Taxonomic and trait-based responses of the orders Ephemeroptera, Plecoptera, Odonata, And Trichoptera (EPOT) to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa
- Authors: Akamagwuna, Frank Chukwuzuoke
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/68082 , vital:29196
- Description: Increased urbanization and industrialisation due to human population growth and associated high demand for food have led to widespread disturbances of freshwater ecosystems and associated resources. A widely recognised consequence of these disturbances is the excessive delivery of sediments into the freshwater ecosystems, which severely affects the functioning and integrity of these systems.. The major water quality impairment in the Tsitsa River and its tributaries, situated in the Mzimvubu catchment in the Eastern Cape Province of South Africa, is known to be excessive sediment input. In this study, the application of macroinvertebrates taxonomic-based and trait-based approaches was used to assess the responses and vulnerability of Ephemeroptera, Plecoptera, Odonata and Trichoptera (EPOT) species to settled and suspended sediments stress in eight selected sampling sites in the Tsitsa River and its tributaries. The eight selected sites were Site 1 (Tsitsa upstream), Site 2 (Tsitsa downstream), Site 3 (Qurana tributary), Site 4 (Pot River upstream), Site 5 (Pot River downstream), Site 6 (Little Pot River), Site 7 (Millstream upstream) and Site 8 (Millstream downstream). The methods used in this study involved the analysis of water physico-chemical variables as well as sediment characteristics, derivation of five EPOT metrics, EPOT species-level taxonomic analysis, individual EPOT trait analysis and the development of a novel trait-based approach using a combination of traits. The sampling of EPOT taxa was done using the SASS5 protocols. Identification of EPOT was done to genus/species level and all data were subjected to relevant statistical analysis. The results of ecological categories derived for the physico-chemical variables generally indicated the ecological categories A and B, which was indicative of good water quality conditions. The result of sediment particle analysis revealed four distinct site groups: site group 1 (Tsitsa River upstream and Qurana tributary), site group 2 (Tsitsa River downstream and Millstream upstream), site group 3 (Pot River, both upstream and downstream, and Millstream downstream) and site group 4 (Little Pot River). The species-level taxonomic analysis of EPOT revealed that site group 1 was the most sediment-influenced sites whereas site group 4 was the least sediment-influenced. Species such as Paragopmhus sp., Aeshna sp. and Baetis sp. were considered sediment-tolerant with strong positive association with site group 1. The novel trait-based approach developed in this study proved useful in predicting the responses of EPOT species to sediment stress, and further discriminated between the study sites. The approach was used to group EPOT species into four vulnerability classes. The result showed that filter feeding EPOT species that have filamentous gills, preferring stone biotopes and feeding on detritus (FPOM) were mostly classified as highly vulnerable to sediment stress and indicated no significant association with the highly sediment-influenced site group 1. The TBA largely corresponded well to the predictions made with the relative abundance of the vulnerable class decreasing in the sediment-influenced sites compared to the tolerant and highly tolerant classes. Overall, the study revealed the importance of the complementary use of taxonomic and trait-based approaches to biomonitoring.
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A pilot wide-field VLBI survey of the GOODS-North field
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
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Where dreams become reality: professionalism in flight training in the Eastern Cape
- Authors: Allison, Martin
- Date: 2019
- Subjects: Professional socialization , Flight training -- South Africa , Flight schools -- South Africa -- Case studies , Air pilots -- Training of -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/95376 , vital:31150
- Description: This study explores the construction of the identity of professional pilots through a case study of a flying school in South Africa. Here, a 15-20-month period of intensive study and training of students, fresh from school or college, leads in most cases to the attainment of a Commercial or Airline Transport Pilot’s Licence. The construction of identity is a continuous process and a lifelong project and hence this study can only reflect upon the factors influencing the early stages of a pilot’s career, until the point where the licenced Pilot leaves the Air School and enters full time employment with a commercial undertaking, but it is argued that this is a crucial step in the formation of professional identity, habitus in Bourdieu’s terms. The culture of the air School reflects the military background of the founders of the school and the staff employed in senior positions. The school, which is residential, observes a strict regime of Ground School and Practical Flying Training and a high standard of performance and personal conduct is demanded, both during training and in off duty hours and excessive consumption of alcohol and smoking are discouraged, and drug use absolutely taboo. Progress with training at the school is closely monitored and a disciplined environment maintained by surveillance cameras, house monitors and security guards; in Foucauldian terms, a modern version of the Panopticon, but somewhat less than Goffman’s Total Institution. It was found that the construction of a flying identity for most of the students entering the air school commenced in childhood or early adulthood, through the influence of friends and relatives and they enter the school with the firm intention of becoming Professional pilots. Full participation of the author in the Ground School revealed how professionalization is implemented through the discipline and rigor of the training methods employed. Through mastery of a complex body of theoretical knowledge in the Ground School and the practical skill of learning to fly in a one-on-one relationship with an instructor, the students gain confidence and efficacy which contributes to their self-respect and maturity. The international reputation of the school, confers prestige upon its graduates and they benefit from membership of a profession which commands respect and a high level of income. In large measure, the thesis shows, the success of the School is a function of the founders’ ‘invention of tradition’ focusing on the wartime training school that existed on the site and the many echoes of those times in the (re)construction of its buildings and facilities, continuing in the approach of the multinational that now owns the School.
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Factors influencing parents’ decisions when choosing a private school
- Authors: Arendse, David
- Date: 2019
- Subjects: School choice -- South Africa -- Case studies , Competition -- South Africa , Private schools -- South Africa , Consumer behavior , VRIO framework (Valuable, Rare, Imitable and Organized) , St. Stithians College
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/92628 , vital:30738
- Description: Purpose: Consumers make decisions based on multiple factors that influence their decision-making process. These decisions can be influenced by deep personal reflection to the simple impulsive purchase done to fulfil a need or want. This research study explored the relationship between the resource-based view and the factors considered by parents when selecting a school for their child/children. The Valuable, Rare, Imitable and Organized (VRIO) framework as developed by Barney, J. (1991) outlines the framework through which an organisations resources can be assessed in terms of their potential competitive advantage. The research study was interested in understanding how an educational institution can identify and then leverage its resources to create a competitive advantage. Methodology: Each family that has one or more child enrolled at St Stithians College, which is a private school in Gauteng, South Africa, was invited to participate in the study. This represented a potential population size of 1 700 families, however a sample of 334 was used. The educational institution caters to both boys and girls from Grade R to 12 (Matric). Each family was requested to participate in the study as they had already chosen to have at least one child enrolled. A self-administered close-ended questionnaire was used as the instrument for data collection and the questionnaire was broken into two sections. Section A focused on building a profile of the respondent while section B assessed the level of influence the factors had on a parent’s decision. Section B’s questions were structured as Likert-Scale questions requiring a response between 1 and 5, with 5 being the highest influence, and 1 being the lowest. The responses to the questions were then grouped into the factors they spoke to and the average results per factor were assessed via an ANOVA table to test the null hypothesis that parents do not consider factors when choosing a school for their children. Findings: As a paper, this study set out to discover what the competitive advantage was of a private education institution in South Africa. It did so by identifying what the key factors were when parents selected the school of their choice and then analysed these findings against the resources of the given institution. The ANOVA table analysis of the responses identified that parents do consider factors and that the factor that they were most influenced by was convenience factor, represented by location of the institution and the distance to it. While there are multiple private education suppliers in South Africa, no other provider has the location that St Stithians College has, and as such, its location is its competitive advantage. Significant: This research study will expand the existing but limited competitive advantage body of knowledge in the South African education sector. South African educational institutions will be able to develop similar studies which will then assist in identifying their own competitive advantages. This can better enable education providers to entice consumers to their education services.
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Investigating the nature of grade six after school mathematics club learners’ shifts in mathematical number sense and procedural fluency
- Authors: Baart, Noluntu Via
- Date: 2019
- Subjects: Mathematics -- Study and teaching (Elementary) -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa -- Case studies , Numeracy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/96825 , vital:31326
- Description: A wide range of research locally points to intermediate phase learners having extremely weak basic number sense resulting in the dominance of inefficient strategies for calculations with the four operations, irrespective of the number range. The grade six Annual National Assessments (ANA) diagnostic reports for 2012 to 2014 also point to errors and misconceptions that tend to dominate learners’ computations in the four basic operations; such errors are often attributed to the use of either tallies or incorrectly applied mathematical procedures. Having the above context in mind and following informal conversations with teachers in the Uitenhage Education District, five teachers expressed an interest in running the afterschool mathematics clubs based on the South African Numeracy Chair (SANC) project model. The SANC project team ran workshops in April, May and June 2016 with nine teachers (five as facilitators and four others as co-facilitators in five different club sites) in which teachers were provided with key resources for use in their clubs. Fifteen club sessions ran in each club with grade six learners across the 2nd and 3rd terms. These clubs form the empirical field for this research, which aims to investigate the nature of learners’ evolving number sense, procedural fluency and teachers’ experiences of working with learners in the club space. The unit of analysis in this study is both the shifts evident in learners’ number sense and procedural fluency as a result of participating in the clubs and the teacher’s experiences of working with learners in those clubs as club facilitators. A social constructivist perspective of learning guides this study. Especially Vygotsky’s (1978) notion that cognitive development stems from social interactions and guided learning within the Zone of Proximal Development (ZPD) of children, guided by more knowledgeable others. Furthermore, Kilpatrick et al.’s (2001) strands of mathematical proficiency provide the conceptual frame with a particular focus on procedural fluency and number sense. A mixed method approach to data collection was used. Quantitative data has been drawn from learner’s scores on pre- and post- assessments on four basic operations. Visual progression spectra have been adopted from the Pushing for Progression (PfP) Programme which is an intervention Programme developed by the SANC project for club facilitators. They provide explanations of learner progression trajectories and how to analyse learner methods. Qualitative narratives were drawn from learner progression data, as well as teacher post club questionnaires and one-to-one teacher interviews. The findings of this research suggest that learner workings when used in conjunction with visual progression spectra can provide important clues to researchers and teachers. This in turn contributes to an understanding of where learners are in their mathematical learning and gives ideas for how to support learners to progress using more flexible methods of calculation, particularly for poor performing learners. Included, is the discussion of the effectiveness of the club space to enable such shifts and improve learner flexibility, fluency and performance as displayed in learner methods and scores of the pre- and post- assessments. The teachers’ observations about the relaxed atmosphere in the club space, small sized groups, learning through play with co-members may have enabled the shifts in procedural fluency and number sense in club learners. Additionally, implications of the study are discussed, and tentative recommendations are made for the DBE to consider.
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The influence of artificial light on the foraging efficiency and diet of insect eating bats
- Authors: Bailey, Lauren
- Date: 2019
- Subjects: Predation (Biology) , Bats -- Effect of light on , Bats -- Nutrition , Moths
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76376 , vital:30555
- Description: Artificial light may be altering the interactions between bats and moth prey. Unable to make use of bat evasion strategies around artificial light, eared moths are susceptible to exploitation by syntonic bats (using echolocation frequencies between 20-50 kHz within the hearing range of eared moths). Using a handheld plasma metabolite analyzer, I evaluated the foraging success of syntonic bats and rarer allotonic bats (using echolocation frequencies outside the hearing range of eared moths), in areas with artificial light and in areas of natural darkness. I used microscope diet analysis to determine whether bats were consuming more or fewer moths in areas with artificial light and in areas of natural darkness. Syntonic bats were more selective for moth prey under lit conditions, likely owing to a reduction in the ability of tympanate moths to evade bats. Moths increased in the diets of generalist syntonic bats (Pipistrellus hesperidus) foraging around artificial light sources. Some P. hesperidus individuals showed high β-hydroxybutyrate levels around lights, but there was no difference in β-hydroxybutyrate levels between lit and unlit conditions. There is insufficient evidence to reject the null hypothesis that the foraging success of syntonic bats is equivalent in lit vs unlit conditions. The foraging success and diets of allotonic bats, Rhinolophus capensis, appear to be negligibly impacted by artificial light on a small scale. My study emphasizes the need for a mechanistic understanding of the influence of artificial light on the foraging success of bat species. Bat-moth interactions may be influenced by other factors apart from the common assumption that increased refuelling rates will occur in syntonic species foraging on moths around artificial light.
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An exploration of social media as a key site for the expression of post-racial politics
- Authors: Bell, Joshua
- Date: 2019
- Subjects: Social media -- Political aspects -- South Africa , South Africa -- Politics and government -- 1994- , South Africa -- In mass media
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/94049 , vital:30995
- Description: This research sets out to examine colourblind racism in contemporary South Africa, specifically, as expressed on social media networks. In South Africa, a nation lauded for its transition from Apartheid to liberal democracy, racism still continues to exist. In the new democracy, racism continues in old, familiar forms but it has been suggested that racism also assumes new and emergent forms such as ‘colourblind’ racism. This is evident in recent controversies involving local public figures and their expressions of ‘soft’, ‘colourblind’ racism on Facebook. It is the new platforms and modes of racism unique to democratic South Africa which this thesis attempts to explore. Specifically, this study is framed by ‘post-racialism’, a concept developed by scholars globally to capture the suggestion that in liberal democratic societies across the world, racism continues with racial inequality now underpinned by an ideology of colourblindness as opposed to overt policies of segregation. Colourblindness denies the relevance of race as a collective issue, proposing instead that other social factors such as class are more pertinent in considerations of social inequality. The purpose of colourblind narratives may be identified as the reduction of racism to mere individual action, denying systemic white privilege and historical responsibility for reparation as well as preventing racially subjugated groups from critically interrogating racial power and privilege (Goldberg, 2015: 28-30). Post-racial theorists agree that the projection of colourblind politics which claims to no longer ‘see race’ has instead served to secure the normalisation of white privilege and black subjugation (Bonilla-Silva et al, 2004: 559-560). The purported existence of colourblind /post-racial racism and its impact requires exploration in the context of South Africa today. In expanding on the definition of racism, we are able to see that racism is an adaptive system of power that is able to reproduce and reconceptualise itself to changes within society. As modalities of racism have evolved, so have the platforms for its propagation. This research offers social media as a site of exploration for post-racial narratives. The case studies of Penny Sparrow, Helen Zille and Mabel Jansen are presented in this study as exemplars of post-racial liberalism, denial and exclusion. This research calls for the expansion of racial understanding so as to contest racial power structures as a continuing systemic issue in contemporary South Africa.
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Targeted attack detection by means of free and open source solutions
- Authors: Bernardo, Louis F
- Date: 2019
- Subjects: Computer networks -- Security measures , Information technology -- Security measures , Computer security -- Management , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92269 , vital:30703
- Description: Compliance requirements are part of everyday business requirements for various areas, such as retail and medical services. As part of compliance it may be required to have infrastructure in place to monitor the activities in the environment to ensure that the relevant data and environment is sufficiently protected. At the core of such monitoring solutions one would find some type of data repository, or database, to store and ultimately correlate the captured events. Such solutions are commonly called Security Information and Event Management, or SIEM for short. Larger companies have been known to use commercial solutions such as IBM's Qradar, Logrythm, or Splunk. However, these come at significant cost and arent suitable for smaller businesses with limited budgets. These solutions require manual configuration of event correlation for detection of activities that place the environment in danger. This usually requires vendor implementation assistance that also would come at a cost. Alternatively, there are open source solutions that provide the required functionality. This research will demonstrate building an open source solution, with minimal to no cost for hardware or software, while still maintaining the capability of detecting targeted attacks. The solution presented in this research includes Wazuh, which is a combination of OSSEC and the ELK stack, integrated with an Network Intrusion Detection System (NIDS). The success of the integration, is determined by measuring postive attack detection based on each different configuration options. To perform the testing, a deliberately vulnerable platform named Metasploitable will be used as a victim host. The victim host vulnerabilities were created specifically to serve as target for Metasploit. The attacks were generated by utilising Metasploit Framework on a prebuilt Kali Linux host.
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Narratives and home: remembering an almost forgotten walk
- Authors: Bezuidenhout, Natasha Belinda
- Date: 2019
- Subjects: Home in literature , Home in art , Artists -- South Africa
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/115039 , vital:34072
- Description: The title of my exhibition Bittersoet alludes to the self-exploratory nature of my practice, as I interrogate the personal memories associated with objects that characterise the relationship between myself and my mother (mamma). This supporting document, Narratives and Home: Remembering an almost forgotten walk, considers the key conceptual concerns informing my practice. In this mini-thesis, I address the question: ‘What is a home?’. Drawing from my own Fine Art Practice, I explore how home can be examined as a product of the imagination, rather than only as a physical place. I consider how ‘home’ is constructed as the primary objective within an ideological framework defined by history, memory and narrative. Engaging beyond the idea of ‘home’ as a fixed structure or place, I examine the idea of ‘home’ as something fluid that is negotiated and defined by the interaction between objects and language. It is concerned with dialectics of memory and narrative as they pertain directly to an experience of both searching for and reimagining home through metaphorical representations. In particular, I explore how home can be seen as equally familiar and unfamiliar, existing in-between, always changing, never fixed, rather in a constant state of flux. The concept of home is addressed in a dialogical process by using Afrikaans as my mother tongue, I narrate informal conversations between myself and my mother. These conversations transform and expand into hybrid words, memories and narratives to form a layered continuous dialogue between my practice and research. This notion relates to exploring oneself and the ‘fictions’ of the past. The self being fundamental to the individual comprehension of both ‘place’ and ‘space’.
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Communicating in/from the Cave: a communication for development/social change project aimed at enhancing communication, action and learning within the science cave, a learner-led Grade 10 science club in a public school in Makhanda
- Authors: Bombi, Thandi
- Date: 2019
- Subjects: Science -- Study and teaching (Secondary) -- South Africa , Communication in science -- South Africa , Science -- Study and teaching (Secondary) -- South Africa -- Makhanda , Communication in science -- South Africa -- Makhanda , Student centered learning -- South Africa , Student centered learning-- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96837 , vital:31330
- Description: This research seeks to design, execute and reflect on a process where the principles and techniques of Communication for Development and Social Change are applied to enhance, support and develop qualitative changes within a learner-led Grade 10 science club at a public school in Makhanda. It draws and reflects on an ethnographic action research (Tacchi et al 2003) cycle proposed to explore the club’s communicative ecology (Foth & Hearn 2007) and resources, and understand how these have the potential to encourage the expression of voice (Couldry 2010: 580) and participation (Carpentier, 2011) in the members of the club. The research then attempts to understand the kind of communication, action and learning that takes place as well as the ways in which the framework is able to support the club (or not). The research uses an ethnographic narrative, told from the perspective of the researcher informed by field notes, interviews and participant reflections written during the intervention. This narrative, alongside an analytical summery of the club’s complex communicative ecology, tells the story of a club building confidence within a closed group and using that to connect with a wider public, articulating its needs, resources and potential supporting stakeholders for the club’s future development. The club is able to share its achievements with a community of peers and uses the platform of Facebook, to communicate with and inspire other like-minded people with an interest in science and their community.
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An investigation of learning and emerging knowledge in the Mpophomeni Sanitation Education Project, Howick, KwaZulu-Natal
- Authors: Boothway, Reinetta Louina
- Date: 2019
- Subjects: Environmental education -- South Africa , Mpophomeni Sanitation Education Project (South Africa) , Water quality management -- Study and teaching -- South Africa , Knowledge and learning
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/115377 , vital:34121
- Description: This study took place within the broader context of water resources management in South Africa. With the democratisation of water stewardship through an enabling international and South African water policy landscape, an opportunity opened up for citizens to participate in the effective management of their own water resources. In this context, a community-engaged citizen science project known as the Mpophomeni Sanitation Education Project emerged to demonstrate how a diverse range of knowledge agents can work and learn together to better manage their water resources and address problems of sewage pollution threatening their provincial water source. The following study aimed to shed light on the learning and emerging knowledge in the MSEP. The study was conducted in three phases. Wenger’s Communities of Practice (CoP) theory provided a lens to look at Phase One, which aimed to answer the following sub-question: Is the MSEP a CoP? Wenger’s CoP theory also assisted with the investigation during Phase Two, which looked at the following question: What is the nature of learning in the MSEP? Social realist theories of knowledge and education, and Tàbara and Chabay with their Ideal Type (IT) worldviews, provided suitable lenses for Phase Three’s investigation of the following question: What is the nature of emerging knowledge in the MSEP? The main finding for Phase One is that the MSEP does function as a CoP. With its strong focus on relationships, it’s clearly defined joint enterprise of solving the problem of sewage pollution, individual and joint commitment to engage with the problem and the sharing of a repertoire of tools, ideas and practices it is cultivating a culture conducive to purposeful learning. Regarding the exploration of the nature of learning in Phase Two, findings confirming the engagement of identity with learning and the importance of context for meaning-making emerged. Finally, study findings about the nature of knowledge in the MSEP found that the knowledge practices in the MSEP that are both social and epistemic in nature are produced by a diverse range of knowledge agents in an open knowledge space.
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Re-surveying the insectivorous bats of northern Kruger National Park, South Africa
- Authors: Brinkley, Erin Reed
- Date: 2019
- Subjects: Bats -- South Africa , Bats -- Behavior , Bats -- South Africa -- Ecology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115697 , vital:34216
- Description: With over 1,300 known species, the order Chiroptera makes up about 20 percent of all mammalian species. Due to its sub-tropical climate, the northern part of Kruger National Park (KNP) in South Africa is believed to have the highest bat species richness in the country. However, the last comprehensive assessment of bat diversity in the region was conducted more than 30 years ago. In 2017 and 2018, I undertook the first detailed re-assessment of the bat communities of the northern KNP since the early 1980’s. I used both live-capture (harp traps and mist-netting) and acoustic technology (SM2 and SM4 Songmeters, Wildlife Acoustics. MA, USA) to sample bats at 24 sites across the northern region of KNP. Through live-capture (336 trapping hours), 155 bats representing 13 species from five families were recorded including Cloetis pervicali, which has never been recorded within the borders of the KNP before. The echolocation calls of all captured bats were recorded to develop a site-specific call reference library that was used (in combination with existing reference calls) as a guide for the identification of bat calls recorded using the acoustic detectors set across 24 sites (278 sampling nights). The acoustic monitoring identified 22 species from six families and two unknown sets of calls. Compared to the historical data of 40 documented species (collected over a 30-year period), the current survey (27 species) resulted in a lower species richness. However, this is likely due to the lower overall sampling effort during my survey. By re-surveying the bats of northern KNP, I have contributed towards an overall bat species inventory for this region. In addition, I have generated an important baseline dataset for the future monitoring of bat diversity across the KNP. Due to bats being important biological indicators, increased research on the various species and their behaviours is essential for improving our understanding of climate change effects as well as the overall health of the environment, especially in protected areas.
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Sulphide textures and compositions associated with the hydrothermal/magmatic system of the Twangiza gold deposit (South Kivu, DRC)
- Authors: Busane, Emmanuel Aganze
- Date: 2019
- Subjects: Gold mines and mining -- Congo (Democratic Republic) , Geology -- Congo (Democratic Republic) , Hydrothermal alteration -- Congo (Democratic Republic) , Sulphide minerals -- Congo (Democratic Republic) , Gold ores -- Geology -- Congo (Democratic Republic) , Geochemistry -- Congo (Democratic Republic) , Twangiza Mine (Congo (Democratic Republic))
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76588 , vital:30610
- Description: Twangiza mine is a gold deposit situated in the eastern Democratic Republic of Congo. The rock types at the Twangiza Mine consist of black shale, including carbonaceous mudstone and thin intercalated layers of siltstone, and feldspar-rich granitoid intrusive sills, referred to as albitite, folded into a major antiformal structure. The gold mineralization at the mine is commonly found associated with sulphides. The sulphide textures and compositions of mineralized and unmineralized samples of black shales, albitite sills and hydrothermal veins in the mine are considered for the understanding of the spatial association of gold with sulphides and gold mineralization history of the mine. The sulphides within the Twangiza mine consist of pyrite, arsenopyrite, pyrrhotite, chalcopyrite and rare cobaltite. The primary pyrite texture occurs in unmineralized black shale and is interpreted to be diagenetic. It consists of fine-grained anhedral pyrite crystals aggregating into spherical nodules and formed in replacement of organic material during the diagenesis process. The secondary pyrite textures resulted from the hydrothermal fluids activity and include (i) aggregates of annealed anhedral crystals into sulphide-rich lenses; (ii) elongated anhedral pyrite in the form of short stringers; (iii) fine-grained subhedral to euhedral pyrite randomly distributed within the rock matrix; (iv) euhedral zoned pyrite crystals occurring within veins; (v) aggregations of fine-grained anhedral pyrite, locally distributed in the matrix; (vi) abundant dissemination of fine-grained subhedral to anhedral pyrite crystals within the vein selvedge in the host rock; (vii) and coarse-grained massive pyrite bodies. The pyrite major elemental composition does not vary significantly in the different textures and sample types. The Fe content ranges from 44.57 to 46.40 wt. %, and the S content ranges from 53.75 to 55.25 wt. %. Pyrite from mineralized black shale and hydrothermal veins contains relatively higher concentrations of As (~ 1 wt. %) than pyrite from other sample types. The arsenopyrite commonly occurs as fine-grained anhedral crystals as inclusions within pyrite, medium-grained crystal intergrowing with pyrite and/or as coarse-grained massive arsenopyrite bodies in the massive sulphide veins. The arsenopyrite composition is uniform in all textural and sample type with Fe content ranging from 33.44 to 35.20 wt. %, S content ranging from 21.13 to 22.55 wt. % and As content ranging from 42.20 to 43.97 wt. %. In mineralized black shale and unmineralized black shale, the arsenopyrite shows, however, minor concentrations of Ni with 0.39 and 0.70 wt. % respectively. The pyrrhotite occurs as fine-grained anhedral patchy crystals randomly distributed within the rock matrix of unmineralized black shale and unmineralized granitoid, and / or as inclusions within pyrite in mineralized granitoid. The pyrrhotite shows a uniform composition in all samples and textural types, though minor concentrations of Ni (2.06 wt. %) content are reported in unmineralized granitoid. Chalcopyrite occurs as fine-grained crystals in inclusions within pyrite; and cobaltite occurs as rare fine-grained anhedral crystals occasionally disseminated in the albitite sill matrix. The chalcopyrite composition does not vary considerably in all sample and textural types, and cobaltite shows minor concentrations of Ni (4.55 wt. %) and Fe (3.45 wt. %). Native gold grains are commonly found associated with the secondary pyrite texture especially within the sulphide-rich lenses and in the massive sulphide veins, and are almost pure with ~97 wt. %. A Na-rich hydrothermal fluid from low-grade metamorphism associated with the E-W compressive tectonic event, which caused formation of the antiform structure which control the mineralization in the deposit area, led to the albitization of the deposit rocks and specially the alteration of the granitic assemblage to form albitite, and the deposition of aggregates of fine-grained anhedral crystals and growth and annealing of pyrite in sulphide-rich lenses. Afterward, the CO2-rich hydrothermal fluids influx circulated through reactivated structures, including quartz veins, and led to the precipitation of dolomite, ankerite, siderite and magnesite. They also led to the precipitation of pyrite of secondary textures as well as arsenopyrite, chalcopyrite and formation of pyrrhotite from the desulphurization of early pyrite. The CO2-rich hydrothermal fluids probably leached gold and other trace elements such as As, Co, etc. from the sedimentary host rocks and deposited them into suitable traps, such as the sulphide-rich lenses and massive sulphide bodies, preferably within the hinge zone of anticline axis constituting a hydrothermal fluid pathway.
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Exploring multiple dimensions of identiy development in black South African adolescents
- Authors: Buso, Masimbulele
- Date: 2019
- Subjects: Identity (Psychology) , Adolescent psychology -- South Africa , Identity (Psychology) in adolescence -- South Africa , Teenagers, Black -- Psychology -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96702 , vital:31310
- Description: South Africa, just like most African countries, is a country rich in social, political and economic history due to colonisation, specifically the apartheid system. The current socio-political and economic climate of the country is said to influence the process of identity development and formation during adolescence. Therefore, the main aim of the study was to explore the various identities that black adolescents are exploring given the context of the country. Additionally, the aim of this research was to explore the methods in which adolescents utilise to develop their identity and the challenges encountered during this process. The study made use of three data collection methods; a Short Reflective exercise, a Nominal Group Technique and Focus Groups. Data was analysed using thematic analysis to generate main themes and sub themes. The main themes discussed in this study revealed that adolescents experiences multiple aspects of their identity, which exist in a complex interwoven system influenced by both external and internal factors. The main challenge was the difficulty in integrating the dominant westernised/individualistic ideology with the collectivistic ideology that adolescents are raised according to. Overall, the study indicated that the majority of the participants had a positive self-concept and a positive outlook with regards to their future. Recommendations emphasise the need for further research that would be based on the South African context to further explore black identity and to gain contextual information that can be used to combat some of the social issues that the South African youth is challenged with.
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Substituent effects on the electrocatalytic activity of cobalt phthalocyanine in the presence of graphene quantum dots
- Authors: Centane, Sixolile Sibongiseni
- Date: 2019
- Subjects: Phthalocyanines , Quantum dots , Electrocatalysis , Electrochemistry
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67614 , vital:29121
- Description: The electrocatalytic activity of metallophthalocyanines derivatives is explored. Cobalt monocarboxyphenoxy phthalocyanine (1), cobalt tetracarboxyphenoxy phthalocyanine (2), cobalt tetraaminophenoxy phthalocyanine (3) and cobalt tris-(tert-butylphenoxy) monocarboxyphenoxy phthalocyanine (4) are the phthalocyanines employed in this work. The metallophthalocyanines were employed alone as well as in the presence of the carbon based graphene quantum dots. The electrocatalytic behaviour of functionalized GQDs is also explored herein. The catalytic processes studies were conducted on a glassy carbon electrode surface. Modification of the electrode was achieved by the adsorption method. The materials were adsorbed either alone, as premixed/covalently linked GQDs/Pc conjugates or sequentially. Sequentially adsorbed electrodes involved the phthalocyanines on top or beneath GQDs. Sequentially modified electrodes where the phthalocyanine had higher currents and low detection limits than when the phthalocyanine is underneath. Premixed conjugates showed better activity than the covalently formed conjugates. The nanomaterials synthesized and used in this work were characterized using transmission electron microscopy, UV-Vis spectroscopy, dynamic light scattering, Raman spectroscopy, X-ray diffraction, Atomic Force Microscopy and X-ray photoelectron spectroscopy. The modified electrodes were characterized using cyclic voltammetry and scanning electrochemical spectroscopy. The electrocatalytic activity of the modified electrodes towards the oxidation of hydrazine was evaluated using cyclic voltammetry and chronoamperometry. Superior catalytic activity was observed for the conjugates compared to that of the individual conjugates.
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Incentive effects: assessing effort and heterogeneity in professional tennis
- Authors: Chadwick, Byron James Rhett
- Date: 2019
- Subjects: Professional sports -- Economic aspects , Tennis players -- Wages , Tennis -- Tournaments , Achievement motivation , Incentive awards
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/69467 , vital:29541
- Description: This study explores the impact incentive effects have on the level of effort exerted by professional men and women tennis players. Understanding what impact incentives have on tennis players can allow for greater understanding of the impact incentives have in the workplace and how employees react to different incentive schemes. The study makes use of data from both the ATP and WTA tour of every tournament played during the 2016 season. This includes player statistics, tournament statistics and in-game statistics from the quarter-finals, semi-finals and finals of each tournament in an attempt to account for initial seeding effects. This provides a total of 440 ATP matches and 389 WTA matches for an overall sample size of 829 professional tennis matches. The findings from this study illustrate in the last three rounds of all the tournaments played, for both male and females, money is not considered to be a key motivator for players. The ATP and WTA results suggest that competitors do not alter their effort levels depending on the level of the tournament. This illustrates that players exert similar effort levels regardless of the amount of money or ranking points available. The outcome of the findings supports that of the capability effect of heterogeneity on players’ performance. This means that the outcome of a match is linked more to the abilities of the competitors involved as opposed to the incentives available. Thus, players will adjust their effort levels according to their opponent and not because there are more money or ranking points available. This suggests that both the ATP and WTA should aim to reduce the differences in abilities amongst the players in an attempt to raise the attractiveness of the sport. Overall, the findings from this study illustrate that the capability effect outweighs that of the incentive effect.
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Understanding the perceived role of mobile media in relation to development in a South African rural area
- Authors: Chatikobo, Tatenda
- Date: 2019
- Subjects: Mobile communication systems -- South Africa , Internet telephony -- South Africa , Mobile communication systems -- Social aspects -- South Africa , Internet telephony -- Social aspects --South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/95360 , vital:31148
- Description: This study explores the different perceptions of mobile media in relation to development within Dwesa, a marginalised rural community in South Africa. The proliferation of mobile phones and increasing access to the internet in Africa, and South Africa in particular, is extensively documented and attempts have been made to explore its impact on development. Drawing on adapted aspects of the Diffusion of innovation theory (DoI), the study seeks to understand the relative advantage, compatibility with needs and values, and observable benefits of using mobile media for a rural community. I provide a critical discussion of the concept of development and its relationship with digital technologies and innovation. I reflect on the Diffusion of innovation theory, highlighting its critiques, adaptations and modifications in studies, particularly in the Global South. The present study employs a qualitative methodology and relies on focus groups, semi-structured interviews and observation as methods of data collection. Participants were divided into three focus groups based on Rogers classification of innovativeness (early adopters, majority adopters and late/non-adopters) and I conducted two follow-up interviews with participants of each focus group. I analysed the data thematically. Research participants identified several areas where mobile media contributed to development and positive change, such as lowering the cost of access to information and communication, staying in touch with distant relatives, increasing access to services and providing entertainment, especially among young people. The participants noted that despite these positive changes, that mobile media on its own cannot be expected to address challenges of infrastructure and public service delivery. Research findings also revealed that mobile media might interfere with socio-cultural values of respect, human dignity and privacy. I conclude that, while mobile media is generally considered as beneficial, its critical role in improving the socio-economic conditions of people in Dwesa still remains in doubt. The study provides an opportunity to further investigate the compatibility of mobile media with socio-cultural values along the lines of age and gender, and address issues of digital skills and digital marginalisation.
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A critical analysis of A2 Fast Track Lowveld sugar cane farms in Zimbabwe in global value chains: interrogating the lives of farmers and farm labourers
- Authors: Chingono, Kudakwashe Rejoice
- Date: 2019
- Subjects: International trade , Sugar trade -- Zimbabwe , Sugar growing -- Zimbabwe -- Social aspects , Agriculture -- Zimbabwe -- Social aspects
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/93933 , vital:30972
- Description: The sugar cane industry has for many years been a lucrative business with a booming global market. In Zimbabwe, the sugar cane industry is no exception, as it has been regarded as one of the most efficient in the region and even in the world. The sugar cane farms and mills in Zimbabwe are located in Triangle and Chiredzi, in the south-eastern part of the country and they are under the ownership of Tongaat Hullet and the Zimbabwean A2 farmers. The focus of this is on the A2 fast track farms in Hippo Valley, which are now owned by black farmers but as out-growers for Tongaat Hullet. The crucial question addressed in the thesis is whether the A2 sugar cane farmers and their workers, located at the production end of the sugar cane global value chain, are benefitting from their involvement in this value chain. A number of scholars argue that global value chains lead to economic and social upgrading at the production end of the chain, based on thoughts contained in modernisation and trickledown theory. There is an assumption, then, that integration into the global economy leads to economic upgrading which translates into social upgrading. In drawing upon critical global value theorists, bolstered by the Marxist perspective, considers the importance of a more critical view of global value chains in relation to the sugar cane industry in Zimbabwe, with the particular focus on A2 farms. Thus, the main objective of the thesis is to consider the lives and livelihoods of A2 sugar cane farmers and sugar cane workers through a case study, in the context of global value chains and arguments around economic and social upgrading. This is pursued through a case study of six A2 farms, which involved interviewing farmers, supervisors, and both permanent and temporary workers. The thesis concludes that there is no significant evidence of social upgrading amongst the labour force, and that the A2 farmers are in constant tension with Tongaat Hullet in seeking to engage in economic upgrading of their status as commercial farmers.
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Biochemical characterization of the β-mannanase activity of Bacillus paralicheniformis SVD1
- Authors: Clarke, Matthew David
- Date: 2019
- Subjects: Mycobacterium avium paratuberculosis , Enzymes -- Biotechnology , Lignocellulose -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67570 , vital:29112
- Description: Products produced via the enzymatic hydrolysis of lignocellulosic biomass, the most abundant renewable terrestrial source of carbon, can potentially replace a lot of the fuels and chemicals currently produced using non-renewable hydrocarbons. Mannan is a polysaccharide component of lignocellulose that is abundant in softwoods and legume seeds. Enzymatic hydrolysis of mannan by β-mannanases has various industrial applications, including use in biofuel and prebiotic mannooligosaccharide (MOS) production for the improvement of human and animal health. The industrial use of β-mannanases depends on their biochemical characteristics, such as their activity, stability and substrate specificity. Knowledge of their synergistic interactions with other enzymes is also useful for effective hydrolysis. Bacillus paralicheniformis SVD1 was used as a source for β-mannanases. The two mannanases of B. paralicheniformis SVD1 have not been biochemically characterized apart from minor characterization of crude β-mannanase activity. The protein sequences of the two β-mannanases, of glycosyl hydrolase family 5 and 26, have a 95% - 96% identity to the β-mannanases of B. licheniformis DSM13T (=ATCC14580T). These small protein sequence differences could lead to quite different biochemical characteristics. These mannanases were characterized as these enzymes may have industrially useful characteristics. To induce mannanase production, B. paralicheniformis SVD1 was cultured in broth containing the mannan substrate locust bean gum. Various growth curve parameters were measured over 72 h. Mannanase activity was the highest after 48 h of growth - this was the time at which mannanase activity was concentrated, using 3 kDa centrifugal filtration devices, for biochemical characterization of the crude activity. Zymography revealed that the crude concentrated mannanase fraction consisted of at least two mannanases with relative molecular weights (MWs) of 29.6 kDa and 33 kDa. This was smaller than expected – based on their theoretical molecular masses. Protease activity, which was detected in the broth, was probably the reason. There were two pH optima, pH 5.0 and pH 7.0, which also indicated the presence of two mannanases. The concentrated mannanase displayed characteristics that were expected of a B. paralicheniformis β-mannanase. The temperature optimum was 50°C and the activity loss was less than 7% at 50°C after 24 h. Substrate specificity assays revealed that there was predominantly mannanase activity present. Thin layer chromatography (TLC) analysis of mannan and MOS hydrolysis showed that mainly M2 and M3 MOS were produced; only MOS with a degree of polymerization of 4 or higher were hydrolyzed. Hydrolysis was minimal on mannoligosaccharides with galactose substituents. Activity and MOS production was the highest on soluble, low branched mannan substrates. The highest activity observed was on konjac glucomannan. Purification of the mannanase activity was then attempted using various methods. Ammonium sulfate precipitation, acetone precipitation, as well as centrifugal filtration device concentration was assessed for concentration of the mannanase activity.Concentration was not very successful due to low activity yields (≤ 20%). Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) was used for purification. AEC gave good activity yield and fold purification, but SDS-PAGE analysis revealed the presence of many different proteins so further purification was necessary. SDS-PAGE analysis showed that there were only a few protein contaminants in the SEC fraction. However, the yield was too low to allow for biochemical characterization. The optimized purification procedure, which partially purified the mannanase activity, used 85% ammonium sulfate precipitation, followed by AEC. The fold purification was high (88.9) and the specific activity was 29.5 U.mg-1. A zymogram of the partially purified mannanase showed a mannanase active band with a MW of 40 - 41 kDa. A serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was added during the purification steps. This indicated that the mannanase/s in the crude concentrate, without PMSF added, was hydrolyzed by serine protease activity. Native PAGE zymograms suggested that at least two different isoforms of mannanases were present. Additional purification would be required to determine the true characteristics of the mannanase/s. The biochemical characteristics of the crude and partially purified mannanases were similar. The pH optima of the partially purified mannanases were different; the pH optima were 6.0 and 9.0. The substrate specificities were similar, except that the partially purified mannanases displayed no cellulase and β-D-galactosidase activity, but showed a small amount of α-L-arabinase activity. The partially purified mannanase and a Cyamopsis tetragonolobus GH27 α-galactosidase synergistically hydrolyzed locust bean gum. The M50G50 combination displayed the highest extent of hydrolysis; after 24 h there was a 1.39 fold increase in reducing sugar release and the degree of synergy (DS) was 4.64. TLC analysis indicated that synergy increased the release of small MOS. These MOS could be useful as prebiotics. The synergy between the partially purified mannanase and the commercial cellulase mixture Cellic® CTec2 (Novozymes) on spent coffee grounds (SCG) was also determined. SCG is an abundant industrial waste product that has high mannan content. The SCG was pretreated using NaOH, and the monosaccharide, soluble phenolics and insoluble contents were determined. Glucose and mannose were the dominant monosaccharides in the SCG; the pretreated SCG contained 20.4% (w/w) glucose and 18.5% (w/w) mannose, respectively. The NaOH pretreatment improved mannanase hydrolysis of SCG. It resulted in the opening up and swelling of the SCG particles and removed some of the insoluble solids. The partially purified B. paralicheniformis SVD1 mannanase displayed no detectable activity on SCG, but showed synergy with CTec2, in terms of DS, on untreated and NaOH pretreated SCG. This is the first report of mannanasecellulase synergy on SCG; other studies found that increased hydrolysis was due to additive effects. The results obtained in this study are only an initial assessment of the biochemical properties of B. paralicheniformis SVD1 mannanase activity and its synergy with other enzymes. These results can be used to inform future studies.
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A case-series evaluation of the impact and processes of a service-learning programme on and for caregivers and their children with neurodevelopmental disabilities
- Authors: Cooke, Nicole
- Date: 2019
- Subjects: Developmentally disabled children -- Care , Caregivers -- Training of , Service learning -- Case studies
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96691 , vital:31309
- Description: This thesis presents a series of three case studies from data collected as part of a research project exploring the process and impact of a service-learning programme with caregivers and their children with neurodevelopmental disabilities. Following a descriptive case series design, both quantitative and qualitative data are presented to create a comprehensive and rich understanding of each case. In particular, the data tracks change processes in the subjective well-being of the caregiver, the quality of the caregiver-child relationship and the functional development of the child over a twenty-one-week period of receiving public health services and an eight-week period of adding the service-learning programme. The paper also presents qualitative data on the caregivers’ perceptions of and experiences of the public services and the servicelearning programme that the caregivers and their children received. The findings provide important insight into the caregivers’ perceptions of giving and receiving care, with the caregivers’ experiencing significant levels of distress and prominent barriers to accessing healthcare that were seemingly eased with the addition of the service-learning programme. The findings also point to a notable disparity between the quantitative findings and the qualitative interviews with questions being raised about the research being viewed as an intervention in itself.
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