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Localizing selected endocytosis protein candidates in Plasmodium falciparum using GFP-tagged fusion constructs

  • Authors: Basson, Travis
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/2680 , vital:20316
  • Description: Malaria is a mosquito-borne infectious disease caused by several obligate intracellular protozoan parasites in the Plasmodium genus, with Plasmodium falciparum causing the most widespread cases and malaria deaths. In 2013 there were approximately 190 million cases of the disease and between 584,000 and 855,000 deaths. It is essential to identify novel drug targets and develop novel drug candidates due to the increase in resistance of P. falciparum parasites to the current arsenal of antimalarial drugs. Endocytosis is an essential process in eukaryotic cells in which the external environment is internalized by the cell in order to obtain various particles from the extracellular space. This extracellular cytoplasm is internalized in membrane-bound invaginations at the plasma membrane. During the blood stage of malaria infection, the parasite requires nutrients from the host red blood cell. To obtain these nutrients, the parasite internalizes haemoglobin in large amounts and degrades it in an acidic, lysosome-like organelle, known as the digestive vacuole. Whilst the exact molecular mechanism of malaria parasite endocytosis is not yet fully understood, a number of proteins have been suggested to be involved. The most expedient approach in identifying candidate endocytosis proteins is to investigate parasite homologues of proteins known to be involved in endocytosis in mammalian cells. The three proteins selected for investigation in this study were the P. falciparum homologues of coronin, dynamin 2, and μ4. The coding sequences for the candidate endocytosis proteins were amplified by PCR and cloned into the pARL2-GFP expression vector. P. falciparum 3D7 parasites were transfected with these vectors and the episomal expression of full-length GFP-tagged fusion protein was confirmed by Western blot analysis using commercially available anti-GFP antibodies. Microscopic analysis of live parasites using fluorescence and confocal microscopy was used to determine the localization of the candidate endocytosis proteins. Coronin appeared to display diffuse cytoplasmic GFP localization during the trophozoite stage, arguing against a role in endocytosis. However, distinct localization during the schizont stage at what appears to be the inner membrane complex was observed. Coronin is thus likely required to coordinate the formation of the actin network between the merozoite IMC and the plasma membrane on which the glideosome is dependant for generating the motile forces required for the merozoite motility and invasion of RBCs. Dynamin 2 displayed localization at three potential locii: the parasite periphery (plasma membrane), punctuate regions within the cytoplasm (potentially at membrane bound organelles) and at the parasite food vacuole. The data suggested that dynamin 2 is involved in endocytosis and membrane trafficking in a similar manner to classical dynamins, potentially as a vesicle scission molecule at the plasma membrane, mediating vesicle formation at the food vacuole to recycle membrane to the plasma membrane, and possibly mitochondria organelle division. μ4 displayed transient localization, cycling between cytosolic localization, and localization to distinct regions at the plasma membrane and the food vacuole. Localization of Pfμ4 to the plasma membrane is indicative of a role for μ4 as a part of an adaptor protein (AP) complex which may be responsible for recruitment of clathrin to initiate endocytosis in a manner similar to mammalian AP-2. As was observed with PfDYN2, Pfμ4 localizes to the FV, which suggests that Pfμ4 forms part of a coat complex that mediates the formation of vesicles that recycle membrane from the FV to the parasite plasma membrane. This study showed that expressing proteins as full-length GFP-tagged fusion constructs is an effective approach in the early stages of determining the localization and function of P. falciparum proteins in vitro, and distinguishing between candidates that have a potential role in endocytosis and those that are unlikely to do so.
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  • Date Issued: 2016

Louder than the frame:

  • Authors: Podesva, K L , Beasley, M , Kataoka, M , Ntombela, N
  • Date: 2016
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/146211 , vital:38505 , ISBN 9783863359140
  • Description: Book abstract. Almost 30 years after the founding of the first curatorial studies program (at the École du Magasin, Grenoble), with the curator remaining a figure of curiosity and fascination in the contemporary art world, a new question has emerged: how do we educate curators? Great Expectations: Prospects for the Future of Curatorial Education explores this question, focusing in particular on the challenges, opportunities and subjects that motivate educators and students. How has curatorial education changed in the past 25 years, and what will the next 25 years bring?.
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  • Date Issued: 2016

Macroinvertebrate communities associated with duckweed (Lemnaceae) in two Eastern Cape rivers, South Africa

  • Authors: Muskett, Phillippa C , Hill, Jaclyn M , Weyl, Philip S R
  • Date: 2016
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/444065 , vital:74182 , https://doi.org/10.2989/16085914.2016.1241173
  • Description: The functional feeding groups and diversity of macroinvertebrate communities associated with duckweed mats in the New Years River (two sites) and Bloukrans River (two sites), Eastern Cape province, South Africa, were assessed. Duckweed (Lemnaceae) is a ubiquitous family of floating macrophytes. A total of 41 macroinvertebrate families were collected monthly over a six-month period from February to July 2014. Duckweed biomass in both rivers was highly variable both temporally and spatially. The majority of identified macroinvertebrate taxa were predators and detritivores, with a small percentage of herbivores. An average of approximately 26% of the macroinvertebrate taxa found were from families that include species from more than one functional feeding group. Although overall measures of diversity and ecosystem health (Fisher’s α and Simpson’s index) remained constant over time in the New Years River, significant differences in macroinvertebrate community structure were seen between sites and months on both rivers, with dissimilarity being driven by a larger number of species in the New Years River. This high variability within macroinvertebrate assemblages probably reflects a combination of heterogeneous duckweed distribution, variation in physico-chemistry, opportunistic behaviours of macroinvertebrate predators and/or successional colonisation of duckweed mats.
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  • Date Issued: 2016

Management factors influencing lamb survival from birth to weaning in two ecologically different resource-limited communal farming systems

  • Authors: Lungu, Nobuhle
  • Date: 2016
  • Subjects: Lambs Communal rangelands Lambs--Feeding and feeds
  • Language: English
  • Type: Thesis , Masters , Animal Science
  • Identifier: http://hdl.handle.net/10353/11806 , vital:39108
  • Description: The objective of the study was to determine the management factors influencing lamb survival from birth to weaning in two ecologically different resource-limited communal farming systems. An annual flock monitoring study in the sourveld and sweetveld regions was preceded by a household check-all-that-apply (CATA). Lamb management practices and constraints faced in raising lambs in the two regions were determined using the check-all-that-apply technique. The results showed that the majority of the households were male headed (75.70percent) and consisted of the elderly (˃50 years, 79.44percent) who were not employed (82.24percent) and had attended primary school (67.29percent). Wool production was ranked the most important reason for keeping sheep in the two regions. The CATA revealed that the management systems between the two regions differed significantly (p˂0.05) in terms of assisting sheep at lambing, attending to twin births and dipping of mature lambs. Farmers‘ age was associated with the type of management performed (p ˂0.05). None of the farmers in the two regions performed navel dipping. Some of the reported constraints in the sweetveld were theft, diarrhoea and drought while predators and cold weather were the major constraints in the sourveld. The CATA identified vaccination and dipping as the major missing practices in both regions. The study showed differences in the use and choice of CATA terms which suggests that a ―one-size-fits-all‖ approach to solving poor management and sheep production constraints is not applicable. In the monitoring study, the results showed that veld type had no significant effect on the birth weights (2.0±0.09 kg) of the lambs. Type of birth had a significant effect (p<0.05) on the birth weights of the lambs. Single born lambs were 0.41kg heavier (p<0.05) than twin lambs. Single born lambs, however, showed an improvement in weights at 90 and 120 days where they had slightly higher weights than single born lambs. Male lambs were significantly (p<0.05) heavier (2.3±0.12 kg) than the female lambs (1.7±0.06 kg) at birth. The lamb birth were highest (P<0.05) in the hot-dry season. Lambs born in the cold-dry season were the lightest (1.63±0.13 kg). Lambs born in the post- rainy and hot-wet season were not significantly different (P<0.05). Weaning weights were not affected by veld type, birth type and sex, but were affected by season of birth. The lambs born in the hot-dry season had the highest weaning weights. The sourveld had a total pre-weaning mortality of 10.6percent while the sweetveld had a total pre-weaning mortality of 14.2percent. Animal housing from both veld types was poorly designed in terms of security against stock theft, drainage, hygiene, overhead shelter from the rain as well as access to feed and water. It was concluded that lamb management practices in the two regions were not the same. Performance of lambs before weaning differed according to veld type which played a role in feed availability during different seasons.
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  • Date Issued: 2016

Management of material waste and cost overrun in the Nigerian construction industry

  • Authors: Saidu, Ibrahim
  • Date: 2016
  • Subjects: Construction industry -- Materials management -- Nigeria , Construction industry -- Nigeria -- Management
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/3792 , vital:20463
  • Description: While wastage of materials has become a serious problem requiring urgent attention in the Nigerian Construction Industry, cost overrun is a problem, which affects 90 percent of the completed projects in the world; the argument on how to reduce/eliminate cost overrun has been on-going for the past 70 years; as the on-site wastage of materials leads to increases in the final project cost. Studies from different parts of the world have shown that construction-material waste represents a relatively large percentage of the production costs. Consequently, as a result of low levels of awareness, the Nigerian construction industry pays little attention to the effects of generated material waste on cost overruns. Thus, this research aimed to investigate the relationship between material waste and cost overrun in the Nigerian construction industry. A comprehensive review of the related literature revealed that all material waste causes are related to cost overrun causes at both pre-contract and post-contract stages of a project; but not vice versa. The mixed method (quantitative and qualitative) approach that is rooted in the positivist paradigm was adopted for this study. Abuja, the federal capital territory of Nigeria was the selected geographical scope of this research, out of which thirty-one (31) construction projects were purposeful selected (projects to the value of 100 million Rand/1.6 billion Naira and above).The research instrument was an interview guide used in conjunction with a tick box. Other sources of data included field investigation (measurement of onsite material waste) and the collection of archival records from bills of quantities, project records, and specifications. Analyses of the findings lead to the conclusion that a relationship exists between material waste and cost overrun; at the pre-contract and at the post-contract stages of a project. The implication is that an increase in material wastage on-site leads to a corresponding increase in the amount of cost overrun, regardless of the percentage allowance for material waste in the process of bill preparation. The study also concluded that the average percentage contribution of material waste to project-cost overruns is four (4) percent. Material-waste sources, causes, and control measures were found to have significant effects (very high, high, medium, low, and very low), in causing or minimising cost overruns at both pre-contract and post-contract stages of projects. The research has developed a conceptual model for the management of material waste and cost overruns in the construction industry based on the results and informed by the theoretical framework. The research has also developed a mathematical model for quantifying the amount of material waste to be generated by a project; as well as a mathematical equation for the effective management of material waste and cost overrun for projects. The study has achieved its aim of establishing an understanding of the issues leading to the relationship between material waste and cost overruns, as well as their management in the Nigerian construction industry. The study recommends that the management of material waste and cost overrun should be revised, based on the findings of this research and included as part of the procurement process. The mathematical models for quantification of onsite material waste, and the mathematical equation for managing material waste and cost overruns developed in the study, could be usefully adopted to improve management of material waste and cost overrun in the Nigerian construction industry.
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  • Date Issued: 2016

Management of material waste and cost overrun in the Nigerian construction industry

  • Authors: Saidu, Ibrahim
  • Date: 2016
  • Subjects: Construction industry -- Materials management -- Nigeria , Construction industry -- Nigeria -- Management
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/48937 , vital:41507
  • Description: While wastage of materials has become a serious problem requiring urgent attention in the Nigerian Construction Industry, cost overrun is a problem, which affects 90 percent of the completed projects in the world; the argument on how to reduce/eliminate cost overrun has been on-going for the past 70 years; as the on-site wastage of materials leads to increases in the final project cost. Studies from different parts of the world have shown that construction-material waste represents a relatively large percentage of the production costs. Consequently, as a result of low levels of awareness, the Nigerian construction industry pays little attention to the effects of generated material waste on cost overruns. Thus, this research aimed to investigate the relationship between material waste and cost overrun in the Nigerian construction industry. A comprehensive review of the related literature revealed that all material waste causes are related to cost overrun causes at both pre-contract and post-contract stages of a project; but not vice versa. The mixed method (quantitative and qualitative) approach that is rooted in the positivist paradigm was adopted for this study. Abuja, the federal capital territory of Nigeria was the selected geographical scope of this research, out of which thirty-one (31) construction projects were purposeful selected (projects to the value of 100 million Rand/1.6 billion Naira and above).The research instrument was an interview guide used in conjunction with a tick box. Other sources of data included field investigation (measurement of onsite material waste) and the collection of archival records from bills of quantities, project records, and specifications. Analyses of the findings lead to the conclusion that a relationship exists between material waste and cost overrun; at the pre-contract and at the post-contract stages of a project. The implication is that an increase in material wastage on-site leads to a corresponding increase in the amount of cost overrun, regardless of the percentage allowance for material waste in the process of bill preparation. The study also concluded that the average percentage contribution of material waste to project-cost overruns is four (4) percent. Material-waste sources, causes, and control measures were found to have significant effects (very high, high, medium, low, and very low), in causing or minimising cost overruns at both pre-contract and post-contract stages of projects. The research has developed a conceptual model for the management of material waste and cost overruns in the construction industry based on the results and informed by the theoretical framework. The research has also developed a mathematical model for quantifying the amount of material waste to be generated by a project; as well as a mathematical equation for the effective management of material waste and cost overrun for projects. The study has achieved its aim of establishing an understanding of the issues leading to the relationship between material waste and cost overruns, as well as their management in the Nigerian construction industry. The study recommends that the management of material waste and cost overrun should be revised, based on the findings of this research and included as part of the procurement process. The mathematical models for quantification of onsite material waste, and the mathematical equation for managing material waste and cost overruns developed in the study, could be usefully adopted to improve management of material waste and cost overrun in the Nigerian construction industry.
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  • Date Issued: 2016

Management of street traders to boost the local economy in King William's Town (Buffalo City Municipality)

  • Authors: Hlope, Sithabiso Patrick
  • Date: 2016
  • Subjects: Economic policy King William's Town (South Africa) -- Economic policy , Street vendors -- South Africa -- King William's Town
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10948/13049 , vital:27147
  • Description: This study deals with the management of street traders to boost the local economy of King William‟s Town. The purpose of the study is to conduct the research on how street traders can be managed to boost the local economy of King William‟s Town. The intention is to research the challenges they have and how to improve them. To be able to conduct the study, the researcher deemed it necessary to study existing literature on Local Economic Development. The way street traders are managed presently has been investigated and analysed in order to develop recommendations for solving the challenges facing street trading in King William‟s Town. The researcher conducted interviews in the form of face-to-face discussions and scheduled interviews with street traders, municipal authorities, and the iQonce Small Business Association. The literature review and interviews enabled the researcher to develop recommendations to solve the challenges. These recommendations will be helpful to the King William‟s Town municipality. The findings of this study reveal that there are challenges in the manner in which street trading is managed in King William‟s Town. Some of the challenges are a lack of a LED policy, poor infrastructure, failure to implement decisions, lack of financial support for street traders, and underutilisation of the budget. The researcher has made some recommendations in terms of support and assistance for street traders, the formulation of a LED policy, and plans and systems needed to be put in place for the management of street trading in King William‟s Town. The researcher summarises the study by claiming that if the proposed recommendations can be thoroughly implemented, there will be some improvement in the manner in which the street traders are managed.
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  • Date Issued: 2016

Management practices, milk quality, haemato-chemical biomarkers of free ranging pregnant goats from three genotypes and linear body measurements of their respective kids

  • Authors: Idamokoro, Emrobowansan Monday
  • Date: 2016
  • Subjects: Milk--Quality Biochemical markers Goat milk
  • Language: English
  • Type: Thesis , Doctoral , Animal Science
  • Identifier: http://hdl.handle.net/10353/11548 , vital:39082
  • Description: The broad objective of this study was to assess farmers’ perceptions on the welfare and management practices of pregnant goats and to determine the effect of genotypes and physiological status on doe’s performance (blood metabolites and milk quality) and their respective kid’s linear body measurements of goats reared in an extensive system of production. A survey was conducted among 153 goat farmers to assess their perception on goat mortality and management practices during and after gestation period. The results from the survey showed that 98.7percent of the farmers depended on pastures to feed their pregnant and lactating does. Majority of the farmers (59.9percent) did not vaccinate their dams against diseases before using them for breeding purposes. An aggregate of 77.8percent respondents allowed their does to mate freely on the veld. Most of the respondents (75.2percent) kept their pregnant goats together with other flocks in mud floor pen (kraals) fenced with tree branches. Farmers indicated that, poor diet (32percent), disease (24 percent) and predators (15percent) were some factors that cause mortality in pregnant does. About 66.7percent respondents perceived that, quality diet is a factor that can boost the reproductive performance of pregnant goats. The haemato-biochemical parameters of Nguni, Boer and Non-descript goats at late and early lactation revealed that, Nguni goat had higher (P ˂ 0.05) values of red cell counts (13.37 x1011/L), haemoglobin (9.07 g/dL) and creatine kinase (269.54 U/L) compared to Boer (9.96 x 1011/L, 7.94 g/ dL and 132.16 U/L) and Non-descript goats (12.98 x 1011 /L, 7.85 g/ dL and 143.50 U/L), respectively. The Nguni goats also had higher (P ˂ 0.05) mean values of glucose (3.38 mmol/L), sodium (141.66 mmol/L) and urea content (5.51 mmol/L) compared to Boer (2.96 mmol/L, 135.70 mmol/L and 4.45 mmol/L) and Non-descript goats (2.50 mmol/L, 141.31 mmol/L and 3.90 mmol/L), respectively. The results of blood metabolites also revealed that, there was significant difference (P < 0.05) in the physiological status of goats. The late stage of pregnancy had higher mean values of red cell counts (14.44 x 1011 /L), haemoglobin (8.57 g/dL), haematocrit (0.67 L/L), glucose (3.12 mmol/L), sodium (141.74 mmol/L) and calcium content (2.37 mmol/L) compared to the early stage of lactation (9.77 x 1011/ L, 8.00 g /dL, 0.55 L/L, 2.77 mmol/L, 137.37 mmol/L and 2.23 mmol/L), respectively. Furthermore, it was revealed that, Nguni goats produced (1.2±0.09, 1.3±0.11 and 1.2±0.07 litres per day) more milk (P ˂ 0.05) at early, mid and late stages of lactation than Boer (0.6±0.10, 1.0±0.17 and 0.6±0.09 litres per day) and Non-descript (0.3±0.10, 0.3±0.12 and 0.3±0.09 litres per day) goats. There was significant difference (P ˂ 0.05) of genotypes on milk fat, milk magnesium and sodium contents among Nguni, Boer and Non-descript goats. Lactation stages had a significant effect (P ˂ 0.05) on some milk compositions (fat, protein, lactose and solid non-fat) and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Lactation stages had a significant effect (P ˂ 0.05) on fat, protein, lactose and solid non-fat content and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Milk protein content of Nguni goat was positively correlated to milk fat but, not in Boer and Non-descript goats. Milk quality parameters from the three goat genotypes possessed relatively moderate milk compositions and mineral profiles which is comparable to some exotic goat breeds. Nguni kids had higher mean weights (7.36 kg, 11.85 kg and 13.72 kg) than the Boer kids (5.20 kg, 7.18 kg and 10.20 kg) and the Non-descript goat kids (5.23 kg, 6.19 kg and 8.01 kg) at weeks 4, 6 and 8 after parturition, respectively. In terms of height at withers, the Nguni kids had higher mean values in heights (41.92 cm, 44.71 cm, 49.38 cm and 55.75 cm) than the Boer kids (35.67 cm, 37.14 cm, 42.40 and 44.20 cm) and the Non-descript kids (36.38 cm, 40.20 cm, 41.14 cm and 43.50 cm) at week 2, 4, 6 and 8 after parturition, respectively. Conversely, there was a positive correlation (P ˂ 0.05) between body lengths and live weights of Nguni goats and not in Boer and Non-descript goats. It was concluded from this study that, the indigenous Nguni, Boer and Non-descript pregnant goats were managed in poor conditions by communal farmers and the perceived causes of mortality of pregnant goats among others include poor feed, diseases and predators. In addition, the Nguni goats had higher mean values in some haematological parameters (red cell counts and haemoglobin) and serum biochemical profiles (glucose, sodium, urea and creatine kinase) than Boer and Non-descript goats during the periods of investigation. Nguni goats also produced more milk at the early and late stages of lactation compared to the Boer and Non-descript goats. The Non-descript goats had a higher mean value of milk fat compared to Nguni and Boer goats. Likewise, the Boer goats were observed to have higher mean value of milk magnesium and sodium content compared to Nguni and Non-descript goats. In terms of body weights and linear body measurments, the Nguni goat kids were superior compared to Boer and Non-descript goats.
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  • Date Issued: 2016

Managerial leadership in committees: a case study in a public rural combined school in the Ohangwena region, Namibia

  • Authors: Vaeta, Simon
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: http://hdl.handle.net/10962/1220 , vital:20036
  • Description: The existing education legislations in Namibia call for school principals to put in place appropriate support mechanisms and create necessary internal conditions for leaders, including teachers who do not hold formal leadership positions, to exert their sphere of influence beyond the classroom and into school-wide leadership activities. The establishment of various committees in the school is to enhance and improve the performance of the school and to create a pleasant work environment and spirit of collaboration and teamwork (Namibia Ministry of Education, [MoE], 2005). Leadership in committees is one of the expectations of new education policy. The aim of this study was to explore the leadership practices within a range of committees in a public rural combined school in the Ohangwena region of Namibia. It further unpacked the purpose, roles and membership of each of the four committees; how these committees were established; what leadership functions the teachers as committee members exercised and what challenges inhibited their leadership practices within committees. The study provided recommendations for future research in the area of leadership practices in committees. This research is a case study. The study is designed within the qualitative interpretive paradigm. It is rooted in a social constructivist tradition and employs a range of data collection tools, namely document analysis, semi-structured interviews, observations and questionnaires to enhance the validity of findings. The study found that committees were established in line with the Namibian education legislation. However, the study found the principal lacked the experience and skills to use the committee system more effectively, and maintained the status quo. This resulted in the committees practising pure management responsibilities rather than leadership interest. The study also found that only the leadership tasks were distributed to the committees but the power was not distributed. It was revealed that committees were dormant; while they were named in school documents, they functioned variously, intermittently or not at all. The significance of the contradiction was there were no regulations to guide the conduct of committee members.
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  • Date Issued: 2016

Managing change in organisational environment

  • Authors: Markova, Elena
  • Date: 2016
  • Subjects: Organizational change , Conflict management , Teams in the workplace
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/8129 , vital:25017
  • Description: Twentieth century has set an unprecedented pace of change, which seems to be ever increasing. The changes are transforming every sphere of social life including business and organisational life. Globalisation has made organisational structures flatter but wider in reach. Advancements in information and communication technologies have made teams larger through vast and powerful information networks. These forces are triggering the reshaping and restructuring of every major industry worldwide nowadays. The main research aim of this study is to explore how organisational conflict is affected by change (and vice versa) in order to work out a set of recommendations which shall take form of practical intervention strategies for the improvement of organizational effectiveness by mitigating the dysfunctions of a conflict and adjusting employees' styles of handling interpersonal and intergroup conflict. Workplace conflict is an everyday reality. It is an inevitable result of human interaction in a competitive environment of the workplace. So, according to this assumption, conflict is not something vicious and destructive, but an intrinsic part of human interaction. Then, the conflict is not a problem in itself, the way it is managed is what defines whether the conflict is destructive or not.
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  • Date Issued: 2016

Mapping epistemic cultures and learning potential of participants in citizen science projects

  • Authors: Vallabh, Priya , Lotz-Sisitka, Heila , O'Donoghue, Rob B , Schudel, Ingrid J
  • Date: 2016
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/128939 , vital:36192 , https://doi.org/10.1111/cobi.12701
  • Description: The ever-widening scope and range of global change and interconnected systemic risks arising from people–environment relationships (social‐ecological risks) appears to be increasing concern among, and involvement of, citizens in an increasingly diversified number of citizen science projects responding to these risks. We examined the relationship between epistemic cultures in citizen science projects and learning potential related to matters of concern. We then developed a typology of purposes and a citizen science epistemic‐cultures heuristic and mapped 56 projects in southern Africa using this framework. The purpose typology represents the range of knowledge‐production purposes, ranging from laboratory science to social learning, whereas the epistemic‐cultures typology is a relational representation of scientist and citizen participation and their approach to knowledge production. Results showed an iterative relationship between matters of fact and matters of concern across the projects; the nexus of citizens’ engagement in knowledge‐production activities varied. The knowledge‐production purposes informed and shaped the epistemic cultures of all the sampled citizen science projects, which in turn influenced the potential for learning within each project. Through a historical review of 3 phases in a long‐term river health‐monitoring project, we found that it is possible to evolve the learning curve of citizen science projects. This evolution involved the development of scientific water monitoring tools, the parallel development of pedagogic practices supporting monitoring activities, and situated engagement around matters of concern within social activism leading to learning‐led change. We conclude that such evolutionary processes serve to increase potential for learning and are necessary if citizen science is to contribute to wider restructuring of the epistemic culture of science under conditions of expanding social-ecological risk.
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  • Date Issued: 2016

Mapping Nitrogen Loading in Freshwater Systems: Using Aquatic Biota to Trace Nutrients

  • Authors: Motitsoe, Samuel Nkopane
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5945 , http://hdl.handle.net/10962/d1020819
  • Description: The majority of river systems in developing countries like South Africa, are found in catchments areas that are densely human populated, therefore are subjected to intense land-use and developmental pressures. Anthropogenic nutrient pollution or the excessive addition of nutrients is one important type of stressors that river systems often experience through intense land-use, which includes poor waste management and agricultural practices. Such events are referred to as the “urban syndrome”, were human populations and developmental demands outpace ecosystem services. Traditional measurements of water quality (e.g. physicochemical and micro-nutrient assessments) and biological monitoring (e.g. South African Scoring System 5, SASS5) techniques for assessing ecosystem health have being widely used to reflect the ecological health and status of river systems. However these techniques have a number of challenges associated with their application. SASS5 which is used most prevalently in southern Africa for example, can only be applied in lotic systems, it is habitat dependent and finally (but arguably most importantly) it cannot identify the source of pollution inputs. Recent laboratory studies using stable isotopic ratios (δ15N and δ13C) of aquatic macrophytes (duckweed: Spirodela sp.) have shown successful differentiation between different N-sources and the mapping of temporal and spatial nitrogen dynamics in freshwater systems. Furthermore δ15N isotopic values of Spirodela sp. showed the capability to act as an early warning indicator of eutrophication, before the onset of aquatic ecosystem degradation. Therefore, this study aimed to field test the potential of sewage plume mapping using the stable isotopic values of Spirodela sp. and aquatic macroinvertebrates at nine study sites on the Bloukrans-Kowie River and ten study sites on the Bushman-New Year’s River systems in the Eastern Cape, South Africa. And more...
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  • Date Issued: 2016

Marie Curie : a psychobiography

  • Authors: Roets, Elmeret
  • Date: 2016
  • Subjects: Curie, Marie -- 1867-1934 -- Psychology , Women chemists -- Poland -- Biography , Scientists -- Biography
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3269 , http://hdl.handle.net/10962/d1020326
  • Description: While researchers debate the value of psychobiographical research, interest in this area is growing on a national and international basis. Every year, the number of psychobiographical studies at universities in South Africa is growing. Psychobiographical research is qualitative research that utilises psychological theory to explore and describe the lives of extraordinary individuals. The primary aim of this psychobiography was to examine the life of Marie Curie (1867–1934) by employing developmental psychologist and psychoanalyst Erik Erikson’s (1959) theory of psychosocial personality development. Marie Curie was chosen as the research subject because of the researcher’s personal interest and the subject’s prominence as a female scientist. She was a Polish-born and naturalised French scientist who conducted pioneering research on radioactivity. Marie Curie’s ground-breaking discoveries changed the way scientists think about matter and energy and introduced a new era in medical knowledge and the treatment of disease. Her life exemplifies a love of science, commitment, and perseverance. Data were collected from several primary and secondary sources on Marie Curie’s life. The researcher developed a data-collection and analysis matrix to facilitate the systematic collection of data and analysis according to Erikson’s stage theory of psychosocial personality development. This psychobiography suggests that unresolved infantile and early childhood crises gave rise to personality traits that eventually contributed to Curie’s extraordinariness. In the case of Curie, personality traits that are often regarded as atypical or malignant, ironically encouraged perseverance, creativity, and productivity. This study complements the psychobiographical studies done in South Africa on extraordinary individuals. It demonstrated the value of psychobiographical research as a teaching instrument, revealed the usefulness of Erikson’s theory, and illustrated the uniqueness of individuals.
  • Full Text:
  • Date Issued: 2016

MARS Motif: Assessment and Ranking Suite for transcription factor binding motifs

  • Authors: Kibet, Cabel K , Machanick, Philip
  • Date: 2016
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/439339 , vital:73568 , https://doi.org/10.1101/065615
  • Description: We describe MARS (Motif Assessment and Ranking Suite), a web-based suite of tools used to evaluate and rank PWM-based motifs. The increased number of learned motif models that are spread across databases and in different PWM formats, leading to a choice dilemma among the users, is our motivation. This increase has been driven by the difficulty of modelling transcription factor binding sites and the advance in high-throughput sequencing technologies at a continually reducing cost. Therefore, several experimental techniques have been developed resulting in diverse motif-finding algorithms and databases. We collate a wide variety of available motifs into a benchmark database, including the corresponding experimental ChIP-seq and PBM data obtained from ENCODE and UniPROBE databases, respectively. The implemented tools include: a data-independent consistency-based motif assessment and ranking (CB-MAR), which is based on the idea that ‘correct motifs’ are more similar to each other while incorrect motifs will differ from each other; and a scoring and classification-based algorithms, which rank binding models by their ability to discriminate sequences known to contain binding sites from those without. The CB-MAR and scoring techniques have a 0.86 and 0.73 median rank correlation using ChIP-seq and PBM respectively. Best motifs selected by CB-MAR achieve a mean AUC of 0.75, comparable to those ranked by held out data at 0.76 – this is based on ChIP-seq motif discovery using five algorithms on 110 transcription factors. We have demonstrated the benefit of this web server in motif choice and ranking, as well as in motif discovery.
  • Full Text:
  • Date Issued: 2016

MARS: Motif Assessment and Ranking Suite for transcription factor binding motifs

  • Authors: Kibet, Caleb K , Machanick, Philip
  • Date: 2016
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/61155 , vital:27985 , http://dx.doi.org/10.1101/065615
  • Description: We describe MARS (Motif Assessment and Ranking Suite), a web-based suite of tools used to evaluate and rank PWM-based motifs. The increased number of learned motif models that are spread across databases and in different PWM formats, leading to a choice dilemma among the users, is our motivation. This increase has been driven by the difficulty of modelling transcription factor binding sites and the advance in high-throughput sequencing technologies at a continually reducing cost. Therefore, several experimental techniques have been developed resulting in diverse motif-finding algorithms and databases. We collate a wide variety of available motifs into a benchmark database, including the corresponding experimental ChIP-seq and PBM data obtained from ENCODE and UniPROBE databases, respectively. The implemented tools include: a data-independent consistency-based motif assessment and ranking (CB-MAR), which is based on the idea that `correct motifs' are more similar to each other while incorrect motifs will differ from each other; and a scoring and classification-based algorithms, which rank binding models by their ability to discriminate sequences known to contain binding sites from those without. The CB-MAR and scoring techniques have a 0.86 and 0.73 median rank correlation using ChIP-seq and PBM respectively. Best motifs selected by CB-MAR achieve a mean AUC of 0.75, comparable to those ranked by held out data at 0.76 { this is based on ChIP-seq motif discovery using five algorithms on 110 transcription factors. We have demonstrated the benefit of this web server in motif choice and ranking, as well as in motif.
  • Full Text:
  • Date Issued: 2016

MCD spectroscopy and TD-DFT calculations of magnesium tetra-(15-crown-5-oxanthreno)-phthalocyanine

  • Authors: Mack, John , Mkhize, Scebi , Safonoya, Evgeniya A , Gorbunova, Yulia G , Tsivadze, Aslan Yu , Nyokong, Tebello
  • Date: 2016
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/240743 , vital:50867 , xlink:href="https://doi.org/10.1142/S1088424616500322"
  • Description: An analysis of the MCD spectroscopy and TD-DFT calculations of magnesium tetra-(15-crown-5-oxanthreno)-phthalocyanine is reported. This study provides a reassessment of an earlier study on the nature of the bands in UV-visible absorption spectra of magnesium and zinc tetra-(15-crown-5-oxanthreno)-phthalocyanine that was based on an analysis of TD-DFT calculations for a series of model complexes with the B3LYP functional. A detailed analysis of MCD spectral data and TD-DFT calculations with the CAM-B3LYP functional for the complete Mg(II) complex provides an additional insight into the optical properties and electronic structures of tetra-(15-crown-5-oxanthreno)-phthalocyanines. Thus, the bands in the Q-band region are reassigned as being due exclusively to the Q transition of Gouterman’s 4-orbital model, since intense pseudo-A1𝒜1 terms are observed in the MCD spectrum in a spectral region that had previously been assigned as charge transfer bands.
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  • Date Issued: 2016

Measures of success of small and medium-sized family and non-family-owned businesses in the Eastern Cape

  • Authors: Carelsen, Mispah
  • Date: 2016
  • Subjects: Success in business -- South Africa -- Eastern Cape , Small business -- South Africa -- Eastern Cape , Family-owned business enterprises -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10948/3479 , vital:20434
  • Description: Small and medium-sized enterprises (SMEs) are recognised internationally and in South Africa as a critical component of the economic development of a country as a result of their contribution to job creation, alleviation of poverty, sustainability and innovation. Furthermore, the majority of SMEs are also family-owned and play an increasingly important role in the South African economy, making up approximately 84 per cent of businesses in the country. Despite the critical role that family and non-family SMEs play in economic development, they are still plagued with high failure rates and unique challenges that make it difficult for them to survive. These challenges include, amongst others, regulatory burdens, restrictive labour policies, a lack of access to finance, markets and technology, as well as an overwhelmingly constant emphasis on survival. As a result of the added dynamic of family relationships within family-owned SMEs, they face additional challenges such as conflict between family members and inadequate succession planning. Focus is often placed on the factors leading to failure, but little is known about success-aiding behaviours that could reduce the high failure rate and improve the success rate of these businesses. As a result, it is important to examine what determines success and how it is measured. Success can be defined as the attainment of goals, therefore the achievement of goals plays a critical role in the success of the business.
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  • Date Issued: 2016

Measuring changes in residential segregation in Port Elizabeth, South Africa, from 1996-2011

  • Authors: Odayar, Luveshni
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/3641 , vital:20532
  • Description: Racial segregation and inequality were the prime objectives of the colonial and apartheid spatial planning policies that governed the spatial development of the South African urban landscape. Since South Africa’s democratic transition after 1994, efforts have been made by government to facilitate racial integration and transform the apartheid urban fabric. Research into post-apartheid segregation is crucial to assess the success of governmental actions enacted thus far, while informing future spatial planning strategies. Most studies of these processes have relied solely on dichotomous indices to measure the extent of segregation between two groups. Few have utilized multi-group indices, which are more suited to investigating changes in multi-ethnic cases. Furthermore, the segregation indices used are typically aspatial. This study investigates the extent to which the segregationist legacy prevails in Port Elizabeth, a place widely considered to be the founding city of urban racial segregation. It also aims to investigate the impact of geographical scale on segregation. Theil’s multi-group Entropy Index and Duncan and Duncan’s Dissimilarity Index were derived from racial population data from the 1996, 2001 and 2011 National Censuses, and GIS was used to map changes in racial diversity both at tract level and across a range of geographical scales. To generate a more holistic understanding of the observed trends, statistical tests were performed to relate the observed patterns to socio-economic determinants, and feedback from the relevant government department was obtained. The results from the entropy indices reveal that segregation levels in Port Elizabeth have declined but still remain high: 84.6 % (1996), 79.2 % (2001) to 71.5 % (2011). This is a similar trend to those found in Cape Town and Johannesburg. The integration that did occur was characterized by one-way patterns of movement into former-White areas; this was predominantly confined to the Indian population, and to a lesser extent, the Coloured population. The vast majority of the African population remains confined to their former designated location areas. The White population remains the most segregated group, despite most of the racial integration occurring in former-White areas. Interview results and statistical tests revealed that persisting racial discrepancies in socio-economic factors (income, employment and education) can be considered major drivers influencing the observed trends in racial integration and persisting desegregation, as well as self-segregation.
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  • Date Issued: 2016

Measuring the performance of the banking sector in Zimbabwe

  • Authors: Abel, Sanderson
  • Date: 2016
  • Subjects: Banks and banking -- Zimbabwe , Bank profits -- Zimbabwe
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/5110 , vital:20806
  • Description: The measurement of the banking sector performance in Zimbabwe is motivated by the unique developments that typified the sector during the period 2009-2014 after emerging from an economic crisis. The Zimbabwean economy returned to stability and growth in 2009, after a decade long economic decline. Economic stability brought about growth in deposits, loans, assets, capitalization and profits during this period. The banking sector has been accused of excessive profiteering through overpricing their products, which culminated in the intervention by the authorities in the sector. The interest rates spread, fees and other charges were presumed to be high which motivated the need to understand whether the banking sector is efficient or inefficient given the high interest rate spreads between the deposit rates and lending rates. Furthermore the high interest rates have raised the question of whether banks were exploiting their market power to price their products highly or whether their prices were determined by the dictates of market forces. Continued profitability of the sector also called for an investigation into what was driving the persistence of profitability over time. The primary objective of this research was to measure the performance of the banking sector during the period 2009-2014. The study contributes to the empirical literature by measuring and assessing the drivers of banking sector competition, efficiency and profitability and applying them at much disaggregated levels. This study also contributes to the debate on the relationships among the performance measures of competition, profitability and efficiency. The study adopted a number of methods which contributes to the array of tools central banks can employ to measure bank performance. The study employed a number of methodologies to measure the competition, efficiency and profitability performance of the banking sector. Competition was estimated using the new empirical industrial organisation methods of Panza and Rose (1987) and the Lerner (1934) Index was used. Cost and revenue efficiency was estimated using the two step methods of Data Envelopment Analysis followed by the Tobit regression method. An assessment of the persistence and drivers of profitability was measured using the Generalised Method of Moments. This study shows that the banking sector was operating under monopolistic competition market structure. This implies that banks held some market power as a result of product differentiation due to unique features such as brands, image and advertising, among others. The study indicates that competition increased during the period 2009-2014. Market power/competition in the banking sector during the study period was driven by capital adequacy, non-performing loans, liquidity risk, cost-income ratio, economic growth and government policy on pricing of bank products. The study suggests that the banking sector experienced an average inefficiency level of approximately 35 per cent in relationship with the best performing institutions in the sample. As a result of stability experienced in the economy, the average revenue and cost efficiency increased between 2009 and 2014. The study further established that the discord around the implementation of the indigenisation and empowerment law, coupled with the government intervention in the banking sector had a negative impact on the banking sector efficiency. It also found that efficiency is determined by market power, capital adequacy, cost income ratio, economic growth, inflation, market share and profitability. The Granger Causality test between cost efficiency and market power suggests that causality is bidirectional. On the other hand granger causality between revenue efficiency and market power is unidirectional and positive, running from revenue efficiency to market power. The result implies that policy measures should bring a balance between increasing competition and improving the revenue efficiency. The study shows that the banking sector was profitable during the period 2009 to 2014. The profitability was a reflection of a stable macroeconomic environment, typified by low inflation levels, despite the crises during this period. It further reveals that the banking sector‟s profitability persisted over time, reflecting the regulatory structure of the sector. The study established that profitability was determined by market power, non-performing loans, liquidity risk, capital adequacy, bank size and cost efficiency. This implies profitability was driven by bank specific determinants. There are a number of policy implications derived from the study. Regulatory measures such as forced consolidations can lead to excessive market power by the banking institution; hence it should be moderated. Banks should enhance credit risk because NPLs has been dragging profits. Banks should take advantage of the various measures introduced, such as the setting up of the special purpose vehicle and credit reference bureau. The government should avoid tampering with market forces as this reduces competition, efficiency and profitability and put in place measures that grow the economy as it increases the efficiency and profitability of the banking sector.
  • Full Text:
  • Date Issued: 2016

Meat and its meanings: representations of meat-eating in selected works of South African literature

  • Authors: Coetzer, Theo
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/3860 , vital:20550
  • Description: This thesis is situated within the burgeoning field of literary animal studies. Its aim is to analyse critically the way in which animals-as-meat are represented in South African literature. While meat pervades our lives and literature, there exists very little scholarship that considers literary depictions of meat. The thesis suggests that literary texts can offer useful reflections of the cultural environments in which they are immersed and, furthermore, can encourage what J. M. Coetzee calls the ‘sympathetic imagination’ in relation to animals. The dissertation offers close readings of three primary texts, while also drawing on a broader range of local fiction. Chapter 1 discusses Eben Venter’s Trencherman, with a specific focus on Venter’s use of the plaasroman and literary dystopia. Both genres are important to the novel’s ubiquitous depictions of meat, serving to illustrate some of the destructive, and irreversible, excesses associated with traditional Afrikaner culture in South Africa. Meat consumption is not only depicted as being among these harmful excesses, but also comes to represent them collectively. Chapter 2 offers a reading of Zakes Mda’s The Madonna of Excelsior, paying particular attention to its representation of the intersection between the objectification of women’s bodies and the transformation of animals into meat. In my approach to this text, I make use of Carol J. Adams’ notion of the ‘absent referent’. I suggest that while Mda ostensibly considers the subjugation of both women and animals, the novel does not ultimately demonstrate concern for animals in their own right. The final chapter considers the representation of suffering in Damon Galgut’s The Beautiful Screaming of Pigs. I argue that Galgut’s text is alone among the three primary texts in its attention to the animal suffering inextricably linked to meat production. The novel depicts this suffering as being comparable to human suffering, while simultaneously demonstrating humans’ indifference to their animal fellows. The dissertation concludes that while meat is infused with a range of meanings in South African literature, the most obvious and intrinsic one – the fact of animal death and animal suffering – is the one most often ignored.
  • Full Text:
  • Date Issued: 2016
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