Investigating the nature of the linguistic challenges of the Department of Basic Education (DBE) 2013 Grade 4 Mathematics ANAs and learners’ and teachers’ experience of them.
- Authors: Sibanda, Lucy
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2079 , http://hdl.handle.net/10962/d1021312
- Description: The underperformance of South African learners in literacy and numeracy is a source of grave concern, especially at the transition from Grade 3 to Grade 4. The challenge that complicates this shift is to some extent linguistic, since at Grade 4 in South Africa the majority of learners begin learning in English, which is an additional language for most. The study adopts a sociocultural view of language and learning. Vygotsky’s influential theoretical work on language and learning, in which language is considered central to learning and learning is a social process embedded in sociocultural settings, informs the study. The introduction of the Annual National Assessments (ANAs) across primary and secondary grades in South Africa in mathematics and literacy in 2011 provides the context for this research. It is against this background that the present study aimed, through a case study approach of three Grade 4 classes of English additional language (EAL) learners, to achieve four things, namely: to investigate the linguistic challenges of the 2013 Grade 4 mathematics ANAs; to analyse the learners’ written responses to the 2013 mathematics ANA items; to explore the 2013 Grade 4 learners’ difficulties and experiences of the 2013 mathematics ANAs, and to investigate the Grade 4 mathematics teachers’ perspectives of the language of the ANAs. In order to achieve these aims, the data was collected in four phases. The first phase of the study addressed the nature of the linguistic challenges of the Department of Basic Education Grade 4 mathematics ANAs. Data collection occurred in two parts: 1) Comparing Grade 4 ANAs to exemplars provided and 2) Analysing the language of the 2013 mathematics ANAs. This was done through content analysis and Shaftel et al.’s (2006) linguistic complexity checklist. Findings for part 1 of the study revealed that there were several inconsistencies in the questioning format and language used in the ANAs and in the exemplars. Findings of the content analysis done on the 2013 mathematics ANA test items using Shaftel et al.’s (2006) linguistic complexity checklist and Vale’s (2013) Linguistic Complexity Index formula point to many linguistic complexities in several test items, particularly in relation to recurrent use of: 7 or more letter words, homophones, prepositional phrases and specific mathematics vocabulary across the majority of questions. In phase 2, the analysis of 106 learners’ written responses for the 2013 mathematics ANA questions revealed that for many of the questions the language used was unfamiliar for Grade 4 learners using English as an additional language. This was aggravated by the inclusion in the ANAs of linguistic forms learners would not have encountered in their workbooks or exemplars intended to prepare the learners for the assessments. Therefore, linguistic complexity of items was a key contributing factor to learners’ poor performance in the test. In the third phase, the quantitative and qualitative analysis of the 26 learners’ interviews revealed that during the task-based interviews, learners experienced difficulties in the following skills: reading, comprehension, transformation, process and encoding. The greatest difficulties were experienced in comprehension and in reading, especially in the two classes where the learners were less proficient in the English language. The fourth phase, in which two Grade 4 mathematics teachers’ perceptions of the linguistic demands of the Grade 4 mathematics ANAs were presented and analysed, the teachers’ perceptions indicated that the mathematical language was mostly too difficult for the Grade 4 learners. Teachers also were of the opinion that learners’ reading skills were poor and they struggled to comprehend what they read. A dilemma regarding whether teachers should assist learners during the ANAs, satisfying the local needs for mediating the language or whether they should comply with the ANA policy which states that they may not assist learners was expressed by one of the teachers. A range of language challenges that teachers managed with various strategies were raised. These included one teacher’s use of code-switching during the teaching of mathematics. The study concludes with implications and recommendations. These include that test designers should minimise the language complexity of test items, especially in the early transition grades of learning in English. Research should be conducted on possibilities for allowing teachers to provide linguistic mediation to ANA questions in these transition years of learners learning in English.
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- Date Issued: 2016
Investigating the role of Hsp90 and LRP1 in FN matrix dynamics
- Authors: Boël, Natasha Marie-Eraine
- Date: 2016
- Subjects: Extracellular matrix , Molecular chaperones , Heat shock proteins , Cancer , Fibronectins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2713 , vital:20319
- Description: Fibronectin (FN), a matrix protein responsible for regulating processes including migration and differentiation, is secreted as a soluble dimer which is assembled into an insoluble extracellular matrix. The dynamics of FN matrix assembly and degradation play a large role in cell migration and invasion contributing to the metastatic potential of cancer cells. Previous studies from our group have shown the direct binding of Hsp90 and FN in vitro and that inhibition of Hsp90 with novobiocin (NOV) caused internalisation of the FN matrix. However, the receptor mediating this internalisation is currently unknown. Low density lipoprotein 1 (LRP1) is a likely candidate as it is a ubiquitous receptor responsible for regulating internalisation of diverse ligands and is known to bind both Hsp90 and FN. We used wild type and knockout LRP1 cell lines to study the endocytosis of FN via this receptor. Here, we demonstrate that LRP1-deficient cells accumulated greatly increased levels of FN and were found to be less sensitive to pharmacological inhibition of Hsp90 by NOV. LRP1-expressing MEF-1 and Hs578T breast cancer cells experienced an increase in total FN in response to NOV, at concentrations below the EC50 value, followed by a dose-dependent loss of FN. We attributed greater FN levels to a loss of extracellular FN matrix coupled with increased internalisation of FN. Cell-surface biotinylation and DOC assays showed that loss of extracellular FN was specific to LRP1-expressing MEF-1 cells. Furthermore, we demonstrate that the loss of extracellular FN is not affected by changes in FN mRNA levels as determined by qRT-PCR, and that treatment with NOV resulted in the accelerated degradation of FN in the presence of cycloheximide. Immunoprecipitation studies reveal a putative complex exists between FN, Hsp90 and LRP1 in both cancer and non-cancer cells which is not perturbed by NOV. Western analyses revealed increased proteolytic processing of LRP1 in response to NOV which we proposed, based on literature, to modulate signalling pathways as a potential mechanism for regulating FN turnover. Moreover, using wound healing assays we identified increased migration to be one of the consequences associated with loss of extracellular FN by Hsp90 inhibition but only in cells containing LRP1. In summary, this study provides new insights into the Hsp90-LRP1 mediated loss of FN matrix and also reveals for the first time the functional consequence related to FN turnover by NOV was an increase in migration in LRP1-expressing cells.
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- Date Issued: 2016
Investigating the use of Arbuscular Mycorrhizas and Plant Growth Promoting Bacteria to improve the drought tolerance of maize (Zea mays L.)
- Authors: Moore, Nicolle Maureen
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54587 , vital:26591
- Description: Maize (Zea mays L.) is a direct staple food crop in Africa and remains an essential component of global food security, with maize crops accounting for over 60% of the total harvested area of annual food crops. Stress caused by drought and high soil salinity limits crop growth and productivity more than any other single environmental factor, with grain yield reductions up to 76% depending on the severity of the drought and the plant growth stage. Arbuscular mycorrhizal (AM) fungi and Plant Growth Promotion Rhizobacteria (PGPR) have previously been shown to improve tolerance of plants to drought stress through a number of chemical and physiological processes. The aim of this investigation was to determine whether mycorrhizal fungi and rhizobacteria adapted to drought and saline conditions and possessing plant growth promoting (PGP) traits were able to stimulate plant growth responses when applied to Zea mays seeds growing under greenhouse conditions Bacterial isolates selected were tolerant to concentrations of NaCl up to 600 mM and maintained 50% growth at low water potentials (-1.44 MPa). They were positive for Indole Acetic Acid (IAA) production, phosphate solubilisation and secretion of siderophores. Bacterial isolates showing plant growth promoting potential were identified using 16S rDNA gene sequencing as Achromobacter xylosoxidans strains A8 and C54 and Klebsiella oxytoca strain M1. Mixed inoculum was prepared from indigenous communities of mycorrhizas in soils sampled from the Cerebos Salt Pan and the Kalahari Desert. Mycorrhizal diversity was investigated using 454-Pyrosequencing which revealed that the community composition was dominated by species in the Ambispora, Glomus and Paraglomus genera with a rare component represented by species in the Redeckera, Archaeospora and Geosiphon genera. Microscopic examination of plant roots at the end of the trial revealed the presence of diagnostic mycorrhizal structures within the root cells, confirming that colonization was successful. Plant growth response to microbial inoculation was assessed by monitoring changes in plant photosynthetic capacity over the duration of a 7 week pot trial. A significant difference in photosynthetic and biomass data was observed between drought and well-watered groups but no mycorrhizal or bacterial treatment effect was evident within the groups, despite the high levels of colonization by mycorrhizas. These results suggest that the beneficial effects of mycorrhizal colonization may be primarily attributed to improved nutrient and mineral uptake in conditions where nutrients are limiting, resulting in improved growth. The improved growth may then have secondary effects on the plant‟s ability to withstand drought. Having controlled for nutrient deficiency, it was not evident in this study that mycorrhizal fungi were able to stimulate a change in plant physiology and confer drought tolerance under the conditions imposed.
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- Date Issued: 2016
Investigating youth perceptions of youth participation in development: a focus on community engagement as a platform for youth/student participation at Rhodes University
- Authors: Dano, Nqaba
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/1444 , vital:20058
- Description: The main objective of the study is to investigate youth perceptions of youth participation in development with a focus on the Rhodes Community Engagement programme as a platform for youth participation. The study was inspired by trying to locate the position that youth put themselves in when they regard their own participation in development. It was further motivated by trying to gain perspectives from the youth themselves because most discourses on youth rarely feature their own voices. The study utilized a qualitative methodology with an interpretive paradigm, which used semi-structured in-depth interviews as a method of data collection. The theoretical framework used was the notion of participatory development. The literature consulted was broken up into participation in development which looked at the history of participation and the need for participation, the importance of participation and the limits of participation and the type of participation. It looked at youth participation, the definition of youth as a group in society and the discourses that surround how youth are defined; lastly it looked at community engage in higher education, the role students place in community engagement and the nature of Rhodes Community engagement. The data was discussed and analysed following the above mentioned themes which were participation in development, youth participation and community engagement. From the data collected it was made evident that if youth are given more spaces and chances to actively participate they could challenge prominent discourses that treat them as irresponsible minors and exclude them from decision-making processes that directly affect them and the society within which they live.
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- Date Issued: 2016
Investigation of α-aryl substituted 3-indolylethanones as potential antiplasmodial agents
- Authors: Svogie, Archibald Lesley
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/55487 , vital:26704
- Description: According to the World Health Organisation (WHO), deaths attributed to Plasmodium falciparum exceeded 584 000 in 2013, with 198 million new cases of malaria being reported. One contributing factor to these alarming figures is the emergence of drug resistance against available antimalarial agents. Therefore, there is a pressing need to develop new therapeutic antimalarial drugs with novel mechanisms of action in order to curb the increasing spread of malaria. The indole scaffold is often associated with biologically active compounds, recently exemplified by the antimalarial agent NITD609, which is currently in phase 1 clinical trials. Based on the biological evaluation of a small series of indolyl-3-amides and esters which showed moderate antimalarial activity, coupled to significant toxicity, we were prompted to investigate the synthesis of a series of indolyl-3-ethanone-α-amines (3.37 and 3.41), ethers (3.39 and 3.44) and thioethers (3.42, 3.43, 3.40, 3.45 – 3.73), where the carbonyl moiety and respective heteroatom were separated by a methine spacer. We further investigated these compounds for in vitro biological activity against P. falciparum and a human HeLa cell line. Our study explored the synthetic pathway of a three-step procedure toward our target compounds, with the initial Friedel-Crafts acetylation of indole, followed by α-bromination of the respective 3-acetylindoles. Finally, the halogen of the α-bromo ketone was substituted with an appropriate nucleophile, to yield our desired compounds. Various reagents were explored to optimise the nucleophilic displacement step, including potassium carbonate and various silver containing compounds. While many of the silver salts were found to assist in nucleophilic substitution, none were superior to the addition of potassium carbonate. The majority of compounds, chiefly the thioethers, displayed promising antimalarial activity, against the chloroquine sensitive 3D7 P. falciparum strain, with two thioethers in particular (3.54 and 3.65) inhibiting P. falciparum in the low nanomolar range. Additionally, active compounds were generally found to be non-toxic against HeLa cells, indicating that indolyl-3-thioethers are selective for the malaria parasite. These findings allowed us to begin hypothesising a structure activity relationship of this class, as well as elucidating the possible pharmacophore. In a speculative attempt to uncover the possible mechanism of action of these active compounds, in silico docking studies were conducted against Staphylococcus aureus HPPK (PDB ID: 4CRJ), which is an enzyme that immediately precedes DHPS in the microbial folate biosynthesis. Inhibition of folate biosynthesis is a validated selective antimalarial pathway and HPPK also exists in P. falciparum. Results from these docking studies suggested that our inhibitors bound well in the HPPK ATP pocket and were supportive of our hypothesized structure activity relationship.
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- Date Issued: 2016
Islamic compliant short term insurance: an exploratory study to develop an Islamic compliant insurance model within a South African context
- Authors: Jeeva, Shakir
- Date: 2016
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193633 , vital:45375
- Description: In a world where there is ever increasing risks to be mitigated, either by choice or due to the law of the country, an insurance instrument is the most popular risk mitigation tool. However, from an Islamic perspective, Muslims have certain parameters to adhere to due to the laws and boundaries as set out in the Quraan, as well as the teachings of the final prophet, Prophet Muhammed (Peace Be Upon Him). This has relevance in this context as, according to Islam, the conventional insurance models are in contravention of certain Islamic laws as they contain elements which are not acceptable in the Muslim faith. Therefore, the Islamic insurance models, or Takaful models, have removed the impermissible elements of usury, speculation, and uncertainty, which are all contained in the current conventional insurance models. By removing these impermissible elements from the insurance model, the Takaful model is acceptable for Muslims to use as a risk mitigation tool. The primary aim of the study sought to propose a short term Islamic compliant insurance model within a South African framework. The secondary aims were to ascertain the Islamic requirements for an Islamic insurance model, how these requirements fit into an insurance model, to then compare and contrast the differences between conventional insurance and Islamic insurance and, lastly, to explore awareness and attitudes towards Islamic insurance. Therefore, from the above, a proposed short term Islamic insurance model was developed within a South African context which conforms to the laws and boundaries of Islam, making this insurance model permissible to use as a Takaful tool. Additionally, semi structured interviews were conducted with certain research participants, using purposive sampling, to examine the attitudes and knowledge of the Muslim community towards the Takaful model within a South African context. It was concluded that while the majority of the research participants understand the Takaful model and the significance of this, they have chosen to use the conventional insurance offerings due to the fact that they were unaware of other Takaful alternatives, or due to the fact that the Takaful alternative was out-priced when compared to the conventional insurance offerings. It was therefore concluded that while there is a need for Takaful offerings within South Africa, this must be done in conjunction with additional marketing, education and competitive pricing for potential clients to consider this as an insurance option. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2016
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- Date Issued: 2016
Isolation, characterization and biomimetic oxidation of selected marine natural products and their analogues
- Authors: Mutsvairo, Tafadzwa
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64685 , vital:28592
- Description: Marine brown algae produce a variety of terpenes with a wide range of biological activities. However, very few phytochemical studies of brown algae have been conducted in South Africa. Therefore, in our continued search for biologically active natural products, we examined the South African brown alga Brassicophycus brassicaeformis. The dichloromethane-methanol extract of B.brassicaeformis was fractionated by silica gel column chromatography followed by normal phase HPLC to give pure four pure compounds which were identified by spectroscopic methods as; fucosterol, fucoxanthin and two monogalactosyldiacylglycerol lipids. Many potential drug molecules such as natural products have failed to reach the market due to poor pharmacokinetic and metabolic profiles despite having potent biological activity. Therefore the importance of early drug metabolism studies in the drug development process is clear. A biomimetic oxidation model was used for in vitro drug metabolism studies to predict any possible metabolites that could be produced by these natural products. Two biomimetic oxidation models catalyzed by two water soluble metalloporphyrins as biomimics of cytochrome P450, in the presence of two terminal oxidants either hydrogen peroxide or iodobenzene diacetete were successfully developed. The models were applied to a range of natural products. The oxidation of the quinone natural products, sargahydroquinoic acid, and lapachol was most easily achieved by metalloporphyrins employed in this study.
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- Date Issued: 2016
Istraight Lendaba
- Authors: Motsei, Mmatshilo T N
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6015 , http://hdl.handle.net/10962/d1021235
- Description: My collection of stories describes the lives of ordinary black people living in post‐apartheid South Africa, especially those living in the margins, and the compromises that poverty forces them to make. In such a world, virtue and vice are flip sides of the same coin. My stories search for hope in an environment which Ayi Kwei Armah describes as “so completely seized with danger and so many different kinds of loss.” My writing is inspired by Mozambican writer Luis Bernardo Honwana, South African writer Joel Matlou whose demotic stories gave voice to everyday life in the townships, and Cameroonian writer Werewere Liking’s as well as Brenda Fassie’s powerful representation of the subversive nature of African women.
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- Date Issued: 2016
Land acquisition for and local livelihood implications of biofuel development in Zimbabwe
- Authors: Thondhlana, Gladman
- Date: 2016
- Subjects: Biomass energy -- Government policy -- Zimbabwe Biomass energy -- Economic aspects -- Zimbabwe Biomass energy -- Environmental aspects -- Zimbabwe
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/49940 , vital:25944
- Description: In recent years, proponents of 'green and clean fuel' have argued that the costs of overreliance on fossil fuels could be reduced through transition to biofuels such as bio-ethanol. Global biofuel discourses suggest that any transition to biofuel invariably results in significant benefits, including energy independence, job creation, development of agro-industrial centres at local level and high revenue generations for the state with minimum negative impacts on the environment. With many risks and costs associated with traditional 'dirty' fuels, it is likely that many countries, particularly African countries, will move towards the 'green and clean fuel' alternative. However, until recently research has arguably paid limited attention to the local livelihood impacts related to land acquisition for biofuel development or the policy frameworks required to maximise biofuel benefits. With regards to biofuel benefits, some recent studies suggest that the much bandied potential for greater tax revenue, lowered fuel costs and wealth distribution from biofuel production have all been perverted with relatively little payoff in wage labour opportunities in return (e.g. Richardson, 2010; Wilkinson and Herrera, 2010). Based on work done in Chisumbanje communal lands of Zimbabwe (Thondhlana, 2015), this policy brief highlights the local livelihood impacts of biofuel development and discusses policy implications of the findings. By highlighting the justifications of biofuel development at any cost by the state, the study sheds some light on the conflicts between state interests and local livelihood needs.
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- Date Issued: 2016
Land-use effects on mammal communities in the Fish-Kowie corridor, Eastern Cape, South Africa, with particular reference to carnivores
- Authors: Kok, Armand du Preez
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/561 , vital:19970
- Description: Human population growth is causing an increase in habitat transformation on a global scale, and this transformation is driven by changes in land-use practices. One consequence of habitat transformation is the negative effect it can have on mammal communities, especially carnivores. Carnivores are important components of ecosystems as they play an essential structuring role, but also often come into conflict with people. I studied the impact of land-use on mammalian diversity, the attitudes of landowners/managers towards carnivores, the distribution of carnivores, and the interactions among carnivore species in the Fish-Kowie corridor (FKC), an area of conservation concern, in the Eastern Cape, South Africa. Livestock and game farming are the two dominant land-use types in the FKC. Carnivore distribution data were collected between 2012 and 2014 using a robust camera trap survey that consisted of 432 camera stations (216 on livestock and 216 on game farms). In addition, the attitudes of 55 landowners/managers were assessed using semi- structured questionnaire interviews that were conducted in person. My results revealed that mammal diversity was similar on the two land-use types. However, individual species differed in their distribution on the two land-use types. In general, both livestock and game farmers had negative attitudes towards carnivores in the FKC, due to their depredation of valuable livestock and game species. Black-backed jackals (Canis mesomelas), caracals (Caracal caracal), leopards (Panthera pardus), and brown hyaenas (Parahyaena brunnea) were considered the most problematic carnivores, but sensitivity to land-use varied among these four species. Black- backed jackals had the highest occupancy rates of all four predators and were 3.8 times more likely to occupy sites on game farms compared to livestock farms. By contrast, leopards and brown hyaenas were only detected on game farms, and caracals did not appear to be sensitive to the effects of land-use. In general, the interactions among carnivores were weak and were likely driven by carnivore diversity, resource partitioning, and anthropogenic pressures. While there were many subtle differences in the distribution of mammal species and human attitudes towards wildlife on livestock and game farms in the FKC, there were also many similarities. My study has produced results that can be used by the FKC community to better understand how mammals and humans interact across the landscape, information that will ultimately contribute to future conservation planning in the area.
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- Date Issued: 2016
Landscapes of division: social movements and the politics of urban and rural space in the Grahamstown region of the Eastern Cape
- Authors: O’Halloran, Paddy
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3950 , vital:20572
- Description: This thesis investigates the politics of two grassroots social movements, the Unemployed People’s Movement (UPM), based in Grahamstown, and the Rural People’s Movement (RPM), based in the rural areas near Peddie, forty miles east. Observing that urban and rural are political designations, the primary question of this thesis is: Do the politics of these social movements challenge the conception of urban and rural as discrete political spaces? To some extent, it responds to and complicates Mamdani’s theory of a bifurcated state in post-apartheid South Africa in which urban zones are the site of civil society and rural zones the site of traditional authorities, and only the former a democratised space (1996). Three themes—race, space, and citizenship—are employed and interrogated in the process of answering the principal question. Broadly historical in nature, and understanding the present political context to be a product of historical processes, the thesis begins with an historical study of the Grahamstown region from the time of the town’s founding in 1812 until the end of apartheid in 1994, keeping the three key themes in focus. Then the politics of UPM and RPM are explored through a series of interviews aimed at understanding the context and experience of movement members and seeking their insight into the question of urban and rural space. Their responses are presented as a dialogue employing a theoretical strategy from Aguilar (2014) that distinguishes between and provides a framework to measure the ‘practical scope’ and the ‘interior horizon’ of movements. The thesis concludes with a discussion of important themes arising in the interviews: citizenship, NGOs, and political parties, and, of course, space. The backdrop to this concluding discussion is the xenophobic violence which occurred in Grahamstown in October 2015, helping situate the research and themes within the broader context of South African politics.
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- Date Issued: 2016
Leopard population density and community attitudes towards leopards in and around Debshan Ranch, Shangani, Zimbabwe
- Authors: Nyoni, Phumuzile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5946 , http://hdl.handle.net/10962/d1020838
- Description: Leopards (Panthera pardus) are regarded as one of the most resilient large carnivore species in the world and can persist in human dominated landscapes, areas with low prey availability nd highly fragmented habitats. However, recent evidence across much of their range reveals declining populations. In Zimbabwe, 500 Convention for the International Trade in Endangered Species (CITES) export tags are available annually for leopards as hunting trophies, despite limited accurate data on the leopard populations of the country. Moreover, when coupled with the massive land conversions under the controversial National Land Reform Programme (NLRP), leopard populations in Zimbabwe are in dire need of assessment. My study was conducted on Debshan ranch, Shangani, Zimbabwe, which is a commercial cattle (Bos indicus) ranch but also supports a high diversity of indigenous wildlife including an apparently healthy leopard population. However, the NLRP has resulted in an increase in small-holder subsistence farming communities around the ranch (the land was previously privately owned and divided into larger sub-units). This change in land-use means that both human and livestock densities have increased and the potential for human leopard conflict has increased. I estimated the leopard population density of the ranch and assessed community attitudes towards leopards in the communities surrounding the ranch. To estimate population densities, I performed spoor counts and conducted a camera trapping survey. Questionnaire interviews were used to assess community attitudes. My spoor counts provided a leopard density estimate of 13.57 leopards/100km2 compared to the camera trapping estimate of between 2.0 and 6.9 leopards/100km2. Although the high density estimate derived from the spoor counts is possible for Debshan because leopards are the apex predators and are adequately protected, potential edge effects are not yet fully understood. Thus, the more conservative estimate of 2.0 leopards/100km2, derived from the camera trapping survey, is probably more appropriate. Attitudes towards predators amongst respondents surrounding Debshan (n = 140) were neither too negative nor positive, attitude index had a mean score of 1.7 ± 3.8 (range: -7 – 10). No single predictor variable used in my analysis was able to adequately explain why the communities held these negative views. However, livestock losses were repeatedly listed by respondents as being one of the main reasons for their lack of tolerance towards predators. The density estimate of 2.0 leopards/100km2 translates to a population of 9 – 26 leopards within Debshan ranch. This density estimate is too low considering the habitat type at Debshan ranch but should be interpreted with caution as it lacks fundamental elements like age and sex ratio. Moreover, the interaction of the leopard population with the surrounding communities is currently unclear. As a precautionary measure, I recommended reducing the annual hunting quota for Debshan from five to one leopard. Future work should aim to improve the attitudes of the surrounding communities to secure broader landscapes for leopard conservation while also reconciling density estimates to fully understand the leopard population of the region.
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- Date Issued: 2016
Life history of the maritime platygastrid Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae: Scelioninae)
- Authors: Owen, Candice Ann
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/837 , vital:19995 , 10.21504/10962/837
- Description: Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae, Scelioninae) is an intertidal parasitoid wasp that uses the eggs of the maritime spider, Desis formidabilis O.P. Cambridge 1890 (Araneae: Desidae), as a host. This species is one of only three known maritime parasitoids globally, and is the only known spider egg parasitoid that attacks its host within the intertidal region in southern Africa. Originally described from ‘The Island’, Kommetjie (Western Cape, South Africa), this shore was the only known locality of the species at the commencement of this thesis. Furthermore, the extent of the parasitism pressure the wasp exerts on D. formidabilis was largely unknown, along with its basic biology (drivers of its broad-scale and fine-scale distribution patterns; parasitism incidence; and sex ratios) and morphological and physiological adaptations for living within the frequently saltwater-inundated environment. This thesis unravelled these aspects, as well as experimentally provided data for many components of the life history of E. lamorali that had only been hypothesized by other authors, at a variety of scales, from the country-wide ecosystem, to single shores, and finally to the scale of the individual. While the distribution of E. lamorali was found to be much wider than previously thought, it remained restricted to the shores of the Cape Peninsula (Western Cape, South Africa). The host spiders were located throughout a much wider distributional range than the wasp, from East London in the east to the Peninsula, but some behavioural and morphological differences were found between those within and outside of the range of the parasitoid, suggesting range-limitation imposed by the host on E. lamorali. This limitation may be strengthened by the general lack of suitable shore types within the close vicinity of the Peninsula. Modelling using macro-climatic conditions suggested that maximum temperatures and humidities were also largely limiting to E. lamorali, although these patterns were not observable in the micro-climates in which the species survives. The wasp populations and spiders within the range of E. lamorali as identified in Chapter 2 were assessed to determine any preferences for local conditions, including location along the Peninsula, nesting sites and intertidal zones within single shores, using AICc modelling, which detected parasitism patterns in D. formidabilis and E. lamorali populations, as well as the sex ratios in the latter species. The models showed that the spider population size and distribution was more influenced by bottom-up factors such as abiotic components of the shore than by parasitism, which only showed density dependence with the host at certain scales. Both host and parasitoid populations illustrated a preference for the middle zone on single shores. Observed spider nest characteristics suggested opportunistic nesting behaviour in the species, although preference was shown for construction along an east-west orientation and in locations with low sun exposure. Along with larger population sizes on the west coast over the east coast (not reflected by E. lamorali), these observations suggest that D. formidabilis prefers cooler environments. Spider brood success was 50% in unparasitized egg-sacs, but this figure halved when E. lamorali gained access to the eggs (of which 100% within a single compartment were parasitized each time). Encapsulation of the embryo was found to be positively correlated with parasitism, indicating some form of host resistance. Resultant parasitoid broods illustrated a strong female bias in the species, as is common for this group of insects. The life history of E. lamorali was then assessed at a smaller scale, that of the individual. Scanning electron microscopy of whole E. lamorali specimens and light microscopy of sectioned specimens demonstrated no morphological adaptations in the trachea and spiracles to cope with saltwater inundation. On the other hand, respirometry experiments categorically demonstrated that the species copes with inundation through the formation of a physical gill over the full habitus, and the induction of a state of torpor to reduce metabolic needs, when submerged. This precludes the need for any further morphological adaptations. Determination of the wasp’s critical thermal tolerance illustrated a wide temperature range with a particularly cold lower limit of -1.1ºC ± 0.16, suggesting the presence of related genera or ancestors in much colder environments. With a much broader distribution than previously thought, and the inclusion of the distributional range of E. lamorali within the Table Mountain National Park, this species is being effectively conserved and managed through the umbrella-conservation of the park. Links to the host proved to vary at differing scales, proving the need for scale considerations to be included in other similar biological and ecological studies. Finally, the species showed physiological adaptation to its intertidal existence. Echthrodesis lamorali, the only discovered maritime spider egg parasitoid in Southern Africa, displayed unusual characteristics at every scale of its life history and as such, warrants further investigation.
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- Date Issued: 2016
Links between valley confinement, landforms and vegetation distribution in a semi-arid valley floor environment, Baviaanskloof, South Africa
- Authors: Smith-Adao, Lindie B
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/953 , vital:20006
- Description: Although a large body of international literature has advanced our understanding of river systems, a considerable amount of gaps exit in the knowledge of dryland systems. River systems reflect complex interactions between biophysical processes and patterns. Understanding how processes generate observed patterns and, in turn, how patterns influence processes is crucial to understanding river structure and function. It requires an interdisciplinary approach in both research and resulting applications. The aim of this thesis was to examine the relationship between valley confinement, fluvial style, valley floor morphology and vegetation in the semi-arid environment of the Baviaanskloof river catchment, South Africa. This interdisciplinary investigation used a mixed method approach that involved desktop analyses and field surveys to understand dynamics at multiple scales, from the whole catchment to local (site, reach and quadrat or sample plot) scales. The desktop analyses included historical rainfall patterns and climate extremes, aerial photograph time-series and remote sensing greenness indices, and the field surveys focussed on cross-valley landform profiles, groundwater depth levels, sediment size distribution and soil chemistry, and vegetation distribution patterns. Based on the integrative assessment of these techniques a framework was developed of the links between valley confinement, surface-groundwater interaction, hydrogeomorphic processes and landforms, vegetation and human activities. Study findings highlighted the fact that very strong links exist between these factors. In this semi-arid area water availability (groundwater and streamflow conditions) was the primary control on valley floor vegetation composition and patterning. One group of species was associated with the wetted channel reaches at confined and semi-confined valley settings, while the other was associated with dry bed channel reaches at unconfined valley settings. The analyses also indicated that the environmental variables which best explained the variation in vegetation at the differing geomorphic landforms were related to landform position (elevation and distance), sediment size (fine and coarse sand) and available phosphorus (i.e. human impacts). The different plants, in turn, also affected landforms through their influence on sediment erosion, transport and deposition. Specially, they build, maintained or modified geomorphic landforms at confined, semi-confined and unconfined valley settings across the valley floor. Valley confinement was a primary control influencing hydrogeomorphic processes and their associated landforms. Alluvial fans and terraces acted as critical additional controls at especially the unconfined valley setting. Implications for restoration efforts in the catchment included strategies that took cognisance of: active revegetation on floodplain surfaces related to former agricultural fields; channel switching associated with the highly dynamic and unpredictable nature of geomorphic features; unstable multi-thread braided channels in the unconfined valley setting; and the selection of representative monitoring sites.
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- Date Issued: 2016
Livelihood strategies of female-headed households in the Coloured community of Sunningdale in Harare, Zimbabwe
- Authors: Wadi, Chenai C
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/3839 , vital:20547
- Description: The turbulent economic and political situation that has plagued Zimbabwe over the past two decades has had a dire effect on its urban population. The country’s tempestuous situation has not only threatened urbanites’ access to basic necessities but has also rendered many households and particularly female-headed households vulnerable to poverty and deprivation. Thus the primary objective of this study was to analyse and understand how coloured female-headed households in Sunningdale, Harare, Zimbabwe are surviving in the context of the current economic and political crises in the country. Essentially the study sought to achieve the three main objectives. The first objective was to identify and document the current livelihood strategies that a small sample of coloured female-headed households have adopted; the second was to explore the challenges and problems faced by female-headed households in their daily lives and lastly, the third was to establish what support mechanisms were available to these households to cope with the challenges and problems they face in generating an income and catering to their household needs. Methodologically the study employed a qualitative research approach with in-depth semi-structured interviews being used to collect data from five female-headed households. The data was then analysed using an interpretive approach and presented textually. Essentially the study found that in terms of the first research objective that coloured female-headed households engaged in a range of livelihood activities in order to earn a living, with informal trading being the main livelihood activity that the participants relied on to acquire an income to support their households. With regards to the second objective, it was revealed that the female heads interviewed faced numerous challenges ranging from economic to social problems that limited their ability to develop sustainable livelihoods, thereby increasing their risk to fall into poverty and validating their feminization of poverty. In terms of the third and last objective, the study found that the female heads did not have many reliable support mechanisms available to them thereby limiting their ability to achieve financial and social empowerment.
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- Date Issued: 2016
Local versus landscape effects of bush encroachment on plant available light, soil moisture, frost occurrence and herbaceous productivity and composition
- Authors: Klopper, Chrisna
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3137 , vital:20376
- Description: Bush encroachment is a global phenomenon and a pressing concern for South Africa rangelands. The expansion and increase in density of Vachellia karroo (hereafter referred to aAcacia karroo) has been documented in the Eastern Cape and KwaZulu Natal in South Africa. This increase in woody species in savannas is often at the expense of grass cover and thus is causing concern about how this will impact agriculture due to possible loss of grazing capacity. To understand the impacts of bush encroachment the effect of trees on their micro-climate and abiotic factors and in turn on the herbaceous layer needs to be examined. The objective of this study was to quantify the effect of Acacia karroo encroachment on the light environment, soil moisture and frost occurrence in the sub-canopy and inter-canopy micro-habitats, and how these changes affected herbaceous player productivity and composition. Another question that is being addressed here is whether, and how, the local tree effects scale up in the landscape and whether prediction can be made based on the effects of individual trees. The study was undertaken on a farm, Endwell, in the Smaldeel, Eastern Cape. At the study site, a semi-arid savanna, Acacia karroo has been encroaching since the 1980’s. The study was conducted at three scales: landscape, stand-wide and local scale. The landscape scale was represented by four areas with 0, 21, 45 and 72% tree canopy cover, the stand-wide scale consisted of transects with varying percentages of tree canopy cover within each of the four levels of encroachment. The local scale was represented by the sub-canopy and inter-canopy environment to test the effect of trees. At the local scale plant available light and soil moisture were lower in the sub-canopy than intercanopy regions, with leaf area index being higher in the sub-canopy. This local negative effect of the tree canopy on light and soil moisture in the sub-canopy did not scale up predictably in the landscape. At the stand-wide scale light in the inter-canopy was reduced as shading increased. Frost was excluded from under the canopies and frost incidence decreased at higher tree cover. Grass productivity was reduced in the sub-canopy, possibly due to lower light and soil moisture. Overall biomass increased from the low to medium level of encroachment but lowest at the high level of encroachment. Grass composition and cover was only slightly affected by tree canopies cover and C4 grass species were still present in the sub-canopy and at lower light environments. At the levels of Acacia karroo encroachment encountered at this study site, it seems unlikely that palatable or desirable C4 would be excluded from the system and that a shift from C4 to shade-tolerant species would occur. This is due to tree canopies at the site not reducing light to such anextent that they would outcompete grasses, and likely the very low grazing pressure at thesesites. Herbaceous biomass at these sites were still sufficient to carry a fire in the inter-canopyregion and sufficient grazing for herbivores. In the sub-canopy region fires will be excluded thus with higher the portion of sub-canopy areas increasing at the high levels of encroachment they may interrupt fire spread. Thus it was concluded that Acacia karroo encroachment up to 45% tree cover is currently not creating negative feedback on herbivory, but low stocking rates appear to be key to maintain this.
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- Date Issued: 2016
Localizing selected endocytosis protein candidates in Plasmodium falciparum using GFP-tagged fusion constructs
- Authors: Basson, Travis
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2680 , vital:20316
- Description: Malaria is a mosquito-borne infectious disease caused by several obligate intracellular protozoan parasites in the Plasmodium genus, with Plasmodium falciparum causing the most widespread cases and malaria deaths. In 2013 there were approximately 190 million cases of the disease and between 584,000 and 855,000 deaths. It is essential to identify novel drug targets and develop novel drug candidates due to the increase in resistance of P. falciparum parasites to the current arsenal of antimalarial drugs. Endocytosis is an essential process in eukaryotic cells in which the external environment is internalized by the cell in order to obtain various particles from the extracellular space. This extracellular cytoplasm is internalized in membrane-bound invaginations at the plasma membrane. During the blood stage of malaria infection, the parasite requires nutrients from the host red blood cell. To obtain these nutrients, the parasite internalizes haemoglobin in large amounts and degrades it in an acidic, lysosome-like organelle, known as the digestive vacuole. Whilst the exact molecular mechanism of malaria parasite endocytosis is not yet fully understood, a number of proteins have been suggested to be involved. The most expedient approach in identifying candidate endocytosis proteins is to investigate parasite homologues of proteins known to be involved in endocytosis in mammalian cells. The three proteins selected for investigation in this study were the P. falciparum homologues of coronin, dynamin 2, and μ4. The coding sequences for the candidate endocytosis proteins were amplified by PCR and cloned into the pARL2-GFP expression vector. P. falciparum 3D7 parasites were transfected with these vectors and the episomal expression of full-length GFP-tagged fusion protein was confirmed by Western blot analysis using commercially available anti-GFP antibodies. Microscopic analysis of live parasites using fluorescence and confocal microscopy was used to determine the localization of the candidate endocytosis proteins. Coronin appeared to display diffuse cytoplasmic GFP localization during the trophozoite stage, arguing against a role in endocytosis. However, distinct localization during the schizont stage at what appears to be the inner membrane complex was observed. Coronin is thus likely required to coordinate the formation of the actin network between the merozoite IMC and the plasma membrane on which the glideosome is dependant for generating the motile forces required for the merozoite motility and invasion of RBCs. Dynamin 2 displayed localization at three potential locii: the parasite periphery (plasma membrane), punctuate regions within the cytoplasm (potentially at membrane bound organelles) and at the parasite food vacuole. The data suggested that dynamin 2 is involved in endocytosis and membrane trafficking in a similar manner to classical dynamins, potentially as a vesicle scission molecule at the plasma membrane, mediating vesicle formation at the food vacuole to recycle membrane to the plasma membrane, and possibly mitochondria organelle division. μ4 displayed transient localization, cycling between cytosolic localization, and localization to distinct regions at the plasma membrane and the food vacuole. Localization of Pfμ4 to the plasma membrane is indicative of a role for μ4 as a part of an adaptor protein (AP) complex which may be responsible for recruitment of clathrin to initiate endocytosis in a manner similar to mammalian AP-2. As was observed with PfDYN2, Pfμ4 localizes to the FV, which suggests that Pfμ4 forms part of a coat complex that mediates the formation of vesicles that recycle membrane from the FV to the parasite plasma membrane. This study showed that expressing proteins as full-length GFP-tagged fusion constructs is an effective approach in the early stages of determining the localization and function of P. falciparum proteins in vitro, and distinguishing between candidates that have a potential role in endocytosis and those that are unlikely to do so.
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- Date Issued: 2016
Managerial leadership in committees: a case study in a public rural combined school in the Ohangwena region, Namibia
- Authors: Vaeta, Simon
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1220 , vital:20036
- Description: The existing education legislations in Namibia call for school principals to put in place appropriate support mechanisms and create necessary internal conditions for leaders, including teachers who do not hold formal leadership positions, to exert their sphere of influence beyond the classroom and into school-wide leadership activities. The establishment of various committees in the school is to enhance and improve the performance of the school and to create a pleasant work environment and spirit of collaboration and teamwork (Namibia Ministry of Education, [MoE], 2005). Leadership in committees is one of the expectations of new education policy. The aim of this study was to explore the leadership practices within a range of committees in a public rural combined school in the Ohangwena region of Namibia. It further unpacked the purpose, roles and membership of each of the four committees; how these committees were established; what leadership functions the teachers as committee members exercised and what challenges inhibited their leadership practices within committees. The study provided recommendations for future research in the area of leadership practices in committees. This research is a case study. The study is designed within the qualitative interpretive paradigm. It is rooted in a social constructivist tradition and employs a range of data collection tools, namely document analysis, semi-structured interviews, observations and questionnaires to enhance the validity of findings. The study found that committees were established in line with the Namibian education legislation. However, the study found the principal lacked the experience and skills to use the committee system more effectively, and maintained the status quo. This resulted in the committees practising pure management responsibilities rather than leadership interest. The study also found that only the leadership tasks were distributed to the committees but the power was not distributed. It was revealed that committees were dormant; while they were named in school documents, they functioned variously, intermittently or not at all. The significance of the contradiction was there were no regulations to guide the conduct of committee members.
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- Date Issued: 2016
Mapping Nitrogen Loading in Freshwater Systems: Using Aquatic Biota to Trace Nutrients
- Authors: Motitsoe, Samuel Nkopane
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5945 , http://hdl.handle.net/10962/d1020819
- Description: The majority of river systems in developing countries like South Africa, are found in catchments areas that are densely human populated, therefore are subjected to intense land-use and developmental pressures. Anthropogenic nutrient pollution or the excessive addition of nutrients is one important type of stressors that river systems often experience through intense land-use, which includes poor waste management and agricultural practices. Such events are referred to as the “urban syndrome”, were human populations and developmental demands outpace ecosystem services. Traditional measurements of water quality (e.g. physicochemical and micro-nutrient assessments) and biological monitoring (e.g. South African Scoring System 5, SASS5) techniques for assessing ecosystem health have being widely used to reflect the ecological health and status of river systems. However these techniques have a number of challenges associated with their application. SASS5 which is used most prevalently in southern Africa for example, can only be applied in lotic systems, it is habitat dependent and finally (but arguably most importantly) it cannot identify the source of pollution inputs. Recent laboratory studies using stable isotopic ratios (δ15N and δ13C) of aquatic macrophytes (duckweed: Spirodela sp.) have shown successful differentiation between different N-sources and the mapping of temporal and spatial nitrogen dynamics in freshwater systems. Furthermore δ15N isotopic values of Spirodela sp. showed the capability to act as an early warning indicator of eutrophication, before the onset of aquatic ecosystem degradation. Therefore, this study aimed to field test the potential of sewage plume mapping using the stable isotopic values of Spirodela sp. and aquatic macroinvertebrates at nine study sites on the Bloukrans-Kowie River and ten study sites on the Bushman-New Year’s River systems in the Eastern Cape, South Africa. And more...
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- Date Issued: 2016
Marie Curie : a psychobiography
- Authors: Roets, Elmeret
- Date: 2016
- Subjects: Curie, Marie -- 1867-1934 -- Psychology , Women chemists -- Poland -- Biography , Scientists -- Biography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3269 , http://hdl.handle.net/10962/d1020326
- Description: While researchers debate the value of psychobiographical research, interest in this area is growing on a national and international basis. Every year, the number of psychobiographical studies at universities in South Africa is growing. Psychobiographical research is qualitative research that utilises psychological theory to explore and describe the lives of extraordinary individuals. The primary aim of this psychobiography was to examine the life of Marie Curie (1867–1934) by employing developmental psychologist and psychoanalyst Erik Erikson’s (1959) theory of psychosocial personality development. Marie Curie was chosen as the research subject because of the researcher’s personal interest and the subject’s prominence as a female scientist. She was a Polish-born and naturalised French scientist who conducted pioneering research on radioactivity. Marie Curie’s ground-breaking discoveries changed the way scientists think about matter and energy and introduced a new era in medical knowledge and the treatment of disease. Her life exemplifies a love of science, commitment, and perseverance. Data were collected from several primary and secondary sources on Marie Curie’s life. The researcher developed a data-collection and analysis matrix to facilitate the systematic collection of data and analysis according to Erikson’s stage theory of psychosocial personality development. This psychobiography suggests that unresolved infantile and early childhood crises gave rise to personality traits that eventually contributed to Curie’s extraordinariness. In the case of Curie, personality traits that are often regarded as atypical or malignant, ironically encouraged perseverance, creativity, and productivity. This study complements the psychobiographical studies done in South Africa on extraordinary individuals. It demonstrated the value of psychobiographical research as a teaching instrument, revealed the usefulness of Erikson’s theory, and illustrated the uniqueness of individuals.
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- Date Issued: 2016