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An internship model for the Free State provincial government
No full textDissertation(M.P.A. (Public Administration and Management))--University of the Free State, 2023: Youth unemployment in South Africa (SA) has been identified as a growing challenge that the SA Government has deemed necessary to address. Due to this challenge, there has been an increasing demand for work experience by youth graduates seeking to be employable in the SA economic market. To address this challenge, the SA Public Service introduced the Public Service Internship Programme (PSIP) as a strategy to provide unemployed youth graduates with critical and scarce skills in the public service. The study therefore aimed to identify the challenges that hamper the effective implementation of the PSIP among unemployed youth graduates in the Free State Provincial Government (FSPG). The effective implementation of the PSIP in the FSPG can only be achieved if the challenges affecting the effective implementation of the programme are identified and addressed.
, , : The research study employed a qualitative research approach and a descriptive case study design. Focus group discussions (FGDs) and semi-structured interviews were used as qualitative research instruments. FGDs were conducted with 89 unemployed youth graduates, who were divided into 8 groups. Furthermore, semi-structured interviews were conducted with 28 supervisors responsible for human resource development and supervision of the unemployed youth graduates and the effective implementation of the PSIP in the FSPG.
: The research found that the PSIP in the FSPG is still faced with various challenges. These include lack of mentorship and coaching of the unemployed youth graduate interns; lack of monitoring and evaluation of the PSIP; and insufficient budget allocations for the programme to incorporate more graduate interns into training interventions and increase stipend payments for the graduate interns. It is therefore important that the FSPG creates an induction programme for the PSIP in which specific factors can be outlined. These include the internship programme policy, the stipends to be provided, contract agreements, performance expectations, and communication channels that the graduate interns can use to raise concerns and challenges experienced during the duration of the PSIP.
: The FSPG and other stakeholders need to realise the importance of the internship programme in career development, succession planning of the departments, and experiential learning towards the development of a capable, development-oriented state and a professional public service. It is important that the PSIP is effectively implemented to help the SA Government achieve its set goals and objectives as outlined in the National Development Plan Vision 2030. An Internship Model for the Free State Provincial Government will further support this.
: The study findings may assist the FSPG to identify the challenges affecting the implementation of the PSIP in order to make the programme more effective towards experiential learning for unemployed youth graduate interns. The study also makes recommendations to the FSPG on how to address some of the pressing challenges affecting the PSIP
Economically viable species and hybrid clones for commercial afforestation of mined sand dunes in the Richards Bay area of KwaZulu-Natal
No full textThesis (Ph.D.(Conservation Biology))--University of the Free State, 2023: Richards Bay Minerals (RBM) is South Africa’s largest mineral sands producer with its principal operations located along the coast just north of Richards Bay in KwaZulu-Natal Province. By dredging the coastal sand dunes, the dune sand becomes nutrient poor and does not support economical land use. Casuarina equisetifolia was initially planted for sand dune stabilisation and fuelwood, but its low economic value was of little benefit to the local community. RBM thus undertook a joint venture with the Council for Scientific and Industrial Research (CSIR) to identify genotypes of tree species that were suitable for deployment on the mined sand dunes as alternatives to C. equisetifolia.
: In this longitudinal study, a multi-method approach which also included Principal Component Analysis (PCA) was followed to gather and analyse quantitative data over a 6-year period of tree growth. Four trials were established in an alpha lattice design on the mined sand dunes to test 70 genotypes of Eucalyptus species and hybrids of related species. Single plot trees were planted in 10 replications per trial, making up 700 trees per trial. The traits of survival, diameter at breast height (DBH), and stem quality were measured over the 6-year period. At 6 years of tree growth, 26 trees belonging to 13 genotypes were felled to measure their wood and Kraft properties which included, kappa number, pulpability factor, screen pulp yield, basic density and fibre yield. Coppicing ability and pests and diseases were recorded on 6-month-old felled tree stumps. Through a stepwise approach, several genotypes with the potential for deployment on the mined sand dunes were identified. Identification of genotypes was achieved by ranking the 70 genotypes according to their relative performance of the traits survival, DBH, height and stem straightness, by calculating a Relative Performance Index (RPI). The 13 genotypes of the felled tree population were also ranked according to Relative Performance Index (RPI) values using the traits kappa number, pulpability factor, screen pulp yield, basic density and fibre yield. All 13 genotypes (interspecific Eucalyptus hybrid clones) of the felled trees were ranked in the top 15 of the 70 genotype ranking. It thus made sense that these 13 genotypes were appropriate for deployment on the mined sand dunes. They were analysed for their appropriateness for use in the pulp and paper industry, as well as for the woodchips export market, by calculating Economic Performance Indices (EPI) for both market sectors.
: The results clearly showed two categories of genotype suitable for deployment on the mined sand dunes. The EPIs revealed a group of genotypes particularly suited to the pulp and paper industry and they consisted of different interspecific hybrid clones of E. grandis and E. urophylla (GxU). Similarly, the EPIs also revealed a group of genotypes that produced dense wood that would be appropriate for woodchip production for the export market. These genotypes were all different interspecific hybrids of E. grandis and E. camaldulensis (GxC). The relatively high-ranking pure species of E. urophylla (Au7 and Au9) and C. equisetifolia (Cas400 and Cas402) also warrant consideration, because they are deployed as seedlings and are substantially cheaper financially to procure than clonal material.
: The knowledge obtained during this study will facilitate the rehabilitation of the mined sand dunes in the Richards Bay area and will also help local communities in gaining access to markets and becoming economically viable
Indigenous biomedicine research centre: adaptable Architecture design for a traditional healing research centre in Emshinini township Mpumalanga
No full textDissertation (M.Arch.(Architecture))--University of the Free State, 2023Traditional medicine is a holistic type of healing, loosely called folk medicine; ethno-medicine or native healing is the oldest form. This dissertation proposes an Indigenous Biomedicine Research Centre that will break the current negative perceptions of traditional medicine. I will address the following Research question: How can a contemporary architectural approach be used to improve heterotopic spaces that currently facilitate the practice of traditional medicine rituals intending to work with the conventions of Western healthcare systems?
The current spaces used for healing rituals need to be more dignified and promote indigenous healthcare systems. I aim to propose an indigenous healthcare facility that follows cultural rules, uses symbolic rituals, and offers opportunities for innovation and integration with biomedicine. I will use local precedents and conduct interviews with traditional healers about their vision of a contemporary “indumba” (rondavel)or traditional healthcare facility. This dissertation aims to create dignity and social recognition for traditional medicine in South Africa and Africa at large
Time trees and clock genes: a systematic review and comparative analysis of contemporary avian migration genetics
No full textTiming is a crucial aspect for survival and reproduction in seasonal environments leading to carefully scheduled annual programs of migration in many species. But what are the exact mechanisms through which birds (class: Aves) can keep track of time, anticipate seasonal changes, and adapt their behaviour? One proposed mechanism regulating annual behaviour is the circadian clock, controlled by a highly conserved set of genes, collectively called ‘clock genes’ which are well established in controlling the daily rhythmicity of physiology and behaviour. Due to diverse migration patterns observed within and among species, in a seemingly endogenously programmed manner, the field of migration genetics has sought and tested several candidate genes within the clock circuitry that may underlie the observed differences in breeding and migration behaviour. Among others, length polymorphisms within genes such as Clock and Adcyap1 have been hypothesised to play a putative role, although association and fitness studies in various species have yielded mixed results. To contextualise the existing body of data, here we conducted a systematic review of all published studies relating polymorphisms in clock genes to seasonality in a phylogenetically and taxonomically informed manner. This was complemented by a standardised comparative re-analysis of candidate gene polymorphisms of 76 bird species, of which 58 are migrants and 18 are residents, along with population genetics analyses for 40 species with available allele data. We tested genetic diversity estimates, used Mantel tests for spatial genetic analyses, and evaluated relationships between candidate gene allele length and population averages for geographic range (breeding- and non-breeding latitude), migration distance, timing of migration, taxonomic relationships, and divergence times. Our combined analysis provided evidence (i) of a putative association between Clock gene variation and autumn migration as well as a putative association between Adcyap1 gene variation and spring migration in migratory species; (ii) that these candidate genes are not diagnostic markers to distinguish migratory from sedentary birds; and (iii) of correlated variability in both genes with divergence time, potentially reflecting ancestrally inherited genotypes rather than contemporary changes driven by selection. These findings highlight a tentative association between these candidate genes and migration attributes as well as genetic constraints on evolutionary adaptation
Blooming the obstinate: the remediation of an abandoned quarry in Garies through the establishment of a saffron farmstead and visitor attraction as a means of fostering a sense of harmony between people and the natural world
No full textDissertation (M.Arch.(Architecture))--University of the Free State, 2023Human activities have a negative impact on our natural environment, especially in the case of post-industrial waste and destruction, such as global quarries, as well as the consequences encountered by a small community in Namaqualand. Can the blooming flowers in the old quarry at Stoffelsfontein farm be recovered by developing a saffron farmstead and visitors’ attraction, thereby remediating a wasteful and destroyed site in Garies, Namaqualand, and globally, investigating the potential for remediation and revitalisation and rehabilitation as a way of ecological empathy? Initiatives to address this problem have been made. Still, they have mainly concentrated on large-scale quarries or abandoned industrial sites, ignoring the effects on our smaller rural towns and farms harmed by trash dumping and quarry activities. To tackle this problem, I aim to remediate, revitalise, and rehabilitate a quarry that was once adorned, with an array of flowers by encouraging ecological awareness and empathy. By considering both human and natural influences, I propose the establishment of a saffron farm and visitors’ attraction that actively involves the local community and attracts the rest of South Africa and tourists, offering new work and leisure experiences. This research draws upon a comparative analysis between man-made destruction and natural forces, incorporating relevant precedent studies. Remediating a destroyed site and its waste not only presents an opportunity for environmental rehabilitation but also offers a chance to reconcile human influences. It can stimulate the local economy by creating job opportunities and skills development
Sustainability of vegetable production systems by small-scale farmers of Limpopo Province in South Africa
No full textThesis (Ph.D.(Sustainable Agriculture))--University of the Free State, 2023The study was conducted in 23 villages of Limpopo Province through an article-based format. The study in area A, was conducted in six villages, four in Makhado Municipality of Vhembe District, and two villages in Greater Letaba Municipality in Mopani District. The objective of the study was to characterise vegetable production systems of small-scale farmers in the study area. Data was collected using a questionnaire and some information was gathered through direct observation. Fifty-two farmers were sampled using a multi-stage random sampling technique and were interviewed. The sample size was calculated using Lovin’s formula. Data was analysed using a SPSS. The results of the study showed that 59.62% of the farmers were males, 57.69% were above 61 years of age. The education status of women was lower than that of men and more women had no formal qualification. The 92.31% owned land and 80% of the plots ranged between 0.5 and two hectares. The 84.62% had vegetable farming experience ranging between 5 and 16 years. Water management system was characterised by some farmers (50%) who adapted to water shortage by planting drought tolerant vegetables, some19.23% used drip irrigation system and others (13.46%) used conservation tillage. The majority (71.15%) of these farmers used furrow irrigation and gravitational canal, and their main source of water was the river. They drew water using gravitation and pipes as well as gravitation and canals. Water availability ranged from daily to monthly. Human resource management was characterised by 48.08% of the vegetable farmers who employed a mixture of youth, male and female workers and 60% of the farmers hired workers on seasonal basis. Soil sampling did not exist because 65.54% did not take soil samples and 67.31% did not know when last they took soil samples, 65.38% used both organic and inorganic fertilisers. About 81% applied between 10-200kg fertiliser per hectare using band placing method. Other vegetable production practices identified include chemical pest control (100%); soil resource management was done through conventional tillage (86.64%); contours to control erosion (71.18%). Weed control was mainly manual (73.08%). Income generated from sale of vegetables was mainly used for labour, production inputs and mechanisation. Farmers in the study area kept records for finance, input, planting dates and yields. Most farmers used 0-10% of vegetables they produce for home consumption. The results of the study showed that vegetable production can be sustainable if water, soil, pests and disease are managed appropriately.
The study in area B, was conducted in six villages situated in the four municipalities within the two districts of the Limpopo Province in South Africa. The study investigated vegetable production systems and consumption patterns as determinants of food security amongst small-scale vegetable farmers. A multi-stage random sampling technique was used to select 52 respondents for this study. The sample size was calculated using Slovin’s formula. Data was collected through a questionnaire and other information through direct observation. Data was analysed using the statistical package for social sciences. The study revealed that 65.38% of the participants were males 42.31% had an average age of 51-61 years and had 5-10 years farming experience. The study shows that male respondents 63.46% had secondary education and are more than females, and 71.16% had dependants ranging from five to above nine per household. The majority 92.31% own land for vegetable cultivation and more respondents who own land are males while 65.38% cultivating vegetables on land size ranging from 1-2 hectares. Most farmers (71.15%) cultivated a variety of vegetables; 90.38% grew vegetables in order to generate income; 38.46% grow vegetables because the market for vegetables is available. The study also revealed that 44.23% used drying method to preserve vegetable seeds; 90.38% used single cropping system for vegetables, and they practiced intensive vegetable production system. Vegetable preparation for food is characterised by 71% who use boiling as a cooking method while 55.77% used tomato and onion to enhance vegetable flavour and used salt to enhance vegetable taste. The study noted that 48.07% experienced pest infestation and high inputs costs as the main constraints in vegetable production. Vegetable consumption is characterised by 40.38% who consumed vegetables once per week; the 51.92% preferred to eat leafy vegetables than other vegetables. Most of the respondents (55.77%) were encouraged to eat vegetables that were appropriately cooked. The study also noted that adult women (38.46%) consume vegetable in the family, and they consumed 50-100g of vegetable per day. The study shows that 57.69% preserved vegetables by drying, because it is the cheapest method. The results of the study show that a variety of vegetables produced, and preservation are the main determinants of food security in the study area.
The study in area C, was conducted in four villages, three from Thulamela municipality and one in Maruleng municipality. The objective of the study was to analyse climate change mitigation strategies adopted by small-scale farmers towards a sustainable vegetable production and resilient from food shortages in Limpopo Province. A multi-stage random sampling technique was used to select 52 respondents for this study. The size of the sample was calculated using Lovin’s formula. Data was collected through a structured questionnaire and direct observations. Data was analysed using the statistical package for social sciences. Results of the study revealed that more (53.85%) women participate in vegetable production. The study also shows that 59.62% had an average of 51-61 and above 61years of age. The 61.54% had secondary education. The 90.38% had no qualification in agriculture. The majority (67.31%) cultivate their crops on 1-2ha. The 81.76% have moderate ability to high ability to adapt to climate change. The majority of the respondents (88.46%) rate decrease in quality of irrigation water, decrease in soil fertility and increased soil erosion as factors that lead to land degradation due to climate change. The 86.54% view drought, high temperatures and more pests as rare events as a result of climate change. The 61.54% experienced a slight decrease in summer rainfall patterns. The adaptation to change in summer rainfall is mitigated by planting drought resistance vegetable crops and irrigating frequently to adapt to that change. The 61.54% experienced increased pest infestation due to climate change and they noticed an increase in the use of pesticides to adapt. An increase in winter temperature was noticed by 80.77% of farmers and 67.32% adapt by growing cool season vegetables. Changes in summer temperatures was noticed by 90.30% who experienced an increase in summer temperatures due to climate change. The respondents are aware that local authorities are concerned about climate change and other activities such as soil mining, veld fires and tree cutting that may be contributing to climate change. Strategies in response to climate changes include knowing about the importance of weather and climate change forecasts. The 57.69% say forecasting helps them to plan planting dates, others say it helps them to make a choice of vegetable varieties and to project rainfall distribution. The majority (84.62%) use Radio and TV as their main source of information about weather and climate. Farmers in the study area apply Climate-smart agriculture technologies including crop rotation by 71.15%, others use mixed cropping, mulching, no till, crop residue, contours to counter the impact of climate change. They also use climate smart agriculture for increased productivity, 51.92% use hybrid seeds, pesticides and fertilisers. The CSA soil fertility technologies are the use of manure (52%), others use crop residue and mulching. Types of fertilisers used, 63.46% use both organic and inorganic fertilisers. Water saving technologies feature 50% who use water harvesting technology as a way of saving water, few use mulching for soils to retain moisture longer. The results of the study show that 59.62% of the respondents use ridges/terraces to control soil erosion, and others use contour planting, other use grass strips. Risks posed by climate change are identified amongst others as reduced crop yield reduced, amount of rain, floods and rise in temperatures. The 63.46% minimise risks by using crop diversification and use hybrid seeds. The study shows that farmers in the study area are aware of the climate change and the related factors. They are also applying CSA technologies as mitigation strategies to ensure sustainable food supply. However, there is a need to support small-scale farmers with improved technologies for them to be able to mitigate and cope with climate change challenges.
The study in area D, was conducted in five villages, the three villages in Vhembe District, and two villages in Mopani District. The objective of the study was to assess the potential of African Indigenous Vegetables (AIVs) towards the formation of a commercial, nutritional and sustainable production system. A total of 53 small-scale vegetable farmers were randomly sampled using a multi-stage cluster sampling procedure. Sample size was calculated using Slovin’s formula. Data was collected by means of a questionnaire and analysed using descriptive statistics. The study revealed that more women (64.15%) participated in the production of AIVs. The 54.72% of the respondents supplied AIVs all-year round. Some respondents (49.06%) grow AIVs for home consumption, while 64.15% are encouraged to grow AIVs because they are well adapted to the area, easy to grow and have short growing period. About 60% of the respondents indicated that AIVs are highly consumed by adults and pregnant women in the families. The study revealed that 90.57% of the respondents could harvest and sell 1-2 tons of AIVs per season. About 57% of the respondents benefited from all types of markets, local, farm stalls and high value markets. The study showed that 86.79% of the farmers in the study area received support from the Department of Agriculture and Rural Development, in the form of advice, and production inputs. The results of the study confirm that there is a potential for the formation of a nutritional and a commercial production system from AIVs in the study area because the market of AIVs is growing.
The study in area E, was conducted in the eight villages, three of Vhembe District, and five villages of Mopani District. The objective of the study was to identify and analyse the opportunities and constraints of a wide adaptation to organic vegetable production systems by small-scale farmers. A total of 52 small-scale vegetable farmers were randomly sampled using a multi-stage cluster sampling procedures. Sample size was calculated using Slovin’s formula. Data was collected through a questionnaire and analysed using the SPSS. The female respondents (55.77%) participated in vegetable production. The study shows that 21.15% of women attended secondary-level education. The study shows that farmers in the study area have experience ranging from 11-21 yeas. The study also revealed that 61.54% of the respondents have access to land they own, lease and communal use. The study also showed that the respondents have dependents ranging from 1-above 9 in number. The study shows that farmers use fertilisers, crop rotation and practicing intercropping in order to promote soil fertility. The study shows that the respondents apply livestock manure, poultry manure and other types to boost their vegetables. It was also revealed that farmers are aware that pesticides are not healthy, and they use protective clothing, and wash their hands with soap after use. Weed is controlled manually. The respondents agreed that organic market has a potential of growth, while others say there is shortage of local organic markets. The study revealed that 80.77% of the respondents considered organic farming (OF) as more profitable, and 78.85% say that it saves on production costs. The study showed that 75.00% of the respondents believed that organic products fetch higher prices. About 53.85% had moderate knowledge of organic farming, while 65.38% were ready to receive technical skills on organic farming (OF). The study captured that 75% viewed conversion to organics as expensive while 44.23% were willing to convert to organic farming in the near future. The results of this study show that there are opportunities in farming on organic vegetables if the constraints and difficulties identified in the study area are dealt with.
It is concluded that vegetable production in the study area is sustainable but can improve further by exploiting the opportunities presented by this sector, however, needs support where the needs and necessities are identified, so that it continues contributing in feeding the nation and generating income for the livelihoods of the small-scale farmers
Exploring ICT approaches to enhance the reading skills of digital FET learners in the 21st century
No full textDissertation (M.Ed.(Language Education))--University of the Free State, 2023The use of Information and Communication Technology (ICT) in education has gained momentum in the last ten years, globally and in South Africa. However, in South Africa, specifically, there is limited information on the impact of the ICT approaches on the development of reading skills of learners. This study, therefore, explored ICT approaches that can enhance the reading skills of digital learners in the first additional language (FAL) classrooms in the Further Education and Training (FET) in the Motheo District, Free State. It sets out to investigate how teachers use ICT approaches to enhance reading skills of the digital 21ˢᵗ century learners; the challenges faced by teachers in the integration of ICT approaches; and the way in which ICT can be used to enhance reading of FET digital learners. Underpinned by Constructivism Theory and Connectivity Theory, the study adopted a qualitative case study research approach within an interpretivist paradigm. Twelve teachers from three high schools in the Motheo District, Free State, participated in this study. Data was collected through semi-structured interviews and focus group interviews. A thematic data analysis framework was adopted. The key findings of the study show that, to some extent, the teachers in the three high schools use diverse ICT approaches to enhance reading skills of their learners. Most teachers agreed that the integration of ICT into the teaching of reading skills has a potential to enhance reading skills of learners. Factors such as managing the use of ICT devices in the reading classrooms; digital divide, teacher professional development, and availability of the internet in the schools were identified by the teachers as key to effective use of ICT to enhance reading skills of learners in the three schools. Despite the challenges of integrating ICT into the reading classrooms, the study found that teachers’ and learner’s positive attitudes towards ICT approaches influenced the interest in the use of ICT devices for improving reading skills. This study recommends that ICT approaches should be intergrated into curriculum to foster the migration from the traditional methods of teaching reading skills into the 21ˢᵗ century approaches that respond to the learning needs of the digital 21ˢᵗ century learners in the classrooms. Some schools need to urgently review their school policies which ban the use of ICT devices for learning and teaching purposes and establish ways to manage and monitor the use of these resources in the classrooms.This study adds to the body of information on ICT in education and offers educators, policymakers, and academics significant insights.The study concludes that ICT approaches have a potential to enhance reading skills of digital 21ˢᵗ century learners. Lastly, the study concludes that teacher professional development is key for the maximum integration of ICT for the development of learners’ reading skills
Flipping the classroom to enhance student engagement in first-year statistics education
No full textThesis (Ph.D(Higher Education Studies))--University of the Free State, 2023This study explores the effectiveness of a flipped classroom (FC) variant based on students engaging with content outside of class by viewing video-lectures. The flipped classroom encouraged students to take responsibility for their own learning. When they were unclear on specific concepts, they could use technology to collaborate with their peers or the lecturer. To encourage viewing of the videos, an incentive was given in the form of weekly assessments that the students had to complete, which formed part of their semester mark. A randomised pre-test-post-test control design was implemented in a sample of Extended Curriculum Programme (ECP) students in a first-year statistics course. The FC approach was exercised in the experimental group (Group A), while the control group (Group B) received traditional face-to-face lecturing. A comparison between the final scores of Group A and Group B was used to give insight into the effectiveness of this treatment. Each group consisted of 67 students. The results showed that a video-based lecturing pedagogy significantly improved ECP students’ final scores. In this study, students applied different learning activities such as inquiring about information, watching video-lectures, and practically applying the knowledge studied when completing weekly online assessments. Students collaborated with the lecturer and their peers via e-mail or WhatsApp to thoroughly understand the subject. Therefore, active learning, which fosters deep learning, was encouraged. This finding is consistent with the constructivist pedagogical theory, which emphasises the importance of interaction with others in knowledge construction and develops a deeper understanding of the subject matter.
These findings align with other studies that report positive student perceptions of blended learning in first-year statistics. This research found that the FC intervention, as applied by the researcher, resulted in a significant increase in student performance on their final marks, which indicates that the FC approach is an important pedagogical approach to increase student achievement. Further, the results confirmed that the FC approach improved student engagement. One factor that significantly enhanced student engagement was the students’ preferred place of study. Students from the experimental group studying at their place of residence significantly outperformed students from the traditional group who studied at their place of residence. Another factor that indicated that student engagement was enhanced was that student-staff interaction significantly increased in the experimental group. Some interesting findings surfaced. An unexpected gender finding evidenced that male students in the experimental group significantly outperformed the male students in the control group. Furthermore, when the place of study was examined, the experimental group performed better when studying at their residences. Many participants in Group A showed a favourable perception towards the videoed-lecturing approach as they enjoyed watching video-lectures at their own pace. They also indicated that they prefer this new variant of flipping because it motivated them to learn. From the survey analysis, many students preferred watching video-lectures at their own pace, time, and space. An overwhelming portion of the participants indicated that the use of technology was pivotal in their learning. It was also derived that the more students participated in all their assessments, the higher their final score was
The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases
No full textThe endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.Publisher's versio
Characterisation of apparent mismatches detected during routine short tandem repeat analysis in parentage investigations
No full textDissertation (MMed.Sc.(Haematology and Cell Biology))--University of the Free State, 2023: Short Tandem Repeat (STR) analysis has proven effective for establishing parentage and biological relatedness. There are commercially available STR kits that allow for reliable PCR amplification and genotyping of STR loci. However, one or two STR loci mismatches may be identified in non-exclusion cases. In routine analysis, these discrepancies are classified as apparent STR loci mismatches. The mismatches result from various mutational mechanisms. However, the mechanisms that drive these mutations are poorly understood. Several STR loci mismatches have previously been reported to impact parentage analysis. The alleles involved in the mismatch affect the interpretation of genetic profiles and can sometimes lead to false parentage exclusions. As such, it is essential to identify and characterise the underlying cause of STR loci mismatches for further validation of the genotypic data produced within a specific DNA profiling laboratory.
: A laboratory-based descriptive-comparative study was conducted. This study consisted of 100 parentage cases with one or two STR loci mismatches from the DNA testing facility, Universitas Academic Unit, National Health Laboratory Services (NHLS) Bloemfontein from 1 January 2021 to 31 March 2022. The following 15 STR autosomal loci were included in the analysis: CSF1PO, FGA, vWA, D2S1338, D3S1358, D5S818, D6S1043, D7S820, D8S1179, D10S1248, D13S317, D16S539, D18S51, D19S433, and D21S11. Both published and designed study primers were used to optimise the PCR assay conditions for the amplification of the selected STR loci using commercially available control DNA. The optimised PCR assay conditions were used to screen the samples across the 15 STR loci. Sanger sequencing and sequence analysis was conducted for each parentage case to identify and characterise the underlying cause of the observed apparent STR mismatches. Furthermore, the sequence-based alleles were evaluated for concordance with genotypes determined by Capillary Electrophoresis-based (CE-based) STR typing previously reported by the facility.
: An average concordance of 82% was observed between STR profiling and Sanger sequencing across the 15 STR loci studied. In 11 of the loci, a 100% concordance was obtained. In contrast, no concordance was observed for the D19S433 locus. The stepwise mutations observed at the various loci were 70% more frequent than other mutation models; these were attributed to DNA polymerase slippage. In comparison, 30% of the mutations were as a result of allelic dropouts, accounted for by primer-binding site sequence variants. It was observed that there were more mutations originating from paternal (n=76) rather than maternal (n=26) lineages.
: The observation of one or two STR loci mismatches in parentage analysis should not be overlooked; all the studied allelic mismatches between the parent and child were characterised successfully. The findings revealed that most of the apparent mismatches occurred due to DNA polymerase slippage. The results of this study provide evidence that sequencing of the core STR repeat and the flanking regions can provide valuable information to characterise STR loci mutational events when inconclusive parentage or kinship results are obtained. Because of the limited sample size, the findings of this study provide evidence that STR mutations are more prevalent in males than females. Furthermore, this study demonstrates the need for DNA testing facilities to have a method in place to characterise and confirm inconclusive genotypic data obtained using the available commercial STR kits