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Male peer talk about menstruation: Discursively bolstering hegemonic masculinities among young men in South Africa
No full textIn this paper, we show how male peer talk about menstruating women may be used to discursively bolster hegemonic masculinities and denigrate women. Focus group discussions among 37 young isiXhosa-speaking men from two South African schools were facilitated by two young men; statements garnered from a sexuality education class about menstruation conducted in the same schools were used as cues. Data were analyzed using discourse analysis. The interactive talk constructed a bifurcation: “disgusting” menstruating women versus “reasonable” non-menstruating women who abide by idealized feminine behavior and are available sexually. We argue that as the non-menstruating woman cyclically become the other (menstruating woman) in women of particular ages, the trace of disgust inhabits the signifier “woman” for these men. Menstruation also disrupted a core identity strategy of local hegemonic masculinities: virile (hetero)sexuality. Given this, discursive distancing of the self from the very topic of menstruation is necessary. Small moments of resistance to these constructions were quickly closed down, and caring masculinity emerged only in the context of negotiating sex during menstruation. Involving men in menstrual hygiene management programs may provide spaces for resistance to denigrating discourses about menstruation
Crystal Structure, Hirshfeld Surface Analysis and Computational Studies of Two Benzo [b][1, 4] Diazepine Derivatives
No full textThe DFT computational studies, crystal structures and Hirshfeld surface analysis of (E)-4-(2-chlorostyryl)-2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (1) and (E)-4-(2-(2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-4-yl)vinyl)phenol (2) have been presented. The compounds crystallized in the monoclinic space group P21/c with 4 molecules in their unit cells each. The experimental and computed bond lengths and bond angles deviated from each other to some extent but also showed good agreement with each other in some cases. Hirshfeld surface analysis of the compounds provided further information about the structural properties of the compounds
Inhibiting human dipeptidyl peptidase IV using cannabinoids and Leonotis leonurus extracts as a potential therapy for the management of diabetes
No full textDiabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM
Applying human factors and ergonomics system analysis methods to the V5-NRS Cessna 441 Conquest II aviation accident
Get PDFIntro: Accidents are complex in nature with multiple contributing factors. The way in which accidents are investigated is important and using system-based analysis tools assists in understanding and mapping these contributing factors to learn from them. There has been an increase in the number of accidents that have occurred within the general aviation industry in South Africa and while accident investigations have been undertaken, these have not included the application of system-based analysis tools. This led to a collaboration between Rhodes University and the Accident and Incident Investigations Division (AIID) of the South African Civil Aviation Authority where it was agreed that two systems-based analysis tools will be applied to a previously investigated accident that occurred in 2015. Aims: The first aim of this thesis was to identify if, through the implementation of these systems-based tools, the systemic contributory factors could be determined using the existing report by the AIID. The second aim of this thesis was to identify if, using the two systems-based tools, the actors and levels involved in the accident could be identified and the third aim was to identify if the implementation of these tools generates the same or different recommendations to that of the AIID. Methods: The two systems-based analysis tools applied were AcciMap and Causal Analysis using Systems Theory (CAST). These tools were applied to the V5-NRS Cessna 441 Conquest II accident report which captured the details of how the aircraft flew into the Tygerberg mountain on its descent into the Cape Town International Airport in August 2015. Results: Through the application of these two systems-based analysis tools the major contributing factors elucidated throughout this analysis were: visual and lighting conditions, pilot experience, training, lack of terrain warning equipment, fatigue, inadequate oversight, and inadequate risk management. In line with these findings, the analysis revealed various actors across various levels (the crew; South African Air Traffic Control, the SACAA, WestAir (the operator) and the Namibian Civil Aviation Authority Through the elucidation of these factors at various levels, 14 to 15 different recommendations were generated which was more than the one recommendation that was generated by the AIID. Discussion: Even when applied to an existing report, both the CAST and Accimap tools were able to bring to light the systemic contributing factors to this accident and importantly, highlight the role that various actors and levels within the system had in this unfortunate event. Consistent with previous literature, most of the contributing factors were found at the lowest level (the crew in this case) and fewer, but key factors were identified at higher levels (management and regulator level). Importantly, the application of the systems tools facilitated a systematic and systemic analysis of this accident, which allowed for the generation of recommendations at all levels, not just at the operator level. Conclusion: This study demonstrates the benefits and importance behind implementing a systems-based analysis method to an accident as these tools generate more useful recommendations which allows for important lessons to be learned following accidents, with the intention of re-designing systems to prevent them from happening again.Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 202
The development of a plate-based assay to detect the activation status of ARF1 GTPase in Plasmodium falciparum parasites
Get PDFThe exponential rise in antimalarial drug resistance in the most infectious malaria species, Plasmodium falciparum, has emphasised the urgency to identify and validate novel drug targets that decrease parasite viability upon inhibition. In addition to several publications indicating that the regulation of human Arf1 GTPase activity (mediated by ArfGEFs and ArfGAPs) serves as a pertinent drug target for cancer research, the identification of Arf1 and its regulatory proteins in Plasmodium falciparum led to the question whether these protein homologs could be exploited as drug targets for anti-malarial drug therapies. To investigate this prospect, the establishment of a novel in vitro colorimetric ELISA-based assay was needed to be able to detect changes in the activation status of P. falciparum Arf1 (PfArf1) in parasite cultures exposed to potential Arf1 inhibitors. By exploiting the selective protein interaction that occurs between active GTP-bound Arf1 and its downstream effector, GGA3, an assay protocol was established that could be used to detect the activation status of purified, truncated PfArf1 obtained from E. coli and endogenous PfArf1 sourced from parasite lysates. The assay relies on the use of anti-Arf1 antibodies to detect the binding of active PfArf1 in the lysates of inhibitor-exposed cultured parasites to GST-GGA3 immobilised in glutathione-coated plates. The results from chemical validation experiments conducted using the novel assay developed in this study, using the known ArfGEF inhibitor brefeldin A (BFA) and ArfGAP inhibitors Chem1099 and Chem3050, yielded the anticipated results: decrease in active PfArf1 after parasite incubation with the ArfGEF inhibitor, and increased active PfArf1 after ArfGAP inhibition. The results confirmed PfArf1 as a potential anti-malarial drug target and encourages the further development of this assay format for the identification of subsequent inhibitors in library screening campaigns. Additional pilot experiments were conducted to further explore whether the assay could detect the activation status of human Arf1 using HeLa cell lysates and to provide further evidence that the assay could be exploited as a tool in the identification of Arf1 GTPase inhibitors with BFA and the known ArfGAP inhibitor, QS11. The results suggested that, while the assay can detect the increase in active cellular Arf1 due to the inhibition of human ArfGEF following BFA treatment, subsequent treatment with QS11 showed no evidence of a reduction in active human Arf1 due to ArfGAP inhibition. Further experimentation is required to investigate the ability the assay to confirm inhibition of human Arf1 deactivation by ArfGAP inhibitors and develop the assay as a useful tool to support cancer drug discovery, in addition to antimalarial drug discovery projects aimed at Arf1.Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 202
Controls of lateral and vertical variations in the geochemistry of the Hotazel Fe-Mn Formation at Nchwaning and Gloria mines, Kalahari Manganese Field, South Africa
Get PDFThe Paleoproterozoic Kalahari manganese field (KMF) in the Northern Cape Province, South Africa, hosts a large resource of manganese ores that has been of great interest over many decades. The Kalahari Manganese deposit (KMD), which is the largest of five erosional relics of the Hotazel Formation in the KMF, hosts three beds of Mn ores with alternating layers of banded iron formation (BIF) and hematite lutite. These three rock types are all evaluated for their mineralogy and geochemistry in this study, with emphasis on lateral and vertical distributions across the Gloria and Nchwaning Mines in the northernmost KMF, an area of high-grade, hydrothermally altered Mn mineralisation. The Mn ores of the Hotazel formation are traditionally categorised into two types. The carbonate-rich low Mn grade (Mn≤40 wt. %) ores (Mamatwan-type) domninates the largest part of the KMD, while carbonate-free, high Mn grade (Mn≥ 45 wt.%) ore (Wessels-type) occurs in the northernmost KMD. The Wessels-type ores are considered as the hydrothermally altered product of Mamatwan-type ores, and as indicated above, are the focus of this study. Five drill cores containing Wessels-type ores from the Nchwaning and Gloria area of the northern KMD were analysed to help understand the petrographic and particularly the geochemical variations in the Hotazel Fe-Mn Formation, both laterally for a given Mn layer of the three, and vertically across Mn layers as captured in specific drillcores. Petrographic and whole-rock geochemical results obtained from the three rock types of the Hotazel Formation show variations in their mineralogical and geochemical compositions, especially in the high-grade Mn ores themselves. Most of the samples of the BIFs layers are dominated by hematite and chert occurring in banded fashion, which is typical of a normal carbonate-free altered BIF discussed in this thesis. The BIFs can also be locally enriched in hematite (ferruginised), occurring as massive hematite ores usually at the top of the stratigraphic profiles. The presence of aegirine-rich assemblages is also noted occurring in some of the BIF and hematite lutite sections immediately above and below the Mn ore beds. The high-grade Mn ore beds vary greatly in mineralogy and texture of the ores laterally and even within a single drill core. In an extreme case, a single drillcore sampled from the Gloria mine (GL57) contains high-grade Wessels-type ore in the upper Mn bed and low-grade, Mamatwan-type ore in the lower Mn layer. Geochemically, the Mn ore bodies also show substantial geochemical variability, although a net increase in the Mn grade downward is usually characterised by a corresponding depletion in mainly bulk Ca, Si and carbonate. However, the Fe content appears to be consistently higher in the upper ore bodies of the drillcores than the lower ones, and the increase in the concentration of the Fe-oxide expectedly causes a relative decrease in the bulk Mn-oxide concentration, usually expressed as an antithetic relationship between the two elements. In terms of trace element distributions, this appears to be more significant in the Mn ores than the other two rock types affected by the same alteration process, probably due to the presence of Mn phases such as hausmannite and braunite serving as good hosts to several trace elements. Cu, Zn, Pb and to a lesser extent Mo are trace metals that appear to show elevated concentration levels (net enrichments) in high-grade Mn ore by comparison to the presumed Mamatwan-type protolith. Ba is an additional element of clear enrichment, manifested mainly as the mineral barite. The Northern KMD has a complex post-depositional history, which includes the intrusion of NE-SW-trending dykes, formation of the Mapedi/Gamagara erosional unconformity, normal faulting associated with the Wessels event and major thrust faults in the western part of the northern KMD. These structural events all have the potential to have contributed to the alteration and subsequent enrichment of the Mn ores in the Nchwaning and Gloria area. As such, the mineralogical, textural, and geochemical variations observed here can tentatively be attributed to the different structural features in the northern KMD. Classic interpretations suggest that normal N-S-trending fault structures have acted as fluid conduits for hydrothermal fluids, which led to the metasomatic alteration of the Mn ore body laterally. Drill cores proximal to and evidently affected by fault-controlled alteration in the SE and SW-portions of the Nchwaning area, have comparable mineralogical and geochemical characteristics for both ore bodies (upper and lower) with subdued alteration effects from the unconformed contact above. Fluids associated with the Mapedi/Gamagara unconformity, would have percolated down-stratigraphy causing oxidative ferruginisation, which led to the formation of massive hematite ores in the top BIF layers and ferruginised Mn ores in the Mn ore beds. This alteration effect appears more prominent in a drill core from the northern part of the study area where the unconformity contact appears more proximal to the upper Mn bed. Drill cores located in the western part of the Nchwaning area seem to also capture evidence of fluid alteration with enrichment in Na recorded in the local abundance of the mineral aegirine. Finally, the dyke structures appear to have acted as impermeable fluid barriers to both lateral and possibly down-dip fluid-flow.Thesis (MSc) -- Faculty of Science, Geology, 202
A framework for understanding the role of culture and the transmission of women entrepreneurship promotion in South Africa
No full textDeveloping countries are increasingly recognising the need for promoting women entrepreneurship. Within Africa, women’s contribution tends to be ignored. Thus, gender discrimination, the lack of finance, limited education, limited technical skills, role conflicts, and culture are among the most cited barriers for women entrepreneurship. Recent literature challenges the notion that all aforementioned factors are barriers to entrepreneurial action. To contribute to knowledge, this study sensitises the culture element. Accordingly, there is a growing body of knowledge that is viewing culture as an enabler (and not a barrier) of women entrepreneurship. Two factors are at the core of this argument: (1) culture, as it is understood, in the contemporary literature is not appropriately conceptualised from an African perspective. (2) The definition of entrepreneurship as it relates to the developing countries is restrictive. These definitions ignore various economic activities undertaken mostly by women, which if carefully considered are indeed entrepreneurship. Therefore, it was appropriate for this thesis to explore the issues of both culture and entrepreneurship within the existing body of literature with the intention of gaining a knowledge of the dynamics of women's entrepreneurship in Africa. The scant research that has been done on the entrepreneurial dynamics of women and, in particular, how culture influences the latter, was recognized as a lacuna in the existing body of literature. Consequently, this study considered cultural determinants of entrepreneurship as well as the transmission of entrepreneurship across generations. The thesis was undertaken using a qualitative methodology. Using snowballing sampling technique, female entrepreneurs from 3 provinces (i.e., Gauteng, Limpopo, and Eastern Cape) in South Africa participated in the study. Data were gathered through in-depth interviews. The transcribed interviews were analyzed using thematic analysis. Findings revealed, among others, that there is a misconception on what constitutes “true African culture.” Thus, results suggest that the conceptualisation of culture in the African context, contrasts the conceptualisation in previous (non-African) literature. Furthermore, some elements of culture are indeed barriers. Interestingly, personal factors such as characteristics of women entrepreneurs and entrepreneurial intentions have also contributed to the barriers to women entrepreneurship. Finally, the study proposes a framework for leveraging culture to be an entrepreneurial enabler for women entrepreneurship.Thesis (PhD) -- Faculty of Management and Commerce, 202
Anaerobic process formulation for methane production during dry fermentation of Acacia Mearnsii (black wattle) feedstock
Get PDFVarious batch anaerobic digestion configurations and procedures, for the production of biogas using different feed-stock, have been undertaken in multiple studies. The research presented is set apart in its approach as it focuses on the use of black wattle leaves and cow dung mixture as feedstock to a micro plant facility creating biogas with a methane content of at least 50% during a short retention period of 30 to 35 days. Varying process parameters were applied to investigate the effect on methane production; the temperature control in a mesophilic range with a target temperature of 37°C, draining and drenching of inoculant as a means of heating reactors, and the effect of mixing mass ratio (black wattle leaves: cow manure) related to carbon and nitrogen were studied. A closed-loop batch anaerobic digester, based on the bio-methane potential principle, was used to conduct three individual experiments, each with two reactors. The carbon and nitrogen content of wet black wattle leaves, cow manure, and dam water were examined in triplicate. The average carbon content of wet black wattle leaves, cow manure, and dam water used during experimentation was found to be 6.75%, 27.84%, v and 1%, respectively with corresponding nitrogen content values of 0.57%, 1.44%, and 1%. The C: N ratio was 19.3:1 for wet black wattle, 11.84:1 for the cow manure, and 1:1 for the dam water with the total extracted solids in wet black wattle and cow manure were 46.32 % and 12.65 %. From the samples tested, the mixture of wet black wattle leaves and cow manure with a C: N ratio of 25:1 for the first reactor and 20:1 for the second reactor was used. Both mixtures had a pH of 6.3. Draining and drenching of reactors twice daily, by inoculation, kept the temperature in a mesophilic range, with 37°C as the optimal temperature to assess the production of methane from a mixture of black wattle leaves and cow manure, with temperature, pH, and C: N ratio kept constant. The results showed that the reactor with a C: N ratio of 25:1 and at an average temperature of 36.74°C produced 9170 ml of biogas within 35 days, of which 1094 ml was methane. The maximum methane production was during week 4 when 335 ml, or 25.81% of total biogas, was collected. Sufficient evidence exist that biogas production from a mixture of wet black wattle leaves and cow manure is feasible, but require further investigation to increase the yield.Thesis (MEng) -- Faculty of Engineering, the Built Environment, and information Technology, School of Engineering: Mechanical, 202
Late delivery of infrastructure projects by the Eastern Cape Department of Public works
Get PDFThe main objective of the study was to evaluate building infrastructure delivery within the Department of Public Works and Infrastructure, Eastern Cape Province. The Department of Public Works and Infrastructure is a governmental section in charge for the development of infrastructure and delivery of government projects. The study adopted a quantitative research approach; the sampling technique that was used for the current study is the convenience sampling technique. This technique is also referred to as availability or accidental sampling. The population for the study consisted of respondents from the construction-consulting firms and contractors such as the Aurecon Group, Haw and Inglis Civil Engineering, the Metro Bay Municipality, and the National Home Builders Registration Council. The number of questionnaire that was distributed is about thirty-three (33) and about 36.4% response rate received. The findings of the study revealed the impact of the late payment on the progress of building infrastructure projects. The study indicated that, delayed payment to the contractor can affect the can affect the productivity adversely. It is also established that delayed payment includes unrealistic cash flows, error in clams, financial challenges and disagreements relating to the valuation of work. This implies that, payments that are processed on time to the contractors can be of critical importance on the success of the project, whilst on the other hand non-payment or delayed payment have a negative impact on the implementation of construction projects. In the context of building infrastructure projects delay is a regular and common problem, which has a negative impact on the overall project success particularly in the Eastern Cape Province.Thesis (MSc) -- Faculty of Engineering, the Built Environment and Technology, School of Built Environment, 202
A strategy for the review and maintenance of the State Information Technology Agency (SITA) information security policies
Get PDFAbstract.Thesis (MSc) -- Faculty of Engineering, the Built Environment, and Technology, School of , School of Information Technology and Governance, 202