The enigmatic subterranean amphipod genus (sternophysinx: sternophysingidae): conservation and systematics
- Authors: Mlungu, Zizile
- Date: 2023-10-13
- Subjects: Amphipoda South Africa , Sternophysingidae , Koi , Groundwater , Groundwater animals South Africa , Cave animals South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424424 , vital:72152
- Description: Sternophysingidae Holsinger, 1992 is a monotypic subterranean amphipod family endemic to Namibia and South Africa. It currently has eight described species under the genus Sternophysinx. The species in this family are considered narrow endemics, having only been identified using morphological characters. However, the apparent wide distribution of certain species, reported in several subterranean waters in different provinces, suggests that our current taxonomic understanding of these species needs to be completed, thus needing revision. Further, detailed knowledge of the distribution and phylogenetic relationship between species of this taxon still needs to be improved. This study aimed to use integrative taxonomy to analyse both morphology and molecular biology to study hidden diversity and to further our understanding of the distribution in this taxon. The available morphological keys were used to identify species, and 12S rRNA was also used to investigate the relationships of Sternophysinx species and delimit species boundaries. The study primarily aimed to use mitochondrial cytochrome c oxidase subunit I (COI). However, due to technical issues such as getting the correct primers, this study's aims were altered, and 12S was used instead of CO1. However, the process of getting CO1 sequences is still ongoing, and the results will be made available elsewhere. The current study aimed to visit all the type localities of the seven species of Sternophysinx reported in South Africa, including all known localities in which these amphipods have been recorded in the past. Nevertheless, this study did not get samples from Nelspruit, De Hoop Nature Reserve, and Nash Nature Reserve, which cover type localities of S. travaleensis, Matlapitse and Chaos cave that harbours S. calceola. Instead, the current study added five new localities Graaff-Reinet, Beaufort West, Hogsback, Makhambathi Nature Reserve and Ntsikeni Nature Reserve, for the distribution, including two new provinces (i.e., Eastern Cape and KwaZulu-Natal) that had records of this genus in the country. Three delimitation methods, Assemble Species by Automatic Partitioning (ASAP), Bayesian implementation of the Poison Tree Processor (bPTP) and Automatic Barcode Gap Discovery (ABGD), were used to identify cryptic species within Sternophysinx. Phylogenetic analyses and three delimitation methods (ASAP, bPTP and ABGD) revealed considerable hidden cryptic diversity within this Sternophysinx. Preliminary morphological examination revealed at least two species as undescribed from Bakwena and Sterkfontein caves, and several that were morphologically identified using the current taxonomic keys did not match with the molecular analysis. For example, S. basilobata from three different systems, Boesmansgat cave (Northern Cape), Beaufort West (Western Cape) and Potchefstroom (North West), was in genetically different putative species. The same is true for S. robertsi and S. alca in Ficus and Peppercorn cave in Limpopo. Overall, the results of the current study demonstrate the need for a comprehensive integrative taxonomic revision of Sternophysinx. These findings suggest that S. basilobata is a complex of distinct lineages and requires further study. On the other hand, species delimitation methods suggested that there are 12- 14 candidate species (Figure 2.5). Lastly, this study investigated the threat posed by the invasive koi fish introduced to an important cave, Boesmansgat cave in the Northern Cape, which is a type locality of two endemic species (S. megacheles and S. basilobata). Stable isotope (δ13C and δ15N) and gut content analyses of the fish were investigated to establish whether this invasive fish feed on these critical creatures, thus endangering their long-term survival. Stable isotope signatures and the stomach gut content proved to be helpful in determining the diet of the koi fish, revealing it to be an omnivorous feeder with high invertebrate preference, including amphipods. These results indicate that the introduction of koi fish in the Boesmansgat cave threatens the long-term sustainability of these amphipods and other invertebrate assemblages in this cave. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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- Date Issued: 2023-10-13
Characterising the sleep wake behaviour of late adolescents living in rural and township areas surrounding Alice in the Eastern Cape of South Africa
- Authors: Dlepu, Phelokazi
- Date: 2022-10-14
- Subjects: Teenagers Sleep South Africa Alice , Rural teenagers South Africa Alice , Sleep-wake cycle
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362808 , vital:65364
- Description: Introduction: School going adolescents have been identified as a group that is at risk of obtaining insufficient sleep due to shortened and irregular sleep, all of which can affect the overall wellbeing of adolescents. While there has been extenstive research on adolescent sleep around the world, research in South Africa has been limited. Of the research performed in this context, most has been conducted in city or urban contexts, but there has been comparatively less research on sleep in adolescents from rural and township areas. Therefore, this study focused on characterising and comparing the sleep-wake behaviour of late adolescents from selected rural and township areas in Alice in the Eastern Cape of South Africa. Methods: An adapted version School Sleep Habits Survey (SSHS) was included in the study and assessed demographic, academic, sleep-wake behaviour, lifestyle, and behavioural information of adolescents from rural and township schools in and around Alice. The survey was distributed physically to all the learners from four co-educational rural and township schools. The responses to the survey were analysed with descriptive and non-parametric inferential statistics, as all data were not normally distributed. Results: A total of 123 learners completed the survey. All the participants were in Grade 12, aged 16 to 26 years (median =18, IQR= 18-19) from rural (n=28) and township (n=95) schools. Seventy-four female and 49 male learners participated in the study. Within the sample, there were also a group of participants who were not adolescents (n=22) whose age ranged between 20 and 26. Reported sleep during both the week and weekend (7hours) was lower than both the recommended duration for adolescents and their own self-reported sleep need of a median of 8 hours and 14 minutes. Bedtimes were significantly earlier on weekdays than weekends. The need to do homework and feeling sleepy were cited as the main reasons for going to sleep during the week and the weekends. Wake times on weekdays and weekends did not differ, with most learners citing being woken up by an alarm clock as the main reason for waking during both weekdays and weekends. Most learners (n=47; 38%) reported walking to get to school, while 41 (33%) relied on public transport to get to school. There were no significant effects of gender or of being rural and township scholars in relation to their sleep variables. Comparisons between non-adolescents and adolescents revealed that non-adolescents reported sleeping longer (7 hours and 30 minutes) compared to adolescents (7 hours) than adolescents did on weekends. As a group, the learners in this sample were morningness-orientated in terms of chronotype, presented with low day time sleepiness, some evidence of sleep-wake behaviour problems and of depressive mood symptoms. Nearly half (n=53; 43%) the group reported napping occasionally on school days. In terms of caffeine consumption, just over half (n=64; 52%) of the learners reported never consuming caffeinated substances such as soda, coffee, or tea. Conclusions: The reported sleep duration of learners in this study was consistent on both the week and weekend but was shorter than the recommended 8-10 hours for late adolescents. While learners in this sample reported early bedtimes, sleep was likely curtailed by the early rise times due to the contextual constraints where scholars had to commute, by either walking or taking public transport, to make the early school start times. There was a high prevalence of sleep disturbances in this sample however, the effects of this (increased daytime sleepiness) were lower which can be attributed to low reported prevalence of caffeine consumption combined with the high prevalence of reported day time napping on school days and weekends. While only a snapshot, the results of this study support previous research that has highlighted the challenges that many adolescents across the globe experience when it comes to obtaining enough sleep. The results of this study highlighted the need for more research to understand the sleep-wake behaviours of learners and their lifestyles more objectively. Given the early starts for many participants in this study, interventions such as delaying school start times may help to improve the amount of sleep that learners get during the week. However, extensive consultations would be needed to ensure that systemic changes that aim to improve sleep of adolescents are applicable for the context of rural and townships areas in South Africa. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-10-14
Drifting towards death: a South African patient safety incident through an HFE Systems lens
- Authors: Agar, Sarah Leigh
- Date: 2022-10-14
- Subjects: Patients Safety measures , Medical errors Prevention , Human engineering , Medical care South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362716 , vital:65356
- Description: Patient Safety Incidents (PSI) are a frequent occurrence within the South African public healthcare system wherein a patient is unnecessarily maimed, harmed, killed, or put through significant trauma, emotional or physical. These incidents have a significant impact on the performance of the system and the well-being of individuals involved. Often PSI are the result of multiple system failings that provide the necessary preconditions for the PSI to occur. Thus, to provide appropriate patient safety recommendations to address and aid in the prevention of future PSI it is necessary to apply a systems approach to PSI analysis. A systems approach supports a ‘bigger picture’ view of an incident which includes looking beyond the immediate causes of a PSI and taking the different levels of the healthcare system into consideration during incident analysis. Human Factors and Ergonomics (HFE) is at its core a systems discipline and has been successfully applied to multiple fields including healthcare. HFE offers multiple incident analysis tools grounded in systems theory. The Life Esidimeni incident, a PSI that resulted in the death of 144 MHCU, is the biggest PSI in recent South African history and is therefore an important potential case study for the application of HFE systems tools within the South African healthcare context (an area that is lacking in existing literature). The objectives of this research were to (i) Systematically uncover the causal factors that led to the outcome of the of the Life Esidimeni incident; (ii) Identify critical faults, and gaps within the healthcare system that led to the Life Esidimeni PSI; and (iii) Provide proactive recommendations for future prevention of PSI. To fulfil these objectives a descriptive case study research method design was adopted using a qualitative systems-based tool, AcciMap. The application of AcciMap to Life Esidimeni enabled both the sharp end and blunt end causal factors that contributed to the outcome of the incident to be identified. Importantly this provided insight into the critical faults and gaps of the South African public healthcare system. The results of the AcciMap indicated that there were four main broad systemic faults in the system. These broad areas were categorized as key themes, which include: (i) competency, (ii) safeguards, (iii) time pressures, and (iv) vertical integration. From these key themes recommendations aimed at addressing the critical faults and gaps in the system and preventing future PSI were made. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-10-14
Effect of Helicosporidium sp. (Chlorophyta; Trebouxiophyceae) infection on Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), a biological control agent for the invasive Salvinia molesta D.S. Mitchell (Salviniaceae) in South
- Authors: Mphephu, Tshililo Emmanuel
- Date: 2022-10-14
- Subjects: Salvinia molesta South Africa , Weeds Biological control , Cyrtobagous salviniae , Ketoconazole
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365815 , vital:65792 , DOI https://doi.org/10.21504/10962/365815
- Description: The effectiveness of established biological control agents depends on biotic and abiotic interactions in the introduced range. The weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), was released as a biological control against Salvinia molesta D.S. Mitchell (Salviniaceae) in South Africa in 1985. This agent has been highly successful against S. molesta and has significantly reduced the weed’s populations around the country. However, in 2007, the parasitic alga, Helicosporidium sp. (an undescribed species), was detected in field-collected C. salviniae adults in South Africa. The distribution and impacts of this disease on the weevil and its efficacy as a control agent were not known. In this thesis, the prevalence, infection load, and impact of Helicosporidium sp. on C. salviniae was determined. In 2019, adult weevils were collected from 10 sites across the Eastern Cape, KwaZulu-Natal, Limpopo, and Western Cape provinces and screened to determine the occurrence, infection load, and geographic distribution of Helicosporidium sp. Transmission mechanisms of this disease in C. salviniae were then evaluated. The possible impact of Helicosporidium sp. was assessed by comparing the feeding rates and the reproductive output of the diseased and healthy adults of C. salviniae. An attempt was then made to eliminate the disease in C. salviniae through the application of the antibiotic, ketoconazole. Further, the role of temperature on infection load in C. salviniae was also assessed. Finally, recommendations for the long-term biological control programme against S. molesta in South Africa were made. The disease covers the entire distribution range of C. salviniae in South Africa, with the disease occurrence rate ranging from 92.15% to 100% insects infected per site. Helicosporidium sp. was found to transmit vertically within the populations of C. salviniae. Infection by the Helicosporidium sp. disease reduced the reproductive output of C. salviniae as well its impact on biomass reduction of S. molesta when a diseased culture was compared to a healthy culture from the USA. 98.44 to 98.55% of Helicosporidium sp. loads were reduced through multiple applications of ketoconazole concentrations under in vitro trials. In vivo treatments resulted in 70% control of Helicosporidium sp. in the adults of C. salviniae that were fed ketoconazole three times over a 21 day period. Adult C. salviniae feeding and survival performances were similar when fed fronds of S. molesta inoculated with ketoconazole and water. The lowest and highest disease loads of Helicosporidium sp. were recorded when the weevils were reared at 30°C and 14°C, respectively. As expected, the highest impact and reproductive output of C. salviniae were at 30°C. The evaluations discussed in this thesis highlight the role of diseases in biological control agents, and gaps in both the pre-release and post-release monitoring that should integrate screening of diseases in these studies. Although the combined application of the antibiotic and temperature will reduce Helicosporidium sp. loads and impact, this technology is most likely only applicable where the weevils are reared in small numbers in a rearing facility and not really applicable to the field situation. It is important to release healthy agents that will cause efficient control of the target weed plant species, therefore, when introducing new biological control agents, the health status of such agents needs to be understood. Therefore, long-term field monitoring and assessment of the impact of C. salviniae on S. molesta should be conducted to track all the changes that may result due to the presence of Helicosporidium sp. This long-term monitoring and assessment will give a more informative role of Helicosporidium sp. in field populations of C. salviniae. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
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- Date Issued: 2022-10-14
Negotiating marginalisation: A socio-economic history of the Kalanga of Mangwe, Zimbabwe, 1940-2015
- Authors: Nyathi, Innocent
- Date: 2022-10-14
- Subjects: Marginalisation , Kalanga (African people) Race identity Zimbabwe , Ethnicity Zimbabwe , Zimbabwe Economic conditions , Zimbabwe Social conditions , Kalanga language (Botswana and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/408705 , vital:70518 , DOI 10.21504/10962/408705
- Description: The thesis explores the relationship between ethnicity, marginalisation, and survival mechanisms amongst the Kalanga people of Mangwe (southwestern Zimbabwe) from the 1940s up until the turn of the 21st century. The study showed how the Kalanga of Mangwe have used ethnicity as a concept to not only claim access to resources but also develop alternative survival strategies that help them seek to navigate their experiences of marginalisation by both the state and the hegemonic position of the Ndebele who dominate the region politically and linguistically. Using evidence from activities such as cross border migration and the mopane economy, I showed how the Kalanga express their displeasure at being dominated through engagement, as was shown in their attempt to fight for their language, for example in the 1940s through regionalised Kalanga organisations as the Kalanga Language and Cultural Development Society (KLCDS), to disengagement such as migration and illegal informal cross border trade. Using ‘conviviality’ and ‘the everyday’, as well as borrowing from the Race Relations Theory (RRT) of Robert Ezra Park as theoretical underpinnings, I demonstrated how amongst the Kalanga of Mangwe ethnic identity can lead to competition for resources, which in turn leads to marginalisation and discrimination which influences their social, political and economic choices that may in turn reinforce ethnic identity in a cycle like scenario. Everyday economic and social activities amongst the Kalanga of Mangwe that appear mundane and ordinary to an uninterested observer, help shape the everyday discourse of the Kalanga as they navigate marginalisation. , Thesis (PhD) -- Faculty of Humanities, History, 2022
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- Date Issued: 2022-10-14
The soul of Mozambique: an autoethnographic and performance-based study on the correlation of glabalisation, Chopi people migrations and the reinterpretation of timbila music in Mozambique
- Authors: Bande Júnior, Venâncio
- Date: 2022-10-14
- Subjects: Timbila , Chopi (African people) Mozambique , Music festivals Mozambique , Traditional knowledge , Music and globalization , Modernity , Traditional folk music
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406818 , vital:70310
- Description: This is an autoethnographic and performance-based study on the correlation between indigenous and modern cultures. It discusses the influence of globalisation, modernity, and of the Chopi people migrations to Maputo, the main city of Mozambique and to gold and platinum mines in South Africa, on timbila music. Timbila is both the name of a musical instrument (xylophone) and of a cultural manifestation, practiced by the Chopi people from Mozambique. It is one of the most documented music and dance cultures in Mozambique and was proclaimed as a masterpiece of the oral and immaterial heritage of humanity by UNESCO in 2005. The oldest references by Father Andre Fernandes date from the 16th century. However, the most well-known timbila sources were written and recorded by Hugh Tracey, the founder of the International Library of African Music (ILAM), from 1940s. All these sources were based on traditional timbila music. None refers to contemporary timbila music, which is a mixture of timbila with Western musical instruments. The research is thus based on both historical and is new research to understand the role of the phenomena mentioned above to the reinterpretation of timbila music over the time. Performance based and autoethnography methods were selected because of my role as a pedagogue of the music and culture of timbila, allowing me to express my knowledge on this cultural expression. Literature review and interviews are the two procedures of data collecting employed to get an understanding of the research methods; the phenomena of modernity, globalisation and of the Chopis migration for the searching of better living conditions in Maputo and South Africa; and the approaches of different scholars who have written about timbila. The use of these methods and methodologies, allowed me to conclude that, Chopis migrations, modernity and globalisation has allowed the emergence of a modern version of timbila music; internationalisation and dissemination of this musical expression; and contributes to the extinction of traditional timbila orchestras in Zavala. Despite considerable studies on timbila music and culture, this thesis is important and pioneering, from the perspective of studying the influence of Chopis migrations, globalisation and modernity on timbila and is one of the few sources that approach the contemporary timbila music. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2022
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- Date Issued: 2022-10-14
Developing taxonomic and trait-based approaches for assessing and predicting macroinvertebrate responses to elevated fine sediments in the Tsitsa River and its tributaries, South Africa
- Authors: Ntloko, Pindiwe
- Date: 2022-04-08
- Subjects: Water quality South Africa Mzimvubu River Watershed , Sedimentation and deposition South Africa Mzimvubu River Watershed , Aquatic invertebrates Effect of sediments on South Africa Mzimvubu River Watershed , Aquatic invertebrates Classification , Environmental monitoring South Africa Mzimvubu River Watershed , Analysis of variance , Multivariate analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294692 , vital:57245 , DOI 10.21504/10962/294692
- Description: Sedimentation of freshwater systems is one of the leading causes of water quality deterioration. The Mzimvubu River catchment, which includes the Tsitsa River and its tributaries, in the Eastern Cape is prone to elevated sediment impact due to dispersive soils that are easily erodible. In this study, taxonomy and trait-based approaches were used to assess the responses of macroinvertebrates to fine sediments in the Tsitsa River and its tributaries. Macroinvertebrates and environmental variables were sampled seasonally in winter, spring, summer and autumn of 2016 to 2018 in six selected sites, using the South African Scoring System version 5 as a collecting protocol. The sites were selected to represent a decreasing gradient of sediment influence from the highly impacted Sites 1 (Tsitsa upstream) 2 (Tsitsa downstream), and 3 (Qurana River) to moderately impacted Sites 4 (Millstream upstream) and 5 (Millstream downstream) and the least impacted Sites 6 (Pot River upstream), 7 (Little Pot River) and 8 (Pot River downstream), which were collectively referred to as the control sites. Analysis of basic physico-chemical variables, dissolved oxygen, pH, electrical conductivity, turbidity, total suspended solids, temperature and nutrients were undertaken seasonally over the study period. Sediments grain sizes were also analysed. All collected data were subjected to appropriate statistical tests – univariate and multivariate techniques. A fine-sediment-specific multimetric index was developed to monitor the impact of fine sediments on macroinvertebrate assemblages of the Tsitsa River and its tributaries. A total of 12 traits, resolved into 48 trait attributes, were selected to explore their distribution in relation to a fine-sediment stress gradient, and identify the trait-based signature of fine-sediment impact. A trait-based approach was then developed to classify South African macroinvertebrates into two groups: taxa that are potentially vulnerable to fine-sediment impact and those potentially resilient, based on the combination of traits possessed. Two-way analysis of variance (ANOVA) indicated that electrical conductivity, turbidity, embeddedness and total suspended solids were statistically significantly different between the sites. Apart from Dissolved oxygen, the remaining variables were statistically significantly lower at the control sites (P < 0.05). The two-way multivariate analysis of variance (MANOVA) indicated global significant differences between sites and seasons. The two-way MANOVA also revealed that the interaction between the sites and seasons were statistically significant. The MANOVA indicated global combined interactive effects across the sites for suspended fine-sediment grain sizes, two-way ANOVA, followed by a Tukey’s post-hoc test, was carried out to indicate where the significant differences lay. The one-way ANOVA results indicated that very fine sand, very coarse silt, medium silt, and fine silt were significantly higher at Tsitsa upstream, Tsitsa downstream, Qurana tributary that is at Millstream upstream, Millstream downstream and Control sites. The rest of the grain sizes did not differ statistically between the sites. In terms of the settled sediment grain sizes, the volumetric analysis did not show considerable differences across the sites. Settled fine-sediment grain sizes were evenly distributed across the sites. Statistically, MANOVA results indicated no significant differences across sites or across seasons. The developed Sediment Multimetric Index indicated that the sites in the Tsitsa River and those in the Qurana River were highly sedimented during the wet season, but became moderately sedimented during the dry season, indicating that the index responded to seasonality. The sediment multimetric index indicated that the control sites were less sedimented during both the wet season and dry seasons, suggesting minimal seasonal effects at the control sites. Traits such as an exposed and soft body, collector-filterers, shredding, feeding on coarse particulate organic matter and a high sensitivity to dissolved oxygen were identified as fine- sediment-sensitive indicator traits. Identified fine-sediment-tolerant traits and ecological preferences included complete sclerotisation, a cased/tubed body, a preference for fine particulate organic matter, a high tolerance to dissolved oxygen depletion, and climbing and skating behaviours. Regarding the trait-based approach followed for classifying macroinvertebrates into vulnerable taxa and resilient taxa, the results revealed that the relative abundance and richness of the vulnerable taxa decreased predictably along the increasing gradient of sediment impact. However, the relative abundance and richness of resilient taxa showed no marked response to the impact of an increasing gradient of fine sediments. Overall, the present study makes a contribution to the complementary application of trait-and taxonomy-based approaches to freshwater biomonitoring. The trait-based approach enables predictions to be made and tested based on the mechanistic understanding of the mediating roles of traits in organism- environment interaction. A fundamental challenge, which showcases the limitation of the current study, is the sparse trait data on Afrotropical macroinvertebrates at the species or generic levels. In this regard, the iv trait-based approaches developed here were the family level instead of species or genus. This is the first study in South Africa to develop explicit trait-based indicators of elevated fine sediments as well as an approach for predicting macroinvertebrate vulnerability and resilience to fine-sediment effects, thus advancing the science and practice of freshwater biomonitoring. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2022
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- Date Issued: 2022-04-08
Individual decision-making and cooperation in freshwater fisheries management at the Somme River, northern France
- Authors: Khumalo, Brian
- Date: 2022-04-07
- Subjects: Fishery management France Somme River , Fisheries France Somme River , Human ecology France Somme River , Traditional ecological knowledge France Somme River , Decision making , Experimental economics , Recreation France Somme River
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/294561 , vital:57233
- Description: Are altruistic individuals more likely to cooperate when exploiting common resources? This research study asks whether or not rates of human altruistic behaviour expressed by individual recreational fishers in interpersonal contexts at the Somme River, Amiens mirror those rates of altruism expressed in collective contexts concerning local fisheries resources. In a natural resources context, altruism manifests as a willingness by fishers to incur personal cost for common-pool resource benefit. Accordingly, it is understood that altruistic behaviour reflected collectively expresses itself as cooperation. The research study takes place in Northern France with the stated objectives to: 1) observe individual fishers’ altruistic propensities in interpersonal contexts involving other fishers, 2) observe individual rates of altruistic behaviour in collective contexts involving common fisheries resources and compare with those expressed interpersonally, and 3) investigate whether or not a local (informal) management system existed in the town of Amiens to better understand if informal tenure of water space influences altruistic behaviour or not. The research design consists of two components, one quantitative and one qualitative. The former employs two economic games; a Dictators Games (DG) and a Public Good Game (PGG) in service of the first and second research objectives, and the latter employs cognitive mapping and free-listing exercises in service of the third. Here economic games stand as proxies for real-world situations involving individual (DG) and collective (PGG) decision-making whereas the exercises seek to uncover local ecological knowledge (LEK). The results found that while individual recreational fishers demonstrated lower rates of interpersonal altruism overall, in a collective setting involving local fisheries resources the rate was higher, implying a greater willingness to incur personal cost. Ecological knowledge was high among experienced fishers, yet no knowledge pertaining to parallel management and or informal rules of exclusion or resource subtraction were observed, suggesting an informal management system did not exist. The study additionally documents freshwater biodiversity, providing an index of fish species present in the river collected from the free-listing exercises, categorized into native and non-native as the latter can negatively affect trophic systems and ecosystem processes. , Thesis (MSocSci) -- Faculty of Humanities, Anthropology, 2022
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- Date Issued: 2022-04-07
A laboratory simulation investigating the impact of sunglass tint on the catching performance of cricket fielders
- Authors: Nellemann, Stacy Amanda
- Date: 2022-04-06
- Subjects: Sunglasses , Cricket Physiological aspects , Cricket players , Glare , Vision , Contrast sensitivity (Vision) , Fielders (Cricket)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291281 , vital:56839
- Description: Background: Sunglasses are popularly worn by outdoor athletes such as cricketers. They are primarily worn to preserve ocular health due to the length of time exposed to the sun’s glare on the field. More recently, sunglasses are now worn for their purported performance-enhancing benefits supposedly allowing athletes to “see clearly, react faster and perform with confidence”. Fielders typically wear sunglasses, but it is rare to see the bowler or the batter wearing sunglasses although they are exposed to the same conditions. If sunglasses provide visual clarity for better reaction time, it is assumed this would also be beneficial for both batsmen and bowlers alike. It is interesting that although fielding plays a key role in the winning of a match, it has received very little research in comparison to the areas of batting and bowling. Research concerning sunglasses in the past has been concerned with its effect on ocular parameters such as colour vision and contrast sensitivity, with minimal research on their effect on performance, specifically on how different colour tints may affect performance such as catching in fielding. Objective: The purpose of this study was to compare the catching performance of fielders when wearing three different colour tints of sunglasses. Methods: Thirty male cricketers currently playing for Rhodes University or country districts sides in Makhanda, South Africa, who were non-habitual sunglass wearers were recruited for this study. An optician administered a pre-screening test to ensure participants did not have any visual defects that would affect the results, determining who was eligible to continue with the research project. Twenty-five participants qualified with a further four withdrawing during the experimentation phase due to personal reasons. Eligible participants were required to complete four testing sessions on separate days thereafter in which they wore a different colour tint at each session (clear, blue, G30 and red). These tints were randomised among participants. Participants were required to catch 18 balls projected from a bowling machine in each session. The number of balls caught as well as the quality of catch was recorded. At the end of the fourth session, participants were presented with a questionnaire investigating their subjective experience of the protocol and preference for any particular colour of lens. Results: Statistically significant results were found between the different colour lenses for the ocular parameters of contrast sensitivity and stereopsis tested by the optician. The red lens was found to be the best for contrast sensitivity with the blue lens performing the worst on this test. With regard to stereopsis, the G30 lens was the worst, with the red lens performing the best. The performance measures resulted in no significant difference between the different colour lenses both concerning the total number of catches taken as well as the quality of catch taken. The same result was found irrespective of the colour of lens used in each session. Data gathered from the questionnaire regarding visual comfort and target visibility resulted in the red lens being rated statistically worse than the other three conditions. In terms of personal preference, the G30 lens was rated statistically as the best coloured lens. Conclusion: It can be concluded that objectively there is no difference in performance between the three coloured lenses. Although from an ocular perspective, the red lens was expected to perform the best in terms of catching performance, there was no difference. Subjectively there was a strong preference among the players for the G30 lens with players strongly disliking the red lens. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-04-06
Academic or ‘zoombie’? Characterizing sleep quality, work and lifestyle behaviours among a cohort of South African academic staff during the Covid-19 pandemic
- Authors: Le Grange, Sarah-Ann
- Date: 2022-04-06
- Subjects: Sleep-wake cycle South Africa Eastern Cape , Sleep Physiological aspects , Lifestyles Health aspects South Africa Eastern Cape , COVID-19 Pandemic, 2020- Influence , Work environment Psychological aspects , Work environment Physiological aspects , College teachers Workload South Africa Eastern Cape , Pittsburgh Sleep Quality Index (PSQI)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291099 , vital:56818
- Description: Working in academe is characterized by high work demands, long and late working hours and balancing multiple roles. This often leaves academic staff (interchangeably referred to as ‘academics’ and ‘staff’) with limited time to prioritize adequate rest and sleep. While sufficient sleep is important for general well-being and work performance, it may be important for academics given the cognitive and interactive nature of their work. However, limited research has characterized sleep behaviours and sleep quality in academic staff globally and specifically in South Africa (SA). Further, research shows that academics from different academic ranks and genders differ in their work experiences but less is known about whether these factors affect their sleep and lifestyle factors. Over and above the demands of academic work, the current study was conducted during COVID-19, which saw unprecedented change in workloads for academic staff due to online teaching and learning. Additionally, the pandemic has been associated with poorer sleep quality and lifestyle behaviours in the general population, but very few studies have explored this in the context of academics. Thus, this study aimed to characterize the sleep quality, work and lifestyle factors among academics from a university in the Eastern Cape province of SA and determine the effects of gender and academic rank on these measures. Additionally, the study aimed to determine the impact of COVID-19 on sleep and work-related factors of this group. This study adopted a cross-sectional design and made use of an online questionnaire that was distributed to all academics employed at the institution via email. The data collection occurred over an 8-week testing period between August and September of 2020. The questionnaire explored sociodemographic, work and lifestyle characteristics, while the characteristics of sleep and sleep quality were explored with the Pittsburgh Sleep Quality Index (PSQI). Additionally, an open-ended section was included to determine the impact of COVID-19-related changes on sleep and work. The questionnaire responses were analyzed with descriptive and inferential statistics and the open-ended questions were analyzed with thematic analyses. A total of 84 respondents completed the questionnaire. On average, sleep quality was poor (global score of 7.09 ± 3.8), the reported sleep duration was short (6.41 ± 1.06 hrs) and the group was classified as overweight according to median BMI (26.67 [23.8-2 29.45] kg/m2). Over a third (35.71%) of academic staff reported not meeting physical activity guidelines and reported using screens one hour prior to bed every night during the week (76.19%) and the weekend (67.88%). Staff also worked long total weekly work hours (54.25 ± 11). Female academics had a poorer sleep quality (p = 0.035), spent a longer time in bed (p = 0.04), experienced more bad dreams (p = <0.01), had their last serving of alcohol earlier (p = 0.04) and worked less weekday (p = 0.04) and less total weekly (p = 0.02) hours compared to male academics. Professorship-level academics were significantly older than junior- and senior-level academics (p = <0.01) while senior-level academics had a poorer PSQI compared to professorship-level academics (p = 0.03). The thematic analysis showed that home environment, neighbourhood noise, work and mental health were the main emerging factors that disturbed sleep. The thematic analysis showed that, in relation to the impact of COVID19, sleep schedules changed and sleep duration and sleep quality improved or got worse. Respondents reported their work hours increasing, work schedules becoming less routine while working from home, dealing with the challenges of working online and experiencing worry, stress and anxiety due to the pandemic. The study highlights that, in the context of lockdown and having to work and teach online from home, academics reported poor quality sleep and short sleep duration. Further, on average, the sample reported working extensive hours and unhealthy lifestyle behaviours. The sleep health, nature of work and overall lifestyles of academic staff deserves more research attention, given the importance of their work and the impact that inadequate sleep could have on academics’ health and work performance. Sleep quality was worse for females and mid-career academics, suggesting that their sleep quality may be at greater risk than other sub-groups. However, the reasons for these differences need to be explored in future studies. The findings contribute to the narrative that academe involves numerous demands and supports previous research that has suggested that academics’ sleep is insufficient. Furthermore, COVID-19 had an impact on staff’s sleep, with staff reporting changes in their sleep quality and duration. The pandemic impacted work of academics by presenting novel demands related to online teaching, intensifying demands overall and disrupting work routines. However, future research is needed to understand academics’ sleep behaviours, work and lifestyles, especially in South Africa. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-04-06
An investigation into stakeholder inclusivity and the board’s ability to create competitive advantage at South Africa’s “big five” retail banks
- Authors: Wolhuter, Darren Wilfred
- Date: 2022-04-06
- Subjects: Stakeholder management South Africa , Strategic planning South Africa , Banks and banking South Africa , Corporate governance South Africa , Competition , Resource-based theory
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284548 , vital:56073
- Description: Stakeholder theory has long put forth the concept that managerial attention must be given to all stakeholders towards the realisation of value creation opportunities. Through the process of stakeholder engagement, and through the adoption of stakeholder inclusivity principles, an organisation can position itself to reap the benefits of understanding the legitimate needs and interests of all its stakeholders by seeking to satisfy all its stakeholders in turn. This study analysed the integrated reports of five retail banks, whose main base of operations were in South Africa, to assess the board’s ability to create value for its stakeholders through adopting a stakeholder inclusive approach to corporate governance as advocated for by the King Code on Corporate Governance in South Africa – King IV™. This assessment was done through an examination of a selection of outcomes relevant to the banking industry and related to each of the six capitals that form part of the value creation process as indicated for in the Integrated Reporting Framework (IIRC, 2013): 1) Financial Capital, 2) Manufactured Capital; 3) Intellectual Capital; 4) Human Capital; 5) Social and Relationship Capital, and; 6) Natural Capital. The results obtained, over a three-year period – 2018 to 2020, revealed that while the directors had a firm understanding of who their material stakeholders were, they struggled to create value that catered to all their stakeholders collectively. In addition, the directors were also unable to create sustainable value over the assessment period. As a result of this, most banks, with the exception of one, were unable to realise the value creation opportunities that could have led to a potential source of competitive advantage. The study concludes that while no observable sustainable competitive advantage was evident over the period of assessment, the concept of stakeholder inclusivity is an important corporate governance principle that drives value creation and, as such, warrants more attention from the director’s point of view. This research is intended to contribute to the growing knowledge on the importance of stakeholder inclusivity in corporate governance execution. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
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- Date Issued: 2022-04-06
Antimalarial activity of quinoline thiosemicarbazones: synthesis and antiplasmodial evaluation
- Authors: Nqeno, Lukhanyiso Khanyisile
- Date: 2022-04-06
- Subjects: Antimalarials , Quinoline , Thiosemicarbazones , Malaria Chemotherapy , Plasmodium falciparum , Malaria Africa, Sub-Saharan , Iron chelates Therapeutic use
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291292 , vital:56841
- Description: Africa is one of the regions that is most affected by malaria, as 90% of all malaria deaths occur in sub-saharan Africa. Malaria is a life threatening disease responsible for an estimated 800000 deaths each year, the majority of these deaths occurred in children under the age of five. The disease is a mosquito-borne, and it is transmitted to humans by the female Anopheles mosquito. The parasite responsible for this disease belong to the Plasmodium genus with Plasmodium falciparum causing the most severe cases of the disease in humans. The most widely available anti-malarials were designed to specifically target the pathogenic blood stage in humans, however, in order to completely eradicate malaria there is a need for the development of medicines that not only target the pathogenic blood stage of the parasite but also block parasite transmission and eliminate asymptomatic and cryptic hepatic forms of the parasite. Iron chelators have recently gained importance as potent antimalarials, to cause infection nearly all protozoa obtain growth essential iron from their hosts. Iron is required for the development of the parasite. Deprivation of utilizable iron by chelation is a proficient approach to arrest parasite growth and associated infection. Thiosemicarbazones are known iron chelating agents by bonding through the sulfur and azomethine nitrogen atoms. This study is aimed at the identification of thiosemicarbazone based derivatives as possible antimalarial agents. Due to their iron chelation abilities there has been increasing interest in the investigation of thiosemicarbazones as possible antimalarials. During the course of this project, several thiosemicarbazone derivatives were synthesized and their structure confirmed using routine analytical techniques (NMR, FTIR, and HRMS). The synthesized compounds were evaluated in vitro against the chloroquine sensitive strain (3D7) of P. falciparum for antimarial activity. The compounds were also evaluated agsinst Hela cells for overt cytotoxicity. The compounds generally showed poor antimalarial activity. One compound (LKN11) was identified to possess intrinsic and moderate antimalarial activity of 6.6 μM. The compounds were generally not cytotoxic against Hela cell at concentrations of up to 20 μM, with only compound LKN10 showing modest cytotoxic activity of 9.5 μM. This research went on to identify two thiosemicarbazone based derivatives which had a significant effect on HeLa and pLDH cells. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
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- Date Issued: 2022-04-06
A wideband spectropolarimetry study of the spatially resolved radio galaxies: Cygnus A & Hydra A
- Authors: Sebokolodi, Makhuduga Lerato Lydia
- Date: 2022-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/454415 , vital:75342 , DOI 10.21504/10962/454415
- Description: This study presented results from our deep, wideband, high-spectral and high-spatial-resolution polarisation observations of the two most powerful radio galaxies, namely Cygnus A and Hydra A, with the Jansky Very Large Array (JVLA). The high surface brightness and strong polarisation of these radio sources enabled detailed polarimetric imaging, providing images at 0.75′′ resolution across 2−18 GHz and 2000 independent lines-of-sight across Cygnus A, and images at 1.5′′ (2 − 12 GHz) and 600 lines-of-sight across Hydra A. Our data revealed significant depolarisation and depolarisation structure, as well as deviations from a _2-law. We also found complicated structures in the Faraday spectra ranging from single-peaked to blended/resolved double- and multiple-peaked. The Faraday spectra of Hydra A were more multiple-peaked than Cygnus A. The fractional polarisation increased monotonically with increasing resolution, as expected. However, there were numerous lines-of-sight with complicated behaviour. We also found that the structure and complexity in the depolarisation increased at lower resolutions, suggesting substantial spatial structures across the lobes/tails. We fitted the 0.3′′ (6−18 GHz) and 0.50′′ (6−12 GHz) images of Cygnus A and Hydra A, respectively, with a simple model incorporating random, unresolved fluctuations in the cluster magnetic field to determine the high-resolution, high-frequency properties of the sources and the cluster. We found rotation measures (RM) between −5000 rad m−2 and +6400 rad m−2 across Cygnus A, and −2000 rad m−2 and +11900 rad m−2 across Hydra A, consistent with previous studies. From these derived properties, we generated predicted polarisation images of the sources at lower frequencies (< 6 GHz), convolved to 0.75′′ for Cygnus A and 1.5′′ for Hydra A. The predictions were remarkably consistent with the observed emission in both sources, providing strong support for the depolarisation being a result of unresolved fluctuations in the magnetic fields. We fitted various analytical models to the wideband data. We found that the data for both sources were inconsistent with a wholly mixed gas of thermal and synchrotron gas, particularly for regions withRM > 1000 rad m−2. Instead, the data required a dominant Faraday rotating screen in the foreground of the radio sources. The wideband modelling also showed preference towards models with at least two or more unresolved Faraday rotating patches. Single depolarising models fail to describe the data. This implies the presence of more than one depolarising screen in the vicinity of these sources. The observations were consistent with the lower-frequency depolarisation due to unresolved fluctuations on scales ≳ 300−700 pc in the magnetic field or the electron density superposed on a partially ordered field component. Both the large-scale magnetic fields and unresolved magnetic field fluctuations are external to the radio emission. The magnetic fields around Cygnus A are located in the ambient cluster gas, the shocked gas in the boundary of the lobes or both, while the magnetic fields around Hydra A are most likely located in the ambient cluster gas. , Thesis (PhD) -- Faculty of Science, Physics, 2022
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- Date Issued: 2022-04-04