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Reimag [in] ing the village as a portrait of a nation-state in Uganda:

- Kakande, Angelo

Authors: Kakande, Angelo
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/145642 , vital:38454 , https://doi.org/10.1162/AFAR_a_00343
Description: In this article I reexamine the ways in which certain contemporary artists based in Uganda problematize the narrative that the ruling National Resistance Movement (the NRM) party is the party of the rural poor (Cheeseman, Lynch, and Willis 2016) in their work while using it as a metaphor to inform their visual expression. I focus on the contest between tradition (imagined as a village) and modernity (imagined as a modern state), as well as the dilemma such a contest causes for a contemporary artist. Cornelius Adepegba (1995) argues that this dilemma influenced the African novel. Agreeing with Adepegba, Freeborn Odiboh (2009) observes that the same dilemma has shaped African visual artists, such as Abayomi Barber, and formal art education institutions like the Barber School in Nigeria; Odiboh then assesses the historical context in which this dilemma evolved as African nationalists struggled to forge postcolonial states based on a national consciousness amid competing ethnic, religious, and ideological interests.
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Date Issued: 2017

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Reimagining our missing histories: Eria Nsubuga SANE and Sikhumbuzo Makandula in conversational partnership

- Makandula, Sikhumbuzo, Nsubuga, Eria

Authors: Makandula, Sikhumbuzo , Nsubuga, Eria
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/145620 , vital:38452 , https://0-doi.org.wam.seals.ac.za/10.1162/AFAR_a_00345
Description: While an interview could be described as a view among, between, betwixt, or in the midst of two subjects—from s'entrevoir (see each other); entre (between) and vue (view)—many interviews in art history are hierarchical not only in the sense of an interviewer “authoring” the material received from the respondent, but also in the sense of the theorist or writer shaping the ideas of the practitioner. As discussed in the First Word, “Situating Africa,” there is a tendency for writers in the “north” to theorize the professional practice of artists in the “south,” developing what Gordon Lewis (2006) refers to as a geography of reason. In their book Qualitative Interviewing: The Art of Hearing Data, Herbert J. Rubin and Irene S. Rubin (2012:7) develop the term “conversational partnership” to describe two or more participants who play an active role in shaping content as they cocreate meaning. This conversational partnership between two artists—one based in Uganda and the other based in South Africa—developed out of the publishing workshop at Rhodes University in June 2016, which aimed to approach the creation of knowledge from the perspective of “sideways learning” (see “Reaching Sideways, Writing Our Ways” in this issue). —Ruth Simbao.
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Date Issued: 2017

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Relationship between migraine triggers, auras and treatment

- Louwrens, Bernadette

Authors: Louwrens, Bernadette
Date: 2017
Subjects: Migraine -- Treatment Headache -- Treatment , Insomnia
Language: English
Type: Thesis , Masters , MPharm
Identifier: http://hdl.handle.net/10948/18266 , vital:28611
Description: Background: Migraine trigger factors are precipitating factors that can contribute to an attack by increasing the probability of a migraine occurring. For some migraineurs, the headache phase is preceded by a transient disturbance in neurological function (an aura). An aura could be visual or sensory in nature. There are medications that can be used to treat a migraine attack when it occurs (acute medication) and medication that can be used to reduce frequency and severity of migraine attacks (prophylactic medication). Objectives: The primary aim of the study was to identify if there was a relationship between migraine trigger factors, auras and treatment. Methods: The study was conducted in 2014 in Port Elizabeth and consisted of two self-administered questionnaire-based surveys, one for pharmacists and one for migraine patients. Migraine patient questionnaires were distributed to migraine patients who frequented pharmacies, physiotherapy practices and health shops. A total of 18 pharmacist questionnaires and 173 migraine patient questionnaires were analysed. Results: Experiencing an aura before a migraine attack was reported by 43.9% of respondents and only “sometimes” by 22.5% of respondents. Visual auras were experienced by 92.0% of respondents who indicated that they suffered from migraine with aura and sensory auras were experienced by 71.5% of respondents, with 62.8% of respondents experiencing both visual and sensory auras. Trigger factors were experienced by 89.0% of respondents. There was no statistical relationship between aura and trigger factors, but there was a statistical relationship between trigger factors and visual aura at the 5% level (Chi-square = 7.966, d.f. = 1, p-value = 0.005). Cramér’s V showed a small practical significance at 0.218. About 80.0% of respondents used over-the-counter (OTC) medication and only 12.6% used migraine specific medication to abort a migraine attack. There was no statistical relationship between aura (visual or sensory) and abortive medication. There was a statistical relationship between abortive medication and the presence of trigger factors (Chi-square = 8.775, d.f. = 3, p-value = 0.032). Cramér’s V showed a small practical significance at 0.244. There was no statistical relationship in the presence of trigger factors between aura and abortive medication. Conclusion: Migraine is a complex disease which affects people of all ages. There appears to be a statistical relationship between visual auras and trigger factors and between abortive medication and trigger factors. There was, however, no statistical relationship between aura and abortive medication in the presence of trigger factors. Further studies need to be conducted to substantiate these findings.
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Date Issued: 2017

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Relative features of the principal and secondary luminescence lifetimes in quartz

- Chithambo, Makaiko L, Ogundare, F O

Authors: Chithambo, Makaiko L , Ogundare, F O
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/125821 , vital:35820 , https://doi.10.1002/pssc.200673721
Description: Quartz is a common natural mineral with properties that make it amenable for application in radiation dosimetry using luminescence methods [1]. The luminescence properties of quartz including its sensitivity and luminescence lifetimes undergo notable changes when the quartz is annealed, and in particular, near its phase inversion temperatures of 573 and 867 oC [2, 3]. The physical processes leading up to the emission of luminescence in quartz may be investigated using time-resolved optical stimulation. The aim of this method is to separate in time the stimulation and emission of luminescence to enable measurement of time-resolved luminescence spectra which may be resolved into associated lifetimes, defined in this sense as the delay between stimulation and emission of luminescence [4, 5]. A number of such studies show that annealing defines the detailed distribution of lifetimes with measurement temperature as well as the irradiation-dependent characteristics of the lifetimes [3, 6]. In particular, it was noted [3] that spectra measured at certain temperatures could be accurately resolved into more than one component, a scenario that pointed to the possibility of involvement of multiple luminescence centers in the emission of luminescence from quartz. The aim of this work is to build on the findings described, specifically to study the influence of measurement temperature and irradiation on the principal and subsidiary luminescence lifetimes in natural quartz.
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Date Issued: 2017

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Release success of captive bred Cape Vultures (Gyps coprotheres) in the Magaliesberg Mountains, South Africa

- Hirschauer, Maggie

Authors: Hirschauer, Maggie
Date: 2017
Subjects: Vultures -- South Africa -- Magaliesburg , Vultures -- South Africa -- Behavior
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/4743 , vital:20720
Description: The Cape Vulture, Gyps coprotheres, is currently classified as ‘endangered’. Endemic to southern Africa, its population has declined continuously over the past 40 years. The species is facing multiple anthropogenic threats. Notably, birds frequently collide with power lines and some cannot be released after treatment. This has led to the establishment of a captive breeding population with the hope that captive bred young can supplement wild populations and re-establish a now- abandoned breeding colony in the Magaliesberg Mountains, South Africa. This study aimed to follow the breeding behaviours of the captive colony and assess the appropriateness of chick rearing conditions. The study also aimed to monitor the behaviour, physical condition and dispersal of ten captive bred vultures after release in relation to their age. Behavioural observations of captive adult breeding and parental behaviours were conducted to establish whether chicks developed under comparable conditions to wild chicks. A high percentage of total colony copulation attempts (22 %) were extra-pair copulations. Four paired males formed ephemeral extra-pair relationships, two of which were homosexual. Chicks fledged earlier than wild chicks, on average at 128 days old. Wild and captive bred birds were observed at carcasses to compare competitive and feeding behaviours. Older birds, both wild and captive, fed the most efficiently. Preliminary evidence suggests females are more dominant and have higher display rates than males. Captive bred juvenile and four year old birds’ competitive and feeding behaviours (interaction rate, feeding rate, display rate, dominance, aggressiveness, and feeding efficiency) were the closest to, but still generally below, average values for same-aged wild birds. An index of body condition, body mass, and the prevalence of fault bars on the rectrices were used to assess their physical condition. After eight months, none of the ten birds had moved more than 8 km from the release site, nor had they foraged away from the vulture restaurant on site. Although altitude records of > 3100 m were recorded, their flight skills seemed inadequate. Future management considerations include the initiation of a pre-release exercise regime, the establishment of an acclimatization enclosure removed from the breeding site, and a varied or reduced post-release feeding schedule. Fledglings should be relocated and housed at the release enclosure until they are four years old.
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Date Issued: 2017

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Reliability analysis: assessment of hardware and human reliability

- Mafu, Masakheke

Authors: Mafu, Masakheke
Date: 2017
Subjects: Bayesian statistical decision theory , Reliability (Engineering) , Human machine systems , Probabilities , Markov processes
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/6280 , vital:21077
Description: Most reliability analyses involve the analysis of binary data. Practitioners in the field of reliability place great emphasis on analysing the time periods over which items or systems function (failure time analyses), which make use of different statistical models. This study intends to introduce, review and investigate four statistical models for modeling failure times of non-repairable items, and to utilise a Bayesian methodology to achieve this. The exponential, Rayleigh, gamma and Weibull distributions will be considered. The performance of the two non-informative priors will be investigated. An application of two failure time distributions will be carried out. To meet these objectives, the failure rate and the reliability functions of failure time distributions are calculated. Two non-informative priors, the Jeffreys prior and the general divergence prior, and the corresponding posteriors are derived for each distribution. Simulation studies for each distribution are carried out, where the coverage rates and credible intervals lengths are calculated and the results of these are discussed. The gamma distribution and the Weibull distribution are applied to failure time data.The Jeffreys prior is found to have better coverage rate than the general divergence prior. The general divergence shows undercoverage when used with the Rayleigh distribution. The Jeffreys prior produces coverage rates that are conservative when used with the exponential distribution. These priors give, on average, the same average interval lengths and increase as the value of the parameter increases. Both priors perform similar when used with the gamma distribution and the Weibull distribution. A thorough discussion and review of human reliability analysis (HRA) techniques will be considered. Twenty human reliability analysis (HRA) techniques are discussed; providing a background, description and advantages and disadvantages for each. Case studies in the nuclear industry, railway industry, and aviation industry are presented to show the importance and applications of HRA. Human error has been shown to be the major contributor to system failure.
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Date Issued: 2017

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Removal rate of endocrine disruptors (phthalates and phenolic compounds) in effluents of selected wastewater treatment plants operated under different treatment technologies in the Eastern Cape, South Africa

- Salaudeen, Taofeek Gbenga

Authors: Salaudeen, Taofeek Gbenga
Date: 2017
Subjects: Water -- Purification Phenols
Language: English
Type: Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10353/8552 , vital:33113
Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
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Date Issued: 2017

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Representing the unrepresentable: an exploration of gendered experiences of mental disorder

- Futcher, Charis Catheryn

Authors: Futcher, Charis Catheryn
Date: 2017
Subjects: Mental illness in art , Women -- Mental health , Art, South African -- 21st century -- Exhibitions , Sculpture, South African -- 21st century -- Exhibitions , Women in art
Language: English
Type: Thesis , Masters , MFA
Identifier: http://hdl.handle.net/10962/42957 , vital:25252
Description: Inspired by personal lived experiences of mental disorder; this thesis attempts to explore the representation of these complex conditions as they are deeply embedded in trauma, guilt, and stigma. The accompanying exhibition, The Inheritance, figures my own tendencies to contain and conceal my disorder, through the assembling of sculptural containers and their disordered contents. The work, presented as something surreal, comments on the complexities of being a woman with a disorder, as well as on the disease I experience in relation to a history of patriarchal ideologies and psychiatric containment that has informed understandings of ‘female madness’. Grounded in my interests in abjection and containment, the artistic processes of trying to express deeply personal experiences of distress allow for the resurfacing of underlying trauma, in regards to the memory of my mother’s struggle with Bipolar disorder and her subsequent estrangement. Instead of catharsis, the exhibition represents an inevitable failure to represent the unrepresentable, an experience inextricably bound to the history of gendered oppression and the repression of subjectivity by dominant powers of belief and control. Through my practice as research, I have ultimately grappled with my reluctance to represent my experience, precisely because the topic of mental disorder, though pervasive, is lived and felt by varying groups of people in different ways. As such, my intention is to avoid a reductive and narrow framing of what mental disorder entails. Similarly, I aim to avoid restrictive and presumptuous definitions of gender – recognizing that, historically, femininity is a contested category that has silenced many individuals who are not white, heterosexual or gender conforming. My literary research has been limited by these norms and silences, in that most texts detailing the historical visual treatment of disordered subjects fail to recognise the possibility of gender categories that transcend the binary masculinity and femininity. With these limitations in mind, my practice has allowed me to reflect upon the distress of generations of people who have been pathologised based on gender.
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Date Issued: 2017

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Researching research culture: a case study of Rhodes University Humanities Faculty research culture

- Hwami, Rudo Fortunate

Authors: Hwami, Rudo Fortunate
Date: 2017
Subjects: Rhodes University. Humanities Faculty , Rhodes University -- Graduate work , Rhodes University. Humanities Faculty -- Research , Research -- South Africa -- Makhanda
Language: English
Type: Thesis , Masters , MSocSc
Identifier: http://hdl.handle.net/10962/7522 , vital:21269
Description: This thesis explores the idea of research having organisational characteristics which are affected by the institutional culture but can not be defined as a subculture of the institutional culture. In particular, it examines how research culture(s) can be exclusionary and reproduce discriminatory practices. Using quantitative data in the form of Rhodes University Annual Reports and interviews conducted with 11 participants, the thesis documents the current research practices of the Faculty of Humanities at Rhodes University. Such practices incorporate multiple dimensions, including how research is done, who does research, what research is done and research funding rituals. The purpose of this study is to reveal how research cultures are constructed through the seemingly mundane and everyday research practices within a research community. Through the analysis of these everyday practices, participants’ experiences and theoretical arguments, this thesis found that research culture and institutional culture are separate entities, and that research culture plays a vital role in the formation of research practices.
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Date Issued: 2017

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Resilience factors in low-income families with an autistic child

- Horak, Alicia

Authors: Horak, Alicia
Date: 2017
Subjects: Developmental psychology , Autistic children -- Care , Low-income parents -- Psychological aspects
Language: English
Type: Thesis , Masters , MA
Identifier: http://hdl.handle.net/10948/16033 , vital:28314
Description: Autism Spectrum Disorder (ASD) encompasses a group of life-long neurodevelopmental disorders. It is an enormous challenge to care for someone with ASD. The majority of people with ASD will need life-long support from family members and will not be able to function independently in society. This places emotional and financial strain on a family. There are many low-income families in South Africa with autistic children who cannot afford specialised intervention. It has been estimated that 135 000 autistic children are not getting the specialized education they need. Despite not receiving the needed support, there are many low-income families who remain resilient after their child is diagnosed. This study aimed to explore how these low-income families remain resilient. Qualitative data was gathered using in-depth, semi-structured interviews conducted in English and Afrikaans; depending on the participant’s language of preference. Six participants were recruited with the help of professionals in a local community in Cape Town, Western Cape. The data obtained was transcribed and analysed through thematic analysis. Lincoln and Guba’s model (Krefting, 1990) was used to determine the trustworthiness of the data. The three themes that emerged from the study were (1) parents’ response to the diagnosis of their child, (2) the resources parents found helpful in their immediate environment and (3) the specific coping skills that parents use to remain resilient. Walsh’s family resilience framework as well as the Resiliency Model of Family Stress, Adjustment and Adaptation (The Resiliency Model) of McCubbin and McCubbin were used to understand how participants adjusted to their circumstance and remained resilient. This study provides a more in-depth understanding of the resilience factors of families with a child with ASD in a resource-limited setting in the Western Cape.
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Date Issued: 2017

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Resisting the desire for the unambiguous: productive gaps in researcher, teacher and student interpretations of a number story task

- Graven, Mellony, Coles, Alf

Authors: Graven, Mellony , Coles, Alf
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/69673 , vital:29564 , https://DOI: 10.1007/s11858-017-0863-7
Description: This article offers reflections on task design in the context of a Grade R (reception year) in-service numeracy project in South Africa. The research explores under what conditions, and for what learning purpose, a task designed by someone else may be recast and how varying given task specifications may support or inhibit learning, as a result of that recasting. This question is situated within a two-pronged task design challenge as to emerging gaps between the task designer’s intentions and teacher’s actions and secondly between the teachers’ intentions and students’ actions. Through analysing two teachers and their respective Grade R students’ interpretations of a worksheet task, provided to teachers in the project, we illuminate the way explicit constraints, in the form of task specifications, can be both enabling and constraining of learning. In so doing we recast this ‘double gap’ as enabling productive learning spaces for teacher educators, teachers and students.
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Date Issued: 2017

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Resource partitioning in the world’s largest gannetry

- Botha, Jonathan Aubrey

Authors: Botha, Jonathan Aubrey
Date: 2017
Subjects: Gannets -- South Africa Birds of prey -- Behavior -- South Africa , Birds -- Behavior
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10948/14707 , vital:27828
Description: Understanding strategies of resource partitioning within populations is a fundamental aspect of the study of ecology, and one which has been well documented across various taxa. In seabirds, sex-specific differences in foraging behaviour are often thought to reflect strategies of resource partitioning to avoid intra-specific competition. At present Bird Island in Algoa Bay hosts the world’s largest breeding population of gannets, with recent population estimates numbering well over 90 000 breeding pairs. Given the large size of this colony, intense levels of intra-specific competition are expected during the breeding season, particularly in years of poor feeding conditions. In addition, continuous foraging around the breeding colony may lead to the local depletion of prey as the season progresses, calling for flexibility in the foraging behaviour and diet of breeding individuals. Therefore, the aim of this dissertation was to investigate resource partitioning in Cape gannets breeding at Bird Island through strategies of sex-specific foraging and intra-seasonal variability in foraging behaviour and diet. To achieve this, the spatial and temporal aspects of Cape gannet foraging behaviour were assessed during the early stages of chick rearing, over two consecutive breeding seasons (2011/12, 2012/13) using GPS tracking and VHF monitoring. In addition, intra-seasonal variability in foraging behaviour and diet were investigated, taking into account the influence of sex and chick age, to provide a comprehensive assessment of foraging behaviour throughout the chick rearing period. GPS tracking data for 79 birds revealed limited evidence for sex-specific differences over spatial dimensions. An extension in the foraging range of females during a year of lower prey availability (2012/13) was, however, evident. This suggests a possible sex-specific response to prey limitation, likely reflecting resource partitioning strategies or differences in nutritional requirements. VHF data for 95 additional birds revealed a clear pattern in temporal foraging behaviour. In general, females were more likely to be on a foraging trip during the early and mid-day hours, with the probability of males being on a foraging trip increasing towards the late afternoon. Continuous tracking of individuals throughout the 2015/16 breeding season further revealed little evidence for sex-specific differences in spatial distribution and forging effort during both the guard and post-guard stages of chick rearing. A clear increase in foraging range was evident during the early stages of chick rearing as the season progressed. However, birds attending chicks older than 50 days showed an unexpected contraction in foraging range, which appeared to coincide with a dietary shift. During the early stages of breeding the diet was comprised almost exclusively of anchovy, the proportion of which decreased progressively in the diet throughout the breeding season. This was mirrored by a substantial increase in the proportion of saury in the diet. These results suggest that Cape gannets increase their foraging range in response to local prey depletion as the breeding season progresses. However, when alternative prey becomes available they may shift their diet, allowing them to access prey closer to the breeding colony. Overall, this dissertation provides insight into sex-specific behaviour in a monomorphic seabird, suggesting a marginal degree of spatial segregation. The results provide the first support for sex-related temporal foraging segregation in gannets. Such separation could potentially be driven by resource partitioning, but could also relate to differential nutritional requirements. In addition, this study also provided the first comprehensive assessment of foraging behaviour throughout the guard and post guard stages of chick rearing in gannets. These results suggest that a combination of foraging and dietary flexibility may allow Cape gannets to buffer the effects of prey depletion during the breeding season. In conclusion, resource partitioning through sex-specific foraging appears to be limited in the Cape gannet population at Bird Island. Segregation via alternative pathways may however be possible and as such, future studies should consider the influence of individual level segregation and habitat specialization.
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Date Issued: 2017

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Revenue, trade and welfare effects of the COMESA FTA on the Democratic Republic of Congo

- Ndungo, Lusenge Patrick

Authors: Ndungo, Lusenge Patrick
Date: 2017
Subjects: Revenue -- Congo (Democratic Republic) -- Econometric models , Welfare economics Congo (Democratic Republic) -- Economic conditions
Language: English
Type: Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10948/14256 , vital:27493
Description: The present research attempts to assess the likely revenue, trade and welfare implications of the Common Market for Eastern and Southern Africa (COMESA) Free Trade Agreement (FTA) on the Democratic Republic of Congo (DRC). The study adopts a partial equilibrium model based on the World Integrated Trade Solution 2010 database and the Software for Market Analysis and Restrictions on Trade (WITS-SMART) as the methodological approach. The findings of the research reveal that the COMESA FTA will be beneficial to the DRC in terms of an increase in exports of US$371.57 million and consumer welfare gain amounting to US$28.49 million. Moreover, The WITS-SMART simulation results indicate that around US$322.10 million of trade will be created in the DRC as a result of the COMESA FTA. Notwithstanding the fact that trade creation will have a positive effect on welfare, as the Congolese consumers would benefit from lower prices, some local industries in the DRC may be threaten of closure due to the lack of competitiveness. In addition, the simultation results show that the country will experience a huge fiscal revenue loss amounting to US$107.01 million due to the implementation of zero per cent tarrif rate on imports duty from the COMESA trading partners. Finally, the simultation results indicate that an equivalent value of US$49.47 million of trade will be diverted from more efficient and low cost non-member states to high cost suppliers from the COMESA region. In light of these results, the research recommends that the DRC’s government needs to come up with a strategic plan in order to protect the national industry that would be negatively affected by the trade-creation effect. In order to mitigate the expected revenue loss, the implementation of the COMESA FTA in the DRC should be accompanied by fiscal reforms to improve the tax-collection system from sales or value-added taxes (VAT) and domestic excise. Regarding the trade-diversion effect, the inefficient producers from the COMESA region could be displaced through building new capacities in short, medium and long term based on comparative advantage in order to address supply constraints in these sectors affected by trade diversion.
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Date Issued: 2017

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Revising the distribution of mangrove forests in South Africa and changes in growth of mangrove species along a latitudinal gradient

- Bolosha, Uviwe

Authors: Bolosha, Uviwe
Date: 2017
Subjects: Mangrove ecology -- South Africa , Mangrove forests -- South Africa , Mangrove plants -- South Africa -- Effect of temperature on
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/7544 , vital:21271
Description: Mangrove forests are a diverse assemblage of trees and shrubs that are adapted to a saline and tidally inundated environment. The global spread of mangrove species is affected by climate, with most confined to areas that are warmer and moist. At a global scale, temperature limits the distribution of mangrove forests but on a regional scale and local scale, rainfall, river flow and tidal exchange have a strong effect on the distribution and biomass of mangrove forests. Other factors that play a role in limiting growth and distribution of mangroves include accessibility of suitable habitats for growth and also conditions that are suitable for propagule dispersal. The objectives of this study were to review the distribution of mangroves in South Africa and determine the number of extreme temperature events that may limit further distribution and secondly to measure growth rates of mangrove species at Mngazana and Nahoon Estuary and the nutrient pools in the sediment of these forests. In 1982, Ward and Steinke published a list of estuaries where mangroves were present. The current study sampled the population structure, microclimate and level of expansion in two estuaries within and outside of the published range. The minimum, maximum temperature and number of extreme temperature events were measured using iButtons. Mangrove expansion will be limited by minimum temperatures (1.1 ° C) and an increase in extreme temperature events (830) (<5 ° C and 5- 10 ° C) at the latitudinal limits. Expansion of A. marina at Kwelera and Tyolomnqa Estuary was evident but sapling survival was low. Mangroves have expanded within and outside the range proposed by Ward and Steinke (1982), but are limited by physical factors, restricted by the presence of saltmarsh and other estuarine macrophytes and natural disturbance regimes. An increase in population growth was recorded over the years at both Mngazana and Nahoon Estuary. Nutrients, (ammonium, nitrates + nitrites and soluble reactive phosphorus) varied amongst sites and were related to seasonality. Nitrogen in both estuaries was available in the form of ammonium (NH4) and its concentration was generally higher (1.3-76.2 pm) than other forms of nitrogen (0.07-6.3 µm). Soluble reactive phosphorus (SRP) was higher during the wet seasons in both estuaries. An increase in porewater salinity since 2007 (41.3 practical salinity unit (PSU)) was measured at Mngazana and this is a result of freshwater abstraction and low rainfall. A. marina saplings and adults grew significantly faster at Nahoon Estuary (the distributional limit) (11.1 ± 1.1 cm year-¹) compared to Mngazana Estuary (5.3 ± 1.8 cm year-¹). Different mangrove species and forests respond differently to environmental factors and changes in mangrove distribution is expected in South Africa but changes are expected to happen slowly and opportunistically.
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Date Issued: 2017

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Revitalisation of the informal township economy in Mdantsane

- Dyantyi, Unathi Sisikelelwe

Authors: Dyantyi, Unathi Sisikelelwe
Date: 2017
Subjects: Informal sector (Economics) -- South Africa -- Mdantsane Economic development -- South Africa -- Mdantsane
Language: English
Type: Thesis , Masters , MBA
Identifier: http://hdl.handle.net/10948/15611 , vital:28276
Description: The main focus of this study was to perform an assessment of viable and sustainable means of creating a vibrant and sustainable economy in the Mdantsane Township. In order to perform the assessment objectives were formulated which aimed at assessing whether the informal small business sector of Mdantsane was generating wealth and livelihoods for the people running them. The study also looked at whether the informal business sector is a preferred option by most South Africans or people in the townships would rather seek employment. A number of data collection methods were used in completing this study such as literature reviews and a semi-structured questionnaire. The study revealed that Local Economic development can be implemented in the townships in order to assist in stimulating a vibrant local township economy. The study also revealed that the central focus of Local Economic Development is to support the development, growth and retention of private or co-operative enterprises. The survey conducted in the study further revealed that most businesses in the township are driven by necessity in order for them to start their businesses mainly due to unemployment. These businesses all agreed on the significant role that Local Economic Development can play in assisting township entrepreneurs and communities to grow and prosper.
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Date Issued: 2017

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Rhenium complexes of benzazole derivatives

- Van Niekerk, Xandri

Authors: Van Niekerk, Xandri
Date: 2017
Subjects: Rhenium Benzimidazoles
Language: English
Type: Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10948/21252 , vital:29467
Description: A series of rhenium(I) complexes with monodentate benzazole ligands containing the fac-[Re(CO)3]+ was synthesized. The rhenium(I) compound [ReCl(Hmbt)2(CO)3] was prepared from the reaction of [Re(CO)5Cl] and 2-aminobenzothiazole (Hmbt) in toluene. The ligand coordinates in a monodentate manner via the thiazole nitrogen atom. A similar reaction between [Re(CO)5Cl] and N-(1,3-benzothiazol-2-yl)-2- chloroacetamide (Hbct) resulted in the formation of [ReCl(Hbct)(CO)3(NCMe)], where only one ligand binds per rhenium in a monodentate fashion. The reaction of ligands 2-mercaptobenzimidazole (Hmbi) (dibenzothiazol-2-yl)tetraazathiapentalene (Hdbt) with rhenium(I) gave [ReCl(Hmbi)2(CO)3] and [ReCl(Hdbt)2(CO)3] respectively. The study on the coordination behaviour between ethyl-(1H-benzimidazol-2-yl-sulfanyl) acetate (Hbsa) and [Re(CO)5Cl] surprisingly gave the dimeric species (μ-Cl)2[Re(Hbsa)(CO)3]2, where the two rhenium atoms are bridged by two chloro ligands. The coordination of Hbsa occurs through the imidazole nitrogen, leaving the ethoxy tail free on each Hbsa ligand. The coordination behaviour of benzimidazole and benzothiazole derivatives gave rhenium complexes in oxidation states I, III and V, where all the ligands coordinate as bidentate N,N-chelating ligands. The study on 2-(2-aminophenyl)-1-benzothiazole (Hapt) and 2-(2-aminophenyl)-1-benzimidazole (H2apz) with [ReVOCl3(PPh3)2] resulted in the formation of [ReVOCl2(apt)(OPPh3)] and [ReVCl2(apz)(PPh3)2](ReO4), respectively. 1,2-Bis(2-benzimidazole)-1,2-ethanediol (Hbed) and 2,6-bis(2- benzimidazol-2-yl)pyridine (H2bip) were studied towards rhenium(I) and rheniumV) respectively. The former gave a dimeric species (μ-bbi)[Re(CO)4]2 (H2bbi – bisbenzimidazole) by reaction with [Re(CO)5Cl], whereas H2bip produced the rhenium(III) cationic salt [ReCl3(H3bip)(PPh3)]Cl, where the ligand coordinates as a cationic H3bip+ with protonation of an uncoordinated imidazole nitrogen atom. The pyridine derivatives 2-hydrazino-pyridinyl-2-benzothiazole (Hhpt) and (E)-1-benzo[d]thiazol-2-yl)-2- (pyridin-2-ylmethylene)hydrazine (btp) were reacted with [Re(CO)5Cl]. The neutral complex [ReCl(Hhpt)(CO)3] was isolated upon reaction with Hhpt, where Hhpt coordinates as a neutral bidentate ligand. The reaction of [Re(CO)5Cl] with btp gave two different complexes when using different solvents. In methanol, [ReCl(btp)(CO)3] was isolated, whereas in toluene, the conjugate of btp (btp1) was formed which resulted in the formation of [ReCl(btp1)(CO)3]. The study on potentially bidentate thiourea derivatives containing a benzothiazole moiety towards [ReI(CO)3]+ and [ReVO]3+ cores gave rise to a wide variety of complexes. The reaction of [Re(CO)5Cl] with N-phenyl-N-(2-benzothiazole)thiourea (Hpbt) produced the rhenium(I) complex [Re(Hpbt)(pbt)(CO)3]. Hpbt coordinates both as a monodentate neutral ligand and as a bidentate monoanionic chelate. The study of the reaction between trans-[ReOCl3(PPh3)2] and Hpbt gave the rhenium(V) product [ReOCl2(pbt)(PPh3)], with pbt acting as a bidentate ligand. The reaction of 1-(1,3- benzothiazol-2-yl)-3-benzoylthiourea (Hbbt) with [Re(CO)5Cl] led to the isolation of [ReCl(Hbbt)(CO)3]. Similar reaction of Hbbt with trans-[ReOCl3(PPh3)2] gave the unique compound [ReOCl2(Hbnt)(PPh3)], where the ligand coordinates via the ketonic oxygen and a methine carbon. The complex [Re(Hmby)(mby)(CO)3] was isolated upon reacting [Re(CO)5Cl] with methylbenzothiazol-2-ylidenecarbamodithioate (Hmby), with Hmby coordinating as a monodentate neutral ligand and mby as a bidentate monoanionic chelate. The coordination behaviour of N-(benzothiazol-2-yl)-S,S’- dimethyldithiocarboimine (Hbdc) towards rhenium(I) led to the formation of [ReCl(Hbdc)(CO)3]. The reactivity of 1-(benzothiozol-2-yl)-3,3-dimethylthiourea (Hbdm), a derivative of Hmby, was studied with trans-[ReOCl3(PPh3)2] and trans- [ReO(OEt)I2(PPh3)2] producing the square pyramidal compound [ReOCl(bdm)2] and the salt [Re(bdm)2(MeCN)2]I3, respectively. Pyrazole derivatives containing a benzothiazole ring were studied towards rhenium in oxidation states +I and +V. The reaction between 2-(3,5-dimethylpyrazol-1-yl)benzothiazole (Hdmp) and [Re(CO)5Cl] gave the neutral rhenium complex [ReCl(Hdmp)(CO)3], whereas its reaction with [ReOCl3(PPh3)2] surprisingly results in the formation of a dimeric complex (μ-O)[ReOCl2(Hdmp)]2. The study on the reactivity of 1-(benzo[d]thiazol-2-yl)-4-methyl-1H-pyrrol-2-ol (Hbtm) with [Re(CO)5Cl] gave the unexpected trimer [Re(btm)(CO)3]3 containing the fac-[Re(CO)3]+ core. The ligand btm forms a bridge between each rhenium metal, serving as a bidentate ligand to one rhenium, and a monodentate ligand to another rhenium atom. The study on the coordination chemistry between trans-[ReOCl3(PPh3)2] and Hbtm gave two different complexes when using different solvents. In ethanol, [ReOCl(btm)(btm1)] formed, whereas [ReOCl(btm1)(btz)] (Hbtz = 1-(benzo[d]thiazol-2-yl)-4-(1-iminoethyl)-3- methyl-1H-pyrazol-5-ol) was isolated in acetonitrile. The reaction of cis-[ReO2I(PPh3)2] also gave two different products when using different solvents, where the respective solvents coordinate to the metal. The rhenium(V) compound [ReO(OMe)(btm)(btm1)] was formed in methanol, whereas [ReO(OEt)(btm)(btm1)] was formed in ethanol. The coordination chemistry of 2-(2-Benzothiazoleyl)-4,5,6,7-tetrahydro-2H-indazol-3-ol (Hbth) was studied towards [Re(CO)5Cl] and trans-[ReOCl3(PPh3)2]. The resulting complexes which formed are [ReCl(Hbth)(CO)3] and [ReOCl(bth)(bth1)] respectively. The reactivity of potentially tridentate Schiff base ligands towards rhenium(I) and (V) was studied. The rhenium(I) precursor [Re(CO)5Cl] was reacted with (E)-1- (benzo[d]thiazol-2-yl)-2-(phenol-2-ylmethylene)hydrazine (H3bph) to give [ReCl(CO)3(H3bph)], which contains the kinetically inert fac-[Re(CO)3]+ core coordinated to a neutral bidentate ligand. The reaction of [ReO2(py)4Cl] with H3bph gave the dimeric species (μ-O)[ReO(Hbph)(py)]2, where the ligand coordinates as a tridentate dianionic chelate. A similar complex was isolated with (E)-1- (benzo[d]thiazol-2-yl)-2-(2,4-dihydroxy-2-ylmethylene)hydrazine (H3bdh) to give (μ-O)[ReO(Hbdh)(py)]2. The reaction of trans-[ReOCl3(PPh3)2] with H3bph afforded [Re(abt)(imp)Cl2(PPh3)] (abt = 2-aminobenzothiazole, imp = 2-(iminomethyl)phenol), where the ligand broke up into two fragments, both of which coordinated without any modification. The dioxo rhenium precursor cis-[ReO2I(PPh3)2] gave [ReO(Hbdh)(imp)] upon reaction with H3bdh. Ligand imp coordinates as a bidentate monoanionic ligand via the imine nitrogen and deprotonated phenolic oxygen and ligand Hbdh coordinatesas a tridentate dianionic chelate.
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Date Issued: 2017

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