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Evaluating rhizosphere soil microbes, grain yield and nutritional composition of two legume species in farmers' fields in four Municipalities of Vhembe district.
No full textMSCAGR (Plant Production)Department of Soil and Plant SciencesDespite the nutritional value and the amounts of N that legumes contribute to the soil, few studies have evaluated rhizosphere soil microbes, grain yield and nutritional composition of indigenous legumes in the fields of South African farmers. To explore the variations in grain yield, rhizospheres soil microbes and nutritional composition in Bambara groundnut and cowpea species, this study evaluated two legume species under five farmer's fields conditions at four locations (Thulamela, Musina, Makhado and Collin Chabane) in the Vhembe district regions of Limpopo province, South Africa during the 2021/2022 summer cropping season. Ten of each Bambara groundnut and cowpea were sampled at 75% physiological maturity from each farmers’ field to determine growth yield and yield components, nutritional composition, and mineral content variations. Ca, K, Mg, Na, B, Cu, Fe, Zn, and protein levels were determined in ground pods and leaves. The rhizosphere soil samples were from 15 cm soil depth. Soil microbial diversity was determined using Carbon Source Utilisation Profiles (CSUP) BIOLOG™ GN2 plates. The abundance and richness of the soil microbes were also determined using the Shannon-Weaver and Evenness diversity indices. The collected data showed significant (p≤0.05) differences in plant dry matter (DM) yield, number of pods, pods dry weight and number of nodules from different farmer’s fields. The high temperature reported in Musina, which exhibited higher growth and yield for Bambara groundnut compared to the other municipalities, indicates the different sites' climatic conditions. A positive correlation was observed between monthly maximum temperature and dry matter for Bambara groundnut (r2 =0.33) and cowpea (r2=0.30). In Makhado municipality, the data showed increased dry matter (144.3 g/plant) and the least in Musina (68.3 g/plant). The legume species studied exhibited differences in the grain protein fractions' profile and grain mineral content. The two species grains showed considerable significant variation for the
following nine mineral contents (mg/g dry matter) obtained for the micro minerals of Bambara groundnut Na 897 mg/kg, Fe 534 mg/kg and Zn 35 mg/kg. Cowpea Na 219 mg/kg, Zn 45 mg/kg, and B 31 mg/kg, and for the macro minerals: Bambara groundnut K 1.55 mg/kg, Ca 0.16 mg/kg, Mg 0.21 mg/kg, P 0.26 mg/kg. Cowpea K 1.30 mg/kg, Ca 0.21 mg/kg, Mg 0.25 mg/kg, and P 0.36 mg/kg.
The significant difference in Shannon Weaver Diversity Index (H’) (i.e., the ability of the microbial community to degrade more or fewer types of carbon sources at a threshold ODi value ≥ 0.25) was observed for samples in cowpea species under Makhado location, which could degrade more types of carbon sources. Statistically significant utilisation was detected for all five groups of carbon sources.
The microbial communities detected the highest AWCD for utilising all carbon sources (carbohydrates, carboxylic acids, amino acids, polymers and amines). This soil diversity and richness is an indicator of the quality of the soil to increase crop yields and agricultural production.
Additional research is needed to determine the microbial diversity and activity yield variations, nutritional composition, and mineral elements of Bambara groundnut and cowpea species.NR
Democratisation of Governance of Local Municipality Ward with specific reference to Ward 01 in Collins Chabane Local Municipality in Vhembe District Limpopo Province
No full textMPMDepartment of Public and Development AdministrationSouth Africa attained its constitutional democracy in 1994 from a contemporary political order that has been shaped by the country’s history of colonialism, segregation, less or no service delivery to black communities, and apartheid. Since the inception of the second decade of democracy, the country experienced numerous service delivery protests which makes one doubt whether democracy exists in South Africa. The current study was carried out in the Hlanganani Cluster in Collins Chabane Local Municipality. A qualitative research methodology which utilised a phenomenological research design was utilised to investigate democratization in the governance of a municipal ward in Hlanganani Cluster, Collins Chabane Local Municipality. A sample of 15 respondents from the area participated in the study. The results of the study revealed that the broader definition of definition of democracy is not familiar in the area, yet the political rhetoric one is more common. Hence the challenges of poor service delivery, lack of accountability of public officials’ lack of transparency, and corruption are key obstacles hindering the full realisation of democracy in the area. It recommended that the government should enhance the participation of local communities in decision-making, encourage the youth as well as create a democratic space for civic society to maintain checks and balances. The results of the study are also useful for crafting strategies for creating an enabling environment to thrive.NR
The Adsorption of bidens pilosa dye molecules onto TiO2 nanoparticle surfaces for optimization of light harvesting efficiency in dye sensitized solar cell: an experimental and theoretical study
No full textMSc (Physics)Department of PhysicsThe availability and high demand for electrical energy is a key global concern, as a result, Dye sensitized solar cells (DSSCs) have attracted a lot of attention in recent years due to their ease of preparation, low toxicity, and environmental friendliness. The current study describes the green synthesis of TiO2 nanoparticles as well as their characterization using ultraviolet-visible, Fourier transformed infrared spectroscopy and X-ray diffraction. Furthermore, the study used Density Functional Theory to describe the optical characteristics of produced nanoparticles. The UV-Vis results showed that the dye extracted using solvents such as water, methanol, and ethanol had a common absorbance at 665 nm among the solvents used ethanol had the highest absorption. The molecules responsible for a broader range of absorbance are known to be pheophytin and porphyrin, which are found in chlorophyll extracted from the B. pilosa plant. FTIR analysis of the prepared TiO2 revealed the absorbed functional groups of the synthesized B. pilosa extracts and confirmed the formation of TiO2 NPs with a vibrational band at 497 cm 1. The TiO2 NPs were heterogeneous in shape under TEM and SEM but spherical under SEM, indicating the formation of paste during agglomeration. XRD analysis confirmed that the polymorph formed is anatase with the highest peak of (101) surface, which was used to computationally adsorb the dye molecule. Pheophytin and porphyrin characteristics were optimized using DFT. For both experimentally and computationally, the UV-vis absorbance was found to be between 420 nm and 665 nm with a higher light harvesting efficiency. pheophytin and porphyrin exhibited energy gaps of 2.1 eV and 2.8 eV respectively. This study demonstrates that the dye molecule synthesized from B. pilosa is an efficient sensitizer for DSSCs. The adsorption results substantiate the spontaneous electron injection and subsequent efficient regeneration of oxidized dye molecules and the strong binding ability of porphyrin dye molecules to the TiO2 surface. The results of this study will be useful for the development of highly efficient organic dyes for DSSCs.
KeywNR
The Small-Scale Broiler Value Chain Configuration and Market Access Constraints in Vhembe District of Limpopo Province, South Africa
No full textAGMARDInstitute of Rural DevelopmentThe number of broiler farmers in developing countries is increasing, however they face several challenges that impede their growth. Access to sustainable market is a critical challenge for broiler farmers which is hampered by underdeveloped value chains. Hence, identifying value chain constraints and areas to strengthen in small-scale broiler production is crucial to enhance competitiveness. Sixty (n = 60) farmers were sampled to assess the value chain configuration and market for small-scale broiler farmers in Vhembe district of Limpopo province in South Africa. Both Quantitative and Qualitative data was gathered using a structured questionnaire with open and close-ended questions. Quantitative data was analysed using statistical package for social science version 27. Moreover, descriptive analysis (SPSS version 27), Thematic analysis (Atlas Ti version 8), Thematic content analysis (Atlas Ti version 8) was used to analyse the data. The results suggest that value chain configuration is directly correlated to marketing configurations. This study also reveals that lack of capital is the main challenge that give birth to many other challenges like lack of abattoirs and access to main production inputs for growth. It also reveals that the combination of these challenges made it difficult for the small-scale broiler producers to penetrate the vertical organized market and growth. Also, the results show that small-scale producers can deepen their value chain participation through amongst others, procuring production inputs, establishing abattoir and leverage government support collectively to increase their production capacity. The study recommends that small-scale producers form input and market cooperatives to collectively source production inputs and market their produce. In terms of support, small-scale broiler farmers require intensified support programmes to strengthen their production capabilities and entrench access the sustainable market for sustained growth.NR
The impact of macroeconomic variables on stock market performance in South Africa
No full textM. Com (Economics)Department of EconomicsA well-functioning stock market is regarded as a reflection of a working economy. The stock market raises primary capital by rechannelling cash resources into productive economic projects aimed at building the economy while enhancing jobs and wealth creation. The South African economy has for the past decade been affected by different macroeconomic challenges which subjected the bourse into different risk factors, most specifically, the systematic risk factors. It is against this backdrop that this study aims to provide a critical review of the impact of macroeconomic changes on stock market performance in South Africa. This study used the Financial Times Stock Exchange (FTSE) and the Johannesburg Stock Exchange (JSE) top 40 index as the stock market performance benchmark, using time series quarterly data covering the period spanning from 2008 to 2021. Seven macroeconomic variables namely: economic growth, interest rate, inflation, money supply, exchange rate, crude oil prices and industrial production were used in the study. A multifactor regression model based on the arbitrage pricing theory was used to estimate the impact of each variable on market performance. Furthermore, the Ordinary Least Squares (OLS) method was used to establish the relationship between stock returns and macroeconomic variables. The study findings shows that economic growth, industrial production, and exchange rate affect stock market positively while inflation, interest rates have a negative impact. The implication of these results is that the government of South Africa should craft policies that increase the Gross Domestic Product (GDP) and industrial production to positively influence stock market performance, while policies to reduce inflation are recommended.NR
Comparison of Some Statistical and Machine Learning Models for Continuous Survival Analysis
No full textM. Sc. (e-Science)Department of Mathematical and Computational SciencesWhile statistical models have been traditionally utilized, there is a growing interest
in exploring the potential of machine learning techniques. Existing literature shows
varying results on their performance which is based on the dateset employed. This
study will conduct a comparative evaluation of the predictive accuracy of both statistical
and machine learning models for continuous survival analysis utilizing two distinct
datasets: time to first alcohol intake and North Carolina recidivism data. LassoCV was
used to select variables for both datasets by encouraging limited coefficient estimates.
Kaplan-Meier survival curves were utilized to compare the survival distributions among
groups of variables incorporated in the model, alongside the logrank test. The proposed
methods include the Cox Proportional Hazards, Lasso-regularized Cox, Survival Trees,
Random Survival Forest, and Neural Networks. Model performance was evaluated using
Integrated Brier score (IBS), Area Under the Curve and Concordance index. Our
findings shows consistent dominance of Neural Network (NN) and Random Survival
Forest (RSF) models across multiple metrics for both datasets. Specifically, Neural
Network demonstrates remarkable performance, closely followed by RSF, CoxPH and
CoxLasso models with slightly lower performance, and Survival Tree (ST) consistently
lags behind. This study can contribute to advancing knowledge and provides practical
guidance for improving survival in recidivism and alcohol intakeNR
Adaptive Strategies to Mitigate Water Scarcity Among Smallholder Cattle Farmers in Vulnerable Areas of the Greater Tzaneen Local Municipality
No full textAGMARDInstitute for Rural DevelopmentThe rapid increase in demand for livestock and livestock products, driven by factors such as population growth, urbanization, and rising incomes, is projected to escalate significantly by 2050. The estimates indicate the utilization of over 60 billion livestock for meat, egg, and dairy production. This surge in demand poses substantial challenges, particularly in the context of climate change impacts on water resources. Smallholder livestock farmers, who are integral to meeting this demand, are disproportionately affected by climate change-induced water scarcity. Despite their significant contribution to the agricultural Gross Domestic Product (GDP), these farmers face daily depletion of water reserves, indicating severe water scarcity. Climate variability further exacerbates this situation, with animal water consumption expected to triple. This study aimed to examine the adaptive strategies employed by smallholder livestock farmers in vulnerable areas of the Greater Tzaneen Local Municipality to mitigate water scarcity. A convergent parallel mixed methods design was utilized, wherein both quantitative and qualitative data were collected and analyzed concurrently. Purposive sampling was used to select participants, primarily through face-to-face interviews. Secondary data was obtained from literature, journal manuscripts, policy documents, and municipal reports. Quantitative data were analyzed using the Statistical Package for Social Sciences (SPSS) version 27, while thematic content analysis was performed using Atlas.ti version 8. The findings revealed several adaptive strategies employed by farmers to address water scarcity, including changes in water sources and collaborations with government agencies such as the Department of Water and Sanitation. Challenges such as cattle mortality due to water scarcity were also identified, highlighting the need for additional adaptive measures to ensure sustainable cattle farming. The study underscores the necessity of enhancing adaptive strategies to mitigate the adverse effects of water scarcity on smallholder livestock farming in the context of increasing climate variability.National Research Foundation (NRF
Behavioural Adjustments in the Absence of Parents: Experience from a Child and Youth Care Centre in Vhembe District, Limpopo Province, South Africa
No full textM.A. (Youth in Development)Institute for Gender and Youth StudiesA large part of how teenagers learn to become law-abiding citizens of their societies, comes from interactions and communications with their parents and parental figures. Through such interactions, they develop a sense of belonging to their communities and imbibe norms and values that help them navigate different situations within their communities. Yet, little is known in the youth studies literature regarding how the absence of parents or similar figures in children’s life, particularly, during the adolescent stage, contributes to lack of positive attitudes and a disposition to criminal activities, in their communities. The current study addresses this research gap. Drawing from the case of teenagers in selected Child and Youth Care Centre in Vhembe District, Limpopo Province of South Africa, the study investigates whether a disposition to negative attitudes towards social life and corresponding disposition to criminality are cultivated by parental absence or lack of parent figure in the lives of the teenagers. The research is based on a qualitative approach and one-on-one semi-structured interviews was used for the collection of data; a non-probability purposive and snowball sampling technique was used to select 22 participants for the study( 12 teenagers,8 boys and 04 girls, 10 adult participants (4 Parents, 2 Social worker, 2 Police officials and 2 Educators). Based on a systematic micro-soft word-based thematic analysis of the data, the study found a significant link between the absence of parents or parental figures, at the adolescence period of the teenagers’ lives, with disconnection and detachment from their communities. The study concludes that operating in such contexts, teenagers easily become susceptible to different social vices and criminal activities.NR
Genetic divesity of Human Herpesvirus Type 8 in Northern South Africa
No full textM.Sc. (Microbiology)Department of Biochemistry and MicrobiologyBackground: Human herpesvirus type 8 (HHV-8), is an oncogenic virus responsible for causing all forms of Kaposi`s sarcoma (KS). HHV-8 prevalence varies globally, however, it is more prevalent in African countries, with South Africa having over 50% of HHV-8 infections. HHV-8 encodes a highly diverse open reading frame (ORF) K1 gene, which has led to the identification of seven major genotypes (A-F and Z) that are heterogeneously distributed across the world. The viral genetic landscape of any geographical area is of paramount importance in vaccine development and diagnostics. However, data on HHV-8 genotypes is scarce in northern South Africa. Therefore, this study will provide genetic diversity of HHV-8 in northern South Africa, and this may aid in the selection of genes for vaccine development.
Objective: The main objective of the study was to describe the genetic diversity of human herpesvirus type 8 in northern South Africa.
Methodology: Deoxyribonucleic acid (DNA) was extracted from 115 archived mouthwash samples collected from five healthcare facilities in northern South Africa. The partial open reading frame (ORF) K1 gene (~840bp) was amplified in a two round conventional PCR using JumpStart REDTaq master mix. The band of interest was extracted by phenol-freeze protocol and enriched using conventional PCR. Enriched amplicons were purified and sequenced in an Illumina MiniSeq platform. K1 genotypes were inferred using an online BioAfrica HHV-8 subtyping tool and confirmed by computing a phylogenetic tree. Intra-genetic diversity among HHV-8 genotypes was described by aligning study sequences with their respective prototype strains. Synonymous and nonsynonymous mutation rates were computed by the online SNAP tool.
Results: K1 gene was successfully amplified in 61.7% (71/115) samples, along with unspecified DNA bands. The band of interest was successfully recovered in 67 amplicons (94.4%). Sixty-five gel extracted products (65/67; 97%) were successfully enriched and purified using magnetic beads. Of the 65 purified samples, 63 were sequenced using Illumina MiniSeq platform. Thirty-seven sequences had an acceptable nucleotide base call. The prevalence of HHV-8 in the study sequences was 94% (35/37) and majority of the sequences (24/35;68%) had sequence reads that span partial or complete K1 gene.
Two major genotypes were detected (A and B); genotype B (19/24;79%) had a higher prevalence than genotype A (5/24; 21%). All sequences which grouped with genotype A were further classified as subtype A5. Interestingly, all sequences that were classified as genotype B did not cluster to any of the B subtypes. A higher genetic drift was observed among the
study sequences reaching up to 33.7% at the amino acid level. Genotypes A and B exhibited 16.67% and 7.41% intra-genetic diversity at the amino acid level, respectively. Several amino acid polymorphisms were observed at the ITAM region of genotype A sequences (OUHC 013 and ODF 029), while the ITAM region of the B sequence was conserved.
Conclusion: In this study, a predominance of HHV-8 genotype B was observed in northern South Africa. Additionally, there was a high degree of evolutionary divergence among the studied sequences. A higher frequency of nonsynonymous mutations was detected at the ITAM region of A5 sequences and these mutations may potentially affect the functionality of ITAM.NR
Investigation of covariability between energy fluxes and CO2 exchange over a semi-arid savanna (Kruger National Park) by Eddie Covariance Technique
No full textM.Sc. (Physics)Department of PhysicsSouth Africa faces climate change, natural disasters, and rising temperatures due to increased levels of carbon dioxide in the atmosphere, primarily caused by deforestation, burning fossil fuels, and releasing carbon dioxide into the atmosphere without additional carbon sinks. The gap in understanding lies in studying the connection between energy flows and Net Ecosystem Exchange (NEE) at the semi-arid savanna of Kruger National Park to gain a more detailed and accurate understanding of these processes, especially in semi-arid savannas that are susceptible to changes in environmental factors. By studying energy fluxes and NEE at Kruger National Park using the eddy covariance technique, the dissertation seeks to deepen our understanding of the mechanisms driving carbon exchange in semi-arid savannas and provide insights into the impact of environmental factors on ecosystem processes. The eddy covariance technique is a powerful tool that directly measures energy and carbon dioxide exchange between the land surface and the atmosphere. The study shows that the correlation between NEE and latent heat flux (LE) and net radiation (Rn) is generally the strongest, while ground heat flux (G) and sensible heat flux (H) have little impact on NEE. The dataset provides insight into the biometeorological and flow dynamics of the Skukuza ecosystem and how it responds to climate change. The study emphasizes the importance of considering seasonality, climatic variability, and precipitation when studying the surface energy balance and its components. The findings have implications for understanding the complex interactions between ecosystem processes and environmental factors.Thunen Institut