent gyrB genes are 147 and 460 bp with a purity between 19 2.0. The XRD SEM TEM, and PZC results of the as-synthesized CeO2 showed an agglomerate of pure cubic-faced centered material and highly crystalline, with a net charge at pH 6.2. Experimental results revealed that the reaction proceeded via pseudo first-order kinetic, and it is governed by electrostatic attraction. The free- DNA solution pH electrolyte, and competing ions impacted on the adsorption process. Further experimental results showed that the as-synthesized CeO2 adsorbent has the potential to be used for the removal of free DNA harboring ARGs from tap-water even under oxic conditions. Alumina Al2O3 is an abundant adsorbent that has also shown high removal capacity towards phosphate. The highly pure synthesized Al2O3 adsorbent exhibit fluid-like behaviour under Scanning Electron Microscope SEM. The XRD pattern corresponds to αAl2O3. The adsorption kinetics was described by pseudo second orderadsorption capacity 11.7 μgg implying chemisorption, which agrees with the electrostatic force of attraction caused by opposing ions. This result was evident by the effect of different ions in the tap water. The synthesized α-Al2O3 has the potential for the removal of cell free DNA harbouring multiply resistant genes. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
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Development and in vitro biological studies of polymer-based wound dressings with a high haemostatic ability for the management of wounds
- Authors: Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- Date: 2022
- Subjects: Wound healing , Surgical wound infections , Wound treatment equipment industry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27970 , vital:71404
- Description: Wounds are usually accompanied by complications such as excessive bleeding and bacteria invasion. The design of wound dressings that rapidly stop excessive bleeding and inhibit bacterial invasion is crucial to promoting accelerated wound healing. To meet the abovementioned requirements in wound dressings, topical gels were prepared from sodium alginate SA and carboxymethylcellulose CMC. The wound dressings were loaded with an antifibrinolytic agent, tranexamic acid TA, essential oils, and a variety of metal-based nanoparticles, and carbon-based biomaterials. The scanning electron microscopy SEM and X-ray diffraction XRD confirmed the successful formation of the nanoparticles. The prepared formulations exhibited in vitro drug release kinetics that best fitted with the Korsmeyer-Peppas model. These gels exhibited good spreadability and viscosity, showing a shear-thinning behaviour with pH between 6.7 and 7.3, signifying suitability for skin application and ease of application. The prepared topical gels exhibited significant antibacterial effects against gram-negative and gram-positive strains of bacteria. SA EO-based formulations showed high antibacterial activity across all bacterial strains, followed by SA-based formulations compared to CMC-based formulations, which exhibited moderate antibacterial activity. Moreover, the prepared gels showed good cytocompatibility, promoted cell proliferation, and exhibited 80 percent wound closure on day 3 compared to the untreated group, which showed a 38 percent wound reduction in vitro. Excellent blood clotting properties were observed with CMC-based gels compared to other formulations. However, all the prepared formulations exhibited outstanding blood clotting ability compared to the control, showing that they can promote rapid blood coagulation. The features presented by the prepared gels reveal that they are suitable for rapid wound healing , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
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Evaluation of functionalized silver and silica nanoparticles for the removal of deoxyribonucleic acid conveying antibiotics resistance genes from water
- Authors: Ezeuko, Adaora Stella
- Date: 2022
- Subjects: DNA , Silica , Water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27765 , vital:69414
- Description: Antibiotic resistance genes ARGs are recognized as a serious public health emergency linked to extensive use of antibiotics by humans and animals as a prophylactic agent that treats and prevents infections. The occurrence of high concentrations being identified in wastewater treatment plants, rivers, etc is due to untreated effluents being discharged from households, hospitals, agriculture, and pharmaceutical industries. The application of adequate treatment techniques and material for the removal of bacteria DNA conveying ARGs from the effluents before their release to the environment cannot be overemphasized. Adsorption techniques seem to be effective due to their easy design, operation, and ability to regenerate adsorbents for use without producing toxic by-products. This concept was employed for the removal of bacteria DNA conveying ARGs from simulated aqueous solution, effluents from hospital, river and WWTPs using silver and silica metallic nanoparticles. This thesis investigated the effectiveness of metallic nanoparticles containing silver AgNPs and mesoporous silica nanoparticles MSNPs as well as magnetite Fe3O4 functionalized with 4 4hydroxyphenyl 2 262-terpyridine onto their surface, for the removal of bacteria DNA conveying antibiotic resistance genes from water samples from hospitals, river, and wastewater treatment plants WWTPs. Silver nanoparticles AgNPs of different molar concentrations 0.1M, 0.5M and 1.0 M and mesoporous silica nanoparticles MSNPs adsorbents were successfully synthesized in their original states and surface functionalization achieved by incorporating magnetite Fe3O4 and 4 4 hydroxyphenyl 2 2 6 2 terpyridine on the silver AgNPs Fe3O4 and silica MSNPs TPPY surfaces respectively. Their effectiveness as adsorbent for the removal of bacteria DNA conveying ARGs from aqueous solutions and real water/wastewater samples were investigated. The DNA uptake by the as-synthesized AgNPs and MSNPs were compared to the functionalized AgNPs Fe3O4 and MSNPsTPPY by determining the adsorbents with the highest removal efficiencies. All as synthesized and functionalized adsorbents were characterized by SEM, EDX, FTIR, XRD, UV spectroscopy and PZC before the removal process. The extraction of genomic DNA from antibiotic-resistant Enterococcus faecium and Vibrio parahaemolyticus was successfully achieved via the boiling method. Antibiotic susceptibility test was conducted using the disk diffusion method before the commencement of genomic DNA extraction. Molecular characterization via gel electrophoresis confirmed the presence of resistance genes at different base pairs. Adsorption batch experiment were investigated, and the best optimum parameters were evaluated through the influence of pH, contact time, initial DNA concentration, adsorbent dose, and competitive ions for each sorption process. The rate determining step were determined by fitting kinetic models such as Natarajan and Khalaf first order, pseudo first order, pseudo second order, Elovich model to experimental data. Also, the adsorption mechanisms determining adsorption equilibrium were investigated by fitting Freundlich, Langmuir and Sips model into the experimental data. The application of AgNPsFe3O4 nanocomposite and MSNPsTPPY for the removal of bacteria DNA demonstrated much enhancement for DNA uptake than the as-synthesized AgNPs and MSNPs materials. The incorporation of magnetite and 4 4hydroxyphenyl 2 2 6 2-terpyridine onto AgNPs and MSNPs significantly enhanced the binding affinity towards the removal the bacteria DNA via strong electrostatic attraction between the active sites on the adsorbent and the negative DNA molecules. Finally, high adsorption capacities were recorded with AgNPsFe3O4 nanocomposite and MSNPsTPPY compared to AgNPs and MSNPs with chaotropic salts. The kinetic adsorption models were mostly best fitted by the pseudo-second order and Elovich models while the adsorption equilibrium was best described by Langmuir and Sips isotherm models. MSNPs with different chaotropic salts, AgNPsFe3O4 nanocomposite and MSNPsTPPY also proved its effectiveness in DNA removal not only in the simulated aqueous solution but in three different real life water samples obtained from Cofimvaba hospital, Ndevana river and Uitenhage WWTPs. High adsorption efficiencies above 90 percent were achieved during the removal of DNA in all the three real water samples. Therefore, application of these adsorbents for the removal of bacteria DNA conveying ARGs may be a promising option that would tackle the consequences of consuming ARGs infected water globally. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
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Preparation, characterization, and in vitro evaluation of polymer-based wound dressings for the management of chronic wounds
- Authors: Alven, Sibusiso
- Date: 2022
- Subjects: Toxicity testing -- In vitro , Wound healing , Chronic diseases
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27992 , vital:71414
- Description: Microbial infections are responsible for the retarded recovery process of chronic wounds. Polymer-based scaffolds possess features suitable for the treatment of chronic injuries. However, these scaffolds are commonly encapsulated with therapeutic agents to enhance their biological activities, including antibacterial efficacy. In this research, two types of polymer-based scaffolds were formulated and evaluated as effective formulations for the treatment of chronic wounds: sponges and topical gels. Sponges were formulated from cross-linking of gelatin and PEG. Ag nanoparticles and metronidazole were incorporated into the sponges to improve their antibacterial activity. Topical gels were loaded with essential oils and Ag nanoparticles and prepared from CMC and poloxamer. The prepared sponges and topical gels were evaluated using various analysis and characterization techniques. SEM/EDX, FTIR, and TGA were employed to characterize gelatin/PEG hybrid sponges followed by porosity, in vitro biodegradability, cytotoxicity, and antibacterial studies. FTIR, SEM/EDX, and TGA confirmed their physicochemical properties and successful fabrication of sponges loaded with metronidazole and Ag nanoparticles. The sponges were biodegradable, indicating their capability to induce skin regeneration. The drug release studies showed a rapid release of metronidazole 28.32-71.97 percent from the sponges over the first hour, followed by a sustained drug release. The Ag nanoparticles were released in a sustained manner, suggesting that these sponges can rapidly destroy bacteria and inhibit persisting bacterial infections as well as protect the lesion bed from further bacteria infections. The in vitro antibacterial studies of sponges displayed superior antibacterial activity against most of the Gram-negative and Gram-positive bacteria strains commonly found in chronic wound infections with a MIC value of 15.625 μg/mL. In vitro cytotoxicity experiments revealed excellent biocompatibility with a percent cell viability of more than 70 percent. The in vitro wound scratch healing assay exhibited that the sponges encapsulated with only metronidazole promoted high cell migration than the dual drug-loaded sponges and untreated cells, suggesting its potential to quicken the wound healing process. CMC/Poloxamer topical gels were also characterized by FTIR, followed by pH, viscosity, spreadability, cytotoxicity, and antibacterial studies. FTIR showed successful preparation of CMC/Poloxamer topical gels loaded with essential oils and Ag nanoparticles. The topical gels exhibited pH in the range of 5.20-6.68, spreadability between 5.4 and 5.9 cm, and viscosity ranged from 216 to 1200 cP at 50 rpm and 210–858 cP at 100 rpm. The in vitro drug release studies demonstrated that Ag nanoparticles were released from the topical gels in a sustained manner. Most formulated topical gels demonstrated superior antimicrobial efficacy against Gram-positive and Gram-negative bacteria strains than the blank gel and controls. The cytotoxicity analysis displayed more than 90.83 percent cell viability for the topical gels, revealing excellent biocompatibility. The outcomes revealed that the topical gels enriched with essential oils lavender and tea tree and Ag nanoparticles and sponges incorporated with metronidazole and Ag nanoparticles are potential wound dressing scaffolds that can be employed for the treatment of chronic infected injuries. The in vitro wound healing experiments showed that the HaCaT cells cultured with gels co-enriched with lavender oil and Ag nanoparticles possessed a higher rate of closure in comparison to the untreated cells for 96 hours. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
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Synthesis and in vitro biological studies of ursolic acid-based hybrid compounds
- Authors: Khwaza, Vuyolwethu
- Date: 2022
- Subjects: Herbal medicine , Herbs -- Therapeutic use , Antineoplastic antibiotics
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27797 , vital:69689
- Description: Ursolic acid UA, a pentacyclic triterpenoid that is commonly found in many medicinal herbs and fruits, has been identified as a potential source of therapeutic agents because of its potent biological effects, which include its potential anticancer and antimicrobial activities. However, its limited solubility, rapid metabolism and poor bioavailability inhibit its clinical applications. Numerous UA derivatives have been prepared over the past years in an effort to mitigate the drawbacks associated with UA, as new chemical entities for the treatment of various infections. There is very little progress in the discovery of efficient UA derivatives. In this study, a class of ester and amide-linked ursolic acid-based hybrid compounds fused with selected pharmaceutical scaffolds were successfully synthesized using amidation and esterification reactions and tested for antibacterial and cytotoxicity activities. Hybridizing UA with other known pharmaceutical scaffolds has the potential of overcoming its drawbacks. FT-IR, Mass Spectroscopy, and 1H13C-NMR spectroscopy were used to confirm the structures of the synthesized hybrid compounds. Among the tested ester-linked hybrid compounds in Chapter three, compounds 3.14-3.19,3.21, 3.34, 3.31, and 3.30 demonstrated significant antibacterial activities against some tested bacteria, with MIC values of 15.625 μgml. Furthermore, the in vitro cytotoxicity of these hybrids was determined using the MTT assay against three human tumor cell lines MCF7, MDA-MB-231, and HeLa cells. Compounds 3.19 and 3.34 were found to have better cytotoxic activity when compared to ursolic acid, with IC50 values of 46.99 and 48.18 μg ml respectively. Both compounds revealed more promising docking results, presenting favourable binding interactions as well as better docking energy against the MCF 7 protein target compared to the parent compound ursolic acid. In Chapter Four, among the tested amide-linked hybrid compounds, Compounds 4.17 and 4.24 demonstrated significant antibacterial activity against the majority of bacterial strains with MIC values of 15.625 gml. Compound 4.24 exhibited a MIC value of 15.625gmL against BS, SA, PV, KO, PM, and EC. Compound 4.23 was more cytotoxic to HeLa cells than ursolic acid. Furthermore, molecular docking calculations revealed that compound 4.16 strongly binds to the protein epidermal growth factor receptor while e compounds 4.17 and 4.24 showed a strong binding affinity for the methionyl-tRNA synthetase. In both cases, the hybrid compounds showed better conformational fittings in the active site of the targeted proteins as compared to the parent ursolic acid. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
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Standards for the admission of forensic scientific evidence in criminal trials through an expert: Lessons and guidelines for South Africa
- Authors: Chetty, Nasholan https://orcid.org/0000-0002-7053-5831
- Date: 2022-01
- Subjects: Evidence, Expert , Forensic sciences , Crime scene searches
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22467 , vital:52324
- Description: Forensic evidence has always captured the imagination of the public and legal fraternity since science entered the courtroom. The first case of forensic science was heard in the matter of John Boodle in 1832, and criminal courts have now come accustomed to hearing a variety of matters that have some form of forensic science evidence in them. Television shows like Crime Scene Investigation and Making a Murderer has heightened the expectation that is placed on the sciences and the ease of which a conviction can be secured or a suspect apprehended. The spate of wrongful convictions that have been overturned, particularly in the United States of America has raised serious questions regarding the use of forensic evidence in courts. Moreover, the people “in-charge” or the so-called experts for providing this analysis’s have come under intense scrutiny. Many reports have been compiled after investigations were conducted into the state of expert evidence in those various jurisdictions. The use of an expert to provide critical details regarding aspects of a crime that goes beyond the ordinary education of presiding officers and legal practitioners has posed to the court, many questions as to how they are being used and whether their evidence should be used. The use of an expert is not new to the South African legal system, and the same can be said for many foreign jurisdictions, but the problem now experienced by courts is whether these experts are in-fact “experts” and whether the information conveyed to the court can be relied upon especially if the evidence is of a scientific nature. An investigation into how expert evidence is presented and evaluated in South African criminal courts will reveal many appealing aspects regarding the development of how an expert is used and how they should be used as well as how their evidence should be evaluated. , Thesis (PhD) -- Faculty of Law, 2022
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Trade openness, economic growth, income inequality and poverty nexus in SADC countries: 1980-2019
- Authors: Gonese, Dorcas https://orcid.org/0000-0003-0774-024X
- Date: 2022-01
- Subjects: Economic development , Income distribution
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23370 , vital:57618
- Description: Trade openness (TO) has been identified as a critical component for sustainable economic growth, income inequality reduction, and poverty reduction in the 2030 Agenda as per the Sustainable Development Goals (SDGs), and the Southern African Development Community (SADC) regional indicative strategic development plan (RISDP). Despite the opening up to the global world, developing countries such as the SADC continue to face exclusive and unstable economic growth, massive income disparity, and poverty. Considering the previous empirical work, many controversies are related to methodologies and measurement issues. The study attempted to examine the impact of trade openness on economic growth of the SADC countries as well as its effect on income inequality and poverty reduction from 1980 to 2019. The study builds on existing studies in the region that have mainly analysed this kind of relationship, assuming that it is only TO and economic growth (EGR) that matters. The study sought to address three analytical objectives. The first objective focused on examining the effects of trade openness on economic growth in the SADC countries. In addressing this objective, the Pooled Mean Group (PMG) was utilised, given the nature of the relationship between the variables of interest. The empirical results revealed that all measures of trade openness (real trade openness, economic globalisation, exports and imports of goods and services) used in the study have a positive effect on economic growth in SADC countries. This implies that the foreign factors account for a share of SADC's economic growth. The PMG indicates that the mediating variables of all measures of trade openness with human capital development have a positive effect on economic growth. This implies that the beneficial impact of the said measures of trade openness, are more effective when investment in human capital increases. The second objective focused on analysing trade openness's direct and indirect impact on income inequality using the PMG model again. The empirical results indicate that trade openness via exports has a negative effect on income inequality. In contrast, real trade openness and imports positively affect income inequality. This implies that the exports of goods and services in SADC are drivers of income inequality reduction while real trade openness and imports worsen it. Therefore, the SADC countries must be wary of real trade openness and import policies addressing income inequality. As for the interaction effects, the empirical results indicate that greater openness via real trade openness, economic globalisation, exports and imports reduce income inequality when economic growth increases and when the financial sector is more developed. The final analytical objective focused on analysing the effects of TO on poverty in the SADC region. The PMG model was utilised for trade openness-non-income poverty (NPOV) relationship. However, because there is a scarcity of income-poverty (IPOV) data, the time dimensions for the income poverty-trade openness model are smaller than the cross sections. Therefore, the current study employed the system generalised method of moments (SGMM) estimation technique which is a more effective and efficient estimation technique for controlling for endogeneity when the time dimension is smaller than the cross sections. The findings indicate that real trade openness has a positive effect on NPOV, whereas economic globalisation, exports, and imports negatively affect NPOV. This implies that real trade openness increases poverty reduction while economic globalisation, exports and imports exacerbate non-income poverty in SADC countries. On testing whether trade openness- NPOV relationship changes with economic growth, income inequality, human capital development, financial development and institutional quality, the complementary variable with EGR is positive and significant for real trade openness and exports, implying that real trade openness and exports reduce NPOV when economic growth increases. The SGMM indicates that only economic globalisation and imports have negative impact on income poverty in SADC countries. This implies that economic globalisation and imports are determinants of income poverty reduction in the SADC countries. The SADC governments and policymakers should be mindful about what ways they should globalise, what goods they export or imports to minimise income poverty. , Thesis (PhD) -- Faculty of Management and Commerce, 2022
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Assessing the implementation of environmental education school policy in Buffalo City Metro Education District South Africa
- Authors: Damoah, Benjamin
- Date: 2021-12
- Subjects: Environmental education , Environmental policy -- South Africa , Education and state -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21602 , vital:51703
- Description: Environmental Education (EE) is essential for addressing environmental challenges.The advantages of EE are undeniable; it might be used to address specific environmental concerns and their implications, as well as to modify behaviours that lead to environmental catastrophes.EE strengthens people's resilience to climaterelated hazards. Global environmental issues have heightened interest in educational policy outcomes and their implications for economic growth and social citizenship. It is worth noting that an effective EE policy has a significant influence on the development of learners' environmental literacy. This study assessed the implementation of environmental education school policy in the Buffalo City Metro Education District, South Africa. This study adopted the pragmatism paradigm of Mixed Method Research(MMR). Concurrent triangulation, which is a design that employs a single data collection technique in which quantitative and qualitative data gathering and analysis are carried out independently yet concurrently, was used for this study. The target population of this study involved 60,412 teachers, 1,770,289 learners in 5205 public schools, and 1 Pro-EE civil society organisation in the Eastern Cape province. This was narrowed down to over 268 public and independent schools, teachers, and principals within the enclave of the Buffalo Metropolitan education district. The study adopted stratified purposeful and simple random probability sampling. In this technique, the sampling frame of the study was divided into strata or groups (principals, teachers, learners, and CSOs) and a sample was purposefully selected from each stratum (Migiro & Magangi, 2011). The stratified purposeful random sampling techniques draw data from 10 principals, 175 teachers, 1500 learners, and 1 CSO. Structured questionnaire; Implementation of EE Policy Questionnaire (IEEPQ) whose reliability co-efficient value using Cronbach Alpha was 0.74, semi-structured interview and documents were the instruments used to collect data for this study. The data were analysed using descriptive statistics of percentage, mean, and standard deviation for the quantitative data while the thematic approach of sorting, coding, transcribing, and categorization was used for the qualitative data. The study revealed the following. When asked whether teachers had studied environmental education in tertiary institutions as part of their professional training, the majority of the teachers'respondents, 108, representing 61.7percent, disagreed with this view. On the flip side, a handful of teachers 67, (38.3percent) agreed with the view of having had some sort of EE knowledge during their professional training as teachers. With regards to the view that learners learn environmental issues through other subjects, most of the learner respondents, 1316 representing 87.7percent, agreed with this view. On the contrary, a minority of the respondents 184 (12,3percent) had a dissenting opinion. This indicates that most learners in school learn about environmental concerns through other traditional subjects. The study established that EE content is manifest in teachers' and learners' textbooks, teaching methods, and co-curricular activities. However, the study identified lapses in how teachers and learners integrate EE into their day-to-day practices. Therefore, the implementation of the EE policy seems to be an exercise in futility. The absence of a policy guideline document has made teachers and school administrators incapacitated in the implementation of EE school policy. , Thesis (PhD) -- Faculty of Education, 2022
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Bayesian spatio-temporal zero-inflated mixed models for overdispersion on chronic disease mapping
- Authors: Osuji, Georgeleen O https://orcid.org/0000-0002-8408-3928
- Date: 2021-12
- Subjects: Medical mapping , Bayesian statistical decision theory
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23644 , vital:58230
- Description: Background: Life expectancy in most developing countries has remarkably increased and decreased in mortality, but under 5 years old mortality has increased due to HIV and Tuberculosis incidence. Many factors have been established to influence the mortality rate among HIV patients and understanding the factors contribution to the risk of under 5-year-old mortality is important for designing appropriate health interventions. Excess zeros usually occur in such HIV mortality count data. Mixed models consisting of count part and zero part are often used to describe the observed excess zero in the data. Poisson models are popular modeling inference, but Negative-Binomial models are more flexible in analyzing count data and dealing with overdispersion. Method: This research proposed to develop two-part hurdle models in analyzing areal zero count data. A spatial Bayesian lognormal-logit hurdle model (BLLHM) with random effects characterizes and cross-spatial dependencies were introduced. The parameter inferences and predictions were evaluated using the Markov Chain Monte Carlo algorithm. The model proposed was applied to HIV-positive under 5-year-old mortality collected from the Eastern Cape Department of Health. Results: Bayesian lognormal-logit hurdle model is selected as the best model fit. It is observed that the total number of HIV patients not on ART-HIVnotTB (0.000612, p <0.000) was positively and statistically significantly associated with the HIV-positive mortality of under 5 years patients. Both CD4 counts were done on newly diagnosed HIV rate (CD4count) and HIV-positive new patients screened for TB rate (HIVTBrate) were negatively and statistically significantly associated with the HIV-positive mortality of under 5 years patients (-0.6294, p = 0.000 and -0.00056, p = 0.0052). However, the covariate HIV positive Tuberculosis Preventive therapy (TPT) uptake rate (HIVandTB) was not statistically significantly associated with the HIV-positive mortality of under 5 years patients (-0.00155, p = 0.5392). Conclusion: The model is flexible to deal with zero-inflated and over-dispersed count data. There is a need to consider the risk of cause-specific under-5-year-old mortality in terms of spatial effects. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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The perceived success of selected therapy programmes on mitigating the relapses of patients with substance use disorders in Gauteng, South Africa
- Authors: Chatikobo, Nyasha
- Date: 2021-12
- Subjects: Substance abuse -- Treatment , Psychotherapy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21860 , vital:51833
- Description: This study aimed at evaluating the perceived success of selected therapy programs in mitigating the relapse of patients with substance use disorders at two selected rehabilitation centres in the Gauteng province of South Africa. The methodology used for this study was a mixed-method approach, although more emphasis was on qualitative methods. The qualitative data was collected from four focus groups, and 6 in-depth interviews from key informants. The quantitative data was collected using questionnaires that were completed by 100 primary carers of discharged patients from the selected drug treatment centres. The main findings of the study showed that substance use disorder is a complex disease that requires several factors to be considered to avoid any relapses. The study showed that rehabilitation centres are hugely contributing to efforts of solving substance use in Gauteng and South Africa as a whole. These rehabilitation centres offered various treatment programs to individuals who suffer from substance use disorders. The findings also indicated that the selected therapy programmes at the rehabilitation centres met their objectives. However, some of the programmes were successful in mitigating the relapses of patients recovering from addiction to a lesser extent. The study also found out that the number of individuals who relapse is relatively high, however, the study did not dive into the depth of the causing factors. This may be room for future studies. Findings further indicated that the rehabilitation centres lacked in the application of a holistic approach to addiction treatment, even though there were several treatment programs offered. The issue of exorbitant residential fees in private rehabilitation facilities was also highlighted by the data collected. The research concluded by suggesting several recommendations such as research to improve policy for substance use with a focus on the human rights approach to the drug problem. Recommendations to the Department of Social Development which is responsible for the rehabilitation centres in South Africa. To ensure that all centres that are registered for offering treatment for substance use disorder be mandated to use a comprehensive multidisciplinary approach, diversifying and individualizing treatments for better outcomes. Lastly, recommendations were suggested to the social work practice, to support rehabilitation facilities by providing continuous specialized training to their social workers. Recommendations to social work training and curriculum to include in-depth substance use disorders during education, training, and field placements, for best practice amongst new social work practitioners placed in rehabilitation centres. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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A comparative appraisal of access and quality of sexual and reproductive health services for gays and lesbians in Bulawayo (Zimbabwe) and Pretoria (South Africa)
- Authors: Jasi, Phineas
- Date: 2021-11
- Subjects: Reproductive health , Sexual health
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21959 , vital:51854
- Description: This study investigated the extent to which gays and lesbians access quality sexual and reproductive health (SRH) services in Pretoria and Bulawayo. The study also examines the facilitators and barriers for accessing the same services. Theoretically, the study was grounded in the Health Belief Model (Hochbaum, 1958, modified by Rosenstock, 1974 and Siddiqui, 2016). To answer the research questions, a mixed methods approach was applied involving both qualitative and quantitative data collection methods. A total of 30 key informant interviews, eight focus group discussions and 387 questionnaires were administered using purposive, time location and snowball sampling approaches in the two cities. The study found that the most commonly available sexual and reproductive health (SRH) services were contraceptive services, sexually transmitted infections (STI) services and Human immunodeficiency syndrome (HIV) services. The services were provided at public health facilities, drop-in centres and through outreach activities operated by Civil Society Organizations (CSOs). The least available services that gays and lesbians required as part of a comprehensive package were access to information, education and communications (IEC) materials and mental health and psychosocial support services (MHPSS). Several service providers were not adhering to the World Health Organization (WHO) guidelines for provision of comprehensive services for key populations including gays and lesbians. Critical gaps noted included the absence of key populations-only service hours, lack of options for clinicians to attend to them, presence of a stigma and discrimination free environment and provision of comprehensive package of services under one roof. Most of the referral facilities had limited drugs, equipment and supplies for cancer screening and they had no HIV prevention, sex change, in-vitro fertilization, and sterilization services and procedures. The quality of physical facilities and SRH services in both cities did not meet the expectations of gays and lesbians, acting as a barrier to their health seeking behaviour. Stigma and discrimination from healthcare workers was a huge barrier affecting access across all public health facilities. The acts of stigmatisation and discrimination affected the perceptions that gays and lesbians had regarding the quality of the services and compromised access of the same. In view of these health system challenges, the study recommends that there is need for public authorities in both cities to address the bottlenecks and barriers affecting access to SRH services and products such as lubricants, affordable quality condoms, dental dams and latex gloves while reinforcing the facilitating factors promoting access. Healthcare workers need further training on how to provide comprehensive services for gays and lesbians according to the WHO guidelines. Public health authorities in Bulawayo and Pretoria should build upon the identified factors which facilitated the access to SRH services and use of products such as condoms and lubricants. These factors require strengthening of community-based organizations and networks that work directly with gays and lesbians in both Bulawayo and Pretoria. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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Impact of press freedom on reportage of corruption in the Nigerian oil and gas industry : a comparative content analysis of four Nigerian Newspapers
- Authors: Ayodeji-Falade, Monisola Bolajoko
- Date: 2021-10
- Subjects: Newspapers -- Nigeria , Freedom of the press , Mass media -- Nigeria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21805 , vital:51787
- Description: A free press is pivotal to eradication of corruption in the society as the press remains the most powerful channel of communication that cut across all publics. Thus, this study seeks to evaluate the impact of press freedom on reportage of corruption in the oil and gas industry through a content analysis of four Nigerian newspapers (The Punch, Vanguard, Guardian and Nigerian Tribune). The study adopted a mixed research method involving both quantitative and qualitative approaches. Quantitative data were collected and analysed through content analysis of the selected newspapers while the qualitative data collected through interview of the respective newspaper correspondents were analysed using thematic analysis. The study revealed that 534 stories were published on corruption in the Nigerian oil and gas sector by all the newspapers within the study period (July 2018-June 2019), with the Punch having the highest magnitude of stories (n = 196, 36.70percent) while Nigerian Tribune had the highest number of stories reported on its front and back pages (n = 143, 92.25percent). However, Guardian had the highest number of full-paged stories (n = 15, 20percent) whereas the Punch and Nigerian Tribune adopted the widest range of publication formats with news being the most dominant format employed by all the dailies (n = 462, 86.52percent). Although, all the newspapers employed more episodic frame (n = 432, 80.89percent) than thematic frame (n = 93,17.41percent), framing analysis revealed oil theft, vandalism, alleged-fraud, environmental consequences and economic consequences as the major frames used in the coverage of stories on corruption in the Nigerian oil and gas industry. Thematic analysis showed that the newspaper correspondents did not have access to adequate information on corruption in the sector while journalists in the country are still being subjected to intimidation, arrest and imprisonment. These findings suggest that the selected newspapers gave prominence to reportage of corruption in the oil and gas sector in country, which implies that the newspapers are fulfilling their agenda-setting roles and social responsibility in the society. Nevertheless, the level of press freedom in Nigeria has partly affected the reportage of corruption in the oil and gas sector of the country as this has restricted the use of investigative reporting occasioned by the lack of access to classified information on corruption and envisaged harm by potential sources and journalists. Nevertheless, this study proposes an anticorruption-media model, which focuses on the significance of the media as an anticorruption agent in a developing country. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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Investigating the feasibility of using remote sensing in index-based crop insurance for South Africa’s smallholder farming systems
- Authors: Masiza, Wonga https://orcid.org/0000-0002-6224-3812
- Date: 2021-10
- Subjects: Precision farming , Agricultural engineering , Climatic changes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23000 , vital:54890
- Description: Crop farming in Sub-Saharan Africa (SSA) is largely practiced by resource-poor farmers under rain-fed and unpredictable weather conditions. Since agriculture is the mainstay of SSA’s economy, the lack of improved and adapted agricultural technologies in this region sets back economic development and the fight against poverty. Overcoming this constraint and achieving the sustainable development goal to end poverty, requires innovative tools that can be used for weather risk management. One tool that has been gaining momentum recently is index-based crop insurance (IBCI). Since the launch of the first IBCI program in Africa around 2005, the number of IBCI programs has increased. Unfortunately, these programs are constrained by poor product design, basis risk, and low uptake of contracts. When these issues were first pointed-out in the earliest IBCI programs, many reports suggested satellite remote sensing (RS) as a viable solution. Hence, the first objective of this study was to assess how RS has been used in IBCI, the challenges RS faces, and potential contributions of RS that have not yet been meaningfully exploited. The literature shows that IBCI programs are increasingly adopting RS. RS has improved demarcation of unit areas of insurance and enabled IBCI to reach inaccessible areas that do not have sufficient meteorological infrastructure. However, the literature also shows that IBCI is still tainted by basis risk, which emanates from poor contract designs, the influence of non-weather factors on crop yields, imperfect correlations between satellite-based indices and crop yields, and the lack of historical data for calibration. Although IBCI reports cover vegetation and crop health monitoring, few to none cover crop type and crop area mapping. Furthermore, areas including high-resolution mapping, data fusion, microwave RS, machine learning, and computer vision have not been sufficiently tested in IBCI. The second objective of this study was to assess how RS and machine learning techniques can be used to enhance the mapping of smallholder crop farming landscapes. The findings show that machine learning ensembles and the combination of optical and microwave data can map a smallholder farming landscape with a maximum accuracy of 97.71 percent. The third objective was to identify factors that influence crop yields and crop losses in order to improve IBCI design. Results demonstrated that the pervasive notion that low yields in smallholder farms are related to rainfall is an oversimplification. Factors including fertilizer use, seed variety, soil properties, soil moisture, growing degree-days, management, and socioeconomic conditions are some of the most important factors influencing crop yields and crop losses in smallholder farming systems. This shows why IBCI needs to be part of a comprehensive risk management system that understands and approaches smallholder crop farming as complex by linking insurance with advisories and input supplies. Improved inputs and good farming practices could reduce the influence of non-weather factors on crop losses, and thereby reduce basis risk in weather-based index insurance (WII) contracts. The fourth objective of this study was to assess how well the combination of synthetic aperture radar (SAR) and optical indices estimate soil moisture. As stated earlier, soil moisture was found to be one of the most important factors affecting crop yields. Although this method better estimated soil moisture over the first half of the growing season, estimation accuracies were comparable to those found in studies that had used similar datasets (RMSE = 0.043 m3 m-3, MAE = 0.034 m3 m- 3). Further interrogation of interaction effects between the variables used in this study and consideration of other factors that affect SAR backscatter could improve the method. More importantly, incorporating high-resolution satellite-based monitoring of soil moisture into IBCI could potentially reduce basis risk. The fifth objective of this study was to develop an IBCI for smallholder crop farming systems. The proposed IBCI scheme covers maize and derives index thresholds from crop water requirements and satellite-based rainfall estimates. It covers rainfall deficits over the vegetative, mid-season, and late-season stages of maize growth. The key contribution of this system is the derivation of index thresholds from CWR and site-specific rainfall conditions. The widely used approach, which calibrates IBCI by correlating yields and rainfall, exposes contracts to basis risk because, by simply correlating yield and rainfall data, it overlooks the influence of non-weather factors on crop yields and losses. The proposed system must be linked or bundled with non-weather variables that affect crop yields. Effectively, this means that the insurance must be linked or bundled with advisories and input supplies to address the influence of non-weather factors on crop losses. This system also incorporates a crop area-mapping component, which was found to be lacking in many IBCI systems. In conclusion, an IBCI that is based on crop water requirements, which incorporates crop area mapping and links insurance with non-weather crop yield-determining factors, is potentially capable of improving crop insurance for smallholder farming systems. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Rethinking the role of councilors in a digital era governance:: a critical analysis of Shinyanga Municipality and Nzega District Council in Tanzania
- Authors: Linje, Anna Peter https://orcid.org/0000-0003-1990-3309
- Date: 2021-10
- Subjects: Internet in public administration , Information technology Political aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21759 , vital:51749
- Description: This study endeavored to rethink the roles of councilors in a digital era governance. The essence of councils’ role according to Adams (2013), is that they are the only level of government with a legislative mandate for the well-being of people and responsive to local risks and opportunities. Therefore, it is important to rethink their roles as they require a full range of interactions which can now be facilitated by the use of digital potentials (Adams, 2013). The study explored the councilors’ undertakings to understand the current situation and if they embrace the new forms of digital governance. Also, the researcher reviewed the laws and policies guiding the councilors in their undertakings and if they accommodated the digital era requirements. Moreover, the researcher examined the capacity of councilors and the challenges they face in their undertakings. The study employed a qualitative approach, whereby semistructured interviews, observation and documentary review were used to collect data. The findings revealed that councils’ practices and processes continue to be outside the digital age. One of the major factors was a dearth of limited practical experiences to upkeep the digital governance opportunities and tailor their decisions accordingly. Regarding legislatives, the findings showed that there was evidence of formulation of new legislatives including the current ICT policy (2016) that respond to the digital governance. Yet, it was indicated that the digital legislatives were not well captured by the individual councilors, while the enforcement mechanisms were still at its infancy. Also, councils could not provide a clear digital platform framework. The capacity of councilors was found to be insufficient, they were not well equipped in terms of facilities, skills and digital technicalities. Generally, lack of political readiness, spirit of fear and poor digital infrastructure were major challenges. The study recommended councils adopt new ways in parallel with the existing ones, this should be inclusive of frequent trainings. , Thesis (PhD) -- Faculty of Management and Commerce, 2021
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Access to justice for female victims of crime: a study of girls and women with disabilities in Mashonaland Central Province of Zimbabwe
- Authors: Shumba, Nyaradzo Dorcas
- Date: 2021-09
- Subjects: Criminal justice, Administration of -- Zimbabwe , Women -- Crimes against , Victims of crimes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22176 , vital:51994
- Description: This thesis utilized a thematic content analysis, looked at how significant barriers affect Mashonaland Central girls and women living with disabilities as victims of crime from accessing justice. Zimbabwe is an optimal case to apply this study, due to its contradictory legislation and evidence of high rate of human rights violations. Mashonaland Central Province is an ideal case study due to the extant records that indicate that it has the highest incidences of violence against women. This study is therefore based in a Victimological epoch with the aim to fill the research gap in acknowledging the process of accessing justice as an important step for protecting and promoting human right. By analyzing interviews conducted with 3 different women aged 18-65 and 3 girls living with disability who were under the age of 18, through the theoretical framework of basic human rights theory and victim dynamics, this thesis contributes to the existing body of knowledge, with suggestions of how these barriers which are inclusive of societal and cultural structures tend to affect the respondents’ everyday lives and in a most pertinent manner towards their right to access justice. This thesis is also governed by the perspectives of key actors in the judicial process including but not limited to the Victim Friendly Unit. The theoretical framework is also operationalized into themes and criteria, which are then applied to analyze the conducted interviews. The emerging findings illuminate that there is a discrepancy between government policy surrounding girls and women living with disabilities and the practical experiences of the respondents. The respondents experienced a lack of accessibility to basic rights such as health care, the law, and to sex education – which are all rights ensured by government policy. Identified consequences included: discouragement in seeking justice due to fears of cultural and social stigma, discouragement in reporting crimes, and receiving adequate support, as well as information from secondhand sources. This study therefore concludes lack of access to justice is a violation of security of person, human dignity and rights to health and life to women and girls living with disability. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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Compartmentalization of mineral elements, nutritional factors, biological potentials and phytochemical profiles in the fruits of Musa sinensis L.(Banana) and Musa paradisiaca L.(Plantain): A comparison among soft flesh, peel and boiled peel extract
- Authors: Oyeyinka, Barnabas Oluwatomide https://orcid.org/0000-0003-1191-9365
- Date: 2021-09
- Subjects: Bananas , Plantain banana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23655 , vital:58274
- Description: Fruits are key contributors to human nutrition and health. However, banana and plantain are typical examples of fruits that have nutritionally under-utilized peel by-products. This study was thus carried out to investigate the compartmental distribution (soft flesh, peel, and boiled peel extract) of mineral elements, nutritional factors, biological potentials, and phytochemical profiles in M. sinensis and M. paradisiaca fruits (ripening stage 4-5), with focus on the peels. Proximal and and antinutritive analyses were done with standard methods of the Association of Official Analytical Chemists (AOAC), while mineral element composition in the fruit components was analyzed with the inductively coupled plasma optical emission spectroscopy (ICP-OES). The pharmacological potential of M. sinensis and M. paradisiaca fruit components was investigated spectrophotometrically by evaluating the polyphenolic constituents (total phenol, proanthocyanidin, flavonoid) and in vitro radical scavenging activities of the aqueous, acetone and ethanol extracts, using DPPH, ABTS, and FRAP assay models. The correlational evaluation of the polyphenolics and antioxidant activity in the components of both fruits using Pearson’s correlational coefficient (r). The proximal assays revealed that moisture content, fiber content, and carbohydratecontent were substantially present in the flesh and peel of M. sinensis and M. paradisiaca, while lipid content was low. The antinutritive results revealed safe levels of alkaloid, oxalate, phytate, and saponin factors in the flesh and peel by-products. Mineral analysis results indicated substantial levels of the macroelements K, Mg, Ca, and P in the peels. Other results revealed that acetone extracts had the highest phenolic, proanthocyanidin and flavonoid constituents respectively, across the soft flesh components ofM. sinensis (119.05 ± 5.80 mgGAE/g; 337.48 ± 13.16 mgCE/g; 602.64 ± 3.65 mgQE/g), M. paradisiaca (114.80 ± 1.49 mgGAE/g; 436.09 ± 36.44 mgCE/g; 777.35 ± 150.95mgQE/g) and the peel component of M. paradisiaca (136.87 ± 5.69 mgGAE/g; 530.06 ± 53.51 mgCE/g; 750.87 ± 55.61 mgQE/g), with an exception of the phenolic content of M. sinensis peel, where it was highest in the ethanol extract (157.19 ± 4.76 mgGAE/g). The ABTS (0.03 mg/mL) and DPPH (0.03 mg/mL) activities were at their highest in the boiled peel extracts of M. sinensis and M. paradisiaca, while ferric reducing power was highest in ethanol extracts across M. sinensis soft flesh, peel, and M. paradisiaca flesh. Acetone extract of M. paradisiaca peel had the highest ferric reducing capacity at peak concentration (0.1 mg/mL). Correlational analysis revealed a negative correlation between respective phenolic, proanthocyanidin, and flavonoid content and the IC50DPPH antioxidant capacity in M. sinensis flesh, M. sinensis peel and M. paradisiaca flesh. Conversely, there was positive correlation between IC50 DPPH with proanthocyanidin and flavonoid in M. paradisiaca peel. Negative correlation was detected between the phenolic, proanthocyanidin and flavonoid contents and IC50ABTS in M. sinensis flesh. Positive correlation was observed between respective phenolic, proanthocyanidin and flavonoid contentwith IC50 ABTS in M. sinensis peel, M. paradisiaca flesh and M. paradisiaca peel. There was negative correlation between the respective phenolic, proanthocyanidin and flavonoid contents and IC50 FRAP in the flesh of M. sinensis, while positive correlation was observed in M. sinensis peel. M. paradisiaca flesh on the other hand, showed positive correlation between the IC50 FRAP and the respective phytochemical contents. However, the peel, there was negative correlation. The correlational evaluation in this study revealed general positive and negative correlational patterns, which implies that no polyphenolic constituent contributed exclusively to antioxidant activity, but rather in combination. Ultrastructure and elemental spectra of M. sinensis and M. paradisiaca exocarps were analysed with electron microscopy (SEM)and energy dispersive x-ray (EDX). Microstructures such as interlocked, polyhedral epidermal cells, ellipsoid-shaped stomata, guard cells, intercellular space, anticlinal-patterned walls, and subsidiary cells were observed. The elemental spectra revealed the presence of elements such as potassium, iron, carbon, oxygen, silicon, and gold, with consistently high to relatively high carbon and oxygen peaks in M. sinensis and M. paradisiaca exocarps. The relative similarity observed in the constituents of a number of the elemental spectra in M. sinensis and M. paradisiaca peels, reflects some degree of relatedness. These outcomes indicate that banana and plantain peel and boiled peel extracts are nutritive, medicinal and potential nutraceuticals, with food preservative, shelf-life and quality enhancement potentials. The instrumentation in this study also have potential relevance in industrial food product analysis. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Conflict-induced displacement: a study of risk and support for the older refugees in South Africa
- Authors: Yusuf, Mohammed Sanusi https://orcid.org/0000-0002-6871-0186
- Date: 2021-09
- Subjects: Migration, Internal , Displacement (Psychology) , Refugees -- Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22231 , vital:52001
- Description: With the exponential rise in conflict scenarios globally, the number of internally displaced persons (IDPs) and refugees in foreign countries continues to grow. Although there has been several international efforts and conventions aimed at alleviating the global refugee crisis, the international community has not found a sustainable answer to this knotty problem. In Africa, with some of the worst conflict situations, the scourge of social displacement resulting in migrations have caused different levels of risks and vulnerability for the refugees, as well as capacity constraints for the host communities, governments of host countries and non-governmental bodies working with refugees. In South Africa, with one of the highest numbers of refugees in Africa, especially those coming from African countries, contention for socio-economic space and cultural differences occasionally result in violence between refugees and local people. For the older refugees, the level of risk exposure and hardship have generated interests for both scholars and officials. This thesis explores the risks and support systems for older refugees in South Africa, with specific focus on the Eastern Cape province. Various stakeholders (such as government, NGOs, host communities and the older refugees) in refugee management in South Africa have argued differently on ‘how best’ to manage older refugees in the country. Using qualitative data gathered from refugee communities in the Eastern Cape province and documentary analysis, the study found that the experiences of older refugees in the Eastern Cape province are nuanced. The dominant narrative on the experiences of older refugees indicate peaceful coexistence and resilient organic community support systems, with minor conflicts – often associated with contestations for scarce economic opportunities. Although the study focuses on one province of South Africa, this finding challenges the often-overgeneralised perception of South Africa as ‘xenophobic’. It unpacks the hidden resilient social systems and networks of relationships that bind local populations and the refugees, especially the older ones. In the search for national, regional and global answers on the best way to manage refugee crisis, this study provides insights into community-level structures and dynamics that would benefit policymaking at the national and international levels , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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Determination of acaricide resistance profiles, and geographic range of boophilid Rhipicephalus tick spp. (Acari: Ixodidae), and sero-status of tick-borne pathogens on communal cattle in the north-eastern regions of the Eastern Cape Province, South Africa
- Authors: Yawa, Mandla https://orcid.org/0000-0002-2402-298X
- Date: 2021-09
- Subjects: Cattle -- Diseases , Ticks as carriers of disease , Ticks
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21590 , vital:49356
- Description: Cattle industry improves livelihoods for many developing farmers in South Africa, however, ticks and tick-borne diseases (TBDs) pose a detriment impact on cattle success; this is due to their resistance to acaricide application. Thus, this study was conducted to determine the extent of acaricide resistance, serostatus of tick-borne pathogens, and geographic range of boophilid ticks in communal grazing cattle in the north-eastern regions of the Eastern Cape Province (ECP), South Africa. A total of 160 structured questionnaires were prepared and randomly administered to cattle farmers to investigate their knowledge, attitudes, and practice on ticks and TBDs affecting cattle, tick control methods used, and their knowledge of acaricide resistance. Engorged visible cattle ticks were collected seasonally from 10 randomly selected cattle from the community cattle herds during dipping days between October 2018 and September 2019, and stored into the labelled test tubes containing 70 percent ethanol. For TBDs determination, a total of 240 cattle from Elundini and Senqu Municipalities were seasonally used to investigate the prevalence of ticks and TBDs, packed cell volume (PCV), and body condition scores (BCS). Shaw Larval Immersion Test (SLIT) method was used to determine the resistance of Rhipicephalus decoloratus larvae to various acaricides such as amidines, organophosphate, and synthetic pyrethroids. This study indicates that approximately 59 percent of the interviewed cattle farmers had no knowledge of the effect of TBDs affecting cattle production, and 78 percent of respondents considered ticks are the major challenge to the success of their cattle farming. Pour-on (61 percent) was the most commonly used acaricidal treatment system with fortnightly (40 percent and 31percent) treatment frequencies during the summer and winter seasons respectively. Synthetic pyrethroids (73 percent) were the most used acaricide compounds to control ticks. Moreover, approximately 85 percent of respondents perceived that they do not practice acaricide rotation, and 88 percent of the respondents had no knowledge of acaricide resistance. Interestingly, the current study record Rhipicephalus microplus for the first time at Elundini, Senqu, and Walter Sisulu. Based on the morphological traits, a total of 6176 ticks belonging to two boophilid tick species of Rhipicephalus were identified: R. decoloratus (98 percent) and R. microplus (2 percent). Rhipicephalus decoloratus was significantly higher (P<0.05) in Elundini during the hot-dry (3.37±0.121) and hot-wet (3.35±0.121) seasons compared to other localit ies. In Senqu, R. microplus had high counts (P<0.05) during the post-rainy season (1.06±0.027) compared to other localities. From this present study, it was observed that Ehrlichia ruminantium was the most prevalent at Elundini (16 percent) and (14 percent) during post-rainy and hot-dry seasons respectively and 15 percent at Senqu during the post-rainy season. Babesia bigemina was more frequent at Elundini (18 percent) and Senqu (16 percent) during the post-rainy season and hot-wet season, respectively. Cattle BCS were significantly negatively correlated with E. ruminantium (P<0.01; r = -0.203), B. bovis (P<0.01; r = -0.125), and A. marginale (P < 0.01; r = -0.122). On the other hand, PCV was significantly negatively correlated with B. bigemina (P<0.01; r =-0.138). E. ruminantium was strongly positively correlated with Amblyomma hebraeum (P<0.05; r = 0.112), while B. bovis (P<0.05; r = 0.134) and B. bigemina (P<0.05; r = 0.188) were strong positively correlated with Rhipicephalus microplus infestation and B. bigemina (P<0.05; r = 0.077) with Rhipicephalus decoloratus. During acaricide resistance testing, Shaw Larvae Immersion Testing (SLIT) was only performed on R. decoloratus larvae as engorged R. microplus ticks could not meet the required sample size for resistance testing. The current study found that the majority of the tick were susceptible at exposure to differe nt acaricide field concentrations of amidines (49 percent at 250ppm), organophosphates (33 percent and 47 percent at 300ppm and 500ppm, respectively), and synthetic pyrethroids (44 percent and 23 percent at 150ppm and 300ppm, respectively). In conclusion, less knowledge of cattle farmers on the threat pose by ticks on their cattle production results in the spatio-temporal spread of boophilid tick from region to region and from season to season thus increases incidence and risk for tick resistance. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Evaluation of bacteria laccase hybrid biosensor and application in the detection of phenolic contaminants in water
- Authors: Edoamodu, Chiedu Epiphany https://orcid.org/0000-0002-9254-3955
- Date: 2021-09
- Subjects: Laccase , Water -- Purification
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22820 , vital:52802
- Description: The continuous outpour of aromatic pollutants in diverse groups, emanating from the industrial and domestic system due to population density, industrialisation and technological advancement is alarming. The increasing strength in wastewater discharge constitutes the main cause of the natural water pollution load, causing scarcity of potable water for consumption with an increasing health challenge. The physiochemical treatment approach has faced a series of limitations with little or no success. Hindrance to wastewater management can cause a point source contamination problem that might increase treatment cost and release a broad range of chemical contaminants in the environment. Hence, green, eco-friendly and cost-effective tools are imperative. The application of laccase has received much attention in bioremediation and bioprocessing matters owing to the oxidising capacity of a wide range of substrates. The process requires available molecular oxygen for its activation, releasing water as a by-product thus, establishing this research. This study was devised to examine the bioprocessing potentials of hybrid and amalgamated laccases extracted from the diverse environmental milieu of the Eastern Cape Province, South Africa. Bacteria producing laccase were isolated from marine sediment, cow dung, and wastewater samples via selective enrichment with some aromatic compounds. The axenic cultures were screened for laccase activity on various phenolic and non-phenolic substrates. The isolates were identified via molecular techniques and they belonged to the gammaproteobacteria and Bacilli classes under the following genera, Enterobacter and Bacillus. They were deposited in the NCBI database as Enterobacter asburiae ES1, Enterobacter sp. Kamsi, Enterobacter sp. AI1, and Bacillus sp. NU2 with the assigned accession number MN686602, MN686603, MN686605, MN686607, respectively. Optimisation of the laccase production via one factor at a time technique (OFAT) from the four bacteria species showed more enzyme yield in all lignocellulosic agro-waste media. However, wheat bran and mandarin peel maximally enhanced laccase production. In addition, xylose, galactose, fructose, and sorbitol were the best carbon sources utilised while (NH₄)₂SO8, KNO3 and NaNO3 were noted as the best nitrogen sources employed. Laccase yields were increased at pH 4 and 5, at temperatures 45 and 55 o C, and at 50 and 100 rpm, and precisely, at day eight of the incubation period. Further purification of the crude laccase yielded a purification fold of 4.18, 4.39, 2.78, 8.11, and the SDS-PAGE analysis showed a molecular size of 90, 55, 75 and 50 kDa for ES1, Kamsi, AI1, and NU2 laccases, respectively. The characterised purified laccase demonstrated polyextremotolerant potentials. The laccases were active through a wide temperature regime (30-90 o C) with maximum activity at 50 o C (ES1/AI1 and Kamsi/NU2) 60 o C (AI1), 70 o C (ES1, Kamsi, NU2); and were stable at 60 o C (ES1, AI1, NU2), 70 o C (ES1/AI1), 80 o C (Kamsi and Kamsi/NU2). Also, the laccases remained active through pH 3 - 8 and optimal at pH 4 (AI1, NU2), pH 5 (Kamsi, ES1/AI1), pH 7 (ES1), pH 8 (Kamsi/NU2), and the individual stability was measured at pH 4 (Kamsi, NU2), pH 5 (AI1), pH 6 (ES1), pH 7 (Kamsi/NU2), pH 10 (ES1/AI1). The purified laccases were either enhanced or left unchanged by a variable concentration of metallic salts, inhibitors, chelating agents and organic solvents. Clearly, the activities of the laccase were enhanced when pre-incubated with 1, 3, and 6 mm of CuCl2, FeCl3, MgCl2, ZnCl2 and AgCl, and 1, 2, 3 mm of Triton x-100, PMSF, EDTA, Tween 20, and NaCl. Additionally, 20, 30, and 10 percent v/v of acetone and DMSO were prominent organic solvents that also stimulated both the hybrid and amalgamated laccase activity. The gene of the purified laccases targeted showed a clear band size of 690 bp for the Enterobacter species laccases and 775 bp for the laccase from Bacillus sp. The protein sequence was deposited in NCBI database with the assigned accession numbers, MW251989, MW25990, MW251992, and MW251994 for ES1, Kamsi, AI1, and NU2 laccases, respectively. The optimised pH and temperature parameter examined on the decolourising potential of the bacteria laccases showed an effective dye removal on the five synthetic dyes (Congo Red (CR), Methyl Orange (MO), Malachite Green (MG), Reactive Blue 4 (RB4), Ramazol Brilliant Blue R (RBBR)) applied. The purified laccases were successfully immobilised in Na-alginate with cca. 88.49, 70.91, 76.04, 76.13, 90.07, and 91.99 laccase yield for the hybrid (ES1, ES1, Kamsi, AI1, NU2) and amalgamated (ES1/AI1 and Kamsi/NU2) laccases. The immobilised laccases were able to retain an average activity of 32 – 52 percent after eight dye decolourising cycles, exhibiting strong catalytic activity than the free laccases. Nonetheless, no significant difference was examined between the hybrid and amalgamated laccase activity. Also, the immobilised laccases were shown to be more efficient in biotechnological application than the free laccases. The result suggests that immobilising an enzyme in a carrier matrix served effectively as the remediation approach than the hybrid and the amalgamation of the free enzymes. Also, the application of lignocellulosic waste served as a cheaper substrate for commercial production of laccase and could help s in promoting es the biotechnology application and the bioeconomy. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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