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Elucidating conformational dynamics and ligand specificity of Schistosoma bovis 28 kDa glutathione transferases: a structural investigation.
No full textDoctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.Schistosomiasis, caused by Schistosoma trematodes is the second most devastating neglected tropical disease. Schistosoma bovis largely affects ruminant hosts, significantly crippling the economic output of livestock farmers and food security. A promising anti-schistosomal drug target is the multifunctional detoxification enzyme Schistosoma bovis 28 kDa glutathione transferase (Sb28GST). While empirical structural techniques are insightful and used in drug design, they fall short in providing the dynamics of the protein of interest. Computer aided drug design (CADD) offers a time and cost-efficient workflow to screen and analyze drug candidates. This method has limitations, whose misinterpretation can hinder drug design and development. In this study we caution the careful selection of the crystal structure space groups used for CADD as isolated analyses influence the conformational states visualized and simulated as we search for Sb28GST drugs for Schistosomiasis intervention. Upon the successful expression and purification of Sb28GST, crystal conditions were manipulated to obtain the protein's crystal structure at 2.4 Å in an orthorhombic crystal system. A 500 ns molecular dynamic simulation consisting of eight stages was performed on the orthorhombic 8BHZ to compare to the monoclinic Sb28GST 8ALS. Two distinct trajectories were undertaken by the apo proteins, revealing significant differences in the dynamic behaviour of the protein systems. A library of flavonoid compounds was used to perform high-throughput virtual screening for the identification of potential Sb28GST ligands, whose outputs were filtered using standard precision and extra precision mode. The screening process showed a diverse selection of flavonoid compounds between the different space groups with strong favourable interactions implied from the low free binding. The only common ligand selected between the protein polymorphs was apigenin 7-O-(2G-Rhamnosyl) Gentiobioside however, quercetin-3-O-Beta-D-Glucose-7-O-Beta-D-Gentiobioside was the best performing ligand overall, with the lowest glide score of -15.6645 kcal/mol. The molecular dynamic simulations of the protein polymorphs with the selected ligands additionally highlighted different molecular interactions in which the proteins used to stabilize the proteins bond to the ligands. Concluding that the combined assessment of protein polymorphs provides more detailed insights into the conformation dynamics of the protein which would not be otherwise identified in a single space group analysis. To test the inhibitory potency of the selected ligands a CDNB-GSH assay showed that both apigenin and quercetin significantly reduced the activity of Sb28GST. The IC50 of the confirmed inhibitors showed that apigenin was a more potent inhibitor (IC50 = 0.130 mM) than quercetin (IC50 = 0.120 mM). The extrinsic fluorescence studies suggest that apigenin and quercetin both bind to the hydrophobic H-site and allosteric L-site at the dimer interface. Analysis of the thermal stability of Sb28GST showed that the presence of the ligands reduces the thermal stability of the protein in a very insignificant way. This study presents the first empirical validation of computationally selected lead flavonoid compounds as inhibitors of Sb28GST for schistosomiasis intervention. From this studies' findings, future research would entail validating the lead flavonoid inhibitors through kinetic and mechanistic studies. In addition, in vitro and in vivo testing of the flavonoid inhibitors would be expanded to other Schistosome GST isoforms to guide clinical candidate development
Genetic analysis of striga resistance and yield-influencing traits in tropical and subtropical maize.
No full textDoctoral Degree. University of KwaZulu-Natal, PietermaritzburgMaize (Zea mays L., 2n = 2x = 20) is a vital food security and economic crop in sub-Saharan Africa (SSA) and globally. In SSA maize production is challenged by an array of biotic and abiotic stresses. Two parasitic weeds belonging to the genus Striga, S. hermonthica (Del.) Benth (Sh) and S. asiatica (L.) Kuntze (Sa) causes marked yield losses varying from 10% to 100% in susceptible maize cultivars. Striga-resistant maize varieties released so far had partial or moderate resistance and were bred for Sh resistance only. There are therefore no commercially grown maize varieties with Sa resistance requiring to develop new-generation maize varieties with durable Sa and Sh resistance and wide adaptability using genetically diverse tropical and subtropical genetic resources and genomic resources. The overall objective of this study was therefore, to improve maize resistance to Sa and Sh by harnessing genetic diversity and identifying markers and genes for resistance breeding. The overall hypothesis of the study was that novel genetic resources, genetic markers and genes associated with Sa and Sh resistance could be identified for dual Striga resistance for maize breeding programs.
The study had further five specific objectives: 1) To undertake a meta-analysis and provide a detailed comparison of the Striga control methods in the production of maize, sorghum, and the major millets as a guide to effective Striga management. 2) To assess the response of 130 tropical and sub-tropical African maize germplasm to Sh and Sa resistance and desirable agronomic traits and select promising genotypes. 3) To determine the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties using phenotypic traits and single nucleotide polymorphism (SNP) markers to select Striga-resistant and complementary genotypes for breeding. 4) To determine the combining ability and gene action controlling grain yield and Striga resistance among single crosses of maize to select desirable hybrids with Sh and Sa resistance and promising agronomic traits. 5) To undertake a genome-wide association analysis of grain yield and Sh and Sa resistance among tropical and sub-tropical maize populations to identify putative genetic markers and genes for marker-assisted resistance breeding and gene pyramiding.
In the first part of the study, a meta-analysis was conducted on already reported Striga control methods on the major cereal crops (i.e., maize, sorghum, and millets) using 66 research articles. The data collected included grain yield (GY), Striga emergence count (SEC), and Striga damage rating (SDR). The search showed mean yield for maize varieties with Striga-resistant genes at 2053.00 kg ha−1, ranging from 281.00 to 6260.00 kg ha−1, and a mean SDR of 4.70, varying from 2.00 to 7.00. Likewise, sorghum varieties with Striga resistance genes achieved greater GY with a mean yield response of 1738.00 kg ha−1, ranging from 850.00 to 2162.00 kg ha−1. A relatively low GY was achieved in maize and sorghum production when deploying integrated Striga management (ISM) (e.g., cultural control + host resistance, and host resistance + chemical herbicides) and chemical Striga control. The outcome of this part of the study was that SDR is the best selection criterion for improving GY performance in maize, while SEC and SDR were the parameters of choice in sorghum selection programs for better GY under Striga infestation. The meta-analysis revealed that host resistance is the most effective method for controlling Striga infestation and boosting GY in maize and sorghum.
The second part of the study focused on screening 130 tropical and sub-tropical maize germplasms, including checks, in a controlled environment for their reaction to Sh and Sa infestations using a 13×10 alpha lattice design with two replications over two seasons. The following data were collected on maize: days to 50% silking (DS), days to anthesis (DA), anthesis-silking interval (ASI), plant height (PLHT), ear height (EHT), Root lodging (RL), the number of ears per plant (EPP), husk cover (HUSK), ear aspect (EASP), and grain yield per plant (GY/plant). Striga parameters included the number of emerged Sa and Sh plants 8 and 10 weeks after planting, denoted as SEC8 and SEC10, and host plant damage by Striga 8 and 10 weeks after planting, designated as SDR8 and SDR10. The mean yield of maize and Striga par were 3.35 and 3.07, respectively. Under Sh-infested conditions, SEC8 and SEC10 mean values were 3.66 and 3.77, respectively, while the SDR8 and SDR10 values were 5.25 and 2.75 respectively. The results suggested that dual resistance to the two Striga species exists in some tropical and sub-tropical maize lines. The study selected genotypes CML440, CML566, CML540, CML539, CLHP0343, CLHP0326, TZISTR1248, TZSTRI115, TZISTR25, TZISTR1205, TZSTRI113, TZISTR1119, TZISTR1174 and the OPVs B.King/1421, Shesha/1421, ZM1421, DTSTR-WSYN13, DTSTR-YSYN14, and 2*TZECOMP3DT/WhiteDTSTRSYN) C2 with dual resistance to Sa and Sh. These genotypes are suitable for use as parents in developing high-performing maize varieties with Striga resistance and improved grain yield.
The third part of the study assessed the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties using Striga resistance and agronomic traits, and SNP markers. The SNP markers demonstrated that the test genotypes had an average gene diversity of 0.34 and a polymorphic information content of 0.44, indicating significant phenotypic variation. Significant variation was recorded within populations (85%) compared to between populations using the analysis of molecular variance. The structure analysis allocated the test genotypes into eight major clusters (K = 8) in concordance with the principal coordinate analysis (PCoA). The following genetically distant inbred lines were selected, displaying good agronomic performance and Sa and Sh resistance: CML540, TZISTR25, TZISTR1248, CLHP0303, TZISTR1174, TZSTRI113, TZDEEI50, TZSTRI115, CML539, TZISTR1015, CZL99017, CML451, CML566, CLHP0343 and CML440. The new selections will now facilitate the breeding of maize varieties with Striga resistance and market-preferred traits.
In the fourth part of the study, a combining ability analysis was undertaken to determine the mode of gene action regulating Sa and Sh resistance and to select good combiner parental maize lines for hybrid breeding. Four preliminarily selected tropical high-yielding and Sh-resistant testers and eight sub-tropical lines with Sa resistance were crossed using a line-by-tester mating design, and 32 single cross hybrids were generated. The crosses and their parents were evaluated under field and controlled environments during the 2023/2024 growing season using a 7 x 6 alpha lattice design with two replications. Combined analysis of variance revealed a significant (p<0.05) effect of the crosses on grain yield (GY), related agronomic traits, Striga emergence counts, and Striga damage rating 8 and 10 weeks after sowing. The ratio of the general combining ability effect (SCA) and the specific combining ability effect (SCA) was less than one for all the traits, indicating the predominance of non-additive genetic effects in trait inheritance and signifying the value of hybrid breeding. The best general combiner tester was TZISTR1248 in the Sa-infested environment, while tester TZISTR1174 was noteworthy under Sh environment. Lines CML540 and CLHP0343 were the best combiners in Sa environment, while CZL99017, CML566, CML540, and CLHP0343 were promising in Sh environment and CML540 was the best general combiner in all test environments. The crosses CML540 x TZISTR1174, CML540 x TZDEEI50, and CML539 x TZISTR1174 exhibited high yields, significant SCA effects, and high heterosis for GY in Sa environment. Whereas, in Sh environment, cross CML440 x TZDEEI50 had the best GCA effect and heterosis for GY. Crosses CML451 x TZISTR1174, CML539 x TZISTR1174, CML440 x TZDEEI50, CML566 x TZDEEI50, CZL99017 x TZISTR1248, and CML539 x TZISTR1248 were relatively the best specific combiners for GY in both Sa and Sh environments. The selected lines and testers and the new experimental hybrids are recommended for multi-environment evaluation in Sa and Sh-prone agroecologies to enhance grain yield and Striga resistance.
In the fifth final part of the study, a genome-wide association analysis of grain yield and Sh and Sa resistance among tropical and sub-tropical maize populations was undertaken to identify putative genetic markers and genes for resistance breeding. The test genotypes were profiled for GY, SEC8, SEC10, SDR8, and SDR10. Population structure analysis and genome-wide association mapping were undertaken based on 16,000 single nucleotide polymorphism (SNP) markers using the Diversity Array Technology Sequencing platform. The genome-wide association study identified 50 significant loci associated with Sh resistance and 22 significant loci linked to Sa resistance, corresponding to 39 and 19 candidate genes, respectively. No significant loci were found associated with dual resistance, suggesting that breeding maize must be specific for resistance to each Striga species using germplasm adapted to the endemic region of each parasite.
Overall, the study finally revealed a novel result that host resistance is the most effective method for controlling Striga infestation and boosting GY despite that research institutions advocate integrated Striga management. Promising genotypes with Sa and Sh resistance were selected, and some tropical and sub-tropical genotypes showed dual resistance. Suitable parental lines and testers and new experimental hybrids were selected for Sa and Sh resistance breeding in SSA. The new selections could be explored for future Striga resistance breeding and the development of new varieties. Significant loci associated with Sh and Sa resistance with their corresponding genes were detected and could be used to facilitate selection for Sh and Sa resistance and GY in tropical and sub-tropical maize genetic resources
The impact of fire and land use on the Kwazulu-Natal Sandstone Sourveld.
No full textMasters Degree. University of KwaZulu-Natal, Pietermaritzburg.The KwaZulu-Natal Sandstone Sourveld (KZNSS) is one of the most prominent South African grassland types and has undergone large-scale transformation through the years. This endangered, species-rich grassland is endemic to KwaZulu-Natal. Much of the KZNSS remains in patches within the eThekwini Municipality area (EMA), many of which are in communal areas and some in nature reserves. These remnants are under-conserved and under-researched. Fire and land use are focal when conducting research and implementing management and conservation practices in these grasslands. Therefore, this study aimed to determine the effect of long-term burning history on species composition and structure in protected and communal agricultural land in KZNSS grassland remnants within the eThekwini Municipality area. The objectives were to examine fire regime variations over 20 years (2002 – 2022) in reserves and communal agricultural areas found in KZNSS remnants within the EMA using Geographic Information Systems (GIS) and remote sensing. Additionally, to determine: 1) the effect of land use; 2) the effect of fire and 3) the effect of the interaction between fire and land use on grassland plant species composition, richness, evenness, and diversity; veld condition and tree density in the burnt and unburnt patches of the study areas. Remote sensing was used to obtain fire records for the last 20 years, of these remnant patches. Within the selected reserves and communal area study sites, one area with a high fire frequency (burnt five or more times in the last 20 years) and one with a low frequency (two or three times over 20 years) or which had not burnt in these 20 years were sampled. Quadrat sampling was utilised to quantify grassland composition in four communal areas (KwaCele, Qadi, Zwelibomvu, and Toyane) and four reserves (Silverglen, New Germany, Roosfontein, and Krantzkloof). A veld condition assessment (VCA) was conducted in these sites. Additionally, tree density was assessed to account for the woody encroachment in these areas. Over the past 20 years, the communal agricultural areas had a higher fire frequency than protected areas. It was also observed from the fire records that the season of burning was consistent over the years, both communal agricultural and protected areas burning mostly in the dry season. However, the percentage area burnt in these grassland patches fluctuated, with the proportion of areas burnt being highest in earlier years. Overall, fire, land use, and their interaction influenced the plant species (grasses and forbs) composition. Land use had an effect on plant species richness, evenness, and diversity. Fire, nor the interaction of fire and land use, had a significant effect on these variables. Communal agricultural areas had the highest plant species richness, evenness, and diversity. This could be explained by the fact that over 20 years, communal agricultural areas had a higher fire frequency than nature reserves. This higher frequency of fire encourages diversity as fire removes dominant vegetation, thereby allowing other plant species to grow, which prevents there just being one dominant species that outcompetes the others. For the veld condition assessments, unburnt patches in the protected areas had greater veld condition scores due to overgrazing and stocking rates being low. However, fire and land use, as well as their interaction, did not affect the tree density observed in the study areas. For the KZNSS to remain healthy and functional, land use and fire, as well as their interaction, are essential aspects. Therefore, to maintain biodiversity, effective management necessitates a balanced strategy that considers both ecological needs and human activities
The possible application of the principles of restorative justice to crimes of violence committed between intimate partners in South Africa.
No full textMasters Degree. University of KwaZulu-Natal, Pietermaritzburg.The subject of restorative justice has been one of the driving forces behind the transformation and development of the South African criminal justice system following the apartheid era. The Constitution of the Republic prioritises and gives recognition to the needs and rights of all citizens of South Africa (hereinafter ‘RSA’), including victims of crime. Our legislature has taken significant steps in developing our law to include restorative justice principles and programs which promote the participation of victims in the criminal justice process, through the department of Correctional Services and department of Justice & Constitutional Development. South African case law requires that the interests of society should be considered from the commencement of criminal proceedings (when bail is considered) right up until the conclusion (sentencing) thereof. This is to ensure that the court always bears in mind throughout the proceedings that injustice has not only been committed against the State but also against the actual victim of crime whose rights have been infringed by the crime. The act of unlawfully and intentionally assaulting another, in cases where direct force is involved, continues to be a growing and ever prevalent offence within our country as evidenced by our crime statistics. South African citizens have the constitutional rights to personal dignity and to bodily integrity and to not be subjected to live in fear especially in their homes. The main focus of this dissertation is to determine the manner in which the principles of restorative justice may be able to play a role in crimes of violence between intimate partners, such violence is commonly referred to as ‘gender-based violence
Hydrological implications of woody encroachment in the semi-arid savannas of South Africa.
No full textDoctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.Many grasslands and savannas across the globe are undergoing large-scale degradation in the form of woody encroachment, a phenomenon where native woody plants are gradually increasing in abundance at the expense of grasses and other herbaceous vegetation. Given the notion that increases in woody cover lead to increases in evapotranspiration (ET), and that some of the most severe cases of woody encroachment have been reported in drylands, concern has been expressed that woody encroachment may be placing further strain on already limited water supplies. Given this concern, a considerable number of hydrological studies pertaining to woody encroachment have been undertaken across the globe, mostly in the southern Great Plains and southwest regions of the United States. These studies have demonstrated that the hydrological response to woody encroachment is highly variable and is largely dependent on the local climate. The studies carried out in more mesic climates have mostly corroborated the belief that woody encroachment increases ET, resulting in reductions in streamflow and/or groundwater recharge. Fewer studies have been carried out in more arid climates, and their findings have varied from little influence to a decrease or increase in streamflow and groundwater recharge, with soil properties and geology also having a significant influence on the hydrological impact. The Greater Kruger National Park is South Africa’s largest conservation area and is heavily encroached by indigenous woody species. There has been significant concern about the impact on water resources in the park’s northern part, which experiences the driest conditions, and future climate projections indicate that these conditions will only worsen. The northern Greater Kruger National Park region also has a high cover of Colophospermum mopane (Mopane). Mopane is a protected species of high socio-economic importance, but it has become a dominant encroacher species growing in monospecific stands, and climatic models project that it will extend its current distribution range as a result of climate change. Mopane is thought to be an aggressive competitor for water, tapping into soil water stores that are critical for groundwater recharge. The hydrological implications of woody encroachment in South Africa's savannas have received little research attention to date. The ground-based research equipment required to fully explore the impact of woody encroachment on ET is capital and human resource demanding. However, developing countries such as South Africa have limited financial resources and technical expertise to pursue such research. A further challenge has been that the high spatio-temporal variability in ET necessitates data collection and analysis at large spatial scales as well as over several years to be able to draw meaningful conclusions for land and water management planning purposes. However, advances in ground-based observation methods, as well as access to remote sensing technologies, have allowed for many of the limitations to be overcome. Therefore, the aim of this study was to advance our understanding of the impact of woody encroachment on ET and other components of the water balance in a semi-arid savanna in South Africa by employing cheaper, simpler, yet robust in situ measurements, and to further evaluate these findings across various spatio-temporal scales using freely available remote sensing resources. A combined systematic review and meta-analysis approach was undertaken first to explore trends in previous research on the water use of different vegetation types located in various climates across South Africa, to ultimately evaluate the likelihood of woody encroachment increasing ET losses in South Africa’s semi-arid savannas. The results revealed mixed support for this idea. On the one hand, the fact that woody encroacher species replace grasses and form dense thickets with extensive rooting systems indicated that there is a high potential for woody encroachment to increase ET. On the other hand, rainfall appeared to be a primary factor limiting ET in semi-arid climates, indicating little potential for woody encroachment to have any effect on ET, unless there is an above-average rainfall year, or the vegetation has access to an additional water source. It was noted that there was relatively little ground-based research available on woody encroachment, especially in the South African context, and that further research was warranted in dryland and susceptible areas. In situ ET measurements were therefore carried out in a semi-arid South African savanna to determine the effect of woody encroachment. Over three hydrological years, ET was measured at an experimental woody plant clearing trial using surface renewal, a simpler, more affordable alternative to the well-established eddy covariance method. Two surface renewal approaches, surface renewal 1 (SR1) and surface renewal dissipation theory (SRDT), were tested against eddy covariance in order to assess their potential for sensible heat flux (H) measurement. The SR1 approach best agreed with eddy covariance, and therefore, ET measurements derived from SR1 were compared at two adjacent plots differing in woody plant density; one encroached plot and one plot thinned of Mopane trees. For the two drier years of the study, thinning had little effect on ET. However, for the wettest year of the study, thinning decreased ET by 12%, supporting the theory that woody encroachment can increase ET, at least during years of above-average rainfall.
It was also important to evaluate the influence of woody plant thinning on soil hydrological processes because any changes to the movement and distribution of water in the soil can have a direct impact on the production of surface runoff and groundwater recharge. Therefore, at the same site, a field-scale paired-plot experiment was conducted, with soil water content, soil temperature and ET measured in three paired plots over a two-and-a-half-year period. Surface infiltration tests were also carried out. Thinning had minor effects on soil water in the soil profile and soil temperature, and no pronounced effect on daily ET. Only one set of infiltration tests indicated a significant increase in infiltration following thinning. Finally, freely available and relatively user-friendly resources provided by Google Earth Engine were leveraged to assess the relationship between woody cover and ET across various spatiotemporal scales in a woody-encroached, semi-arid savanna catchment. Woody cover in the study catchment was mapped using Sentinel-2 imagery and Gradient Tree Boost algorithms within the Google Earth Engine platform, while remotely sensed ET estimates were obtained from Earth Engine Evapotranspiration Flux (EEFlux) validated by in situ surface renewal measurements. It was found that while woody encroachment can increase ET in semi-arid savannas, this increase occurs gradually over time and typically only during wet seasons and wet years. Moreover, this
increase only becomes evident at larger scales. The key conclusions from the research were as follows: • Woody encroachment in semi-arid savannas can increase ET losses, however, this is a gradual process that is only distinguishable during wet seasons or extended wet periods; • The increase in ET in semi-arid savannas caused by woody encroachment is more evident at larger scales;
• The SR1 approach with eddy covariance calibration produced reliable ET estimates with reasonable accuracy over semi-arid savanna-type vegetation; • ET in semi-arid savannas is highly seasonal, rising during the wet season in response to increased soil water availability and higher net radiation (Rn), and dropping significantly during the dry season due to low soil water availability and the deciduous nature of the vegetation;
• Woody plant thinning had little effect on infiltration and soil water in the soil profile;
• Sentinel-2 imagery and supervised pixel-based classification algorithms within Google Earth Engine accurately mapped woody cover in densely wooded areas, but in sparsely wooded areas, woody cover was either over- or under-classified; and
• EEFlux was able to estimate daily ET in semi-arid savanna vegetation with a reasonable level of accuracy, despite an underestimation of ET.
While there is still a need to continue ET monitoring, further improve remote sensing-based ET models for use in natural environments, and better understand how woody encroachment affects deep drainage and groundwater recharge, this research added to our understanding of the
hydrological implications of the woody encroachment phenomenon in drylands. It further provided invaluable insight for developing land and water management strategies to increase resilience under a changing climate and increasing socio-ecological pressures
Functional characterization of novel mycobacterial zinc metalloprotease MSMEG3019 and its role in bacterial physiology.
No full textMasters Degree. University of KwaZulu-Natal, Durban.Tuberculosis (TB), the infectious disease caused by the pathogenic bacteria Mycobacterium tuberculosis (Mtb), remains amongst the ten leading causes of death worldwide. Although TB is
preventable and curable, approximately 10 million people are diagnosed with TB and 1.5 million TB fatalities are reported annually globally. Complete eradication of TB remains a challenge due to its ability to establish a latent infection and its highly effective virulence mechanisms which facilitates manipulation and colonization of the host, as well as cause subsequent suppression and evasion of the host’s immune system. Furthermore, current TB treatment strategies face numerous limitations, such as socio-economic barriers and the emergence of drug resistant TB strains. The pathogenic success of Mtb can be attributed to its stellar virulence factors, one of which are zinc metalloproteases, which are proteases that catalyze the hydrolysis of proteins into peptides by the use of an indispensable zinc ion. In mycobacteria, zinc metalloproteases play essential roles in the intracellular survival of Mtb in host macrophages. Therefore, investigating other novel zinc metalloproteases, such as Rv2568c, is of significant interest. In this study, the Rv2568c ortholog MSMEG3019 was investigated in M. smegmatis mc2155, which is a model organism for TB research. The characterization of MSMEG3019 involved the creation of a deletion mutant strain, named MΔ3019, which harbored a non-functional version of MSMEG3019. The gene deletion method utilized in this study was the two-step allelic exchange method, this was followed by analysis and comparison of the resultant phenotype, to the wild type and complementation strains. Bioinformatics analyses revealed the presence of zinc metalloprotease and zinc ribbon domains inMSMEG3019 and Rv2568c, in addition to predicting protein-protein interactions with transglutaminase genes directly upstream. Bioinformatics were also utilized to identify proteins with structural homology to the target genes. These homologs were involved in pathogenesis of their respective species, which indicates Rv2568c’s involvement in Mtb virulence. MΔ3019 exhibited a reduced capacity to support the exponential phase of mycobacterial growth. Additionally, MΔ3019 cells displayed increased lengths and decreased widths, when compared to mc2155. MSMEG3019 was also discovered to be implicated in mycobacterial translocation, as evidenced by MΔ3019’s impaired sliding capability. Furthermore, MΔ3019 presented increased susceptibility to the peptidoglycan-targeting drug, Vancomycin. These phenotypic attributes were correlated to the disruption of peptidoglycan synthesis/regulation as the result of MSMEG3019 deletion. The observations made in this study suggests that MSMEG3019 is implicated in peptidoglycan-mediated mycobacterial growth, proliferation and dissemination, which represents Rv2568c’s contribution to pathogenesis in Mtb. The findings of this study demonstrated the importance of zinc metalloproteases to mycobacterial viability and physiology, thereby further corroborating that zinc metalloproteases remain an excellent reservoir of drug targets for TB drug development
The breastfeeding practices of workingmothers and the lactation support that they receive at the formal workplace.
No full textMasters Degree. University of KwaZulu-Natal, PietermaritzburgIntroduction: The promotion of breastfeeding is a strategy for child health and development. The work environment and the availability of infant formula may hinder exclusive breastfeeding of infants for the recommended six months. In order to promote, protect and support breastfeeding, mothers need detailed education to initiate breastfeeding successfully and to continue breastfeeding successfully with support from healthcare workers, family and the workplace. International studies have reported on the successful implementation of breastfeeding policies and the workplace support thereof that assists mothers to successfully continue breastfeeding once they are back at work. The Tshwane Declaration of Support for Breastfeeding in South Africa (SA) was agreed upon by South African stakeholders and aims to promote, protect and support exclusive breastfeeding. It has been suggested that supporting and empowering mothers to breastfeed within the workplace can be achieved through maternity leave policies and supportive workplace policies. It would be beneficial to determine if mothers know if their workplaces have policies regarding breastfeeding in place and if the workplace implements these policies.
Aim: The aim of this study was to determine the breastfeeding practices of working mothers and the lactation support that they receive at the formal workplace, as well as their awareness of the Tshwane Declaration of Support for Breastfeeding in SA. Objectives: i) To determine the demographic characteristics of breastfeeding mothers working in the private and public sectors in the eThekwini Metropolitan, KwaZulu-Natal (KZN), SA: To determine the breastfeeding practices of working mothers while at the workplace and if they lactate during the workday; iii) To determine the support (physical and technical) that breastfeeding mothers receive from their employers to enable them to express breast milk or lactate at work; iv) To determine if working women who are breastfeeding are aware of the Tshwane Declaration of Support for Breastfeeding in SA with regards to continuing breastfeeding when they return to work.
Methods: A descriptive cross-sectional study using an interviewer-assisted self-administered questionnaire was conducted using breastfeeding mothers who were employed in the private and public sectors in the eThekwini Metropolitan. Convenience sampling was used to select the study participants. The questionnaire was based on a validated and previously used questionnaire regarding the same topic. The questionnaire developed for the current study was validated by a statistician and an expert in breastfeeding and it consisted of three sections. The first section of the questionnaire collected information regarding demographic characteristics and breastfeeding practices. The second section collected information on the breastfeeding support that working mothers received at work and the third section obtained information on the awareness of mothers regarding the Tshwane Declaration of Support for Breastfeeding in SA. Data were analysed using the International Business Machines Statistical Product and Service Solutions (IBM SPSS) version 25 (IBM Corp, Armonk, NY, USA).
Results: The questionnaire was completed by 134 participants. About 65% (n=87) of the participants were aged 31 to 40 years old. The mean age of the infants that accompanied the participants was 5.9 months. About 37% (n=49) of participants had an undergraduate degree, while 66.4% (n=89) were married and 48.5% (n=65) had only one child. Most participants worked full-time (n=122; 91.0%) and 62.7% (n=84) worked in the private sector. A significant number of participants received maternity leave (n=119; 88.8%) (p=0.000) and 47% (n=63) were planning to return to work after maternity leave. Of those who received maternity leave, 52.2% (n=70) were granted four months maternity leave. Of the participants who were on maternity leave, 63.5% (n=40) were exclusively breastfeeding, while 70.4% (n=50) of those who had returned to work were mixed feeding. A significant number of participants were breastfeeding their infants 1-2 times per day (n=30; 25.9%) (p=0.037). Furthermore, 57.6% (n=68) of the participants were not expressing breast milk at all (p=0.000). About 43% (n=57) of the participants received support from their spouse/partner in order to continue breastfeeding successfully. While breastfeeding, some participants experienced problems such as “low milk supply” (n=17; 29.8%) and “cracked nipples” (n=12; 21.1%). At the time of data collection, a significant number of participants (n=44; 77.2%) were still breastfeeding despite the problems that they had experienced (p=0.000). While pregnant, a significant number of participants did not receive any education regarding the support that they would receive at work, upon their return (n=110; 90.2%) (p=0.000). However, they indicated that they would continue breastfeeding once they returned to work (n=63; 51.6%). Furthermore, the participants were not aware that they could request breastfeeding breaks when they returned to work (n=85; 69.7%). Upon returning to work, 53.1% (n=34) of the participants did not receive breastfeeding breaks and 68.8% (n=44) did not receive any support at work. A significant number of workplaces did not have written policies regarding breastfeeding support once mothers returned to work (n=34; 53.1%) (p=0.000). A significant number of participants (n=128; 95.5%) were not aware of the Tshwane Declaration of Support for Breastfeeding in SA (p=0.000).
Conclusion: Mothers mostly mixed fed their infants after returning to work as they were unable to sustain exclusive breastfeeding after returning to work. The workplace does not adequately support breastfeeding mothers at the workplace to express breastmilk. This study highlights the need for workplace breastfeeding policies to be in place and communicated in order to support working mothers to sustain breastfeeding after returning to work
Tracing 19th-century scientific racism and its implications for contemporary gender discourses of religion in South Africa.
No full textMasters Degree. University of KwaZulu-Natal, Pietermaritzburg.This study hypothesizes that current Christian religious discourses and attitudes toward the black female body, such as religious identity marked through sexuality, purity culture, (in)fertility rituals, menstruation and the exclusion from communion or prayers, have been influenced and informed by 19th-century scientific assumptions of the black female body as 1) source of pollution, 2) hypersexual/oversexed, and 3) unruly and feral. These scientific assumptions of the black female body can be said to be the genesis of our current realities as (black) women in South Africa of gender-based violence, sexual assault and femicide (Roberts, 1997; Baderoon, 2014). In postcolonial South Africa, the black female body continues to be seen as the measure of moral order, and social order, conversion and civility are maintained through the regulation of (black) women's sexuality. How the black female body and sexuality are defined and controlled using Western and Christian religious discourse calls for the need for a decolonial feminist lens to make sense of the present by searching the past in hopes of constructing a new narrative about the black female body and a new hope for black women living in a world not meant for them.
In this study, I am interested in tracing how the Church in South Africa viewed and still views the black female body through the lens of 19th-century scientific racism and sexism. To unearth the interconnections of race, science, and religion regarding the black female body, my study uses the feminist philosophy of science as a framework. Employing feminist philosophy of science will enable the study to illuminate the Black female as a gendered body, how 19th-century science has commodified, dehumanized, hypersexualized, and exploited this gendered body and how the colonial classifications of race and black(ness) have played a significant role in this. Drawing on selected colonial texts and scholars, I hope to show how their ideas shaped how people thought about race, gender and religion in the colonial period. As its methodology, my study employs Feminist Critical Discourse Analysis (FCDA). This methodology hones on social justice issues and transformation. Similar to the aims of Feminist Critical Discourse Analysis, my research hopes to challenge current Christian religious discourses that subordinate black women and repress their agency and autonomy in the name of culture and religion
Corruption and state capture : an interpretive reading of the reports of the Judicial Commission of Inquiry into Allegations of State Capture.
No full textMasters Degree. University of KwaZulu-Natal, Pietermaritzburg.State capture and corruption gained ground and became topical during the tenure of Jacob Zuma as the president of the Republic of South Africa. As rumours made their way to the media, the then-Public Protector, Thuli Madonsela, was tasked with investigating corruption and state capture. The Public Protector recommended the creation of a body to further investigate these allegations. As a result, the Judicial Commission of Inquiry into Allegations of State Capture was established. This study analyzed and interpreted the reports produced by the Judicial Commission of Inquiry into Allegations of State Capture. The study answered the following research questions: What is a state according to the Judicial Commission of Inquiry into Allegations of State Capture reports? What are the concepts and theories of state capture that guided the Judicial Commission of Inquiry into Allegations of State Capture? How does state capture manifest itself in the Judicial Commission of Inquiry into Allegations of State Capture? What are the consequences of state capture? As its primary data sources, this study used the Judicial Commission of Inquiry into State Capture Report: Part VI Vol I - Estina, Vrede and the Judicial Commission of Inquiry into State Capture Report: Part VI Vol 2. Books and academic journals were used as secondary sources. This research utilized liberal, neoliberal and new institutional economic perspectives as its theoretical lenses. This qualitative study utilized the case study method to collect data, which was also used to analyze the data
Academic staff development in a changing South African higher education context.
No full textDoctoral Degree. University of KwaZulu-Natal, Durban.This study explores the life history of academic staff development (ASD) within the context of South African higher education's significant transformation over the past three decades. Through a multiparadigmatic research design incorporating interpretivism, criticalism, and postmodernism, the research examines how academic staff developers enact their roles in response to changing institutional and national imperatives and investigates the underlying forces shaping these practices. The study employs theoretical pluralism, drawing on Bourdieu's Field Theory, Samuel's Force Field Model, and Mezirow's Transformative Learning Theory as an initial lens for this study. Data was produced from academic developers across a range of institutional types in South African higher education. Data was also produced through engaging senior academic developers located across the SA HE. Through innovative representational strategies including narrative assemblages and a diffractive analysis, the research reveals ASD as a field-in-becoming characterised by rhizomatic features and complex entanglements between human and non-human actors. The study critically examines ASD's paradoxical nature through the concept of pharmakon, highlighting its simultaneous potential as both a benefit to and a constraint in addressing higher education challenges. A key contribution of this research is the development of a southern gaze for ASD, grounded in decolonial praxis and an ethico-onto-epistemology. This perspective challenges the hegemony of Global North theories while advocating for more inclusive and transformative approaches through embracing pluralism for academic staff development. The study culminates in the proposal of the LOTUS RHIZE framework, which conceptualises ASD as a rhizomatous phenomenon capable of flourishing amid complexity through collaboration, dialogue, critique, and decolonial love