List of Titles

Potential Synergism between Entomopathogenic Fungi and Entomopathogenic Nematodes for the control of false codling moth (Thaumatotibia leucotreta)

- Prinsloo, Samantha Lee

Authors: Prinsloo, Samantha Lee
Date: 2021-10
Subjects: Cryptophlebia leucotreta , Entomopathogenic fungi , Insect nematodes , Citrus Diseases and pests , Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents
Language: English
Type: Masters theses , text
Identifier: http://hdl.handle.net/10962/188832 , vital:44790
Description: False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) (FCM), is a major phytosanitary pest of citrus in South Africa. Sufficient control measures for the soil-dwelling life stages of FCM have yet to be identified and owing to restrictions on the use of insecticides, non-chemical control options have been investigated including the use of entomopathogenic fungi (EPF) and entomopathogenic nematodes (EPN). Laboratory and field trials on an indigenous EPF, Metarhizium anisopliae FCM Ar 23 B3, have shown that this isolate is capable of inducing mortality in FCM soil-dwelling life stages. Other agents that have been highlighted as potential controls for soil-dwelling FCM life stages are the EPN species Steinernema yirgalemense 157-C, S. jeffreyense J194 and H. noenieputensis 158-C. This study conducted laboratory bioassays to assess the virulence of these four control agents on fifth instar FCM, in 24-well plates. These results reaffirmed the virulence of the four microbial control agents at their recommended doses of 50 IJs (EPN) and 1×107 conidia/ml (EPF) against fifth instar FCM with 80 to 96% larval mortality recorded. The EPF isolate exhibited the lowest mortality whilst S. yirgalemense induced the greatest mortality. In addition, the lethal concentration (LC) values for each isolate were determined using dose response bioassays. These values were previously unknown for all EPN species and for the EPF isolate based on the methodology used in this study. The LC50 results in order from lowest to highest EPN IJ concentration requirements were 4.38 IJs (S. yirgalemense), 4.47 IJs (S. jeffreyense) and 7.11 IJs (H. noenieputensis). The EPF isolate exhibited an LC50 of 3.42×105 conidia/ml. Lastly, research has shown that the combination of two control agents may increase control of late instar lepidopteran and coleopteran larvae, through synergistic interactions. Thus, the interactions that occurred between the combination of these EPN species with the EPF isolate were determined. This study found that when all three EPN species were combined simultaneously and sequentially with the EPF isolate M. anisopliae FCM AR 23 B3, additive interactions took place with exception of the simultaneous application of S. yirgalemense and H. noenieputensis, with the EPF and S. jeffreyense applied 24 h post EPF application. For the former, a synergistic interaction was found, whilst for the latter two, an antagonistic interaction. Although no strongly synergistic interactions were observed, additive interactions have been shown to reach a synergistic level when certain parameters are changed. Moving forward, a uniform methodology for conducting EPF/EPN interaction experiments has been suggested. It has also been recommended that due to the additive interactions observed in this study, laboratory soil-bioassays and field trials should be carried out for all three EPN species in combination with the EPF isolate. This research will inevitably facilitate the constant knowledge into management strategies for the phytosanitary pest, FCM in South African citrus. , Thesis (MSc) -- Science, Zoology and Entomology, 2021
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Date Issued: 2021-10

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Practicing conciliation: Towards a practical application of the Equal Weight View

- Hartley, Danyel Jordan

Authors: Hartley, Danyel Jordan
Date: 2021-10-29
Subjects: Knowledge, Theory of , Opinion (Philosophy) , Verbal self-defense , Epistemics , Interpersonal relations , Equal Weight View
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/188341 , vital:44745
Description: The Equal Weight View is a frequently discussed position in the philosophy of disagreement. It holds that when someone disagrees with an epistemic peer, they should adjust their belief to be closer to their peer’s belief. While the reasons for adopting this response to disagreement have been debated, there has been less discussion about its utility as a tool for handling real-world disagreements. In this thesis I pursue a version of the Equal Weight View which is useful in practice. I argue that traditional applications of the Equal Weight View do not reflect its underlying principles when they are used to resolve real-world disagreements. I develop an idealized application of the Equal Weight View that addresses the problems traditional applications face in real-world scenarios. Unfortunately, addressing these problems results in an application that is unrealistically cognitively demanding. The application trades being insensitive to the environment it would be used in for being insensitive to the limits of its user. I suggest that we might be able to save the idealized application and work around those limits by either externalizing or simplifying the most demanding aspects of the application. Externalization is best achieved by making use of some kind of computer assistance. Simplification involves replacing taxing data tracking and computation with heuristic methods. While neither approach is ideal, I argue that both get us closer to resolving disagreements in accordance with the underlying principles of the Equal Weight View than traditional applications do. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
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Date Issued: 2021-10-29

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Production performance, socioeconomic benefits, and agricultural extension services support of scavenging chicken farmers in Raymond Mhlaba Local Municipality, Eastern Cape Province

- Fentele, Ziphozethu https://orcid.org/ 0000-0001-7939-2964

Authors: Fentele, Ziphozethu https://orcid.org/ 0000-0001-7939-2964
Date: 2021-03
Subjects: Broilers (Chickens) , Poultry -- Breeding
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10353/21490 , vital:48751
Description: Scavenging chicken production plays a significant role in the lives of rural farmers as it ensures food security by providing eggs and meat to rural farmers almost in all developing nations. Rural farmers not only consume scavenging chickens, they also sell live chickens to customers to generate immediate income and are able to acquire other products using the money from the sales. The purpose of this study was to investigate production performance, socioeconomic benefits, and agricultural extension services support for scavenging chicken producers. The study was carried out in eight villages in Raymond Mhlaba Local Municipality in the Eastern Cape Province of South Africa. This study employed the multistage sampling technique for data collection from respondents between October and November 2018. The study used descriptive statistics, frequencies, percentages and multiple linear regression models to analyse quantitative data that was collected from a survey of 161 rural farmers that rear scavenging chickens. The results reveal that the majority (68.3percent) of the respondents in Raymond Mhlaba Local Municipality were women, while 52percent were married. Forty-eight percent of the respondents had attained high school education. The majority (53.4percent) relied on social grants and a further majority (68.3percent) had 1 to 10 years of experience in scavenging chicken production. The majority (84.5percent) of the households had between 1 and 50 chickens, with an overwhelming majority (95percent) practising free range system. Most (74.5percent) of the chicken houses were built with scrap material found within the community. The supplementary feed that was mostly offered to scavenging chickens was maize. The majority (95.7percent) of respondents experienced disease outbreaks, the most dominant of which was the Newcastle disease. Most (94.4percent) of the farmers offered a variety of indigenous medicines, mainly Aloe Ferrox. In addition, the majority (88.8percent) of the respondents experienced predation challenges The primary purpose of rearing scavenging chickens was consumption. Chickens were slaughtered for home consumption while forty-two percent at most. Most (50.9percent) of the respondents indicated that they offered chickens as gifts and as friendly gestures. The majority (82.0percent) indicated that they did not use chicken for any cultural rituals. A large (88.2percent) number of the respondents felt food secured as a result of rearing scavenging chickens, as they access products such as eggs and meat. The majority (98.8percent) of the respondents had never received any form of training from agricultural extension services. The results of the multiple linear regression model revealed that independent variables such as number of chickens, type of cockerels, number of hens, type of housing, type of training and cost of trainings had strong statistical significant values (p<0.001) zero-order correlation with production performance,while age and gender had statistical significant values at (p<0.05) and (p<0.010). For the improvement of the production performance of scavenging chicken production of rural farmers, the study recommends massive campaign among the farmers by agricultural extension services to create awareness on the dangers inherent in the use of unorthodox approaches to treating pests and diseases in scavenging chicken. Scavenging chicken farmers could be supported with simple technologies that are affordable on housing, medication and feed supplements. Training should focus on housing, disease management and feeding of scavenging chickens. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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Date Issued: 2021-03

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Quantifying the ecological and socioeconomic implications of a recovery/collapse of South Africa’s West Coast rock lobster fishery

- Eggers, Jessica Marguerite

Authors: Eggers, Jessica Marguerite
Date: 2021-10
Subjects: Jasus lalandii South Africa , Lobster fisheries South Africa , Lobster fisheries Catch effort South Africa , Fishery management South Africa , Small-scale fisheries South Africa , Economics Sociological aspects , Value chain analysis
Language: English
Type: Masters theses , text
Identifier: http://hdl.handle.net/10962/188854 , vital:44792
Description: The West Coast rock lobster (WCRL) Jasus lalandii fishery is South Africa’s third most valuable fishery, but the stock is currently at less than 2% of its pristine biomass. Scientists are warning that if no measures are taken, the WCRL could face commercial extinction. The necessary reductions in the global Total allowable Catch (TAC) seen in past years have had large economic implications for the WCRL value chain, but research into the socio-economic aspects of this fishery is limited. This study, therefore, aims to establish an overview of the economic revenue over the seasons 2016/17 – 2018/19 by exploring changes and trends in the net seasonal income (NSI) for the fishery, sectors within the fishery and different stakeholders. It also investigates the prospects for the sectors and different actors in this fishery over the seasons 2019/2020 - 2030/31 through analysis of the net present value (NPV) under three proposed global TAC management scenarios (global TAC of 640 tonnes, 1084 tonnes and 1280 tonnes). Data concerning costs and incomes as well as dynamics, mechanisms and concerns surrounding the fishery were collected from stakeholders in the different sectors through interviews and surveys. Further, official records from DEFF (catches, actors, vessels and quotas) and projections made by the Marine Resource Assessment (MARAM) team at the University of Cape Town (rates of recovery of the resource and future catches under the different TAC scenarios) were obtained and analysed. Cost and income data were summarised and models characterising the economic flows within the fishery were created. Calculations regarding the NSI and NPV were made using Monte Carlo simulations to account for the uncertainty surrounding many of the input variables. Results show that while the fishery as a whole made economic profits for the three seasons, the decreasing quotas in 2018/19 had a disproportionately negative impact on some of the representative individuals examined within the different sectors. The projections indicate that while each of the sectors as a whole would continue to make profits largely proportional to their allocation under the different TAC scenarios, many vessel owners in the fishery are likely to face economic losses or very marginal gains under the lower quota options, while the NPV for quota holders who outsource the catching of their quota are likely to be proportionally less affected by the changes in global TAC. This dynamic is important to consider for the future of this fishery. If the resource is to recover, and fishing activity is to continue equitably under the decreased quotas that the recovery of the biomass necessitates, the socio-economic context and the dynamics within which the fishers operate must be considered and studied more extensively and socio-economic consequences of a lower global TAC mitigated while improving the ecological status of the resource. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
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Date Issued: 2021-10

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Role of the Amathole Marine Protected Area in protecting vulnerable and threatened reef fish

- Phillips, Moraea Megan Taberer

Authors: Phillips, Moraea Megan Taberer
Date: 2021-10-29
Subjects: Reef fishes South Africa Amathole District Municipality , Reef fishes Conservation South Africa Amathole District Municipality , Reef ecology South Africa Amathole District Municipality , Rare fishes South Africa Amathole District Municipality , Fish populations South Africa Amathole District Municipality Monitoring , Fish declines South Africa Amathole District Municipality , Underwater videography in wildlife monitoring South Africa Amathole District Municipality , Amathole Marine Protected Area , Petrus rupestris (Red Steenbras) , Polysteganus undulosus (Seventyfour seabream) , Chrysoblephus cristiceps (Daggerhead seabream)
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/192152 , vital:45200
Description: The Amathole Marine Protected Area (MPA) was first established on a voluntary basis in the 1980’s by local ski-boat fishermen and comprised three small no-take areas near East London. In 2011, the areas received official recognition as the Amathole MPA and in 2019 an offshore extension was granted, increasing the area covered from 250 km2 to over 4000 km2. Though the inshore Amathole MPA has benefitted from decades longer of reprieve from fishing activity than the offshore MPA, it is limited in both its coastal and depth extent, placing in doubt its capacity to provide meaningful protection to several heavily threatened target species. Among the numerous endemic Sparids for which the Amathole region constitutes a vital portion of their distributional range are red steenbras (Petrus rupestris), seventyfour (Polysteganus undulosus), and dageraad (Chrysoblephus cristiceps). The stocks of all three species have collapsed and urgent intervention has been recommended to enable their recovery, including protection in strategically placed MPAs. The offshore Amathole MPA covers an extensive portion of prime habitat for these and other species, but no formal research has been carried out on fish assemblages in the region. As such, data to substantiate the benefits of the inshore Amathole MPA and to provide a baseline reference for the offshore MPA are lacking. This study made use of baited remote underwater stereo-video systems (stereo-BRUVS) to survey fish assemblages in the inshore Amathole MPA, adjacent inshore exploited areas, and exploited areas seaward of the inshore MPA. Sampling was carried out in 2015 and 2016, prior to the establishment of the offshore Amathole MPA. Fish assemblages from the inshore MPA were compared with those from adjacent exploited areas within the same depth range and from the offshore zone between 76 and 112 m depth. Within the inshore zone, biomass and abundance of target species were greater inside the MPA than in adjacent exploited areas, with vulnerable fisheries species showing the strongest response to protection. Offshore assemblages consisted of fewer species and fewer fish overall than those from the inshore zone but were dominated by larger individuals and those from higher trophic levels. The size of C. cristiceps was consistent across the sampled depth range but abundance of this species declined rapidly at depths of more than 60 m. Within the inshore zone, both abundance and size of C. cristiceps were greater in the MPA than in adjacent exploited areas. The size of P. rupestris was consistent across the sampled depth range and between protected and exploited areas, but this species was considerably more abundant offshore. Where P. rupestris was detected inshore it was almost exclusively in the MPA. No difference in the size or abundance of P. undulosus was found between the inshore MPA and inshore Abstract exploited areas, but both measures were found to increase with depth, with reproductive-sized adults restricted to the offshore zone. Despite its limited benefits for larger species, the inshore Amathole MPA is a critical refuge for smaller and more resident species like C. cristiceps, demonstrating the possibilities for conservation and management of endangered species in small MPAs. Baseline abundance and size measures for P. rupestris and P. undulosus recorded here indicate that the offshore extension of the Amathole MPA is ideally situated to protect spawner stock of these species and potentially contribute to the recovery of their stocks across a wider distributional range. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
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Date Issued: 2021-10-29

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Self-inquiry: Comparing Plato and Patanjali

- Coughlan, Daniel Michael

Authors: Coughlan, Daniel Michael
Date: 2021-10
Subjects: Plato , Patañjali , Self , Identity (Philosophical concept) , Comparison (Philosophy) , Justification (Theory of knowledge)
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/190066 , vital:44960
Description: At its most effective my research hopes to re-affirm the central value and importance of self-inquiry. That is, I hope to echo the familiar call of the wise to know thyself. Of the many mouths and temple walls that have lent authority to this precept there is perhaps no mouth more important than one’s own. To know thyself is the task and responsibility of the individual. In order to arrive at the point where I can re-affirm its value I explore the nature of self-inquiry with the help of Plato, Patanjali and a comparison between them. I propose two general senses in which we might understand self-inquiry and seek to bring out the core problems faced by each. We find an account of these two senses and the relationship between them in both Plato and Patanjali, so too, though less obviously, in the comparison between them. The comparison provides the opportunity for reflecting on the ground that it moves from and depends on, the common ground we assume between the two compared philosophers/ies. I contend that this ground is ultimately the comparer, one’s self. The consequence is that the comparative project and the project of self-inquiry both meet and are mutually beneficial. The three together; Plato, Patanjali, and the comparison between them help us account for nature of self-inquiry in helping us to better understand the relationship between the two senses in which we can come to understand and think about it. In the first sense, self-inquiry is cast as the examination of one’s life. In the second sense, we are invited to consider the possibility of an unmediated knowing of the examiner, an unmediated self-knowing. With a better understanding of what self-inquiry is I stand to conclude by re-affirming its value. , Thesis (MPhil) -- Faculty of Humanities, Philosophy, 2021
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Date Issued: 2021-10

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Settlement and metamorphosis in the veliger larvae of the South African abalone Haliotis midae exposed to ambient grown biofilms treated with conspecific mucous

- Van Staden, Jefferson Luke

Authors: Van Staden, Jefferson Luke
Date: 2021-10-29
Subjects: Haliotis midae , Biofilms , Haliotis midae Larvae Behavior , Haliotis midae Metamorphosis , Biosecurity , Aquaculture , Metamorphosis , Attachment mechanisms (Biology) , Mucous‎
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/192187 , vital:45203
Description: The South African abalone, Haliotis midae, is a commercially important species of mollusc which contributes significantly to the value of the South African mariculture industry. One of the primary challenges experienced by abalone farmers is the consistent production of juvenile abalone (spat) in sufficient volumes to keep stocking farms and facilitate expansion of the industry. One of the key production bottlenecks of H. midae is achieving adequate levels of larval attachment and metamorphosis (settlement). The larvae of H. midae are settled on polycarbonate plates which have been pre-conditioned with biofilms in seawater which is pumped ashore onto farms. The seasonal variability in settlement success reported by hatchery managers in South Africa is hypothesised to be as a result of different diatom species compositions colonising the settlement plates at different times of the year, with settlement success being lowest during the winter months. The following study investigated whether the addition of conspecific mucous to biofilms could result in elevated settlement success, and whether there was potential for sterilisation of this mucous. A novel method of mucous application, spraying it onto the plates as opposed to pre-grazing, was tested in settlement assays and the trials revealed the following results: • The addition of H. midae mucous induced significantly more larvae to attach to settlement plates, when mucous was harvested around the spawning season. • Elevated attachment of larvae on mucous treated plates did not result in more post-larvae occupying the plates at the end of trials, and increased mortality is likely attributed to introduction of pathogens in conjunction with mucous. • No increase in the final proportion of settled larvae which had metamorphosed or the rate at which they metamorphosed was observed between mucous application treatments and biofilm only treatments. Subsequent trials assessed whether methods of mucous handling could reduce the biosecurity risk associated with mucous use, and so mucous was either UV irradiated or autoclaved. These trials revealed the following findings: • No difference in attachment was seen between any treatments, including the untreated mucous. This is contrary to the findings of our initial experiments and illustrates that the attachment-inducing properties within mucous may be seasonally expressed. ii • Numbers of observed larvae/post-larvae on plates applied with UV and autoclaved mucous where less stable than biofilms only, especially in the second trial, illustrating that mucous still presents a biosecurity risk even after undergoing these handling methods as it may act as a substrate on which pathogenic bacteria could colonise. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
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Date Issued: 2021-10-29

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Synthesis, characterization and in vitro biological studies of cholesterol-based carriers as potential therapeutic agents

- Ruwizhi, Ngonidzashe

Authors: Ruwizhi, Ngonidzashe
Date: 2021-03
Subjects: Drug delivery systems , Cholesterol
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10353/20708 , vital:46443
Description: Malaria, cancer and bacterial infections are numbered among the highest causes of fatalities. Most of the drugs used to combat these diseases suffer from resistance, poor absorption and bioavailability and high toxicity. Therefore, delivering a drug requires an excellent drug delivery system that must provide the medication at the site of action in the minimum time possible. Cholesterol is a sterol that is abundantly found in the human body and forms a part in the structure and organization of cell membranes. Many researchers have used cholesterol, especially in organic synthesis, because of its ready availability, low cost and functional groups that can be readily derivatized. In this research, different therapeutic agents (anticancer, antimalarial and antibacterial) were conjugated to cholesterol, and the synthesized compounds were characterized using FTIR, 1H and 13C NMR, Mass Spectroscopy, 2D 1H-13C, HSQC NMR and tested for in vitro biological activity. Thirteen compounds were successfully synthesized. CHS-Cur was the most effective against all Gram-positive bacterial strains, while CHS-Cur, CHS-ZD and C-CAC-ZD were effective against all the bacterial strains. C-CAC-Pyr showed good antiplasmodial activity with 97.75 and 97.83% inhibition at 20 and 10 μg/ml concentrations, respectively. The biological activity of some of the compounds was increased by the conjugation of cholesterol, while others displayed reduced biological activity. In vitro cytotoxicity of the synthesized compounds on HeLa (cervical cancer) cells showed that compounds 2 (7.559 μg/mL), 3 (5.840 μg/mL), 5 (1.44 mg/mL), 7 (4.308 μg/mL) and 11 (3.295 μg/mL) exhibited some good anticancer activity with IC50 values of less than 10 μg/mL. Treating T3T fibroblast cells with compounds 2, 4, 5, 6, and 10 did not reveal a cytotoxic effect on the normal cells when compared to the control, cisplatin. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
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Date Issued: 2021-03

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Tense and aspect in Xhosa

- Savić, Stefan

Authors: Savić, Stefan
Date: 2021-10-29
Subjects: Xhosa language , Xhosa language Grammar , Xhosa language Semantics , Xhosa language Tense , Xhosa language Aspect , Xhosa language Syntax , Xhosa language Morphology , Xhosa language Grammar, Comparative , Information structure
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/192897 , vital:45277 , 10.21504/10962/192897
Description: This dissertation investigates the semantics of each tense and aspect in Xhosa. Since tense and aspect perform important pragmatic functions, the analysis takes into account the correlation between the verb and the wider discourse in which it is embedded. Tense reflects the temporal relation between the time of the utterance (speech time) and an interval the speaker makes the assertion about (reference time). The Remote Past and the Remote Future tenses differ from their Recent/Immediate counterparts in that they denote events which occurred in a significantly different situation than the speech time and/or events in the surrounding discourse. Aspect does not only indicate the relation between the time occupied by the real world event and the reference time chosen by the speaker. The Perfective aspect represents an event as a unique change-of-state that pertains to a single point on the timeline which at the same time functions as the reference time. By contrast, for the Imperfective aspect temporally links the event to a contextually provided reference time, e.g. the utterance time, a time adverbial, a period of time previously introduced in the preceding discourse, or the interlocutors’ shared experience. At the pragmatic level, the Perfective aspect tends to introduce an event’s resulting state into the discourse, whereas the Imperfective aspect tends to rule it out. Like the Imperfective aspect, the Anterior and the Prospective aspects assert an event’s occurrence from a contextually defined reference time. They refer to the consequent and the preparatory states of an event, respectively. On the pragmatic level, the Anterior aspect may also indicate that the truth-conditionality of the event’s resulting state is contradicted in the immediate discourse. This study shows that tense and aspect temporally represent different means of temporally assigning an event to a particular portion of the timeline. I further argue that aspect indicates whether the reference time is provided in the context (Imperfective, Anterior, Prospective) or whether it is introduced by the verb itself (Perfective). Furthermore, this study shows that aspect exhibits a pragmatic function by laying focus on different parts of the event that are relevant in the upcoming discourse. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Languages Studies, 2021
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Date Issued: 2021-10-29

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The bastards of Euripides: illegitimacy in the Hippolytus, the Andromache, and the Ion

- Sülter, James Nicholas Edwin

Authors: Sülter, James Nicholas Edwin
Date: 2021-10-29
Subjects: Euripides , Euripides Criticism and interpretation , Euripides. Hippolytus , Euripides. Andromache , Euripides. Ion , Illegitimacy in literature , Tragedy History and criticism , Citizenship in literature
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/190030 , vital:44957
Description: The Pericles Citizenship Law of 451 made citizenship contingent on an individual man having Athenian blood on both his father and mother’s side. Men with foreign mothers were denied any rights to the key institutions that conferred Athenian belonging, such as deme and phratry membership, as well as, of course, citizenship. When, however, the Peloponnesian War began in 431, the population of Athenian citizens was quickly diminished by military conflict and plague and they sought a solution to repopulate their numbers with as little change to the original law as possible. The result was an amendment in 429 allowing citizens with no living legitimate (γνήσιοι) heirs to legitimise their bastards (νόθοι) in their place. A year after this, Euripides wrote the Hippolytus, a play that deals very closely with the issues of bastardy, bastards’ place in the polis and the oikos, and their treatment by those who are legitimate. As the war went on, he proceeded to produce two other plays containing bastard characters, the Andromache (c.425) and the Ion (c.413), in which he similarly explored the consequences of illegitimacy. In all three plays his attitude towards bastards is overwhelmingly sympathetic and the way he chooses to present their situations suggests his disagreement with the arrogance and antipathy that continued to push many of these often very worthy individuals to the fringes of society. This thesis seeks to examine Euripides’ presentation of bastards through a close reading of the relevant texts, in order to understand how the plays reacted to the contemporary circumstances of and what comments they are making. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
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Date Issued: 2021-10-29

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The classification of fuzzy subgroups of some finite non-cyclic abelian p- groups of rank 3, with emphasis on the number of distinct fuzzy subgroups

- Appiah, Isaac Kwadwo

Authors: Appiah, Isaac Kwadwo
Date: 2021-03
Subjects: Fuzzy sets , Commutative algebra
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10353/20783 , vital:46563
Description: In [6] and [7] we classi_ed fuzzy subgroups of some rank-3 abelian groups of the form G = Zpn + Zp + Zp for any _xed prime integer p and any positive integer n, using the natural equivalence relation de_ned in [40]. In this thesis, we extend our classi_cation of fuzzy subgroups in [6] to the group G = Zpn + Zpm + Zp for any _xed prime integer p; m = 2 and any positive integer n using the same natural equivalence relation studied in [40]. We present and prove explicit polynomial formulae for the number of (i) subgroups, (ii) maximal chains of subgroups of G for any n;m _ 2 and (iii) distinct fuzzy subgroups for m = 2 and n _ 2. We have also developed user-friendly polynomial formulae for the number of (iv) subgroups, (v) maximal chains for the group G = Zpn + Zpm for any n;m _ 2; any _xed prime positive integer p and (vi) distinct fuzzy subgroups of Zpn + Zpm for m equal to 2 and 3, and n _ 2 and provided their proofs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
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Date Issued: 2021-03

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The construction of phthalocyanine- carbon nanoparticle conjugates for applications in photodynamic therapy and non-linear optics

- Matshitse, Refilwe Manyama Stephina

Authors: Matshitse, Refilwe Manyama Stephina
Date: 2021-10-29
Subjects: Phthalocyanines , Nanodiamonds , Photochemotherapy , Nonlinear optics , Quantum dots
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10962/188397 , vital:44750 , 10.21504/10962/188397
Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position and sometimes positively charged are reported. The Pcs had either H2, zinc or silicon as central metals and have pyridyloxy, benzothiozole phenoxy, and respective cationic analogues as ring substituents. The Pcs were linked to carbon based nanoparticles such as graphene quantum dots, carbon dots, and detonation nanodiamonds (DNDs) via an ester, amide bond and/or π - π stacking. The physicochemical characteristics of the Pcs were assessed when alone and when in a conjugated system. Both symmetrically and asymmetrically substituted benzothiozole Pcs when quaternised displayed higher triplet and singlet oxygen quantum yields than their unquaternised counterparts. Linkage to carbon nanoparticles (especially to detonation nanodiamonds) had an increasing effect on triplet and singlet oxygen quantum yield. However, a general decrease in singlet oxygen quantum yield on linkage to doped detonation nanodiamonds was associated with the screening effect of DNDs. Heteroatom doped DNDs-Pc nanohybrids have less singlet oxygen than Pcs alone due to molecular structural stability associated with strain that is relatively reduced upon linking Pcs. The In vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. When Pc complexes are alone, there is less phototoxicity with >22% cell viability at concentrations ≤ 50 μg/mL relative to conjugates with <22% cell viability at concentrations ≤ 50 μg/mL. There was no direct relationship between PDT and singlet oxygen quantum yields. Nonlinear optical characteristics of complexes was improved upon conjugation of DNDs. Absorbance, input energy, percentage loading, central metal, substituent of Pc and nature of interaction (covalent, noncovalent) are amongst some of the factors that influence nonlinear absorption properties of materials used in this study. All materials followed reverse saturable absorption through two photon absorption mechanism at the excitation wavelength of 532 nm. Aggregates reduce excited state lifetime and Beff under high concentrations/absorbance. A direct relationship between absorbance and Beff of DNDs nanoconjugated systems at low concentrations result in increased optical limiting characteristics of materials. The findings from this work show the importance of linking (nonlinear optics and photodynamic therapy) and doping (photodynamic therapy) photosensitisers such as phthalocyanines and sometimes boron dipyrromethenes onto carbon based nanoparticles for the enhanced characteristics in variable applications. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
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Date Issued: 2021-10-29

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The de novo biosynthesis of biotin is required for the optimal growth of Salmonella enterica serovar Typhimurium in the intracellular environment

- McLaughlin, Claire

Authors: McLaughlin, Claire
Date: 2021-10-29
Subjects: Salmonella , Biotin , Biosynthesis , Salmonella typhimurium , Antibacterial agents , Anti-infective agents , Pathogenic bacteria , Salmonella food poisoning
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/192097 , vital:45195
Description: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a foodborne pathogen infecting humans and animals, contributing to significant morbidity and mortality worldwide each year. The increase in antibiotic-resistant S. Typhimurium infections in recent years has highlighted the need for new antibacterial drugs and drug targets. S. Typhimurium can acquire biotin through de novo biosynthesis or via transport from its extracellular environment. The importance of the vitamin for bacterial survival, coupled with the absence of the biotin biosynthetic pathway in humans, makes the biotin biosynthetic enzymes attractive targets for drug discovery. The study's primary aim was to determine the relative importance of the biotin biosynthesis and transport pathways for the in vitro and ex vivo growth and survival of S. Typhimurium, with the goal of validating the pathways as valid targets for antimicrobial drug development. In order to achieve this aim, we generated S. Typhimurium mutant strains harbouring deletions in either the biotin biosynthetic gene, bioB, or putative high-affinity biotin transporter, yigM (ΔbioB and ΔyigM, respectively), as well as a double mutant in which the two mutations were combined (ΔbioB ΔyigM). Since the simultaneous disruption of biotin biosynthesis and transport in the double mutant may form a synthetic lethal combination, preventing further analysis of the strain, we also constructed a conditional mutant in which the promoter of the yigM gene was replaced by the arabinose-regulatable, PBAD promoter in the ΔbioB background (ΔbioB PBAD::yigM). Since the expression of the YigM in this strain is arabinose-regulatable, its role as a biotin transporter can be evaluated by altering the arabinose concentration in the growth media. Once the mutant strains were isolated and verified genetically, their growth and that of their genetically complemented counterparts were analysed in liquid and/or solid M9 minimal medium in the absence of biotin. Consistent with previous observations, the ΔbioB auxotrophic mutant's growth was severely compromised in minimal media in the absence of biotin. The growth of the strain could, however, be restored by supplementation with exogenous biotin or expression of the wild type bioB gene from an episomal plasmid. The ability of biotin to reverse the growth defect of the ΔbioB mutant strain was, however, dependent on the presence of a functional YigM, since biotin supplementation did not affect the growth of the ΔbioB ΔyigM double mutant strain. The introduction of a second copy of the yigM gene in the ΔbioB ΔyigM background, however, restored the growth of the strain in the presence, but not absence, of biotin. The dependence of the double mutant on both YigM and biotin for growth supports the idea that the protein functions as the sole or primary biotin transporter in S. Typhimurium, as it has recently been shown for E. coli (Ringsletter, 2010; Finkenwirth et al, 2013). The essentiality of YigM for biotin transport was subsequently verified by two independent means. Firstly, the growth of the ΔbioB PBAD::yigM promoter-replacement mutant was strictly dependent on the inclusion of arabinose in biotin-supplemented M9 minimal media supplemented, indicating that the expression of YigM from the PBAD promoter is essential for biotin transport. Secondly, following treatment with a known small-molecule inhibitor of the biotin biosynthesis, MAC-13772, exogenous biotin was capable of restoring the growth defect of the YigM+ wild type S. Typhimurium strain, but not the YigM− ΔyigM mutant. Taken together, these findings confirm that YigM serves as the biotin transporter for S. Typhimurium and that the corresponding ΔyigM mutant is, as a result, defective for biotin transport. Having confirmed the genotypes and phenotypes of the ΔbioB, ΔyigM, and ΔbioB ΔyigM mutants, we next analysed the importance of the biotin biosynthesis and transport pathways for the growth and survival of S. Typhimurium within the intracellular environment. To this end, we determined the proliferation of each of the mutant strains following infection of HeLa epithelial and RAW264.7 macrophage-like cell lines. Our results revealed that the de novo biosynthesis of biotin is required for the optimal growth of S. Typhimurium following infection of both epithelial and macrophage-like cell lines. Disruption of biotin transport, by contrast, had no significant effect on the intracellular proliferation of S. Typhimurium when a functional pathway for the biosynthesis of biotin was present. The simultaneous disruption of biotin biosynthesis and transport, however, resulted in significant attenuation of S. Typhimurium in epithelial cells, while bacterial survival in macrophages decreased to below the limit of detection. Overall, our results suggest the S. Typhimurium relies primarily on biotin produced by the de novo biosynthesis pathway to support its growth in the intracellular environment. While YigM-mediated biotin transport is essential for sustaining the viability of intracellular S. Typhimurium in the absence of de novo biosynthesis, it appears to play a relatively minor role in the acquisition of biotin during growth in the nutrient-limited Salmonella containing vacuole. Our findings suggest that inhibiting biotin biosynthesis may be a viable strategy for combating systemic infections caused by Salmonella, as has been recently proposed for other medically important bacterial pathogens (Carfrae et al., 2020). , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
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Date Issued: 2021-10-29

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The economic valuation of ecosystem services using deliberation as a tool for value elicitation

- Marriner, James Derek

Authors: Marriner, James Derek
Date: 2021-10-29
Subjects: Seagrasses Economic aspects South Africa , Ecosystem services South Africa , Focus groups , Deliberative democracy South Africa , Nature Effect of human beings on South Africa , Environmental economics , Contingent valuation
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/294712 , vital:57247
Description: Marine seagrass, Zostera capensis, is a highly productive flowering marine seagrass found on the eastern and southern coasts of South Africa and provides a variety of ecosystem services, which include reducing the effects of erosion, trapping nutrients, creating a nursery habitat for fish species and reducing sedimentation. Despite their formal protection status, Z. capensis meadows are regressing, often due to anthropogenic influences. Globally, multiple studies have documented the ecological importance of seagrass services, to both humans and nature, but economic evaluations of these services have not been as extensive. Numerous valuation methods have been used in literature and in practice to value non-market environmental resources and ecosystem services, where results vary. The most widely used non-market environmental valuation method is the contingent valuation (CV) method, which allows for the valuation of environmental resources that are not sold in the market through a stated willingness to pay (WTP) amount, contingent upon a particular scenario. However, the CV method is susceptible to various limitations and forms of bias. As a result, alternative environmental valuation techniques have been reviewed in literature. Deliberation has been suggested as an improved valuation approach to overcome the criticisms of the CV technique, as it increases respondents’ understanding and knowledge of the environmental resource under discussion, through the incorporation of debate, discussion, participation and social learning, thereby producing more reliable valuations of non-market environmental resources. The deliberative monetary valuation (DMV) method has been advocated as an important valuation method to achieve more comprehensive and reliable valuations of complex and unfamiliar public goods, such as ecosystem services. This thesis explored the determinants of WTP for the protection of seagrass, and whether deliberation can be used to supplement findings and values obtained from the individually sourced WTP values. As a result, the study used a dual-method approach to obtain both individual and deliberated WTP values from a range of stakeholders with varied socio-demographic characteristics by using both the CV method and a deliberative focus group, for the ecosystem services that seagrass Z. capensis provides to the Knysna community, South Africa. The results showed that age, education, use frequency and mistrust in local government were determinants in WTP, while deliberative elements uncovered that respondents’ knowledge of an environmental resource and a consideration of the valuation scenario were important factors in determining WTP. It was found that 55% of the respondents were willing to pay to conserve the ecosystem services of seagrass in the Knysna estuary through a monitoring programme. Among those that were willing, the mean WTP amount was approximately R132 per month per household. Although the circumstances in which the deliberative focus group discussion were run were not ideal because of the COVID-19 lockdown, the results showed some interesting potential benefits of using deliberation in complex public good valuation studies. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2021
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Date Issued: 2021-10-29

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The effects of supply chain cooperation on humanitarian relief operations: A case of Cyclone Idai in Zimbabwe

- Chari, Felix, Muzinda, Ozwell, Novukela, Cawe, Ngcamu, Bethuel S.

Authors: Chari, Felix , Muzinda, Ozwell , Novukela, Cawe , Ngcamu, Bethuel S.
Date: 2021
Subjects: Cyclone damage Business logistics Article
Language: English
Type: text , article
Identifier: http://hdl.handle.net/11260/7155 , vital:53076 , xlink:href="https://doi.org/10.4102/jtscm.v15i0.532"
Description: Background: The increased frequency of occurrence and complexity of disasters, the world over, have called for increased cooperation amongst stakeholders to deliver humanitarian aid. Objectives: This study came as a result of the growing interest focussed on creating and implementing cooperation to facilitate management of supply chain-related activities in the humanitarian sector. This study therefore sought to gain a better understanding of the effectiveness of supply chain cooperation in aid delivery performance variables, specifically in the context of Cyclone Idai humanitarian relief operations in Zimbabwe. Method: A pragmatic research paradigm was adopted, where the researchers took a mixed approach informed by both quantitative and qualitative research tools. Results: Findings of this study show a significant and positive impact of humanitarian supply chain (HSC) cooperation in achieving output, resource and flexibility performance in the delivery of aid. These findings will change the shape of humanitarian response to have more cooperation amongst organisations rather than responding as single entities. Conclusion: This study will therefore contribute to how humanitarian organisations improve their approach to future disasters through cooperation in their supply chain activities. Theoretically, the study will show how supply chain cooperation is key to humanitarian responses, thus improving effectiveness of HSC when put into practice. Policymakers can use these findings to develop a standard framework of how humanitarian organisations should collectively respond to disasters. Keywords: cyclone; humanitarian logistics; relief operations; supply chain; supply chain cooperation.
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Date Issued: 2021

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The factors to be considered by the competition authorities when a fine may cause the firm to exit

- Quilliam, Layne Edwin

Authors: Quilliam, Layne Edwin
Date: 2021-10
Subjects: South Africa. Competition Act, 1998 , Competition Tribunal (South Africa) , Business enterprises Law and legislation South Africa , Debt-to-equity ratio South Africa , Bankruptcy Prevention , Causation , Competition
Language: English
Type: Masters theses , text
Identifier: http://hdl.handle.net/10962/188408 , vital:44751
Description: The Competition Act empowers the Competition Tribunal to levy fines against a firm for certain contraventions of the Act. Such fines are statutorily capped to prevent the fine from causing the firm’s exit. This maximum is based on the overarching principle of fairness which precludes a fine, on its own, from destroying a firm’s business. However, the Competition Appeal Court acknowledged in 2013 that fines below this cap may still cause a firm to exit. The purpose of this paper is to propose the factors that should be considered when determining a firm’s ability to pay such a below-cap fine. These factors are the calculation of the fine, probable exit, causation of exit and the competitive effect of the firm’s exit. The fining provisions of the Act are initially explored to provide context for the discussion and are then compared to equivalent provisions in Europe. Liquidation and business rescue proceedings are then described as the most common forms of a firm’s exit from the market. Methods for determining the causal relationship between the fine and the firm’s exit are explored through delictual law’s factual and legal causation. The competitive effects of the firm’s exit are premised on the purpose of the Competition Act and are evaluated through the Competition Act’s merger provisions, specifically, the failing firm factor. These proposed factors are then tested through hypothetical facts to analyse their possible interactions and efficacy. , Thesis (LLM) -- Faculty of Law, Law, 2021
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Date Issued: 2021-10

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The impact of translanguaging and acculturation towards implementation of the Incremental Indigenous African Languages programme in former Model-C schools (Alfred Nzo West District, Eastern Cape)

- Lepheana, Jeremia

Authors: Lepheana, Jeremia
Date: 2021-04
Subjects: Translanguaging (Linguistics) , Acculturation -- South Africa -- Eastern Cape , Model C schools (South Africa) , Multilingual education -- South Africa -- Eastern Cape , Multicultural education -- South Africa -- Eastern Cape , Incremental Indigenous African Languages Programme
Language: English
Type: thesis , text , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/177236 , vital:42802 , 10.21504/10962/177236
Description: This thesis explores the possibilities of multilingual language instruction within multi-ethnic classrooms in former Model-C schools shaped by multiple discursive practices. The researcher reviews current research on multilingualism and teaching and proposes strategies for overcoming the English prescriptivism, and monolingual mind-set in education. The research reported in this dissertation is both a qualitative and quantitative study, which sought to investigate the patterns of translanguaging in classrooms in five primary schools in Alfred Nzo West district (Maluti sub-district). In quantitative research, questionnaires were used to gather data from teachers and learners. In the qualitative research methodology, document analysis method of collecting data was employed. Purposive sampling was the major sampling method to ensure that relevant data was collected. Language in Education Policy formed the major analytical framework for this study. The aim of the study was to investigate the impact of translanguaging as it is used by teachers and learners in the class in selected primary schools in Alfred Nzo West district. The research focuses on how primary school learners and their teachers engage with teaching and learning, and the strategies that teachers use to promote the use of two or three languages in classrooms to help learners to understand content and concepts in English, Sesotho and isiXhosa as there are multi-ethnic classrooms in the district. The dissertation concludes with some reflections on the findings, implications of the findings for future research and training, and recommendations to use the languages of school children as rich resources for teaching and learning. The Socio-cultural theory formed the theoretical framework that guided this study. According to Vygotsky’s theory of cognitive development, children learn through social interaction that includes collaborative and cooperative dialogue with someone who is more skilled in tasks they are trying to learn. The findings of this study show the misunderstandings of the LiEP, translanguaging and multilingual education. The study also shows the lack of confidence in the ability of African languages to provide quality education. , Thesis (PhD) -- Faculty of Humanities, School of Languages, 2021
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Date Issued: 2021-04

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