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An epidemiological analysis of the occurence of brucellosis in cattle and adopted control measures in South Africa during the period 2014 to 2019
Get PDFThesis (M.Sc. Agriculture (Animal Protection)) -- University of Limpopo, 2024Bovine brucellosis is among the most neglected zoonotic diseases in developing countries, where it is endemic and a growing challenge to public health. The development of cost-effective control measures of the disease can only be affirmed by knowledge of the disease epidemiology and the ability to define its risk profiles. The study aimed to document the trend of bovine brucellosis and the control measures adopted following reported cases during the period 2014 to 2019 in South Africa. Data on confirmed cases of bovine brucellosis was retrieved from the website of the World Organisation of Animal Health (WOAH). Data was analysed using the Statistical Package for Social Sciences (IBM SPSS, 2022) version 29.0. Descriptive analysis (frequencies and percentages) and the Analysis of variance (ANOVA) were utilized for statistical significance (p<0.05). The data retrieved revealed an overall average bovine brucellosis prevalence rate of 8.48%. There were statistically significance differences in bovine brucellosis prevalence across the provinces except for the year 2016 (p<0.05), with Eastern Cape province having the highest prevalence rate in 2016. Vaccination, kill and disposed were the documented control measures in place for the control of bovine brucellosis in the current study, with vaccination being the most commonly adopted strategy. The study identified gaps, such as the lack of invaluable information on the adoption of comprehensive control measures, testing of only suspect cases, and export livestock, that may contribute to brucellosis underreporting in South Africa. More research on the epidemiology alongside the adoption of comprehensive control measures can help to reduce the outbreaks of bovine brucellosis and economic impact in the South African livestock secto
African languages in teaching and learning : Implementing and promoting multilingualism and decolonisation in South African higher education
Get PDFJournal article published in African Perspectives of Research in Teaching and Learning Journal Issue 3, Volume 8, 2024 Special IssueRefer to the documen
Exploring affordances and constraints of blended learning in enhancing life sciences grade 12 learners' understanding of genetics
Get PDFThesis (M.Ed. (Science Education) -- University of Limpopo, 2024The study explored the affordances and constrains of blended learning on enhancing Life Sciences Grade 12 learners understanding of Genetics. The study took place in Limpopo province, Capricorn region under Capricorn South circuit. This study used Situated Learning theory as a theoretical framework and qualitative research approach where single case study served as a design. Furthermore, the study conveniently sampled 22 Grade 12 Life Sciences learners and data was collected through participative observation, semi-structured interviews and document review (written tasks). Among other things the findings of the study revealed that the integration of blended learning afforded learners‘ understanding of Genetics and also caused language constrains among the learners. It was recommended that future studies look into teachers and learners‘ attitudes towards blended learning
Competitiveness of the South Africa citrus fruit industry relative to it's Southern Hemisphere counterparts from 1989 to 2019
Get PDFThesis (M.Sc. Agriculture (Agricultural Economics)) -- University of Limpopo, 2024The citrus fruit industry holds a significant position within South Africa's agricultural sector due to its labour-intensive and export-oriented practices. However, this industry faces growing competition not only on a global scale but particularly from citrus fruit producers in the Southern Hemisphere. The Southern Hemisphere counterparts benefit from similar climatic conditions and have access to the same export markets. Thus, the objective of this study was to compare and analyse the competitiveness of South Africa's citrus fruit industry with its counterparts in the Southern Hemisphere from 1989 to 2019. To conduct this analysis, annual time series data was collected from reputable sources such as the Food and Agricultural Organisation of the United Nations and the International Trade Centre (ITC). The data was analysed using Microsoft Excel spreadsheet and Eviews 12 software. The Balassa Revealed Comparative
Advantage (RCA) index and the Net Export index (NXI) were employed as measures to assess the competitive performance of South African citrus fruit in comparison to its Southern Hemisphere counterparts. The competitiveness of different South African citrus fruits in major markets was analysed using the Constant Market Share (CMS) model. Additionally, the Armington model was utilized to examine the macroeconomic factors that impact the competitiveness of the South African citrus industry. The findings from the Balassa Revealed Comparative Advantage (RCA) index indicated that the South African citrus industry demonstrates a stronger and relatively higher competitive advantage in the production and
exportation of most citrus fruit product categories compared to its Southern Hemisphere
counterparts. The results from the Net Export index align with the RCA findings, showing that South Africa is a net exporter of citrus fruits. Moreover, the CMS results shed light on the pecific markets where different citrus fruits exhibit competitiveness. Lastly, this study identified various macroeconomic factors, both in the short and long run, that influence the competitiveness of the South African citrus industry at different levels of significance. For the industry to be sustainable and to enhance its competitiveness, several recommendations and strategies are suggested at the end of this study which includes exploring potential strategic markets like the Russian and the Asian market, reducing reliance on the EU and producing and exporting more lemons and limes; and soft citrus
Sarcasm detection in political speeches using recurrent neural networks
Get PDFThesis (M.Sc. (Computer [Science])) -- University of Limpopo, 2024Sarcasm detection is a challenging task in natural language processing (NLP) that has
received significant attention in recent years. Sarcasm is a form of indirect speech in
which the speaker says the opposite of what they mean. It can be used to express a
variety of emotions, such as humour, irony, or contempt. Sarcasm is often difficult to
detect, especially in written text, because it often relies on context and the speaker's
intent. Recurrent neural networks (RNNs) have been shown to be effective in sarcasm
detection, but there is still room for improvement. In this work, we propose a stacking
and weighted average ensemble model using simpleRNN, LSTM, and GRU as base
models for sarcasm detection. The news headline dataset was used in the study. The
dataset contains sarcastic and non-sarcastic labels for the headlines, and contains a
total of 55325 headlines, the dataset is split into 80% (44260) testing and 20% (11065)
validation. The aim of this study was to develop a model to detect sarcasm in political
speech using Recurrent Neural Networks, incorporating sarcasm detection into
sentiment analysis for political text can significantly enhance the accuracy and depth
of sentiment understanding. The results suggest that the ensemble models outperform
individual neural network models, with the two-level stacking model achieving the best
overall performance.ETDP SIT
Interactive effect of maturity stages and fruit accessions on primary and secondary metabolites profile of Mimusops zeyheri sond
Get PDFThesis (M. Agricultural Management (Plant Production)) -- University of Limpopo, 2024Mimusops zeyheri Sond is a member of the Sapotaceae Family and it is an undervalued or unappreciated indigenous fruit tree consumed raw as a healthful snack in rural communities across Sub-Saharan Africa. It is known for its predominantly high vitamin C content. The objectives of this study were to investigate whether the interaction between different accessions and fruit maturity stages has effect on post-harvest quality, physicochemical attributes, primary and secondary metabolites in M. zeyheri. To achieve the objectives of this study, fruits of M. zeyheri were harvested from trees of five accessions namely, 6E, M7, 3E, HY, and 3L at four different maturity stages: dark green (T1), breaker (T2), pale yellow (T3), and yellow (T4). A 5 × 4 factorial experiment was established as an interaction between five accessions and four fruit maturity stages. The experiment was laid in a randomised complete design with four replication per accession and maturity stage. The mean separation was done using a Duncan’s Multiple Range Test at the significance level of 5% using the GenStat 18th version.
Five accessions and four fruit maturity stages demonstrated significant variation (p< 0.05) on quality and physicochemical attributes. Accession 6E had the highest fruit length at T1 to T4 maturity stage (25.85-27.63 mm). The other accessions including 3E, HY, and 3L had similar moderate length however, these were higher than that of accession M7 which exhibited the least, irrespective of maturity stage. Fruit firmness declined as fruits ripened with the highest values recorded at T1 and lowest values at T4 fruit maturity stages, for all five accessions. Fruits of accession HY had the highest total soluble solids (32.80%) at T4 maturity stage while that of accession 3L had lowest total soluble solids (2.40%) at T1 maturity stage. Accession M7 had the highest total titratable acid (3.20%) at T1 maturity stage, whilst accession 6E had the lowest total titratable acidity (0.22%) at T4 maturity stage. The highest TSS/TA ratio values were reported in accession M7 (32.20%) at T4 maturity stage than all accessions. All the accessions at T1 to T4 stages demonstrated different values of colour change on Hunter a*. The Hunter L* values were lower at T1 and highest at T4 maturity stages. The H˚ angle were high at T1 and lowest at T4 maturity stages as fruit reached ripening period. On the nutritional compositions, accession HY recorded highest values of moisture content at T1 to T4 maturity stages (93-97%) and protein content at T2 to T4 maturity stages (0.41-0.40%), whilst accession HY recorded at T4 maturity stage (0.43%). The moisture content was highest in accession 6E at T1 and T3 maturity stages (92 and 89%) and ash content (4.20-3.75%) at T1 to T3 maturity stages. The dry matter, ash and protein content were reduced from T1 to T4 maturity stages, while moisture content enhanced with advanced of fruit maturity stages. The mineral such as calcium, potassium, iron, magnesium, manganese, sodium, zinc and phosphorus were assessed. Accession M7 had highest values of calcium at T1 maturity stage (27.73 mg/L), magnesium (5.96 and 4.37 mg/L) at T1 and T2 maturity stages and sodium (5.63-3.64 mg/L) at T1 to T4 maturity stages. Accession 3E had highest values of potassium at T2 maturity stage (8.70 mg/L) and Manganese at T1 and T2 maturity stages (0.07 and 0.06 mg/L). Furthermore, accession HY had highest values of calcium at T2 to T4 maturity stages ranged from (21.50-17.17 mg/L), T1 to T3 maturity stages were recorded in iron (1.57-0.37 mg/L) and potassium (50.83-44.93 mg/L). Accession 3E had highest values of phosphorus at T1 to T3 maturity stages ranged from (9.39-6.83 mg/L), zinc ranged from (1.73-0.60 mg/L). The mineral compositions decreased with advanced of fruit maturity stages in all accessions. This study demonstrated that fruits of five accessions of M. zeyheri at T1 maturity stage should be used for the food fortification program due to high amount of mineral compositions and fruits at T4 maturity stage should be consumed as raw fruits for snacking, dried fruits and can also be processed to generate fermented juices, jellies and dried fruits to reduce the malnutrition and food insecurity.
Secondary metabolites, such polyphenolic and flavonoids were identified and quantified in five accessions of M. zeyheri at two different fruit maturity stages, which were T1 and T4. For untargeted secondary metabolites, methanol extracts were analysed using ultra-performance liquid chromatography mass spectrometer. In five accessions of M. zeyheri, exploratory principal component analysis plot revealed five major clusters based on the heterogeneity of metabolites. The highest value of 3,4-bis(acetyloxy)-5-acetamido-6-(3-nitrophenoxy)oxan-2-yl]methyl acetate was recorded in accession 3L at the T1 fruit maturity stage (719.90 mg/kg) including paeonoside (48.98 mg/kg) and T4 fruit maturity stage of 7-oxo-8,9-dihydroxy-4'-N-demethyl staurosporine (122.48 mg/kg). The highest value in accession HY was recorded at the T4 fruit maturity stage (646.70 mg/kg). The three flavonoid metabolites found in M. zeyheri that were most abundant were quercetin, quercetin galactoside, and quercetin glucoside. The results discovered that M. zeyheri fruit possesses a high level of concentration at T1 and T4 fruit maturity stages which could contribute and serve as a food source, especially for vulnerable rural communities that need food security, and prevent chronic non-communicable diseases
Lived experience of young females raised by social fathers : a case of Driekop Community, Limpopo Province, South Africa
Get PDFThesis (M. A. (Psychology)) -- University of Limpopo, 2024The number of children growing up in stepfamilies is rising globally. This rise is accelerated due to parental remarriage following divorce, death or immigration. Undeniably, children growing in these newly formed stepfamilies remain susceptible to enormous challenges at the hands of their stepparents, most particularly young females. Amongst other challenges, these children may experience psychological, emotional, and academic challenges. The aim of this study was to describe the lived experiences of young females raised by social fathers in the Driekop community in the South African Limpopo province. The study adopted a qualitative research approach and utilised a phenomenological research design to obtain first-hand information from the research participants. The research targeted young black females raised by social fathers in Driekop community in Limpopo province. Seven participants were sampled using the purposive sampling technique, which falls under the non-probability sampling methods. Data was collected through face-to-face interviews, and the data was analysed using an inductive thematic analysis method. The study found that young females raised by social fathers suffer from psychological challenges, such as feelings of worthlessness, loneliness, a lack of sense of belonging, fear of abuse, and being unable to speak about their challenges. It was also established that these young females are discriminated against, and that they lack their mothers’ support when they raise the challenges that they face due to the presence of their social fathers. To cope with these challenges, the young females resort to seeking support from their significant others, pray, and/or use substances, such as alcohol to numb the pain. This study recommends educational campaigns that could assist both young females and social fathers in adjusting to the new living circumstances. The study also recommends awareness campaigns to educate and encourage young females to report any form of abuse by their social father
Constructing designs and codes from fixed points of alternating groups
Get PDFThesis (M.Sc. (Mathematics)) -- University of Limpopo, 2024The study of finite structures in discrete mathematics is a broad area which has many in
influential results not only in mathematics but also in practice. It is well known that 1designs
have many applications in coding theory. The construction of these designs and codes from xed points of alternating groups plays a central role in obtaining properties of codes, structures and other general results that are useful in application of coding theory.
In this dissertation we construct some 1designs from (Key-Moori method 2) and J Moori
Method 3. In (Key-Moori method 2), we have a technique from which a large number of nonsymmetric 1designs could be constructed from maximal subgroups and conjugacy classes of elements of nite groups. In this dissertation, we consider the alternating group G = An with its maximal subgroup M = An1 where nX is a conjugacy class of elements of order n in G. Let g 2 nX, then jCgj = j[g]j = [G : CG(g)]. Using J Moori Method 3, we construct some 1designs from the xed points of elements of alternating groups. While J Moori has accomplished most of the work by constructing all designs and codes for alternating groups, and A Saeidi constructed designs and codes from involutions of alternating groups An and for maximamal subgoup isomorphic to Sn2. In this dissertation we will be looking at other maximal subgroups (particularly the maximal
subgroup An1 of An) which are not covered by J Moori and A Saeidi. Therefore, making
this work an extention to J Moori and A Saeidi work
The prevalence of hydronephrosis on ultrasound imaging in women with cervical cancer in Mankweng Hospital, Limpopo Province
Get PDFThesis (M.Med. (Diagnostic Radiology)) -- University of Limpopo, 2024Introduction
Cervical cancer is the leading cause of cancer mortality in females particularly in sub-Saharan Africa and the fourth most frequently diagnosed malignancy globally. In 2020 cervical cancer was responsible for 5870 deaths in South Africa. Hydronephrosis is a frequent urological complication of advanced cancer of the cervix, with a prevalence of between 21.2% and 43.7%. The aim of the study was to evaluate the prevalence of hydronephrosis in women with cervical cancer diagnosed through trans-abdominal ultrasound at Mankweng Tertiary Hospital, Limpopo, South Africa.
Methods
A retrospective record-based analysis was conducted in the Radiology Department of Mankweng Hospital. Patients with histologically diagnosed cervical cancer who underwent trans-abdominal staging ultrasound between 01 July 2019 and 31 December 2019 were included. Data on patient age, parity, source of income, area of residence, size of the cervical lesion and the ultrasound imaging findings were extracted. Data was analysed using STATA v15. Descriptive statistics such as frequency and percentages were used to summarise all variables. Association between hydronephrosis and independent variables was evaluated using the Fisher’s exact score. Statistical significance was set at p-value <0.05.
Results
Two hundred patient records were evaluated. The patients’ age ranged from 27 to 89 years with the majority (68.4%, n=136) of the women aged between 31 - 60 years, and 28.5% (n=57) being older than 60 years. The majority of the women presented with a large tumour of >4cm (72.5%, n=143). Eighty-five patients had hydronephrosis (prevalence rate =42.5%), which was either bilateral (68.2%), or unilateral (31.8%). Tumour size was strongly associated with the occurrence of hydronephrosis. Other ultrasound findings were urinary bladder wall infiltration (13%, n=26), liver metastasis (3%, n=6), para-aortic lymph nodes involvement (1%, 2), and vesico-vaginal fistula (0.5%, n=1).Conclusion
Hydronephrosis was the most frequent urological complication in advanced cancer of the cervix on ultrasound imaging, and was associated with a tumour size of >4cm
The effect of long-term high-fat diet feeding on intestinal health of aged vervet monkeys
Get PDFThesis (M.Sc. (Biochemistry)) -- University of Limpopo, 2024The consumption of Westernised high-fat diets (HFDs) dysregulates intestinal barrier components which may lead to subclinical systemic and tissue inflammation implicated in type 2 diabetes (T2D) development. It is essential to understand the intestinal barrier‘s role in developing T2D. This may aid in the identification of potential therapeutic and preventative targets for intestinal barrier defects and downstream metabolic impairments. This study investigated intestinal barrier function and inflammation in intestinal tissues of vervet monkeys (Chlorocebus aethiops) towards the development of T2D. The study made use of intestinal tissues (duodenum, jejunum, ileum and colon) and serum that was previously collected from nine vervet monkeys that were maintained on a maize-based control diet (MD) (n=3) and an HFD (n=6), respectively for 15 years. Serum was used to assess glycaemic and lipogram parameters. Haematoxylin and Eosin (H&E) staining was used for general morphological assessment and immunohistochemistry (IHC) was used to assess the expression of intestinal immunity marker, immunoglobulin-A-positive (IgA+) cells of the duodenum, jejunum, ileum and colon. IHC was also used to assess the expression of intestinal barrier integrity marker, occludin in the ileum and colon. Western blot analysis was used to assess the expression levels of markers that are involved in the synthesis of pro-inflammatory mediators, extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 in the ileum and colon. The expression levels of leaky gut biomarkers in serum: lipopolysaccharide-binding protein (LBP) and cluster of differentiation 14 (CD14) were assessed using respective enzyme-linked immunosorbent assay (ELISA) kits. The results revealed that the HFD did not induce significant changes in fasting blood glucose nor glycated haemoglobin levels of the vervet monkeys when compared to MD-fed vervet monkeys. There were no significant changes in triglyceride between HFD-fed and MD-fed vervet monkeys. Furthermore, total cholesterol levels were marginally increased (p=0.071), high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels were significantly increased (p=0.048 and p=0.017 respectively) in HFD-fed vervet monkeys as compared to MD- fed monkeys. H&E staining revealed that an HFD did not affect the morphology of the ileum and colon of vervet monkeys as evidenced by no significant changes in the villus length and crypt depth respectively when compared to MD-fed vervet monkeys. Immunohistochemical analysis revealed that an HFD significantly increased (p=0.046) the population of IgA+ cells in the duodenum of vervet monkeys when compared to MD-fed vervet monkeys. However, no significant changes in the population of IgA+ cells were demonstrated in the jejunum, ileum and colon between HFD-fed and MD- fed vervet monkeys. HFD-fed vervet monkeys did not demonstrate significant changes in the expression of occludin in the ileum and colon when compared to MD-fed vervet monkeys. Western blot analysis revealed that there were no significant changes in the expression of ERK1/2 and p38 in the ileum and colon between HFD-fed and MD-fed vervet monkeys. There were no significant differences in serum levels of LBP and CD14 assessed by ELISA between HFD-fed and MD-fed vervet monkeys. In conclusion, this study demonstrated that an HFD dysregulated lipid metabolism in HFD-fed vervet monkeys, suggesting a probable predisposition to developing metabolic disease. In addition, the increased population of IgA+ cells in the duodenum of HFD-fed vervet monkeys suggests dysregulated mucosal immunity. However, further research is warranted to elucidate underlying mechanisms.Biomedical Research and Innovation Platform of the SAMRC
National Research Foundation of South Africa (NRF