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The effect of ultraviolet and gamma irradation on soluble calf-skin collagen

  • Authors: Davidson, Raymond John
  • Date: 1967
  • Subjects: Collagen -- Hide powder Irradiation Solids -- Effect of radiation on Gamma rays -- Dose-response relationship
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4290 , http://hdl.handle.net/10962/d1003718
  • Description: Initially the present study was confined to the effects of ultraviolet irradiation on acid-soluble collagen. Such a study was undertaken in order to demonstrate the critical role played by tyrosine and phenylalanine in the intermolecular interaction of the telopeptides protruding from the rigid parent collagen molecule. Since both tyrosine and phenylalanine are photosensitive, and because the collagen telopeptides are relatively rich in these aromatic amino acids, carefully controlled degradation studies involving telopeptide liberation could be made. It became increasingly apparent during the course of investigation, that a better understanding of the subunit composition of thermally denatured acid-soluble collagen was necessary if a satisfactory interpretation of the irradiation studies was to be made. A subsequent study of the subunit composition of thermally denatured acid-soluble collagen resulted in the isolation and characterisation of two major and two minor dimeric components as well as the α- and β - subunits. Three acidic telopeptides and three basic telopeptides were also isolated from acid-soluble collagen during the course of the present study. The presence of the dimeric components while related directly to the method of preparation, suggested that acid-soluble collagen was largely dimeric in nature. Such a conclusion suggested an intermolecular rather than an intraolecular relationship between neutral-salt-soluble and acid-soluble collagen. While it is currently accepted that an intramolecular relationship exists between neutral-salt-soluble and acid-soluble collagen, such a relationship does not satisfactorily explain the very different solubility characteristics displayed by these soluble collagen extracts. With this in mind, and using the study on the subunit composition of thermally denatured acid-soluble collagen as a basis for comparison, the intra and intermolecular relationship between neutral-salt-soluble and acid-soluble collagen was investigated using ultraviolet and gamma irradiation. The effects of ultraviolet and gamma irradiation on soluble collagen preparations proved very similar. Although collagen samples were irradiated in solution from an ultraviolet source; and under anhydrous conditions from a gamma source, much the same degradation mechanism resulted. The initial depolymerisation of dimeric material followed by peptide fission, yielding irradiation-resistant crystalline portions of the parent triple helix, took place in both instances. At the same time, both studies indicated no significant differences in the intra or intermolecular structures of the neutral-salt-soluble and acid-soluble preparations investigated. The dimer content of neutral-salt-soluble collagen preparations was, however, noted to be smaller. To current methods for the preparation of soluble collagens, it may be concluded that such preparations are peptideless to some degree. While the native tropocollagen monomer with its full complement of telopeptide side chains may actively undergo linear polymerisation resulting in fibre formation, the soluble collagen preparations referred to above may only aggregate in a rather random fashion.
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  • Date Issued: 1967

Representations of the ‘other’: a comparison between Roman descriptions of Britons, Gauls and Germans pre-AD 300 and Sir Harry Smith’s portrayal of the Xhosa 1830s – 1850s

  • Authors: Van Wezel, Amy Hester
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/4223 , vital:20634
  • Description: Stereotypical representations of an ‘ethnically’ or ‘racially’ different ‘other’ in ancient texts would seem to reappear throughout history. By comparing Roman views of Britons, Gauls and Germans, with Sir Harry Smith’s views of the Xhosa, this study seeks to explore the extent to which these stereotypical images were employed and for what reasons. Through close textual analyses, the descriptions of these peoples are examined and compared, taking into consideration the different authors’ context and agendas. By highlighting Caesar’s views of the abilities of the ‘other’ and Tacitus’ judgements of the moral character of the ‘other’, compared with Smith’s view of the same, the study aims to draw out the role of the author’s ‘self’ in complex and contradictory representations of the ‘other’, while arguing that various overwhelmingly negative images served to justify imperial conquest and rule. The extent to which the ‘other’ was perceived as remote and different from themselves, epitomised in the dichotomy between the ‘barbarism’ and ‘civilisation’, is examined, comparing a variety of Roman authors with Smith. The similar idea of ‘civilising missions’ are discussed, while acknowledging the differences between the policies of the Roman and British Empires toward the ‘other’. The connections between how the ‘other’ was portrayed in relation to ‘Empire’ and the ways in which they were treated is also explored stressing even further the different approaches taken by Roman and British authorities to include these peoples within their Empires. While certain stereotypes are shown to have persisted from Roman times, reappearing in the writing of Sir Harry Smith, summed up in the archetypal ‘barbarian’, I argue that the use of these images was varied, inconsistent and reflected more the motives and personalities of the writers themselves, whofor the most part ascribed to imperial ideologies.
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  • Date Issued: 2016

How an eco-school sanitation community of practice fosters action competence for sanitation management in a rural school : the case of Ramashobohle High School Eco-Schools Community of Practice in Mankweng circuit Polokwane Municipality Capricorn district in Limpopo Province, South Africa

  • Authors: Manaka, Ngoanamoshala Maria
  • Date: 2011
  • Subjects: Sanitation -- South Africa -- Management -- Citizen participation Public utilities -- South Africa -- Management -- Citizen participation Sanitation, Rural -- South Africa Sanitation -- Study and teaching -- South Africa School children -- Health and hygiene -- South Africa School hygiene -- South Africa Sanitation -- Health aspects -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1917 , http://hdl.handle.net/10962/d1007319
  • Description: Providing adequate sanitation facilities for the poor remains one of the major challenges in all developing countries. In South Africa, an estimated 11,7% of the schools are without sanitation. The South African government has a constitutional responsibility to ensure that all South Africans have access to adequate sanitation. When sanitation systems fail, or are inadequate, the impact of the health of the community, on the health of others and the negative impact on the environment can be extremely serious. In rural South African schools, many Enviro-Ioo toilets are available today. They are designed to suit a variety of water scarce areas and where there is a high risk of contamination of ground water resources. It is important to realize that any Enviro-Ioo system programme requires an education programme to ensure that the principles of use and maintenance are clearly understood by the user group. Their maintenance requires more responsibility and commitment by users. This study is an interpretive case study that indicates how sanitation in a rural Ramashobohle High School in Polokwane municipality was managed through an EcoSchools Sanitation Community of Practice, and how this developed action competence for sanitation management in the school. The study established that the earlier practice and knowledge of the Ramashobohle Eco-Schools community of practice exercised in maintaining Enviro-Ioo systems was inadequate; unhealthy and unsafe according to the data generated through focus group interviews, observations, interviews, action plan, workshops and reflection interviews. The data generated also indicates that the Eco-Schools community of practice was not committed to maintaining sanitation in their school because they were not sharing sanitation knowledge; they were not communicating and not updating one another concerning Enviro-Ioo systems maintenance as they had no adequate knowledge as to how to maintain the facilities; and the school management was also not supportive and was not taking responsibility. The study shows how this situation was turned around as an Eco-Schools Sanitation Community of Practice focussed on developing action competence in the school community. It provides a case based example of how knowledge and action competence, supported by an Eco-Schools Community of Practice, can find and implement solutions to inadequate sanitation management practices in rural schools, and shows how members of the school community can be engaged in learning how to manage and maintain school sanitation systems through a participatory process that develops action competence. The study points to important dimensions of developing action competence, such as providing knowledge and demonstrations, inviting experts to the school, involving learners in observations and monitoring and in ensuring that adequate facilities are available. In particular, a workshop conducted by Enviro-Ioo consultants, organised and supported by the Eco-Schools Sanitation COP, together with a follow up action plan, provided the main impetus for changes in practice in the school and served to support action competence development. Finally the study provides research findings and recommendations for further research.
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  • Date Issued: 2011

The reading of extended text in Oshindonga in grade 2 in selected Namibian schools

  • Authors: Ngula, Elizabeth Njanjukweni-Aluhe
  • Date: 2011
  • Subjects: Ndonga language -- Study and teaching -- Namibia Reading comprehension -- Study and teaching (Primary) -- Namibia Reading (Primary) -- Namibia Teaching -- Namibia Teachers -- Attitudes -- Namibia Literacy -- Namibia
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1720 , http://hdl.handle.net/10962/d1003603
  • Description: This study was conducted in order to understand to what extent Grade 2 teachers use books (or other forms of extended text) in their reading lessons in Oshindonga where very little published material is available, and, if so, whether they engage in shared reading with these materials or not. The study also explored ways to introduce more books (or other forms of extended text) into Oshindonga classrooms. The study took the form of an interpretive case study. It was conducted in two primary schools in Otjiwarongo district in the Otjozondjupa region of Namibia. Two qualified Grade 2 teachers were selected. The purpose of this sampling was to gain an in depth understanding of how these two selected teachers taught reading in Oshindonga. The data was gathered by using semi-structured interviews with open-ended questions, as well as lesson observations and stimulated recall with each individual teacher after each lesson. The purpose of this was to gain clarity in areas that were not clear during lesson presentations. A focus group interview was also conducted in order to generate ideas about how to introduce more extended texts into the classroom. The key fmdings are that both schools in the study lacked books in Oshindonga, and the teachers lacked an understanding of the importance of using books (or other forms of extended text). Other key findings are that teachers had a problem in choosing appropriate texts to read with their learners; teachers understand reading more as decoding than reading for meaning and pleasure; children were not asked any comprehension questions and the two teachers had different views on the value of shared reading. The research data revealed that there are problems in teaching literacy in Namibian African languages.
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  • Date Issued: 2011

Presentation and representation of environmental problems and problem-solving methods and processes in the Grade 10 Geography syllabus: a Namibian case study

  • Authors: Zokka, Herman Kankara
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:2074 , http://hdl.handle.net/10962/d1021253
  • Description: Environmental issues in Namibia are considered to be one of the major threats to the lives of the Namibian people (Namibia. Ministry of National Planning Commission [MNPC], 2004). This study explored problem solving as one of the teaching methods used in Grade 10 Geography syllabuses as a response to such environmental issues/risks. Geography provides learners with an understanding of the issues and risks in their world that need to be addressed in order to improve the quality of their lives and health of their environment. This study focused on how environmental problems and problem-solving methods are presented in the Namibian Grade 10 Geography syllabus and how these are represented and implemented through teacher intentionality and practice. The theoretical framework for this study was informed by two theories namely risk society and social constructivism. This study was conducted at three schools in the Rundu circuit in the Kavango region and one teacher was involved in the study at each school. This study was conducted within an interpretive research tradition and was qualitative in nature. The study used document analysis, focus group discussion and classroom observation as data generation methods. The findings of the study reveal that the complexity of environmental issues is highlighted in the syllabus and in teachers’ intentionality and practice. The findings also show that a limited variety of teaching methods were used in problem solving strategies. The study also found that problem solving was influenced by different constructivist learning principles. The study further found that limited numbers of problem-solving steps were used in the process of problem solving. The study concludes by calling for further research into problem solving strategies. This can be done to empower Geography teachers to use more complex problem solving strategies to deepen problem solving and to engage problems in more depth.
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  • Date Issued: 2016

The consumption and use of wild foods by children across a deforestation gradient in Zomba District, Malawi

  • Authors: Maseko, Heather Nonhlanhla
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/3212 , vital:20392
  • Description: Despite consensus on their significant nutritional value, wild foods are continually excluded from both food security statistics and economic values of natural resources. Though largely unexplored, there is evidence on the use of wild foods by children to supplement their diets and as a source of income. Children have knowledge on the gathering and hunting of selected wild food species and sources thereof. Wetlands, agro-ecosystems, natural forests, human landscapes and river systems remain important sources of wild food resources. The provision of and access to these resources are significantly affected by the interference and disruption to natural ecosystems. In Malawi, interference has been largely due to deforestation and land use change caused by an interplay of pressures from population growth for development and agricultural expansion. Against this background, the implications of deforestation and vegetation cover on the availability of wild foods and their access and use by children is largely unexplored. Through a comprehensive analysis of data collected from 150 children and 50 elderly men and women, the integration of Participatory Rural Appraisal (PRA) exercises and Geographic Information System (GIS), in the four sites of Mpheta, Mtuluma, Kasonga and Makombe in Zomba district, wild foods availability was established and their contribution to the nutritional status of children and households’ food security assessed. Study sites were identified along the deforestation gradient of Lake Chilwa, Zomba Mountain and Shire River basin with an additional focus on varying landscapes. One hundred and twenty species of wild foods were identified with greatest availability in areas of high vegetation cover and the lowest in areas of low vegetation cover, but with meaningful differences per wild food category. There was considerable reduction in the availability of wild foods with increasing deforestation; mainly wild game and fruits species and, in turn, decreased access of these by children. Nevertheless, small game, insects, other wild fruits and wild vegetables thrive well in agro-ecosystems and therefore were minimally affected by deforestation but largely by management practices of those systems and can be possibly improved through the promotion of agro-ecological farming systems. The research reveals that wild foods form an important component of the starch based diets of households from agricultural communities in the various landscapes. Besides securing the household’s food base, all children largely supplemented their diets with wild foods but with increased dependence by children from poorer households who are highly vulnerable to food insecurity. Access and use of wild foods was largely dependent on children’s knowledge, perceptions of the wild food and ease of access, with considerable variations due to gender and socio-cultural norms. Besides contributing to the nutritional status and food security, commercialisation of wild foods was common among children, hence providing them with an alternative livelihood strategy and in some cases only viable source of income.
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  • Date Issued: 2016

Selecting educational computer software and evaluating its use, with special reference to biology education

  • Authors: Beyers, Ronald Noel
  • Date: 1992
  • Subjects: Biology -- Study and teaching -- Computer programs Education -- Data processing Biology -- Computer-assisted instruction
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1764 , http://hdl.handle.net/10962/d1003649
  • Description: In the field of Biology there is a reasonable amount of software available for educational use but in the researcher's experience there are few teachers who take the computer into the classroom/laboratory, Teachers will make use of video machines and tape recorders quite happily, but a computer is a piece of apparatus which they are not prepared to use in the classroom/laboratory. This thesis is an attempt to devise an educational package, consisting of a Selection Form and an Evaluation Form, which can be used by teachers to select and evaluate educational software in the field of Biology. The forms were designed specifically for teachers to use in preparation of a computer lesson. The evaluation package also provides the teacher with a means of identifying whether the lesson has achieved its objectives or not. The teacher may also be provided with feedback about the lesson. The data is gathered by means of a questionnaire which the pupils complete. It would appear that teachers are uncertain as regards the purchase of software for their subject from the many catalogues that are available. The evaluation package implemented in this research can be regarded as the beginnings of a data base for the accumulation of information to assist teachers with details on which software to select. Evidence is provided in this thesis for the practical application of the Selection and Evaluation Forms, using Biology software.
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  • Date Issued: 1992

The experiences of secondary traumatic stress among social workers who deal with traumatised populations : a case study of Buffalo City Municipality, Eastern Cape, South Africa

  • Authors: Anyi, Marynet Ema Tangwe
  • Date: 2018
  • Subjects: Secondary traumatic stress Social workers -- Mental health Social service -- Psychological aspects
  • Language: English
  • Type: Thesis , Masters , Social Work
  • Identifier: http://hdl.handle.net/10353/9951 , vital:35207
  • Description: The aim of the research study was to investigate the experiences of secondary traumatic stress among social workers who deal with traumatised populations in the Buffalo City Municipality in the province of the Eastern Cape in South Africa. Qualitative research methods were employed to collect data from thirty participants; twenty were interviewed and 10 participated in a focus group discussion. The most significant finding of this study was that there is a high rate of secondary traumatic stress among social workers, particularly among those who practice in nongovernmental organisations (NGOs), especially those social workers who work with children. The intensity of secondary traumatic stress among social workers appears to be growing steadily, owing to either inadequate or a complete lack of supervision and support on the part of the agencies concerned. The study concludes that social workers are highly at risk of experiencing secondary traumatic stress. The study therefore recommends that policies that are there to protect social workers should be implemented and institutions of higher learning which educate and train social workers need to implement courses in their syllabuses which prepare students for the stresses which they will inevitably encounter while working in the field of social work, particularly secondary traumatic stress.
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  • Date Issued: 2018

The hydrogeology of a Karoo basalt/sandstone contact aquifer moretele II district Republic of Bophuthatswana southern Africa

  • Authors: Martinelli, Giorgio Luigi
  • Date: 1988
  • Subjects: Basalt -- South Africa -- Bophuthatswana Sandstone -- South Africa -- Bophuthatswana Aquifers -- South Africa -- Bophuthatswana Hydrogeology -- South Africa -- Bophuthatswana
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4802 , http://hdl.handle.net/10962/d1001902
  • Description: As part of a development programme in the Moretele II District, the Government of the Republic of Bophuthatswana, commissioned in 1983 the building of a dry system coal-fired power station. The lack of local surface water to cool the power station resulted in a decision to investigate the potential of the ground water resources. The resources will be required to supply an anticipated 30 year water demand. Because of the high capital investment and the importance of establishing an accurate assessement of the ground water potential there was a need for a comprehensive and detailed hydrogeological study. The specific aim of the investigation is to assess and quantify the long term reliability of the ground water resources. The very limited data for the area necessitated a particularly thorough and detailed investigation. This thesis describes the hydrogeological investigation carried out to define the ground water resource potential of this area. The main objectives of the study are to identify, recognize and evaluate the hydrogeological processes operating on this previously ill-defined Karoo aquifer. To achieve the research objectives the hydrogeological investigation was formulated to make use of various traditional geological, hydrogeological, geophysical and hydrochemical techniques in a logical framework. More specifically, the work involved a hydrocensus, a geophysical survey, the drilling of exploratory boreholes, aquifer tests to determine the intrinsic hydraulic parameters, water level measurements and the collection and analysis of water samples. The combined results of these various techniques provided data to quantify, evaluate and then propose management strategies for the identified resources. The study provided an understanding of the local hydrogeological conditions and has allowed for a conceptual model of the aquifer system to be derived
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  • Date Issued: 1988

The tablet teacher: learning literacy through technology in Northern Sotho

  • Authors: Shiohira, Kelly
  • Date: 2017
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/7034 , vital:21211
  • Description: This study evaluates the efficacy of the Bridges to the Future Initiative - South Africa 2 (BFI) tablet program on early literacy skills, as well as the ways in which learner-operated technology interacts with a traditional South African education system. The BFI is a curriculum-aligned early literacy development intervention implemented through technology in grades 2 and 3 in Northern Sotho1 first-language schools. A mixed-methods research design was utilized, involving three components: a literacy skills test administered through a time sequence trial design; a curriculum-aligned uptake and retention test using a pre-post design; and a qualitative research component including classroom observation, participant interviews and prompted drawings by learners. Paired sample t-tests show significantly higher gains during the treatment period in fluency and comprehension, and significantly higher gains in the control period in decoding individual words. It is theorized that this is due to teacher emphasis on emergent literacy. When initial ability is taken into consideration, all ability levels gain more on average during the treatment period in at least one measured skill. Regression analysis determines that time spent on the BFI program is not the most significant determiner of gains in the intervention period. Qualitative analysis supports this finding and suggests that program use cannot replace quality classroom practice in advancing literacy skills. Learners performed better after a delayed retention period than in an initial uptake test, indicating high rates of retention of knowledge gained through program use and traditional instruction, but inconsistent access to literacy skills gained.
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  • Date Issued: 2017

Labour hire: the impact of labour broking on employee job satisfaction and commitment in a number of Namibian organizations

  • Authors: Shivangulula, Shirley Euginia
  • Date: 2009
  • Subjects: Temporary employment -- Namibia , Industrial relations -- Namibia , Employee motivation , Labor market -- Namibia , Labor policy -- Namibia
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: vital:3054 , http://hdl.handle.net/10962/d1002563 , Temporary employment -- Namibia , Industrial relations -- Namibia , Employee motivation , Labor market -- Namibia , Labor policy -- Namibia
  • Description: Over decades, job satisfaction has generated active empirical research. Similarly, organizational commitment, another attitudinal variable in the work domain, strongly related to, but distinctly different from job satisfaction, received comparatively equal research scrutiny. However, research on the impact of labour broking on employees’ job satisfaction and organizational commitment is nonexistent in Namibia. Using a quantitative approach, within a positivist paradigm, the purpose of this thesis was to examine the impact of labour broking on employees’ job satisfaction and organizational commitment as well as to determine the dynamics that mediate such experiences. These experiences were examined through a 5-dimensional, 72-item Job Descriptive Index and a 3-dimensional, 12-item Organizational Commitment Questionnaire over a sample size of 108 temporary and permanent employees, drawn through random probability sampling in a number of Namibian organizations that make use of labour hire services. These experiences were further amplified by face-to-face interviews over a sub sample of 20 employees. Data analysis was carried out using the chi-square, correlation, t-tests and multiple regression techniques of the STATISTICA software. Drawing on the principles of the multi dimensional theory of organizational commitment, the Cornell dispositional theory of job satisfaction and the temporary employee stigmatization model, results revealed that variables of employment status, tenure, inadequate income, inappropriate supervision and fear of job losses ahead of a newly proposed piece of legislat st labour hire ractices significantly influenced job satisfaction and organizational commitment of employees. Estimates indicate that for a mere change in tenure, job satisfaction levels will significantly rise by 0.26 units, whereas organizational commitment will augment by 0.03 units. However, for every N$ fall in employees’ pay, we can expect job satisfaction levels to decrease by 26%, but with significant effects. The study recommends that organizations must adopt policies that grant permanent tenure to all their employees, position them in respected and challenging jobs in which they will grow skills and ensure that all employees are remunerated with pay that signals their contribution to the organizations. In doing so, the negative effects of labour broking will disappear and employees will be satisfied with their jobs and Tommitted to their organizations.
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  • Date Issued: 2009

The role of microzooplankton in carbon cycling in the Southern Ocean

  • Authors: Froneman, Pierre William
  • Date: 1996
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:21066 , http://hdl.handle.net/10962/6234
  • Description: A 3-year study was carried out on the role of microzooplankton in carbon cycling in the south Atlantic and the Atlantic sector of the Southern Ocean. Microzooplankton grazing impact on phytoplankton was estimated during austral summer and winter employing the dilution technique. Carnivory by larger zooplankton on microzooplankton during summer was estimated using in vitro incubations. Microzooplankton assemblages were always dominated by protozoans comprising ciliates and dinoflagellates. In the ( 20 um chlorophyll fraction, microzooplankton grazing was sufficient to control the growth of the nano- and picophytoplankton suggesting that, where larger microphytoplankton cells dominate, micro zooplankton maintain the background concentrations of the nano- and picophytoplankton. During winter, when small nano- and picophytoplankton cells dominate total chlorophyll concentrations, the microzooplankton grazing impact on phytoplankton is dramatically increased. Microzooplankton removed on average 37% of the initial phytoplankton stock or 70% of the daily phytoplankton production. These results suggest that in winter, micro zooplankton are the main sink for phytoplankton production. Carnivory experiments conducted with selected meso- (copepods) and macro zooplankton (euphausiids and tunicates) showed that all species examined consumed micro zooplankton in the presence of substantial chlorophyll concentrations. Microzooplankton can, therefore, be regarded as trophic intermediates between bacterioplankton, small phytoplankton cells and larger zooplankton species in the Southern Ocean. The results of this investigation suggest a spatiotemporal shift in efficiency of the biological pump mediated by changes in the size composition of the phytoplankton assemblages. South of the Antarctic Polar Front (APF) large IV microphytoplankton cells dominate the summer chlorophyll biomass, suggesting that larger zooplankton grazers represent the main sink for phytoplankton production. Under these conditions, carbon flux to the interior of the ocean will be high due to diel vertical migrations by grazers and the production of large, fast sinking faecal pellets. The sedimentation of large phytoplankton cells also contributes to flux. In the permanently open waters south of the APF and throughout the Southern Ocean during winter, small phytoplankton cells dominate total chlorophyll, resulting in the microbial loop being the main sink for phytoplankton production. The close coupling between the micro zooplankton and the microbial loop dramatically reduces the transfer of organic carbon from the surface layers to depth. Carnivory by metazoans on microzooplankton may reduce the high grazing impact of micro zooplankton and, may also represent an important source of carbon flux originating from the microbial loop.
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  • Date Issued: 1996

The contribution of William Gurnall (1616-1679) to the puritan concept of spiritual combat, with special emphasis on the role of faith

  • Authors: Van Zyl, Frederick William James
  • Date: 1986
  • Subjects: Gurnall, William, 1617-1679 , Puritans , Faith , Spiritual life -- Christianity -- History of doctrines
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:1223 , http://hdl.handle.net/10962/d1003916
  • Description: The Central figure in this thesis is William Gurnall M.A. (Cambridge) who lived from 1616 to 1679. He was the Rector of the Lavenham Parish church for 35 years, 1644/45-1679. He was one of the few Puritans who remained in the Established Church after the 1662 Act of Uniformity had been promulgated. His 'The Christian in Complete Armour' is one of the greatest practical-pastoral works to come from the pen of any Puritan. It is firmly based on Calvinistic theological principles. While holding common beliefs in many areas, Gurnall nevertheless was at odds with his fellow Puritans over certain crucial issues that directly affected his attitude to the Puritan revolution. His analysis of the person, being, nature, wiles, strategies and weapons of the Christian's great enemy and description of the Christian's resources such as the role of the shield of faith in its multiple uses, which constitute an important contribution to pastoral theory and practice are shown to arise out of Gurnall's theological stance, his own personal history, the history of East Anglia and of Lavenham in particular; his reflections on the 'Days of Great Confusions' and his deep concern for the breakdown in orderly society and the decline of genuine piety in the church. Basically we will concentrate on three issues: First. The real nature and locus of the Christian's spiritual warfare. Second. -- The means used for his investigation, namely, an examination of the person, power, methods and wiles of the Christian's great enemy and the vital role of the shield of faith. -- Third. His conclusions.
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  • Date Issued: 1986

Prospects and challenges of the rural non-farm economy in Zimbabwe: a case of Seke rural district

  • Authors: Mukozho, Delight
  • Date: 2011
  • Subjects: Sustainable development -- Zimbabwe , Poverty -- Zimbabwe , Rural development -- Zimbabwe , Farmers -- Zimbabwe , Community development -- Zimbabwe , Food security -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , M Soc Sc (Dev)
  • Identifier: vital:11429 , http://hdl.handle.net/10353/568 , Sustainable development -- Zimbabwe , Poverty -- Zimbabwe , Rural development -- Zimbabwe , Farmers -- Zimbabwe , Community development -- Zimbabwe , Food security -- Zimbabwe
  • Description: The Rural Non-Farm Economy (RNFE) is a concept that has gained significance quite recently. Its significance has been prompted by the realisation that agriculture alone cannot sustain the poor subsistence farmers in Zimbabwe. This realisation comes amid the growing concern over increased hunger and poverty in the country‟s rural areas due to a decline in agricultural production. Drawing on the Sustainable Livelihoods Approach (SLA) this study postulates that RNFE is a livelihood strategy that can address rural poverty and social transformation in Zimbabwe. Such an approach to rural development can take up the slack and provide the much needed income for the rural communities to survive. However, RNFE has not yet been used as a social mechanism for poverty alleviation in Zimbabwe. Therefore, this study was undertaken with the objective of investigating the prospects and challenges of the RNFE in Seke District. Although the study is focusing on Zimbabwe, the study may also address the problem of rural development in other countries in Sub-Saharan Africa. The study revealed that only a few household heads in Sekewere engaged in both traditional and non-traditional activities. However, the study noted that the household heads encountered many challenges which include; poor market, low income obtained, shortage of inputs, no access to credit and no support from government or other development agencies.Overall, it was recognised that the household heads engaged in RNFE were not realizing the full benefits of RNFE. Therefore, in order to promote the growth of RNFE and make it more productive, the study posits the following key points to be take into consideration by the various stakeholders in rural development; agricultural development, infrastructural development, rural town development, improving access to financial services, facilitating rural-urban linkages and the implementation of development projects aimed at promoting self-employment in the non-farm sector.
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  • Date Issued: 2011

Health promotion: approaches to dietary salt reduction

  • Authors: Mushoriwa, Fadzai
  • Date: 2017
  • Language: English
  • Type: Thesis , Masters , MPharm
  • Identifier: http://hdl.handle.net/10962/44761 , vital:25439
  • Description: Background Globally, non-communicable diseases are the leading causes of mortality and morbidity, with the majority of these occurring in low-middle income countries. The devastating consequences of non-communicable diseases could be curtailed through better management of four modifiable factors: physical inactivity; tobacco use; harmful use of alcohol; and unhealthy diets. The World Health Organisation has recommended dietary salt reduction as a cost-effective strategy in combatting the burden of NCDs. Consumer awareness and education is one of three primary strategies that have been identified by the World Health Organisation to achieve population-wide salt reduction. It involves the provision of salt reduction knowledge and the promotion of healthy salt related practices. These campaigns are a necessity in populations with high discretionary salt use such as South Africa. For these health promotion activities to succeed, they need to be developed with consideration of factors such as the environment, culture, and socio-economic standing of the intended target population. This two-phase health promotion study was conducted at St Mary’s Development and Care Centre and the Assumption Sisters Nutrition Centre. These are two community based organisations located in Grahamstown, South Africa. A needs assessment was conducted to identify the knowledge and practices of cooks and guardians from these centres on dietary salt reduction. The aim of the second phase of the study was to conduct an educational intervention and to develop a culturally appropriate and contextually specific health information intervention through a participatory process. Method: This was a qualitative study that was supported by elements of quantitative research.. The first phase of the current study was a needs assessment. The first step involved an observational phase with cooks from the centres. The aim was to observe their discretionary salt use during food preparation and to document the salt content in the processed foods available at each centre. Semi-structured interviews were then conducted, with 3 cooks and 16 guardians1 from the centres, to assess their knowledge and practices regarding salt reduction.Parents or the people responsible for the care of the children attending both centres. Guided by findings from the needs assessment phase, an educational intervention was developed. This phase involved the participatory development of three health information leaflets and a series of educational interactive sessions were conducted. Quantitative tests to assess the readability, suitability, and actionability were conducted on the leaflets. Qualitative assessment of the leaflets involved formative evaluations conducted by health care professionals, phase 1 participants, Rhodes University peer educators, an African languages and cultural expert, and a Rhodes University student wellness manager. This step was included to assess the content validity, context specificity, acceptability, and cultural appropriateness of the materials. Educational interactive sessions were guided by constructs of the Social Cognitive Theory and were conducted on three main topics: ‘Salt and my health’, ‘Reducing salt in my diet’, and ‘Reading food labels’. Results: The majority of the processed foods available at both centres contained low to medium levels of salt. Children at the centres were not provided with salt shakers on the tables during meal times. Cooks did not use measuring utensils when adding salt during meal preparation. Semistructured interviews revealed that participants lacked both declarative and procedural knowledge. In terms of declarative knowledge, they were unaware of the daily salt intake recommendations and the relationship between salt and sodium. Participants were able to identify hypertension as one of the health related consequences of high salt consumption. Most participants were responsible for purchasing groceries in their households. Their selfreported food label reading behaviours and inability to read food labels highlighted their lack of procedural knowledge. Most participants reported that they added salt during meal preparation and at mealtimes, highlighting high discretionary salt use. Some participants were also aware of cultural or religious uses of salt. The developed health information leaflets were considered to be written at a readability level appropriate for the target audience. The leaflets were also deemed to be actionable, culturally appropriate, and contextually specific and suitable materials. The educational interactive sessions were found to be interesting and informative. Conclusions: Findings from the needs assessment revealed the need for an educational intervention to address the identified gaps in the participants’ knowledge and practices regarding dietary salt reduction. The developed health information leaflets were found to be informative, culturally appropriate, and contextually specific, as planned. Interactive sessions provided an excellent platform to supply participants with concise and accurate information, increasing the possibility of improving their salt reduction related knowledge.
  • Full Text:
  • Date Issued: 2017

Data reduction techniques for Very Long Baseline Interferometric spectropolarimetry

  • Authors: Kemball, Athol James
  • Date: 1993
  • Subjects: Very long baseline interferometry Radio interferometers Data reduction -- Research
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5457 , http://hdl.handle.net/10962/d1005242
  • Description: This thesis reports the results of an investigation into techniques for the calibration and imaging of spectral line polarization observations in Very Long Baseline Interferometry (VLBI). A review is given of the instrumental and propagation effects which need to be removed in the course of calibrating such obervations, with particular reference to their polarization dependence. The removal of amplitude and phase errors and the determination of the instrumental feed response is described. The polarization imaging of such data is discussed with particular reference to the case of poorly sampled cross-polarization data. The software implementation of the algorithms within the Astronomical Image Processing System (AlPS) is discussed and the specific case of spectral line polarization reduction for data observed using the MK3 VLBI system is considered in detail. VLBI observations at two separate epochs of the 1612 MHz OH masers towards the source IRC+ 10420 are reduced as part of this work. Spectral line polarization maps of the source structure are presented, including a discussion of source morphology and variability. The source is sigmficantly circularly polarized at VLBI resolution, but does not display appreciable linear polarization. A proper motion study of the circumstellar envelope is presented, which supports an ellipsoidal kinematic model with anisotropic radial outflow. Kinematic modelling of the measured proper motions suggests a distance to the source of ~ 3 kpc. The cirumstellar magnetic field strength in the masing regions is determined as 1-3 mG, assuming Zeeman splitting as the polarization mechanism.
  • Full Text:
  • Date Issued: 1993

Bayesian spatial modelling of tuberculosis and its effects on socio-economic and demographic factors in South Africa : a case study of the Eastern Cape Province

  • Authors: Obaromi, Abiodun Davies
  • Date: 2018
  • Subjects: Tuberculosis -- South Africa -- Eastern Cape Tuberculosis -- Epidemiology -- Statistics
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10353/9648 , vital:34813
  • Description: This dissertation is concerned with evolving and extending statistical models in the area of Bayesian spatial modelling, an increasingly important field of spatial epidemiology with particular interest towards application to Tuberculosis data in the Eastern Cape province of South Africa. In spatial epidemiology, the diseases to be examined usually occur within a map that needs spatial statistical methods that are appropriate, to model the observed data in the presence of some covariates and also cater for the variation of the disease. In this thesis, the Bayesian models were developed in such a way that they allowed several factors classified as fixed and random effects, to be included in the models and using the Bayesian approach. The basic model used in disease mapping is the Besag, York and Mollie model, which incorporates two random effects; one which is spatially structured and the other random effect which is spatially unstructured. The effects (fixed and random) were the covariate effects, socio-economic and demographic variability and the spatial variability respectively, which were all investigated in seven different hierarchical/multilevel Bayesian models. These factors showed varying and substantial effects in the posterior relative risk estimation of the disease. We assumed a negative binomial and generalized Poisson distributions to the response variable or relative risk estimate, 𝑦𝑖 ,to capture the over-dispersion phenomenon that is common and inherent with Poisson density for counts data. Spatial and non-spatial models were developed to model over-dispersion with all the distributions; Poisson, negative binomial and generalized Poisson. Negative binomial and generalized Poisson showed varying properties from comparisons with DIC values and parameter estimates to standard errors, which made either of them fit depending on the choice of model selection. It was found that a lower DIC value could be insufficient to determine a best fit model, if other models present estimates with lower variances even at higher DIC values. The generalized Poisson, a two parameter distribution like the negative binomial, which also has the ability to capture both under-dispersion and over-dispersion, was found to perform better in the results than the negative binomial on the basis of a lower variance and with more exact parameter estimates. A new weighted prior distribution, the “Besag2” ICAR model for the structured spatial random effects, which is an extension of the traditional ICAR prior model with two hyperparameters, was also developed and compared with some existing prior models; BYM and ICAR, to measure for spatial dependency in the regions. This new prior distribution was found to show a better fit, when compared to the basic ICAR prior usually assumed for the spatial random effect in the BYM model. This newly parameterized prior distribution in the Besag, York and Mollie model also led to improved parameter control, as the hyperparameters can be seen independently from each other. The result also showed that the new model performed well, both presenting good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performed at least equally well and better than the existing models, and the new formulation also gave parameters that are interpretable and have a clearer meaning. To interpolate scattered or regularly distributed data, there are imprecise or exact methods, but there are some of these methods that could be used for interpolating data in a regular grid and others in an irregular grid. Linear and biharmonic spline methods were implemented in MATLAB, to compare for smoothing in the distribution patterns of tuberculosis in the province. This smoothing spline is a method of fitting a smooth curve to a set of noisy observations using a spline function. This new method is rarely used in disease mapping applications, but it has a superior advantage to be assessed at subjective locations rather than only on a rectangular grid as seen in most traditional GIS methods of geospatial analyses. The proposed new models and methods in this thesis were found to be flexible and robust, since they can be reduced or extended according to the nature of the data. Nevertheless, great care must be considered in the choice of prior densities. The approaches developed in this dissertation helped to broaden the scope for spatial analysis and disease mapping applications in epidemiology and public health studies.
  • Full Text:
  • Date Issued: 2018

An ecological study of the ixodid tick rhipicephalus glabroscutatum (Du Toit, 1941)

  • Authors: Macivor, Keith Malcolm de Falloux
  • Date: 1983
  • Subjects: Ticks -- Control -- South Africa -- Eastern Cape Parasites -- South Africa -- Eastern Cape Rhipicephalus -- South Africa -- Eastern Cape Angora goat -- South Africa -- Eastern Cape Larvae -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5602 , http://hdl.handle.net/10962/d1002052
  • Description: An intensive study was conducted on the free-living larvae and parasitic life stages of R.glabroscutatum on Angora and Boer goats in the Uitenhage district. Free-living larvae exhibited periods of maximum relative abundance during months of generally lower rainfall, from the end of autumn to the beginning of spring. Relative larval abundance in open and gully sites was low while larvae were rarely found in bush sites. Relative abundance was higher at 20h00 than at 08h00 and 14h00. Repeated sampling in the same areas did not reduce larval numbers. Over 99% of parasitic ticks removed from Angora and Boer goats were located on the feet. The annual occurrence of a low and variable number of parasitic immatures was synchronous with the occurrence of free-living larvae. High, less variable numbers of adult ticks were removed from goat feet from September to December, the highest numbers being recorded during October and November. The occurrence of a single period of parasitic adult abundance annually indicated a life cycle with 1 generation per anum. There were higher numbers of adult ticks on the feet of the Angora goats than on the Boer goats. Adult numbers were higher on the hind feet of both breeds of goats than on the front feet. R.glabroscutatum adults seem to be implicated in the aetiology of foot abscesses since more infections were observed in Angora goats than in Boer goats and on the hind feet rather than the front feet within both goat groups. In addition R.glabroscutatum adults attached at interdigital sites where abscesses also originated and reached highest numbers in October and November when abscesses were most frequently observed. A review of distribution and host records indicated that R.glabroscutatum was limited in its distribution to the eastern Cape Province, being primarily located in South Africa's major mohair producing areas. R.glabroscutatum was classed an obligative xerophile on the basis of its recorded occurrence in non coastal areas with a low annual rainfall and Karoo and Karroid Bush vegetation. Host records for R.glabroscutatum included 10 species of wild ungulate, sheep, goats and cattle. The common site of occurrence on small stock and on small to medium sized wild animals appeared to be the legs and feet.
  • Full Text:
  • Date Issued: 1983

The servant of Yahweh : a critical and exegetical study of the Servant Songs in Deutero-Isaiah

  • Authors: Dijkman, Jan Hendrik Leonard
  • Date: 1961
  • Subjects: Bible -- Criticism, interpretation, etc. , Servant songs
  • Language: English
  • Type: Thesis , Bachelor , BDiv
  • Identifier: vital:1293 , http://hdl.handle.net/10962/d1014812
  • Description: For more than two thousand years the question of tbe identity of the Servant of Yahweh in Is. 40 - 55, and especially in the so-called "Servant Songs", has exercised the minds of students of the Old Testament. The first answer which we may trace with any certainty is that of the translator of this particular section in the Septuagint, who adds the words "Jacob" and "Israel" to the text. This is closely followed in the New Testament by the answer which Philip gave to the Ethiopian eunuch's query, "Of whom speaketh the prophet this ? of himself, or of some other ?" ( Acts 8:34f,). These two answers are typical of the two possible extremes in solving the problem. The first sees the Servant as a collective entity, the people Israel, while the second sees him as an individual figure, namely, Jesus Christ. The second answer explains why the interpretation of the Servant figure has been such a live issue throughout the entire history of Christendom. In it Christians have seen a prophecy of Jesus Christ - and more particularly in the suffering of the Servant, a prophecy of the facts which form the basis of the Christian Salvation, the death and resurrection of Jesus. Until the close of the eighteenth century, the generally accepted interpretation of the figure of the Suffering Servant among Christians was to identify him completely with Christ. With the development of the scientific study of the Old Testament during the last two centuries, every generation has raised the question afresh and sought to answer it. There is hardly an Old Testament scholar who has not laboured over it, and many have published their attempts at a solution. Hence the literature on the subject is enormous. In the present study no attempt has been made to give an exhaustive survey of all the interpretations of the Servant figure, but the text of the Servant Songs has been examined before an interpretation of the Servant figure was attempted. It is to be hoped that the final interpretation here given will reflect the thought of the prophet rather than that of the interpreter.
  • Full Text:
  • Date Issued: 1961

Teachers’ experiences in identifying learners with learning barriers in a Full Service School

  • Authors: Dakada, Alinda
  • Date: 2015
  • Subjects: Inclusive education Learning disabilities -- South Africa -- Eastern Cape Teaching -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: http://hdl.handle.net/10353/6147 , vital:29495
  • Description: This study investigates teachers‟ experiences in identifying learners with learning barriers in one primary school in the East London District. It focuses on diversity and inclusive education as well as practices and procedures within the school. This is a phenomenological study conceptualized in terms of social constructivism(Leatherman, 2007), Kurt Lewin‟s Field Theory(Neill, 2004) and ecological systems theory(Maddock, 2000).The literature review encompasses four focal points: conceptualisation of inclusive education, inclusive education in South Africa, policy implementation, and lessons learned from inclusive education implementation both internationally and in South Africa. A qualitative research method is employed in this study through the use of semistructured interviews and observations. The findings are analysed using content analysis. The key findings of this might help the teachers working in full service or mainstream schools to have a good understanding and a sense of what diversity and inclusive education entails. The findings might attempt to examine how educators manage inclusion in the classroom, their competencies and the strategies they need in order to be competent inclusive teachers. Recommendations are developed that point to how practices could be put in place to facilitate an effective implementation strategy for the development of an inclusive education system.
  • Full Text:
  • Date Issued: 2015
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