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The characterisation of trypanosomal type 1 DnaJ-like proteins

  • Authors: Ludewig, Michael Hans
  • Date: 2010
  • Subjects: Molecular genetics , Molecular chaperones , Protozoa , Heat shock proteins , Trypanosoma
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4126 , http://hdl.handle.net/10962/d1015205
  • Description: Trypanosomes are protozoans, of which many are parasitic, and possess complex lifecycles which alternate between mammalian and arthropod hosts. As is the case with most organisms, molecular chaperones and heat shock proteins are encoded within the genomes of these protozoans. These proteins are an integral part of maintaining the structural integrity of proteins during normal and stress conditions. Heat shock protein 40 (Hsp40) is a co-chaperone of heat shock protein 70 (Hsp70) and in some cases can act as a chaperone. These proteins work together to bind non-native polypeptide structures to prevent unfolded protein aggregrate formation in times of stress, translocate proteins across organelle membranes, and transport unsalvageable proteins to proteolytic degradation by the cellular proteasome. Hsp40s are divided into four types based on their domain structure. Analysis of the nuclear genomes of eight trypanosomatid species revealed that less than 10 of the approximate 70 Hsp40 sequences per genome were Type 1 Hsp40s, many of which contained putative orthologues in the other seven trypanosomatid genomes. One of these Type 1 Hsp40s from T b. brucei, Trypanosoma brucei DnaJ 2 (Tbj2), was functionally characterised in T brucei brucei. RNA interference knockdown of expression in T brucei brucei showed that cells deficient in Tbj2 displayed a severe inhibition of the growth of the cell population. The levels of the Tbj2 protein population in T brucei brucei cells increases after exposure to 42°c and the protein was found to have a generalized cytoplasmic subcellular localization at 37°c. These findings provide evidence that Tbj2 is an orthologue of Yeast DnaJ 1 (Y dj l), an essential S. cerevisiae protein. Hsp40s interact with their partner Hsp70s through their J-domain. The amino acids of the J-domain important for a functional interaction with Hsp70 were examined in Trypanosoma cruzi DnaJ 2 (Tcj2) (the orthologue of Tbj2) and T cruzi DnaJ protein 3 (Tcj3) by testing their ability to substitute for Y dj l in Saccharomyces cerevisae and for DnaJ in Escherichia coli. In both systems, the positively charged amino acids of Helix II and III of the J-domain disrupted the functional interaction of these Hsp40s with their partner Hsp70s. Substitutions in Helix I and IV of the J-domains of Tcj2 and Tcj3 produced varied results in the two different systems, possibly suggesting that these helices serve to define with which Hsp70s a given Hsp40 can interact. The inability of an Hsp40 and an Hsp70 to interact functionally does not necessarily mean a total absence of physical interaction between these proteins. The amino acid substitution of the histidine in the HPD motif (H34Q) of the J-domain of Tcj2 and Tcj3 removed the ability of these proteins to interact functionally with S. cerevisiae Hsp70 (Ssal) in vivo. However, preliminary binding studies using the quartz crystal microbalance with dissipation monitoring (QCM-D) show that Tcj2 and Tcj2(H34Q) both physically interact with M sativa Hsp70 in vitro. This study is the first report to provide evidence that certain trypanosoma! Type 1 Hsp40s are essential proteins. Futhermore, the interaction of these Hsp40s with Hsp70 identified important features of the functional interface of this chaperone machinery.
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  • Date Issued: 2010

Provost Tower back view

African universities and the challenges of a developmental state

Social capital and first-generation South African students at Rhodes University

  • Authors: Hlatshwayo, Mlamuli Nkosingphile
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: http://hdl.handle.net/10962/1466 , vital:20060
  • Description: The post-1994 democratic dispensation was presented with a challenge of how to improve equity of access for the incoming Black majority in institutions of higher learning (Cloete and Moja, 2005; Badat, 2010). Democratization of access to institutions of higher learning led to what has been called a “revolution” in the student demographics of higher education institutions in South Africa (Cloete and Moja, 2005). Many of the new entrants, particularly those entering historically white institutions, are from working backgrounds and are the first in their families to have the opportunity obtain a tertiary qualification – they are ‘first generation’ students. This thesis is interested in the experiences of first-generation working class students as they negotiate the terrain of an elite, historically white, South African university. While a prior body of research on first-generation students has focused primarily on the educational, cultural and economic deficits and challenges that these students experience, the present project was interested in the question of social capital in relation to these students. The thesis set out to explore what social networks these students do and do not have access to, and the various ways that they create, access and take advantage of alternative social networks in order to overcome their marginality in their everyday lived experiences at the university. In depth qualitative interviews with 31 participants were employed to gain an insight into the experiences of first-generation Black working class students at one university. The study finds that while first-generation students are not bereft of social capital, their networks are often inward-looking, based as they are on mutual recognition of markers of marginalisation and poverty which risks restricting these students to the margins of university life.
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  • Date Issued: 2016

"Soap operas as a platform for disseminating health information regarding ART and the use of 'reel' versus 'real' role models"

  • Authors: Deiner, Catherine Anne
  • Date: 2015
  • Subjects: Isidingo (Television program) , Television soap operas -- South Africa , Health in mass media , Mass media in health education -- South Africa , Antiretroviral agents -- South Africa , Public health -- Moral and ethical aspects , HIV-positive women -- South Africa -- Grahamstown
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3542 , http://hdl.handle.net/10962/d1017783
  • Description: The media, through development communication and edutainment, plays a critical role in the transformation of societies. In line with this, this thesis discusses the extent to which commercially driven prosocial soap operas can provide a platform for public health messaging, in the context of the HIV/AIDS epidemic in South Africa, for antiretroviral treatment (ART) and for encouraging ART adherence to foster national development. Furthermore, this thesis examined the potential of celebrities as HIV/AIDS ambassadors and the potential of both fictional characters and ‘real-life’ celebrities to disseminate these health messages. Although the HIV/AIDS epidemic in South Africa is stabilising, this is not the time to relax the communication around the disease, particularly regarding adherence to ARVs, considering that South Africa has the largest ARV rollout in the world. The qualitative methodological approach taken for this thesis is a three-step approach examining the intended message, the text and the appropriated message by viewers. Firstly, a thematic content analysis of an episode of Isidingo, that illustrated Nandipha as HIV-positive and the side-effects that came with her ART adherence, and the 3Talk interview with Lesego Motsepe, where she announced that she was weaning herself off ART, was done in order to understand the intended health messaging in the soap opera and the health message disseminated by an HIV-positive actress with regards to ART. Thereafter interview responses by the production team as well as by HIV-positive viewers, using ARVs, were thematised. In addition media texts which provided commentary on the use of a celebrity as a HIV-positive role model were examined. In doing this, this thesis has offered up the meanings of how HIV-positive women taking ARVs and living in Makana experience and understand the media, particularly health messaging relating to ARVs. The findings of this study suggest that commercial soap operas are the perfect platform to address HIV/AIDS and that prosocial health messaging regarding ARV adherence is still necessary in this country. Soap operas have the potential to have an educational angle. Although, HIV-positive individuals serve as better role models as they are authentic; given human nature, fictional characters, such as Nandipha Matabane in Isidingo, may be more sustainable role models as their message can be scientifically-based and well-researched. Realistic characters serve as role models whose behaviour is to be emulated. Soap operas appeal to a wide audience and so storylines can be tailor-made according to the times and the needs in terms of health issues and messaging. Thus, soap operas are not a single platform but rather one which can be exploited to maximum advantage for public health messaging.
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  • Date Issued: 2015

An analysis of some variables of in-camera editing of anthropological video: a case study

  • Authors: Hayman, Graham Peter
  • Date: 1993
  • Subjects: Ethnology -- Methodology -- Case studies , Motion pictures in ethnology -- Case studies , Anthropology -- Study and teaching -- Audio-visual aids -- Case studies , Video tapes -- Editing -- Case studies
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3433 , http://hdl.handle.net/10962/d1002887 , Ethnology -- Methodology -- Case studies , Motion pictures in ethnology -- Case studies , Anthropology -- Study and teaching -- Audio-visual aids -- Case studies , Video tapes -- Editing -- Case studies
  • Description: Anthropological film and videomakers use their media for both research and education. In both cases, a formal technique of observational camerawork is required. In this thesis, appropriate continuity methods and a model of decision-making in camerawork are proposed, which are designed to deal with the certainties and uncertainties encountered in the observational type of ethnographic film. The ethnographic context of the research is the community in the Shixini area of the Transkei, where the author made video-recordings of a number of ritual and everyday events between 1981 and 1984. The model is tested on the case study of a "small event". There is an extensive amount of video material of a four-day mortuary ritual. The model is examined through a first-person account of the influences on decisions during shooting, and through formal analysis. Both of these examinations refer in detail to the unedited video material which accompanies the thesis, and assess how the decisions deal with time and space: with regard to the ritual markers and the continuity method. The thesis concludes that the model of camera work can be used to provide a coherent observation of the small event. The suitability of the model for editing is then tested. The unedited material of the case study is compared with an edited version. The ritual is represented in a narrative segment within a longer documentary, "Shixini December: Responses to Poverty in the Transkei". The complexity of editing operations is examined in detail by a variety of methods, and refers closely to the longer documentary. The fit between continuity in the unedited camera work and the edited version is established. A video copy of this documentary also accompanies the thesis. The unedited observational material is then tested for its use in research. An anthropologist screened the unedited material to ritual participants to elicit their responses, and with the results wrote a dissertation combining interpretation and ethnography. The detail of the ethnography and the consistency of the interpretation demonstrates the value of an observational video record. It does not conclusively demonstrate its validity for research, because the effect of video on memory needs further exploration. Instead of stimulating memory of off-camera action as may be expected, the video seems to anaesthetise it. Continuity methods can provide a clear but partial and fragmented observational record. This record has formal characteristics which are a necessary but not sufficient condition for editing into narrative. Continuity methods may provide a video record that is useful for research. If the video is used for reflexive validation, then a possible effect on the memory of off-camera events must be taken into account. The continuity characteristics of unedited video which result from in-camera editing can, but need not be, evident in subsequent texts based on them.
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  • Date Issued: 1993

Patterns of plant diversity and cultural meaning in a rural landscape in the Albany Thicket: effects of land-use and topography

  • Authors: Ngqiyaza, Nozuko Princess
  • Date: 2017
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/50237 , vital:25969
  • Description: South Africa is the world's third most bio-diverse country, but pressures on this biodiversity are many and widespread. It is now well recognised that protected areas on their own are insufficient to protect biodiversity, and increasing emphasis is placed on developing models for ensuring the persistence of biodiversity in agricultural and rural landscapes. One of the major challenges, especially in rural areas, is the need to reconcile people’s need to use natural resources with biodiversity conservation. This study aimed to (1) examine the ecosystem services people derive from the natural vegetation and how this is distributed in space and (2) the effects of land use and topo-edaphic factors on species richness, composition and structure and how this is spatially distributed. I investigated two land-use types, i.e. a rural village and adjacent lightly used game farm(s) by comparing 20 sites under each land-use representing the range of topographic position. I sampled respondent’s uses and values, species richness and composition, woody density, structure and composition at these 40 sites. This allowed for comparison between the two land uses but also allowed me to examine the effect of topography and relative soil moisture (both known to have a string influence on vegetation in semi-arid areas), and to relate the ecosystem services to plant species richness, structure and woody composition. People derived a wide range of ecosystem services and this differed with distance from the village and vegetation type. Men and women performed different tasks and had different feelings and derived different use values across the landscapes. Both men and women showed a great appreciation for the thicket forest, Pteronia-dominated and grasslands sites. They recognised these areas and as sacred grounds where they have a strong connection with their ancestors. Women preferred utilising areas closer to the village because they feared crime and wild animals in more remote thicket or forest, while men utilised all areas across the land, but more frequently closer to the village. The older generation had a strong attachment to nature, perceiving it as a provider. The younger generation, especially the young women did not express such a deeply felt connection, but enjoyed getting to see where some of the medicinal plants and useful wood structures were harvested. Younger men would go far into the forest quite regularly, often as far the Great Fish River, when they hunt with their peers. Although a diversity of perceptions were presented, and not all conformed to traditional views and practices, most respondents derived a mix of ecosystem services, with the areas closer to the village providing recreational and direct use value to more people on a more regular basis but spiritual values associated with deep forest persisted, especially among the older generation. Species richness and composition was analysed in relation to Topographic Relative Moisture Index (TRMI), land use and distance from the village to see the effect of topography versus land use on the vegetation. The total number of plant species recorded was 386 for both study sites. Two hundred and ninety two species were recorded in Ntloko and 265 on the game farms. Of the species that were sampled, 121 were recorded in Ntloko only, 94 in the game farms only, and 171 species were shared. The number of useful plant species (fuel, medicine, forage, cultural and edibles) was recorded to be 110, 83 in Ntloko and 63 on the game farms. There was no significant difference in species richness and alpha diversity between the study sites, but the game farms had a higher projected total number of species, reflecting higher beta diversity in the game farms than the communal area. The point-centered quarter method (PCQ) was used to describe woody plant composition, tree density and structure. The woody structure and composition was analysed in relation to the above-mentioned factors and I found no significant difference in the density and overall woody structure and composition between the two study sites. Sites at Ntloko had a positive correlation between soil moisture and woody plant density and a higher density of palatable and unpalatable species. The game farms showed no significant changes in woody plant density with TRMI. This study showed that the communal area maintained comparable plant species richness and vegetation structure and composition to game farms. The rural landscape comprised a gradient from sites close to the village that were heavily impacted, not considered particularly special or sacred but safe, familiar and of utilitarian importance, to sites farther away with denser, less transformed thicket vegetation, which are considered to be of greater cultural, spiritual and aesthetic importance but less safe, familiar and accessible. This suggests that conservation outcomes can be achieved outside protected areas, and that biodiversity is valuable to local residents. Resource management should be implemented to maintain the ecosystem services provided in rural areas in a way that integrates local peoples’ perceptions, goals and values with ecological evidence.
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  • Date Issued: 2017

Quantifying degraded subtropical thicket structure and composition: a multi-scale approach in the Eastern Cape, South Africa

  • Authors: Lunderstedt, Kyra Elizabeth
  • Date: 2017
  • Subjects: Portulacaceae -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Savanna ecology -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/5281 , vital:20804
  • Description: The loss in canopy cover from over-browsing severely degrades the ecological integrity of spekboom-dominated thicket in the Eastern Cape. A homogenisation of species across the landscape and high heterogeneity at fine scales has been reported with little evidence of recovery. As an interlinked consequence, the loss in important biological structures and composition impacts greatly on soil resources and therefore function. This thesis provides a baseline of degraded thicket abiotic and biotic structure and composition over both spatial and temporal scales within the Greater Addo Elephant National Park (GAENP), including Darlington, Kabouga and Addo Main and within the Baviaanskloof. The study aimed to find correlates of species composition within sites and assess changes in composition with degradation and recovery times. Across the GAENP, landscape degradation was most evident in post-1960 aerial imagery. The duration since sampled sites have been incorporated into the GAENP did not influence species composition, however the period of degradation and severity, did. Across the landscape, communities were strongly associated with each of the four sites and separated predominantly by rainfall, gravel and altitude. A total of 345 plant species were identified across the landscape and despite degradation, each site was characterised into three to five communities each, barring Baviaanskloof which had no significantly different communities. Across the landscape, matrix composition comprised predominantly of Pentzia incana, Drosanthemum hispidum, Galenia pubescens and Cynodon species. Woody cover within patches included smaller Grewia robusta, Rhigozum obovatum and Vachellia karroo and the larger Pappea capensis and Euclea undulata. The succulent shrub Euphorbia caerulescens in Darlington and succulent tree Aloe ferox in Baviaanskloof occurred abundantly as a consequence of degradation. Species richness was significantly correlated to patch size in all sites, but Kabouga had the greatest richness and probability of a suite of species occurring within a patch. Higher woody and succulent cover in Kabouga was therefore associated with higher soil C, root percentage and bulk density. Other sites were higher in Ca, Na, K and P. The method of degradation scoring was not sufficiently accurate and it is recommended that indicator species within the matrix should be used instead of growth forms. The findings of this thesis are conceptualised within a double-cusped catastrophe model and recommendations for restoration are provided.
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  • Date Issued: 2017

The theory of the firm and pricing behaviour in South African manufacturing industry

Environmental and socio-economic effects associated with the planting of Atriplex nummularia Lindl. (Oldman saltbush) in the Karoo

  • Authors: Hobson, Colin Desmond
  • Date: 1991
  • Subjects: Botany, Economic Plant introduction -- South Africa -- Karoo Plants, Cultivated
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: vital:4175 , http://hdl.handle.net/10962/d1002023
  • Description: This study examines the environmental and socio-economic effects associated with the planting of Atriplex nummularia Lindl. (Oldman saltbush) in the karoo. This is the first study of its kind on oldman saltbush and serves as an important scoping exercise in assessing the impact of saltbush on its surrounds and in identifying additional aspects which require investigation. The environmental parameters investigated include microclimatic effects, soil induced changes, salinity effects on the germination of selected karoo species and compositional changes in the indigenous plant community within a saltbush plantation. When compared to indigenous karoo plant species oldman saltbush is found to ameliorate soil temperatures and increase surface soil salinity (specifically sodium chloride), on an individual plant basis. Salinity is shown to have a differential effect on the germination of selected karoo shrubs. The indigenous plant community within a forty year old saltbush plantation is impoverished with both density of individuals and species richness being markedly reduced. Saltbush is identified as an unsuitable nurse plant for the majority of karoo shrubs. Farm size in relation to both actual and intended area established to saltbush is considered. The area of saltbush already established in the karoo is considered too insignificant to have any wide socio-economic impact. Farmers who intend planting large areas of their farms to saltbush are in the minority. It is those farmers who already have some saltbush planted, who intend planting more. Ecologically based management guidelines are presented, suggesting practices which minimize the detrimental effects of saltbush on soil salinity and the indigenous plant community. These guidelines are practical and in keeping with the overall objectives of optimum resource utilisation and the national grazing strategy for South Africa.
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  • Date Issued: 1991

Where Leaders Learn' - relevant leadership for our society

  • Authors: Badat, Saleem
  • Date: 2011-02-19
  • Language: English
  • Type: Text
  • Identifier: vital:7839 , http://hdl.handle.net/10962/d1016032
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  • Date Issued: 2011-02-19

Rhodeo, Vol. 27, No. 12

  • Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
  • Language: English
  • Type: Text
  • Identifier: vital:14653 , http://hdl.handle.net/10962/d1019525
  • Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
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An analysis of the impact of tax changes between 1996 and 2012 on the tax burden of individuals in South Africa

  • Authors: Krug, Lee
  • Date: 2012
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: vital:885 , http://hdl.handle.net/10962/d1001639
  • Description: The objective of the research was to determine whether the changes made to the Income Tax Act, 58 of 1962 between 1996 and 2012, in respect of fringe benefits, allowances, deductions, tax tables and rebates, where these changes apply to individuals, have resulted in relieving the tax burden placed on individuals in South Africa. The research was conducted by means of a critical analysis of documentary data with specific reference to the Income Tax Act, annual amendments to the Income Tax Act, statistics relating to tax collections, the National Budget and the Annual Budget Speeches as tabled by the Minister of Finance. These sources were utilised to analyse the amendments to the Act that have taken place over the last sixteen years, where they impact on the tax liability of an individual. A hypothetical example incorporating all the variables identified in the analysis of the tax amendments was used to provide a detailed analysis of the tax payable by an individual on an inflation-adjusted year-on-year basis. The research found that, whilst personal income tax is still the largest contributor to the national budget of South Africa, its contribution has decreased from 40.2 percent in 1996 to 34.3 percent in 2010. This decrease is partly attributable to the extensive tax reforms undertaken by Government with respect to the tax tables, resulting in a reduction in the marginal tax rates and increased tax rebates which had the effect that the individual taxpayer (as illustrated in the hypothetical example) experienced a decrease in the average rate of tax. In contrast to this, the increase in the taxable income of the hypothetical taxpayer exceeded the average rate of inflation over the period. Furthermore, the actual revenue collected by the government from personal income tax has increased by approximately eleven percent per annum, which far exceeds the average inflation rate of 6.23 percent. The research indicated that this could be the result of the increase in the taxable value of fringe benefits, specifically medical aid contributions and company cars, as well as the inclusion of the full amount of allowances in taxable income and the limits placed on the deductions an individual may claim. The result is a broadening of the tax base of the individual taxpayer. Therefore, although the government may have achieved its goal of a fairer tax system, the amendments made to fringe benefits, allowances and deductions have resulted in an increase in the average taxable income of individuals.
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  • Date Issued: 2012

An application of the natural area concept to East London apartment areas

  • Authors: Brehmer, D A E
  • Date: 1975
  • Subjects: Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:4872 , http://hdl.handle.net/10962/d1009694 , Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
  • Description: The world is faced with a population explosion, and cities are becoming ever larger. The world population will grow from its present 3500 million to more than 7 000 million by the year 2 000. The majority of cities are thus faced with the problem of housing vast numbers of people living in single family dwellings forming low density urban sprawl. Conditions are no different in South Africa where the present white population of about four million is expected to grow to between six and seven million by the year 2000. The present housing requirement (1970-75) for Whites, based on low and high population projections, is 32 732 and 40 150 houses respectively. From 1995-2000 the figures will have risen to 42 742 and 65 580 respectively. At that rate sprawl here will reach alarming proportions unless it can be curtailed by higher density housing. As the population trend does not seem likely to be reversed the problem lies in how to provide housing for an escalating population but at the same time to reduce urban sprawl and provide satisfactory living conditions.
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  • Date Issued: 1975

Exploring the course-led development of a learning network as a community of practice around a shared interest of rainwater harvesting and conservation agricultural practices: a case study in the Amathole District in the Eastern Cape, South Africa

  • Authors: Weaver, Kim Nichole
  • Date: 2016
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: http://hdl.handle.net/10962/1184 , vital:20032
  • Description: South Africa has water and food security challenges, especially the Eastern Cape Province where there is a high level of poverty. These challenges place heavy pressure on the agricultural sector as it is the main user of the allocated water in the country. Rainwater harvesting and conservation (RWH&C) practices are explored as a response to these challenges, however information on these practices is not readily available to rural farmers. Agricultural extension has been moving from a top down approach towards a more participatory, collaborative process where what farmers need and want is considered. These participatory approaches need to be explored to enable change in farmer’s practice. This research forms part of a Water Resource Commission (WRC) project, Amanzi for Food. (Project K5/2277). The project has the explicit intention of supporting the use of two sets of WRC materials on RWH&C and expanding the learning of these practices through a courseled process within a learning network structure centred around an agricultural college. The network was established with a participatory, applied training of trainer’s course that supports and expands knowledge of RWH&C practices amongst network members from different groups within the sector; farmers, trainers, researchers and educators. My main research question was to investigate the process of cultivating a learning network amongst different agricultural actors through a course-led initiative to strengthen the engagement with RWH&C practices. To address this research I used focus group discussions, course observations, participant interviews, participant questionnaires and participant assignment progress to generate data. These data were analysed using Wenger’s theory of communities of practice to gauge levels of engagement, participation and learning. Main findings of the study are that the course-led activation of the learning network supported the community of practice members to share their personal experience and achieve social competence in the learning of RWH&C agricultural practices in their context.
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  • Date Issued: 2016

Isolation and characterization of a novel thermostable and catalytically efficient laccase from Peniophora sp. strain UD4

  • Authors: Jordaan, Justin
  • Date: 2005
  • Subjects: Enzymes Enzymes -- Industrial applications Peniophora Laccase
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3970 , http://hdl.handle.net/10962/d1004029
  • Description: Enzymes are becoming an effective tool in industrial processes, from crude applications such as bioremediation to fine processes such as chirally selective biocatalysis. The ligninolytic enzymes have recently received considerable attention for industrial application due to both their broad substrate range and their ability to degrade the most recalcitrant natural polymer, lignin. This group of enzymes was therefore identified as the target group for this study. Improved enzyme properties are constantly being sought to enhance the range of applications for enzymes. Biodiversity provides a wide variety of enzymes. Several researchers have concentrated on extremophiles as their primary source of superior enzymes, consequently neglecting temperate environments in their search for these enzymes. The relatively neglected fungal biodiversity of South Africa provided an opportunity to test the hypothesis that potentially important industrial enzymes with unusual properties could be isolated from mesophilic basidiomycetous fungi. Subsequent screening of Eastern Cape biodiversity for thermostable ligninolytic enzymes from basidiomycetes resulted in the isolation of a novel laccase enzyme from a basidiomycetous species. This fungus was identified as Peniophora sp. UD4 by phylogenetic analysis of rDNA ITS sequences. Initial studies indicated a superior optimum temperature of 70°C and thermostability, indicated by no loss in activity at 60°C over nine hours. Further characterization of the laccase revealed a broader than usual substrate range through its unusual ability to oxidatively couple DMAB and MBTH. The laccase also exhibited a broad pH oxidation range for ABTS (pH 2 – 6.8), and a relatively high affinity (K_m_ = 0.0123 mM) and catalytic efficiency (63 252 mM^(-1)^s^(-1)^) for ABTS as a substrate. The laccase activity from Peniophora sp. UD4 was shown to be comprised of three isozymes with a molecular weight of 62 kDa and pI’s of 6.33, 6.45 and 6.50. Investigation of the nutrient and physical factors affecting ligninolytic enzyme production and growth of Peniophora sp. UD4 indicated that the wild-type organism was unsuitable for large scale production of the thermostable laccase due to the low levels of laccase production. The thermostable laccase was applied to defouling of ultrafiltration membranes, bioremediation of industrial waste streams, biocatalysis, and biosensor technology as potential applications. Application of the Peniophora sp. UD4 laccase to defouling of membranes used for ultrafiltration of brown water showed large flux recoveries of 31, 21 and 21% after the first three defouling recycles respectively, compared to 3% for the control without immobilized enzyme. The novel laccase showed potential for the bioremediation of industrial waste streams, the most successful being that of bleach plant effluent, where a reduction of 66% of the phenolic load was achieved. Application of the novel laccase to biocatalytic oxidation of ferulic acid and (±)-α-pinene showed higher product yield as compared to oxidation of these compounds by Trametes versicolor laccase in mediated and non-mediated systems. The major products of (±)-α-pinene oxidation were identified as verbenol and trans-sorberol. The Peniophora sp. UD4 laccase was successfully applied to biosensor technology, which benchmarked significantly better than Trametes versicolor laccase for the detection of 4-chlorophenol. The biosensor developed with laccase from UD4 by covalent binding to a glassy carbon electrode exhibited the best combination of sensitivity and stability. This thesis shows that a laccase with superior properties was obtained from a mesophilic South African basidiomycete. The catalytic properties displayed by the novel laccase from Peniophora sp. UD4 all contribute to the increased industrial applicability of laccases, and may be the most industrially feasible enzyme of its class isolated to date.
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  • Date Issued: 2005

SANLiC 2013 Workshop : Ever Evolving Ebooks

Current practice in the field of architectural and autonomous stained glass in Europe and the United States of America

  • Authors: Nesbit, G H H
  • Date: 1987
  • Subjects: Glass painting and staining -- Europe , Glass painting and staining -- United States
  • Language: English
  • Type: Thesis , Masters , MFA
  • Identifier: vital:2488 , http://hdl.handle.net/10962/d1012955
  • Description: This prodrome sought to define through research, the material. composition, historic foundations, significance and technical development of glass as a window-glazing material for ecclesiastical, and later secular purposes, and examining thus its determining role in the development of architecture. The history and techniques of stained glass, an art-form linked more than any other to the mythology and dogma of the Roman Catholic Church, were traced; its history is thus one with that of the church, rising to its greatest glory during the twelfth and thirteenth centuries, and declining from the late fifteenth to the seventeenth centuries. The iconography of the church was examined, and the development of window and tracery types discussed through reference to pertinent examples on both sides of the English Channel. Subjects, stylistic and technical factors, sources of reference, ecclesiastical influences, were all within the context of social and political history . viewed. Intro., p. 1-2.
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  • Date Issued: 1987

An exploration of the social worker's role in promoting sustainability of poverty alleviating projects

  • Authors: Ndude, Peace-Maker Mqokeleli
  • Date: 2002
  • Subjects: Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:6058 , http://hdl.handle.net/10962/d1006664 , Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
  • Description: In this research study the researcher attempted to gain an insight on what constitutes sustainability of poverty alleviating projects. Further, the researcher attempted to explore and gain understanding of the role of social worker in promoting sustainability of poverty alleviating projects. Since the literature on sustainability is limited, it is hoped that this study will provide valuable information for further research on the topic. In the limited literature study undertaken however, it was evident that despite the generic service that they provide, social workers have a role to play in community development. It was found that social workers can no longer afford to restrict their service provision to the traditional methods of social work. The egalitarian nature of their profession demands that they occupy the centre stage in poverty alleviation as they are strategically placed between the poor and the decision-makers in government. Eighteen respondents composed of six social workers, six committee members and six community members from six poverty alleviating projects were interviewed. One project from each of the six districts of Tsomo, Nqamakwe, Butterworth, Centane, Idutywa and Willowvale were used in the research study. The fmdings suggested that social workers, committee members and community members have differing opinions on what promotes or impedes sustainability of poverty alleviating projects, All respondents however agreed that participation as well as empowerment through training were basic requirements towards sustainability of poverty alleviating projects. Again the findings agreed with the literature that social workers have an important role to play in promoting sustainability of poverty alleviating projects.
  • Full Text:
  • Date Issued: 2002

The geology and alteration-mineralisation of the Gamigab Tin Prospect, Damaraland, Namibia

  • Authors: Walraven, Felix Caspar
  • Date: 1990
  • Subjects: Mineralogy -- Namibia -- Damaraland , Geology -- Namibia -- Damaraland , Tin mines and mining -- Namibia -- Damaraland
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4956 , http://hdl.handle.net/10962/d1005568 , Mineralogy -- Namibia -- Damaraland , Geology -- Namibia -- Damaraland , Tin mines and mining -- Namibia -- Damaraland
  • Description: The stratigraphy at the Gamigab Sn prospect consists of two mainly schistose units separated by a thick marble unit which have been assigned to the Orusewa, the Karibib and the Kuiseb Formations respectively. Four phases of folding affected the lithologies with the south-south-west trending F2 folds defining the main structures in the region. The area underwent low grades of metamorphism. Temperatures were in the range 420° to 500°C and pressures less than 2 kbars. The effects of contact metamorphism are seen in the south-east and south-west. Regional metamorphism outlasted the deformation and contact metamorphism started late during deformation. Two Karoo-age intrusions penetrated the metasediments north of the mineralisation. One is an altered porphyry plug and the other is a weathered dolerite plug, the latter containing xenoliths of undeformed Karoo sediments. Cassiterite is hosted within east-west trending quartz veins that cross-cut previously altered schistose country rocks. The alteration types include sericitisation, tourmalinisation, carbonatisation and ferruginisation. Preliminary Rb/Sr dating on muscovite from the alteration zone suggests an age of 509 ± 11 Ma. Breccias of probable hydrothermal origin are spatially associated with the mineralisation. These hydraulic breccias occur in antiformal structures within the marble and developed in response to a sudden pressure release due to a build up of fluids at the contact between the schistose Orusewa and carbonate Karibib Formations.
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  • Date Issued: 1990
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