Justin Davy of Burning Museum: an interview
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147070 , vital:38590 , https://www.on-curating.org/issue-32-reader/justin-davy-of-the-burning-museum.html#.Xs0mCmgzbIU
- Description: The Burning Museum is an arts collective based in Cape Town, South Africa. This interview is the result of a three-part Skype conversation between Justin Davy of the Burning Museum and Nancy Dantas, an independent curator and researcher with an interest in recovering the neglected and overlooked exhibition histories and practices of the south.
- Full Text:
- Date Issued: 2017
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147070 , vital:38590 , https://www.on-curating.org/issue-32-reader/justin-davy-of-the-burning-museum.html#.Xs0mCmgzbIU
- Description: The Burning Museum is an arts collective based in Cape Town, South Africa. This interview is the result of a three-part Skype conversation between Justin Davy of the Burning Museum and Nancy Dantas, an independent curator and researcher with an interest in recovering the neglected and overlooked exhibition histories and practices of the south.
- Full Text:
- Date Issued: 2017
Looking after freedom?:
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147081 , vital:38591 , https://www.buala.org/en/ill-visit/looking-after-freedom
- Description: Did freedom come to South Africa in 1994? Should it be marked and set in time, or is it a fragile process, an ambition and a becoming? Do we see ourselves coming closer to this ideal, or desperately receding from it as an invisible rip current pulls us away? To think of freedom as a given, a day in the year or a landmark on the horizon is to neglect that liberty from bondage and oppression, in all its disastrous and fatidic forms requires vigilance, nurturing and a spirit of insatiable demand. When our freedom becomes commodified, transformed into a mark on annual calendars, a mere commemoration; something we think have obtained and cannot possibly stand to loose, we are all in for trouble.
- Full Text:
- Date Issued: 2017
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147081 , vital:38591 , https://www.buala.org/en/ill-visit/looking-after-freedom
- Description: Did freedom come to South Africa in 1994? Should it be marked and set in time, or is it a fragile process, an ambition and a becoming? Do we see ourselves coming closer to this ideal, or desperately receding from it as an invisible rip current pulls us away? To think of freedom as a given, a day in the year or a landmark on the horizon is to neglect that liberty from bondage and oppression, in all its disastrous and fatidic forms requires vigilance, nurturing and a spirit of insatiable demand. When our freedom becomes commodified, transformed into a mark on annual calendars, a mere commemoration; something we think have obtained and cannot possibly stand to loose, we are all in for trouble.
- Full Text:
- Date Issued: 2017
Facile synthesis of glutathione-l-Cysteine co-capped CdTe core shell system
- Daramola, Olamide A, Siwe-Noundou, Xavier, Krause, Rui W M, Marks, John A
- Authors: Daramola, Olamide A , Siwe-Noundou, Xavier , Krause, Rui W M , Marks, John A
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195003 , vital:45518 , xlink:href="https://doi.org/10.1166/jnn.2017.13823"
- Description: Semiconductor nanoparticles also known as quantum dots (QDs) have been used in diverse areas of application due to their good optical and photo-physical properties. The synthesis of core–shell QDs have assisted to improve the stability of most nano-particles but the size and long term stability of such materials have been problematic. However, thiol-capped CdTe QDs have been regarded as some of the most widely synthesized nanoparticles due to their unique optical properties. The use of un-stable tellurium source such as NaHTe or highly toxic H2Te gas makes the reaction condition cumbersome. In this study, we prepared some CdTe QDs and core–shell QDs using K2TeO3 as a stable source of tellurium without inert gas protection. This was done using a co-capped bio-compatible coating such as cysteine and glutathione following a modified standard method to produce QDs in the yields of about 60 to 80%. All the synthesized materials were subsequently characterized using various characterization techniques. The systematic optimization of the reaction parameters such as reaction time, pH and mole ratio results with a drastic red shift in wavelength (546–600 nm) by the CdTe core proved that an extra material has been deposited unto the surface of the CdTe core. The 60 days stability test conducted demonstrated that the core–shell nanoparticles were quite stable. Since this reaction was performed under open air conditions and no special ligand or buffer solution was used, it may suitably be applied on an industrial scale.
- Full Text:
- Date Issued: 2017
- Authors: Daramola, Olamide A , Siwe-Noundou, Xavier , Krause, Rui W M , Marks, John A
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195003 , vital:45518 , xlink:href="https://doi.org/10.1166/jnn.2017.13823"
- Description: Semiconductor nanoparticles also known as quantum dots (QDs) have been used in diverse areas of application due to their good optical and photo-physical properties. The synthesis of core–shell QDs have assisted to improve the stability of most nano-particles but the size and long term stability of such materials have been problematic. However, thiol-capped CdTe QDs have been regarded as some of the most widely synthesized nanoparticles due to their unique optical properties. The use of un-stable tellurium source such as NaHTe or highly toxic H2Te gas makes the reaction condition cumbersome. In this study, we prepared some CdTe QDs and core–shell QDs using K2TeO3 as a stable source of tellurium without inert gas protection. This was done using a co-capped bio-compatible coating such as cysteine and glutathione following a modified standard method to produce QDs in the yields of about 60 to 80%. All the synthesized materials were subsequently characterized using various characterization techniques. The systematic optimization of the reaction parameters such as reaction time, pH and mole ratio results with a drastic red shift in wavelength (546–600 nm) by the CdTe core proved that an extra material has been deposited unto the surface of the CdTe core. The 60 days stability test conducted demonstrated that the core–shell nanoparticles were quite stable. Since this reaction was performed under open air conditions and no special ligand or buffer solution was used, it may suitably be applied on an industrial scale.
- Full Text:
- Date Issued: 2017
Commerce powered by 'National culture'? : an assessment of "Wear Local" campaigns as tools for reinvigorating the textile and clothing industries in Ghana and South Africa
- Authors: Darku, Esther Naa Dodua
- Date: 2017
- Subjects: Textile industry -- Economic aspects -- Ghana Textile industry -- Economic aspects -- South Africa Sustainable development -- Ghana , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2172 , vital:27619
- Description: This study examines the use of ‘cultural’ imagery and messaging as a tool to revitalise crucial national industries. Specifically, it examines the use of Wear Local campaigns in Ghana and South Africa as strategies to rejuvenate their textile industries and to make them viable in an increasingly competitive global market. Conceptualising Wear Local campaigns as possessing both cultural and economic imperatives, this study highlights how both factors contribute to making products of Buy Local campaigns marketable by showing their importance as both cultural and economic products. Using a descriptive-evaluative design, the study adopted a triangulated research approach comprising a survey, key informant interviews and document analysis. Survey questionnaires were administered to a total sample of 308 respondents in Ghana and South Africa. The qualitative phase of the study involved 10 key informant interviews (comprising textile labour unions, clothing designers, and government officials in both countries) and document/documentary research. The quantitative data were analysed using descriptive and inferential statistics, while the qualitative data were analysed using interpretive approaches, such as content analysis. The results indicate significant uses of national cultural elements in the campaign messaging in both Ghana and South Africa, as well as notable differences in the ways in which these campaigns resonated with consumers in the two countries. For instance, cultural differences accounted for high popularity of the campaign in Ghana and low popularity in South Africa. Following from these findings, the study concludes that the discourse on Buy Local and Wear Local, and the use of national culture in commerce, must go beyond the question of efficacy to examine the conditions under which these campaigns can become an effective economic/market tool. The study makes an important contribution to the existing knowledge on national culture, national economy and globalisation.
- Full Text:
- Date Issued: 2017
- Authors: Darku, Esther Naa Dodua
- Date: 2017
- Subjects: Textile industry -- Economic aspects -- Ghana Textile industry -- Economic aspects -- South Africa Sustainable development -- Ghana , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2172 , vital:27619
- Description: This study examines the use of ‘cultural’ imagery and messaging as a tool to revitalise crucial national industries. Specifically, it examines the use of Wear Local campaigns in Ghana and South Africa as strategies to rejuvenate their textile industries and to make them viable in an increasingly competitive global market. Conceptualising Wear Local campaigns as possessing both cultural and economic imperatives, this study highlights how both factors contribute to making products of Buy Local campaigns marketable by showing their importance as both cultural and economic products. Using a descriptive-evaluative design, the study adopted a triangulated research approach comprising a survey, key informant interviews and document analysis. Survey questionnaires were administered to a total sample of 308 respondents in Ghana and South Africa. The qualitative phase of the study involved 10 key informant interviews (comprising textile labour unions, clothing designers, and government officials in both countries) and document/documentary research. The quantitative data were analysed using descriptive and inferential statistics, while the qualitative data were analysed using interpretive approaches, such as content analysis. The results indicate significant uses of national cultural elements in the campaign messaging in both Ghana and South Africa, as well as notable differences in the ways in which these campaigns resonated with consumers in the two countries. For instance, cultural differences accounted for high popularity of the campaign in Ghana and low popularity in South Africa. Following from these findings, the study concludes that the discourse on Buy Local and Wear Local, and the use of national culture in commerce, must go beyond the question of efficacy to examine the conditions under which these campaigns can become an effective economic/market tool. The study makes an important contribution to the existing knowledge on national culture, national economy and globalisation.
- Full Text:
- Date Issued: 2017
Cosmopolitanism and the unfollowable routines and rituals in Ishtiyaq Shukri’s The Silent Minaret:
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142531 , vital:38088 , DOI: 10.1080/02564718.2017.1290382
- Description: This article explores how Ishtiyaq Shukri’s The Silent Minaret critiques the limited and severely uneven forms of hospitality that characterise post-9/11 Britain. It also examines how the text gestures towards the possibility of a non-violent, inclusive cosmopolitanism. The piece begins by relating recent debates surrounding the “War on Terror”, as well as Britain’s decision to leave the European Union to the novel’s major concerns. It then turns to the novel, and summarises incidents in which the principal character, Issa Shamshuddin, is traumatised and harmed by the Islamophobia and anti-immigration policies evident in the London portrayed in the text. Next, it turns to an analysis of the strange and irreproducible rituals of Issa’s neighbour, Frances. The article concludes that that these unfollowable rituals posit how a truly cosmopolitan society would function.
- Full Text:
- Date Issued: 2017
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142531 , vital:38088 , DOI: 10.1080/02564718.2017.1290382
- Description: This article explores how Ishtiyaq Shukri’s The Silent Minaret critiques the limited and severely uneven forms of hospitality that characterise post-9/11 Britain. It also examines how the text gestures towards the possibility of a non-violent, inclusive cosmopolitanism. The piece begins by relating recent debates surrounding the “War on Terror”, as well as Britain’s decision to leave the European Union to the novel’s major concerns. It then turns to the novel, and summarises incidents in which the principal character, Issa Shamshuddin, is traumatised and harmed by the Islamophobia and anti-immigration policies evident in the London portrayed in the text. Next, it turns to an analysis of the strange and irreproducible rituals of Issa’s neighbour, Frances. The article concludes that that these unfollowable rituals posit how a truly cosmopolitan society would function.
- Full Text:
- Date Issued: 2017
“Wishy-washy liberalism” and “the art of getting lost” in Ivan Vladislavić’s Double Negative:
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142633 , vital:38097 , DOI: 10.4314/eia.v44i3.1
- Description: The politics of the protagonist of Ivan Vladislavić’s Double Negative, Neville Lister, are broadly liberal during apartheid, but show signs of becoming more conservative during the post-apartheid era. In this article, I argue that this development is unsurprising because bourgeois white liberals and conservatives in South Africa continue to cling to the privileges afforded them as the propertied class. For this reason, acknowledgements of privilege and quests for discomfort, while not necessarily dishonest, do not in and of themselves constitute progressive politics. Rather, one can, as Neville does, become comfortable with discomfort so long as it allows one to enjoy a privileged lifestyle. I therefore draw a distinction between the unease argued for in much of what constitutes whiteness studies, and a sense of being lost that seems to demand the loss of the home and its attendant association with control. This sense of lostness emerges in two ways in the novel: in a description of a photograph that contains the spectral presence of a dead child, and in a game that Neville played when he was a young boy. Both of these sections of the text also deal with the limits of art – of writing and of photography in particular. I propose that these self-reflexive episodes suggest the novel’s own limits, and gesture beyond them in ways that are worth consideration by its middle-class readership.
- Full Text:
- Date Issued: 2017
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142633 , vital:38097 , DOI: 10.4314/eia.v44i3.1
- Description: The politics of the protagonist of Ivan Vladislavić’s Double Negative, Neville Lister, are broadly liberal during apartheid, but show signs of becoming more conservative during the post-apartheid era. In this article, I argue that this development is unsurprising because bourgeois white liberals and conservatives in South Africa continue to cling to the privileges afforded them as the propertied class. For this reason, acknowledgements of privilege and quests for discomfort, while not necessarily dishonest, do not in and of themselves constitute progressive politics. Rather, one can, as Neville does, become comfortable with discomfort so long as it allows one to enjoy a privileged lifestyle. I therefore draw a distinction between the unease argued for in much of what constitutes whiteness studies, and a sense of being lost that seems to demand the loss of the home and its attendant association with control. This sense of lostness emerges in two ways in the novel: in a description of a photograph that contains the spectral presence of a dead child, and in a game that Neville played when he was a young boy. Both of these sections of the text also deal with the limits of art – of writing and of photography in particular. I propose that these self-reflexive episodes suggest the novel’s own limits, and gesture beyond them in ways that are worth consideration by its middle-class readership.
- Full Text:
- Date Issued: 2017
“[A] ll just surface and veneer”: the challenge of seeing and reading in Ishtiyaq Shukri’s I See You
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142577 , vital:38092 , DOI: 10.1080/17533171.2017.1312749
- Description: This article considers challenges posed to reading practices and hermeneutics by Ishtiyaq Shukri’s I See You. The content of the novel is at times didactic, and surface reading might seem an appropriate means of analysis, yet the form is experimental: it includes radio reports, characters’ reflections and journalistic work. The connection between these “documents” is not readily apparent, thus one is obliged to study the gaps between them to make sense of the text. Symptomatic reading might seem apposite, but the protagonist’s photographic work reveals the limits of this form of reading, too. I argue that Shukri’s text demands a process that interweaves symptomatic and surface reading in complex ways that require the reader to assess the ideological position from which s/he reads. The novel therefore draws attention to the ways in which reading, like seeing, is a political act.
- Full Text:
- Date Issued: 2017
“[A] ll just surface and veneer”: the challenge of seeing and reading in Ishtiyaq Shukri’s I See You
- Authors: Dass, Minesh
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142577 , vital:38092 , DOI: 10.1080/17533171.2017.1312749
- Description: This article considers challenges posed to reading practices and hermeneutics by Ishtiyaq Shukri’s I See You. The content of the novel is at times didactic, and surface reading might seem an appropriate means of analysis, yet the form is experimental: it includes radio reports, characters’ reflections and journalistic work. The connection between these “documents” is not readily apparent, thus one is obliged to study the gaps between them to make sense of the text. Symptomatic reading might seem apposite, but the protagonist’s photographic work reveals the limits of this form of reading, too. I argue that Shukri’s text demands a process that interweaves symptomatic and surface reading in complex ways that require the reader to assess the ideological position from which s/he reads. The novel therefore draws attention to the ways in which reading, like seeing, is a political act.
- Full Text:
- Date Issued: 2017
The effect of synthetically-derived xanthone compounds on the suppression of the progression of breast cancer and the associated complications
- Authors: Davison, Candace
- Date: 2017
- Subjects: Breast -- Cancer -- Chemotherapy Breast -- Cancer -- Prevention , Antibacterial agents -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/13889 , vital:27354
- Description: Breast cancer is the most frequently diagnosed cancer in women worldwide.A treatment regime, both effective and safe and can only be achieved once more effective chemotherapeutic agents are discovered or identified. These “drugs” must selectively induce cell death such as apoptosis or necroptosis in the cancer cells. Apoptotic cell death allows a cell to “commit suicide” in genetically- controlled or programmed mechanism(s). The microenvironment of the tumour is important since a nurturing malignant environment is required for tumour maintenance, progression and ultimately the development of metastasis. Due to the correlation of the tumour microenvironment to aggressive tumour progression, emphasis should be placed on the constituents of the tumour’s microenvironment. In recent years, the understanding of intracellular pathways in cancer cells has increased rapidly, contributing to the development of drugs with more specific targets such as growth factors, signalling molecules, cell adhesion proteins, proteases, cell-cycle proteins, modulators of apoptosis and molecules that promote angiogenesis and metastasis. The main aim of this study was thus to identify a few potential or active compounds from a library of synthetically-derived compounds as possible alternative breast cancer treatment candidates.
- Full Text:
- Date Issued: 2017
- Authors: Davison, Candace
- Date: 2017
- Subjects: Breast -- Cancer -- Chemotherapy Breast -- Cancer -- Prevention , Antibacterial agents -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/13889 , vital:27354
- Description: Breast cancer is the most frequently diagnosed cancer in women worldwide.A treatment regime, both effective and safe and can only be achieved once more effective chemotherapeutic agents are discovered or identified. These “drugs” must selectively induce cell death such as apoptosis or necroptosis in the cancer cells. Apoptotic cell death allows a cell to “commit suicide” in genetically- controlled or programmed mechanism(s). The microenvironment of the tumour is important since a nurturing malignant environment is required for tumour maintenance, progression and ultimately the development of metastasis. Due to the correlation of the tumour microenvironment to aggressive tumour progression, emphasis should be placed on the constituents of the tumour’s microenvironment. In recent years, the understanding of intracellular pathways in cancer cells has increased rapidly, contributing to the development of drugs with more specific targets such as growth factors, signalling molecules, cell adhesion proteins, proteases, cell-cycle proteins, modulators of apoptosis and molecules that promote angiogenesis and metastasis. The main aim of this study was thus to identify a few potential or active compounds from a library of synthetically-derived compounds as possible alternative breast cancer treatment candidates.
- Full Text:
- Date Issued: 2017
Tribocorrosion properties of friction stir welded and laser welded titanium alloy
- Authors: Davoren, Brandon Hilton
- Date: 2017
- Subjects: Chemistry, Technical -- Research Materials -- Mechanical properties , Aluminum alloys
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/33250 , vital:32605
- Description: Titanium alloy Ti6Al4V has extensive uses in aerospace, dentistry and the biomedical industry. When used in these applications there is often a need to weld two or more pieces of titanium alloy together. This can be done by either friction stir weld or laser weld methods. These welded regions are often exposed to corrosive environments in addition to factors such as induced additional mechanical wear. Thus to accurately report on the viability of the material in a specific application, the corrosion, wear and their synergistic effects need to be studied. Friction stir welding, which is a well-suited method for joining plates of Ti6Al4V, creates regions in the material that are affected differently. These regions can be described as the parent material, advancing side, retreating side and the weld zone. The tribological properties of the different friction stir weld regions were analysed in air using different loads, frequencies, experimental duration and surrounding environments. When the applied load was increased some of the weld regions showed an increase in the specific wear rate. For example, the weld zone region showed a decrease when compared to the parent material. In this tribology study the effect of the counter material was evaluated. E52100, Si3N4, SS 316 and alumina counter materials were used in the test procedure which was conducted in air on the weld regions. The parent material was found to have the highest average specific wear rates with the four counter materials when compared to the weld zone samples. The regions affected by the friction stir weld process all showed, on average, lower specific wear rates than the parent material. For the various tested samples, the coefficient of friction and material compatibility that was found to be the most stable, was the alumina ball. Owing to this as well as its chemical stability, alumina was determined to be the best material for further tribocorrosion studies. The friction stir welded samples, that were cut from a cross section of a friction stir weld plate, were analyzed in 3.5% NaCl and dilute Harrison’s solution respectively. The effect of wear on the electrochemical properties was studied under open circuit voltage (OCV) and fixed 0.2 V and 0.4 V applied potential conditions respectively. The effect of wear on the corrosion properties was studied using potentiodynamic polarization. From analyzing the friction stir weld regions in both a wear and wear-free environment, the synergistic properties, namely the effect of wear on corrosion and the effect of corrosion on wear, were able to be calculated. The first electrochemical study was performed under OCV conditions. In the presence of applied wear, the open circuit potential of the friction stir weld samples, in both 3.5% NaCl and dilute Harrison’s solution, was found to decrease from the initial stabilized value. Of interest was the rate at which the OCV recovered. It was found to follow a second order repassivation growth model which was explained in terms of an initial film growth stage, followed by a film thickening stage that results in a new OCV. The second synergized electrochemical-wear study was under fixed 0.2 V and 0.4 V applied potential conditions. In both solutions, 3.5% NaCl and dilute Harrison’s solution, a large increase in the current was observed during the applied wear experiment. The samples submerged in 3.5% NaCl were found to have higher average currents during the wear experiment than those in dilute Harrison’s solution. The rapid decrease in the current, after the applied wear ceased, was found to also follow the second order repassivation model. The electrochemical-wear synergism was done by using potentiodynamic polarization tests. The friction stir weld regions as well as the laser samples were analysed in a wear as well as a wear-free environment in order to determine the effect that wear had on the corrosion properties. In both 3.5% NaCl and dilute Harrison’s solution the corrosion rates were found to increase by 100-fold when the wear was present. The effect of the wear process on corrosion could also be described by synergistic factor, where values close to 1 would imply that applied wear had little effect on the corrosion properties and vice versa. The synergistic factors showed that the corrosion rate was greatly affected by the presence of wear with corrosion synergistic factors of 20 and upward for the friction stir welded samples. The results showed that the weld zone region had a lower corrosion rate than the parent material. This implied that the main weld zone was shown to have the least effect of wear on corrosion and would therefore show the lowest likelihood of failure due to corrosion when compared to the parent material. The wear synergistic factor was found to be between 1 and 1.6 for the friction stir weld regions. This implied that the wear rates of the friction stir welded samples were slightly affected by the presence of a corrosive environment and that the wear properties of the laser welded samples were enhanced by the presence of a corrosive environment. Similar studies performed on laser welded samples showed unusually different results due to the small nature of the laser weld region, with inconclusive results when compared to the friction stir welded samples.
- Full Text:
- Date Issued: 2017
- Authors: Davoren, Brandon Hilton
- Date: 2017
- Subjects: Chemistry, Technical -- Research Materials -- Mechanical properties , Aluminum alloys
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/33250 , vital:32605
- Description: Titanium alloy Ti6Al4V has extensive uses in aerospace, dentistry and the biomedical industry. When used in these applications there is often a need to weld two or more pieces of titanium alloy together. This can be done by either friction stir weld or laser weld methods. These welded regions are often exposed to corrosive environments in addition to factors such as induced additional mechanical wear. Thus to accurately report on the viability of the material in a specific application, the corrosion, wear and their synergistic effects need to be studied. Friction stir welding, which is a well-suited method for joining plates of Ti6Al4V, creates regions in the material that are affected differently. These regions can be described as the parent material, advancing side, retreating side and the weld zone. The tribological properties of the different friction stir weld regions were analysed in air using different loads, frequencies, experimental duration and surrounding environments. When the applied load was increased some of the weld regions showed an increase in the specific wear rate. For example, the weld zone region showed a decrease when compared to the parent material. In this tribology study the effect of the counter material was evaluated. E52100, Si3N4, SS 316 and alumina counter materials were used in the test procedure which was conducted in air on the weld regions. The parent material was found to have the highest average specific wear rates with the four counter materials when compared to the weld zone samples. The regions affected by the friction stir weld process all showed, on average, lower specific wear rates than the parent material. For the various tested samples, the coefficient of friction and material compatibility that was found to be the most stable, was the alumina ball. Owing to this as well as its chemical stability, alumina was determined to be the best material for further tribocorrosion studies. The friction stir welded samples, that were cut from a cross section of a friction stir weld plate, were analyzed in 3.5% NaCl and dilute Harrison’s solution respectively. The effect of wear on the electrochemical properties was studied under open circuit voltage (OCV) and fixed 0.2 V and 0.4 V applied potential conditions respectively. The effect of wear on the corrosion properties was studied using potentiodynamic polarization. From analyzing the friction stir weld regions in both a wear and wear-free environment, the synergistic properties, namely the effect of wear on corrosion and the effect of corrosion on wear, were able to be calculated. The first electrochemical study was performed under OCV conditions. In the presence of applied wear, the open circuit potential of the friction stir weld samples, in both 3.5% NaCl and dilute Harrison’s solution, was found to decrease from the initial stabilized value. Of interest was the rate at which the OCV recovered. It was found to follow a second order repassivation growth model which was explained in terms of an initial film growth stage, followed by a film thickening stage that results in a new OCV. The second synergized electrochemical-wear study was under fixed 0.2 V and 0.4 V applied potential conditions. In both solutions, 3.5% NaCl and dilute Harrison’s solution, a large increase in the current was observed during the applied wear experiment. The samples submerged in 3.5% NaCl were found to have higher average currents during the wear experiment than those in dilute Harrison’s solution. The rapid decrease in the current, after the applied wear ceased, was found to also follow the second order repassivation model. The electrochemical-wear synergism was done by using potentiodynamic polarization tests. The friction stir weld regions as well as the laser samples were analysed in a wear as well as a wear-free environment in order to determine the effect that wear had on the corrosion properties. In both 3.5% NaCl and dilute Harrison’s solution the corrosion rates were found to increase by 100-fold when the wear was present. The effect of the wear process on corrosion could also be described by synergistic factor, where values close to 1 would imply that applied wear had little effect on the corrosion properties and vice versa. The synergistic factors showed that the corrosion rate was greatly affected by the presence of wear with corrosion synergistic factors of 20 and upward for the friction stir welded samples. The results showed that the weld zone region had a lower corrosion rate than the parent material. This implied that the main weld zone was shown to have the least effect of wear on corrosion and would therefore show the lowest likelihood of failure due to corrosion when compared to the parent material. The wear synergistic factor was found to be between 1 and 1.6 for the friction stir weld regions. This implied that the wear rates of the friction stir welded samples were slightly affected by the presence of a corrosive environment and that the wear properties of the laser welded samples were enhanced by the presence of a corrosive environment. Similar studies performed on laser welded samples showed unusually different results due to the small nature of the laser weld region, with inconclusive results when compared to the friction stir welded samples.
- Full Text:
- Date Issued: 2017
Implementation of visual arts education in one technical and vocational education and training college in the Eastern Cape : the voices of lecturers and students
- Authors: Dayimani, Mbulelo
- Date: 2017
- Subjects: Curriculum planning Vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/12744 , vital:39318
- Description: It can be observed that students actively participate in the learning process of education in our country, and the curriculum gives expression to the knowledge, skills and values worth learning in South African schools and institutions. However, Technical and Vocational Education Training (TVET) Colleges still continue using traditional learning methods, in which the teacher is in the centre, devoid of artistic culture, and practical work. These implementation methods and techniques have been identified as less motivating for students especially for those with no background in Visual Arts (VA) in high school. The aim of this study therefore was to investigate the views of students and lecturers on the implementation of Visual Arts Education (VAE) in the TVET Colleges in the Eastern Cape. This study was premised from a qualitative research approach and therefore interpretivist paradigm was relevant in assisting the researcher making sense of the data gathered. Face-to-face interviews were used to collect the data from five lecturers and fifteen students in N4 level. The interviews were tape-recorded. The research showed that Visual Arts Education can be an engine that drives creativity and innovation in schools, higher Education institution and all tertiary level settings. It is also reasoned that the visual arts, as with other creative arts disciplines, will not become important and necessary engines for change in education without a determination to critically review its implementation starting with how VAE policies are used in the TVET Colleges. It also emerged from the study that the policies that are available for VAE in the College relate to syllabus as well as assessment and enrolment procedures. The syllabus was found by the lecturers to be inappropriate and less motivating for the students. Also the assessment procedure was revealed to be done according to both practical and theoretical components based on task, test, and practical moderation. However, the practical component was based on seventy five percent and the theory on twenty five percent thereby disadvantaging learners who do not have the theoretical background of the VAE. The study therefore recommends that policies that are used in TVET Colleges for VAE need to be revised, re-applied and implemented so as to cater for the needs of lecturers and students pursuing a career in Visual Arts or VAE.
- Full Text:
- Date Issued: 2017
- Authors: Dayimani, Mbulelo
- Date: 2017
- Subjects: Curriculum planning Vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/12744 , vital:39318
- Description: It can be observed that students actively participate in the learning process of education in our country, and the curriculum gives expression to the knowledge, skills and values worth learning in South African schools and institutions. However, Technical and Vocational Education Training (TVET) Colleges still continue using traditional learning methods, in which the teacher is in the centre, devoid of artistic culture, and practical work. These implementation methods and techniques have been identified as less motivating for students especially for those with no background in Visual Arts (VA) in high school. The aim of this study therefore was to investigate the views of students and lecturers on the implementation of Visual Arts Education (VAE) in the TVET Colleges in the Eastern Cape. This study was premised from a qualitative research approach and therefore interpretivist paradigm was relevant in assisting the researcher making sense of the data gathered. Face-to-face interviews were used to collect the data from five lecturers and fifteen students in N4 level. The interviews were tape-recorded. The research showed that Visual Arts Education can be an engine that drives creativity and innovation in schools, higher Education institution and all tertiary level settings. It is also reasoned that the visual arts, as with other creative arts disciplines, will not become important and necessary engines for change in education without a determination to critically review its implementation starting with how VAE policies are used in the TVET Colleges. It also emerged from the study that the policies that are available for VAE in the College relate to syllabus as well as assessment and enrolment procedures. The syllabus was found by the lecturers to be inappropriate and less motivating for the students. Also the assessment procedure was revealed to be done according to both practical and theoretical components based on task, test, and practical moderation. However, the practical component was based on seventy five percent and the theory on twenty five percent thereby disadvantaging learners who do not have the theoretical background of the VAE. The study therefore recommends that policies that are used in TVET Colleges for VAE need to be revised, re-applied and implemented so as to cater for the needs of lecturers and students pursuing a career in Visual Arts or VAE.
- Full Text:
- Date Issued: 2017
Wh-question formation in South African sign language: a case study
- Authors: De Barros, Courtney Leigh
- Date: 2017
- Subjects: South African sign language , South African sign language -- Syntax , Sign language -- Grammar
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/42800 , vital:25237
- Description: This thesis is a case study investigating wh-question formation in South African Sign Language (SASL). It provides the first descriptive and syntactic analysis of wh-question formation in this language, based on a collected sample. The evidence gathered for this study shows that SASL makes use of non-manual features to mark wh-question formation and possesses a full question word paradigm including WHAT, WHERE, WHEN, WHO and HOW. In the methodology, I critically engage with two issues: informant selection and data elicitation. These can greatly impact data validity – specifically with respect to sign language research. Ultimately, I adopt a novel, multi-layered data collection approach to ensure a valid sample. The data reveals SASL’s almost exclusive placement of wh-question words in the right periphery. The absence of moved sentence-initial wh-elements in SASL poses problems for syntactic analysis using only leftward movement. It seems typologically unusual that a language predominantly selecting the right periphery as a position for wh-words would allow a complex syntactic derivation involving some null wh-element in a leftward Spec, CP and then allow for another ‘copy’ to appear in the right periphery. On the other hand, having Spec, CP on the right allows for far less complex derivations of wh-movement. In SASL, as in spoken language, the wh-word moves to Spec, CP to check the [WH] feature in C. The difference is that this movement is rightward. Further support for a rightward analysis comes from SASL’s distribution of non-manual features, and its hierarchy of negative elements and adverbials. This research represents a first step towards filling a gap in the SASL literature concerning wh-question formation, as well as a contribution to the growing body of research surrounding sign languages. Furthermore, at a higher level, this study evaluates current linguistic theory on sign languages, challenging the current cross-linguistic generalisation that wh-movement is leftward.
- Full Text:
- Date Issued: 2017
- Authors: De Barros, Courtney Leigh
- Date: 2017
- Subjects: South African sign language , South African sign language -- Syntax , Sign language -- Grammar
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/42800 , vital:25237
- Description: This thesis is a case study investigating wh-question formation in South African Sign Language (SASL). It provides the first descriptive and syntactic analysis of wh-question formation in this language, based on a collected sample. The evidence gathered for this study shows that SASL makes use of non-manual features to mark wh-question formation and possesses a full question word paradigm including WHAT, WHERE, WHEN, WHO and HOW. In the methodology, I critically engage with two issues: informant selection and data elicitation. These can greatly impact data validity – specifically with respect to sign language research. Ultimately, I adopt a novel, multi-layered data collection approach to ensure a valid sample. The data reveals SASL’s almost exclusive placement of wh-question words in the right periphery. The absence of moved sentence-initial wh-elements in SASL poses problems for syntactic analysis using only leftward movement. It seems typologically unusual that a language predominantly selecting the right periphery as a position for wh-words would allow a complex syntactic derivation involving some null wh-element in a leftward Spec, CP and then allow for another ‘copy’ to appear in the right periphery. On the other hand, having Spec, CP on the right allows for far less complex derivations of wh-movement. In SASL, as in spoken language, the wh-word moves to Spec, CP to check the [WH] feature in C. The difference is that this movement is rightward. Further support for a rightward analysis comes from SASL’s distribution of non-manual features, and its hierarchy of negative elements and adverbials. This research represents a first step towards filling a gap in the SASL literature concerning wh-question formation, as well as a contribution to the growing body of research surrounding sign languages. Furthermore, at a higher level, this study evaluates current linguistic theory on sign languages, challenging the current cross-linguistic generalisation that wh-movement is leftward.
- Full Text:
- Date Issued: 2017
Analysis of a foundational biomedical curriculum: exploring cumulative knowledge-building in the rehabilitative health professions
- Authors: De Bie, Gabrielle
- Date: 2017
- Subjects: Medical education -- Curricula , Human anatomy -- Study and teaching -- Curricula , Physiology -- Study and teaching -- Curricula , Occupational therapy -- Study and teaching -- Curricula , Physical therapy -- Study and teaching -- Curricula , Medical rehabilitation -- Study and teaching -- Curricula , Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/18617 , vital:22361
- Description: This study was motivated by the researcher's experience that students in the rehabilitative health professional programmes were finding it difficult to access fundamental knowledge upon which their professional practices and clinical contexts are based. An important focus of the research was the extent to which cumulative knowledge-building was impacted after the foundational biomedical curriculum became an interdisciplinary programme. The study explored whether the organisation of the interdisciplinary foundational curriculum served the fundamental needs of the professions, and whether, as a matter of social justice, students' access to powerful knowledge was enabled by the form that the fundamental curriculum assumed. This curriculum study at a particular Faculty of Health Sciences foregrounds the structuring, organisation and differentiation of disciplinary knowledge, and reflects a twenty year period that included not only transitions in professional education but also extensive transformation in, and a different approach to, health delivery. At the institution, physiology and anatomy, the biomedical sciences basic to the health professions, underwent disciplinary merging and subsequent altered positioning in curricula. Medicine opted for a problem-based learning approach whereas the rehabilitation health sciences did not. Legitimation Code Theory (LCT) provided the means for analysis of the extent to which interdisciplinary organisation in the foundational curriculum for Physiotherapy and Occupational Therapy enabled integrative, cumulative building of knowledge for professional and clinical contexts. Specialisation and Semantics dimensions of Legitimation Code Theory were used to reveal the principles underpinning practices, contexts and dispositions of Anatomy and Physiology at the Faculty of Health Sciences over a twenty year period post democratisation in South Africa (1994 - 2013). Disciplinary positioning in curriculum prior- and post-merger, were compared and contrasted. LCT were used to characterise the distinctiveness of Physiotherapy and Occupational Therapy at the university including the kind of knowledge and the kind of knower that specialises the different professions, and what is valorised and legitimated for each kind of professional. Semantic gravity was used to explore the expected knowledge recontextualisations in diverse and complex clinical settings for each of the professions. Registered professionals who are clinical educators as well as curriculum designers for clinical studies were interviewed. Profession-specific course outlines were further data sources. The biomedical disciplines Anatomy and Physiology were characterised for their measures of distinction and their respective knowledge-knower structures. Analysis traced each discipline from its strongly classified form in autonomous curricula when there were separate learner-cohorts for physiotherapists and occupational therapists, to post-merger when the disciplines were framed as human biology in an integrated foundational curriculum for a joint cohort of students. Curricular documents for the twenty year period were analysed quantitatively and qualitatively to establish the positioning of Physiology and Anatomy before and after the disciplines merged to a single course of Human Biology. Teaching staff were interviewed for their understanding of what specialises the physiological and anatomical components of the Human Biology curriculum, what they considered as powerful knowledge for the professions, and who they envisaged as the ideal student-knower exiting the basic sciences platform to enter more advanced clinical studies. The degree of context-dependence for meaning-making in the different disciplinary domains and the condensation of meanings inherent in the respective practices and contexts, were analysed. The thesis argues that following the merger Anatomy is preferentially legitimated as powerful knowledge at the expense of Physiology; that the ideal of disciplinary integration is not reached, and that the segmental organisation and structuring of the curriculum negatively impacted on cumulative knowledge-building and application of professional knowledge in the clinical arena. After the merger the disciplines lost their shape, and in particular the hierarchical knowledge structure of Physiology collapsed. By not having access to the necessary disciplinary knowledge structures and their associated practices, students' ability for scaffolding and integrating knowledge into the clinical arena was constrained. The organisation of the current Human Biology curriculum does not facilitate cumulative learning, and in so doing may not contribute to the envisaged graduate professional who is required to practice within a complex and demanding healthcare work environment. The significance of this study conveys that interdisciplinary programmes should be carefully considered, and there is an added imperative in the health professions which ultimately realise treatment of patients. If, aside from interdisciplinary teaching, there are also merged cohorts of participant students, then a sound understanding of the epistemic requirements of each profession is required. Those involved in curriculum development in various fields need to take these recommendations into account to enable cumulative learning and enable epistemological access to powerful knowledge for an increasingly diverse student body.
- Full Text:
- Date Issued: 2017
- Authors: De Bie, Gabrielle
- Date: 2017
- Subjects: Medical education -- Curricula , Human anatomy -- Study and teaching -- Curricula , Physiology -- Study and teaching -- Curricula , Occupational therapy -- Study and teaching -- Curricula , Physical therapy -- Study and teaching -- Curricula , Medical rehabilitation -- Study and teaching -- Curricula , Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/18617 , vital:22361
- Description: This study was motivated by the researcher's experience that students in the rehabilitative health professional programmes were finding it difficult to access fundamental knowledge upon which their professional practices and clinical contexts are based. An important focus of the research was the extent to which cumulative knowledge-building was impacted after the foundational biomedical curriculum became an interdisciplinary programme. The study explored whether the organisation of the interdisciplinary foundational curriculum served the fundamental needs of the professions, and whether, as a matter of social justice, students' access to powerful knowledge was enabled by the form that the fundamental curriculum assumed. This curriculum study at a particular Faculty of Health Sciences foregrounds the structuring, organisation and differentiation of disciplinary knowledge, and reflects a twenty year period that included not only transitions in professional education but also extensive transformation in, and a different approach to, health delivery. At the institution, physiology and anatomy, the biomedical sciences basic to the health professions, underwent disciplinary merging and subsequent altered positioning in curricula. Medicine opted for a problem-based learning approach whereas the rehabilitation health sciences did not. Legitimation Code Theory (LCT) provided the means for analysis of the extent to which interdisciplinary organisation in the foundational curriculum for Physiotherapy and Occupational Therapy enabled integrative, cumulative building of knowledge for professional and clinical contexts. Specialisation and Semantics dimensions of Legitimation Code Theory were used to reveal the principles underpinning practices, contexts and dispositions of Anatomy and Physiology at the Faculty of Health Sciences over a twenty year period post democratisation in South Africa (1994 - 2013). Disciplinary positioning in curriculum prior- and post-merger, were compared and contrasted. LCT were used to characterise the distinctiveness of Physiotherapy and Occupational Therapy at the university including the kind of knowledge and the kind of knower that specialises the different professions, and what is valorised and legitimated for each kind of professional. Semantic gravity was used to explore the expected knowledge recontextualisations in diverse and complex clinical settings for each of the professions. Registered professionals who are clinical educators as well as curriculum designers for clinical studies were interviewed. Profession-specific course outlines were further data sources. The biomedical disciplines Anatomy and Physiology were characterised for their measures of distinction and their respective knowledge-knower structures. Analysis traced each discipline from its strongly classified form in autonomous curricula when there were separate learner-cohorts for physiotherapists and occupational therapists, to post-merger when the disciplines were framed as human biology in an integrated foundational curriculum for a joint cohort of students. Curricular documents for the twenty year period were analysed quantitatively and qualitatively to establish the positioning of Physiology and Anatomy before and after the disciplines merged to a single course of Human Biology. Teaching staff were interviewed for their understanding of what specialises the physiological and anatomical components of the Human Biology curriculum, what they considered as powerful knowledge for the professions, and who they envisaged as the ideal student-knower exiting the basic sciences platform to enter more advanced clinical studies. The degree of context-dependence for meaning-making in the different disciplinary domains and the condensation of meanings inherent in the respective practices and contexts, were analysed. The thesis argues that following the merger Anatomy is preferentially legitimated as powerful knowledge at the expense of Physiology; that the ideal of disciplinary integration is not reached, and that the segmental organisation and structuring of the curriculum negatively impacted on cumulative knowledge-building and application of professional knowledge in the clinical arena. After the merger the disciplines lost their shape, and in particular the hierarchical knowledge structure of Physiology collapsed. By not having access to the necessary disciplinary knowledge structures and their associated practices, students' ability for scaffolding and integrating knowledge into the clinical arena was constrained. The organisation of the current Human Biology curriculum does not facilitate cumulative learning, and in so doing may not contribute to the envisaged graduate professional who is required to practice within a complex and demanding healthcare work environment. The significance of this study conveys that interdisciplinary programmes should be carefully considered, and there is an added imperative in the health professions which ultimately realise treatment of patients. If, aside from interdisciplinary teaching, there are also merged cohorts of participant students, then a sound understanding of the epistemic requirements of each profession is required. Those involved in curriculum development in various fields need to take these recommendations into account to enable cumulative learning and enable epistemological access to powerful knowledge for an increasingly diverse student body.
- Full Text:
- Date Issued: 2017
Dietary diversity amongst adults who buy at shopping malls in the Nelson Mandela Bay area
- Authors: De Bruin, Eunice Mari
- Date: 2017
- Subjects: Nutrition -- South Africa -- Port Elizabeth , Older people -- Nutrition Diet Food security -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/15027 , vital:28114
- Description: Background: Assessing the level of dietary diversity and contributing factors that influence the level of dietary diversity amongst adults can highlight gaps in nutrition interventions, policies and programmes, which aim at combating the double burden of malnutrition. Aim: The aim of this study was to determine which factors and relationships affect the level of dietary diversity of adults in the Nelson Mandela Bay area. Design: An exploratory comparative, cross-sectional, quantitative study design with a qualitative component that was utilised. Both interviewer- and participantadministered questionnaire sections were applied. Data were analysed using IBM SPSS Statistics, Statistica Version 12, Microsoft Office Excel 2007, Spearman rho correlation co-efficient and Pearson’s chi-square test (p-value <0.05). Participants and setting: A convenience-stratified sample (n=480) was used, consisting of adults who reside and shop at shopping centres in the Nelson Mandela area, after obtaining informed consent. Results: The findings indicated that adults in the Nelson Mandela Bay area who shopped at shopping malls had a medium level of dietary diversity. The dietary patterns found were not in line with the South African Food Based Dietary Guidelines. The most consumed food items were ‘cereals' (95%), 'sweetening agents and sweets' (89%) and ‘spices, condiments and beverages’ (87%). Fruit (45,2%) and vegetables (64,8%) were generally poorly consumed. Significance was shown as having an effect on the level of dietary diversity for factors such as ethnicity, level of education, amount of money spent on food purchase per month, distance travelled to purchase food, and nutrition knowledge. Conclusion: The study suggests that adults living in the Nelson Mandela Bay area have a medium level of dietary diversity, with practices that are not in line with the recommended South African Food Based Dietary Guidelines. Strategies, including nutrition education promotion and the implementation of current policies, programmes and interventions, should be implemented and/or strengthened to encourage behaviour change.
- Full Text:
- Date Issued: 2017
- Authors: De Bruin, Eunice Mari
- Date: 2017
- Subjects: Nutrition -- South Africa -- Port Elizabeth , Older people -- Nutrition Diet Food security -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/15027 , vital:28114
- Description: Background: Assessing the level of dietary diversity and contributing factors that influence the level of dietary diversity amongst adults can highlight gaps in nutrition interventions, policies and programmes, which aim at combating the double burden of malnutrition. Aim: The aim of this study was to determine which factors and relationships affect the level of dietary diversity of adults in the Nelson Mandela Bay area. Design: An exploratory comparative, cross-sectional, quantitative study design with a qualitative component that was utilised. Both interviewer- and participantadministered questionnaire sections were applied. Data were analysed using IBM SPSS Statistics, Statistica Version 12, Microsoft Office Excel 2007, Spearman rho correlation co-efficient and Pearson’s chi-square test (p-value <0.05). Participants and setting: A convenience-stratified sample (n=480) was used, consisting of adults who reside and shop at shopping centres in the Nelson Mandela area, after obtaining informed consent. Results: The findings indicated that adults in the Nelson Mandela Bay area who shopped at shopping malls had a medium level of dietary diversity. The dietary patterns found were not in line with the South African Food Based Dietary Guidelines. The most consumed food items were ‘cereals' (95%), 'sweetening agents and sweets' (89%) and ‘spices, condiments and beverages’ (87%). Fruit (45,2%) and vegetables (64,8%) were generally poorly consumed. Significance was shown as having an effect on the level of dietary diversity for factors such as ethnicity, level of education, amount of money spent on food purchase per month, distance travelled to purchase food, and nutrition knowledge. Conclusion: The study suggests that adults living in the Nelson Mandela Bay area have a medium level of dietary diversity, with practices that are not in line with the recommended South African Food Based Dietary Guidelines. Strategies, including nutrition education promotion and the implementation of current policies, programmes and interventions, should be implemented and/or strengthened to encourage behaviour change.
- Full Text:
- Date Issued: 2017
Investigating the expression of three small open reading frames encoded on Helicoverpa armigera stunt virus RNA 1
- Authors: De Bruyn, Mart-Mari
- Date: 2017
- Subjects: Helicoverpa armigera , RNA viruses , Insects Viruses , Proteins
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59168 , vital:27448
- Description: The Helicoverpa armigera stunt virus (HaSV), belonging to the Family Alphatetraviridae (Genus: Omegatetravirus), is a non-enveloped insect virus encapsidating a bi-partite, positive-sense single-stranded RNA genome. RNA1 encodes the replicase, as well as three small open reading frames (ORFs) arranged in tandem, and overlapping with the 3’ end of the replicase ORF. These ORFs, designated p11, p15 and p8, encode putative proteins of unknown function. The p11 and p15 ORFs are conserved in the genome of the related Omegatetravirus, Dendrolimus punctatus tetravirus. In HaSV, the stop codon of p11 is followed immediately by the start of p15, whereas the stop of p15 and start of p8 are separated by a glycine intercodon. Furthermore, only p11 is known to have a recognizable Kozak sequence. The aim of this study was to determine the expression and function of these three small proteins in the HaSV infectious lifecycle. The authenticity of the viral cDNA sequence, encoding the three small ORFs, was validated by sequencing multiple cDNA clones of the relevant region in viral RNA (vRNA), purified from infectious HaSV particles. The sequence of all three ORFs was conserved in seven cDNA clones, while point mutations were observed in each of two remaining cDNA clones, suggesting that the ORFs were conserved in infectious virus. Polyclonal antisera were raised against a p11 peptide, and a recombinant p15-p8 fusion protein (p23) expressed and purified from Escherichia coli. The affinity of the anti-p23 antiserum was confirmed by western blot analysis, while that of the anti-p11 antiserum was confirmed using immunofluorescence microscopy, as attempted expression of recombinant p11 in E. coli appeared to be toxic. The antisera were used to detect expression of the small proteins in HaSV-infected H. armigera larvae by western blot analysis. A band migrating at approximately 34 kDa was detected by both antisera in infected larvae, absent in uninfected larvae, suggesting the expression of a p11-p15-p8 polyprotein. Protein bands of 11 kDa and 8 kDa were also detected by the anti-p11 and anti-p23 antisera, respectively. Bioinformatic analysis revealed that the polyprotein would be produced by a novel type of stop codon read-through, however the mechanism required for individual expression could not be definitively determined. The mechanism by which these ORFs are translated was further investigated by expressing p11-p15, tagged with FLAG and enhanced green flourescent protein (EGFP) at its amino- and carboxyl-termini respectively (FLAG-p11-p15-EGFP), in Spodoptera frugiperda (Sf9) cells detected by flourescence microscopy. Punctate structures were observed throughout the cytoplasm that were also detected with antiFLAG, anti-p11 and anti-p23 antisera, complementing results obtained in previous studies. Since p15 does not exhibit a strong recognizable Kozak like p11, the dependency of p15 expression on that of p11 was investigated by mutating this construct such that p15 occurred in a +1 frame to p11. Both EGFP and anti-p23 fluorescence was detected with the same cytoplasmic distribution as the unmutated construct, whereas nothing was detected by anti-FLAG and anti-p11. Preliminary results therefore suggested p15 may also be expressed as a discrete protein, independent of p11. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2017
- Authors: De Bruyn, Mart-Mari
- Date: 2017
- Subjects: Helicoverpa armigera , RNA viruses , Insects Viruses , Proteins
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59168 , vital:27448
- Description: The Helicoverpa armigera stunt virus (HaSV), belonging to the Family Alphatetraviridae (Genus: Omegatetravirus), is a non-enveloped insect virus encapsidating a bi-partite, positive-sense single-stranded RNA genome. RNA1 encodes the replicase, as well as three small open reading frames (ORFs) arranged in tandem, and overlapping with the 3’ end of the replicase ORF. These ORFs, designated p11, p15 and p8, encode putative proteins of unknown function. The p11 and p15 ORFs are conserved in the genome of the related Omegatetravirus, Dendrolimus punctatus tetravirus. In HaSV, the stop codon of p11 is followed immediately by the start of p15, whereas the stop of p15 and start of p8 are separated by a glycine intercodon. Furthermore, only p11 is known to have a recognizable Kozak sequence. The aim of this study was to determine the expression and function of these three small proteins in the HaSV infectious lifecycle. The authenticity of the viral cDNA sequence, encoding the three small ORFs, was validated by sequencing multiple cDNA clones of the relevant region in viral RNA (vRNA), purified from infectious HaSV particles. The sequence of all three ORFs was conserved in seven cDNA clones, while point mutations were observed in each of two remaining cDNA clones, suggesting that the ORFs were conserved in infectious virus. Polyclonal antisera were raised against a p11 peptide, and a recombinant p15-p8 fusion protein (p23) expressed and purified from Escherichia coli. The affinity of the anti-p23 antiserum was confirmed by western blot analysis, while that of the anti-p11 antiserum was confirmed using immunofluorescence microscopy, as attempted expression of recombinant p11 in E. coli appeared to be toxic. The antisera were used to detect expression of the small proteins in HaSV-infected H. armigera larvae by western blot analysis. A band migrating at approximately 34 kDa was detected by both antisera in infected larvae, absent in uninfected larvae, suggesting the expression of a p11-p15-p8 polyprotein. Protein bands of 11 kDa and 8 kDa were also detected by the anti-p11 and anti-p23 antisera, respectively. Bioinformatic analysis revealed that the polyprotein would be produced by a novel type of stop codon read-through, however the mechanism required for individual expression could not be definitively determined. The mechanism by which these ORFs are translated was further investigated by expressing p11-p15, tagged with FLAG and enhanced green flourescent protein (EGFP) at its amino- and carboxyl-termini respectively (FLAG-p11-p15-EGFP), in Spodoptera frugiperda (Sf9) cells detected by flourescence microscopy. Punctate structures were observed throughout the cytoplasm that were also detected with antiFLAG, anti-p11 and anti-p23 antisera, complementing results obtained in previous studies. Since p15 does not exhibit a strong recognizable Kozak like p11, the dependency of p15 expression on that of p11 was investigated by mutating this construct such that p15 occurred in a +1 frame to p11. Both EGFP and anti-p23 fluorescence was detected with the same cytoplasmic distribution as the unmutated construct, whereas nothing was detected by anti-FLAG and anti-p11. Preliminary results therefore suggested p15 may also be expressed as a discrete protein, independent of p11. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2017
Refocusing the traumatic past (an essay in two parts):
- Authors: de Jager, Maureen
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147380 , vital:38631 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC-a867f5bb0
- Description: In the greater landscape of South Africa’s traumatic past, the South African War of 1899-1902 is arguably “old history”, surpassed in time and importance by more pressing traumas. Moreover, because it was usurped by Afrikaner nationalism as a myth of national origin and used to justify claims of Afrikaner sovereignty, it is also often seen as “old Afrikaner history”: at best, an episode of limited relevance to the many South Africans effectively written out of this narrative; at worst, a platform for nostalgic hankering by a conservative few.
- Full Text:
- Date Issued: 2017
- Authors: de Jager, Maureen
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147380 , vital:38631 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC-a867f5bb0
- Description: In the greater landscape of South Africa’s traumatic past, the South African War of 1899-1902 is arguably “old history”, surpassed in time and importance by more pressing traumas. Moreover, because it was usurped by Afrikaner nationalism as a myth of national origin and used to justify claims of Afrikaner sovereignty, it is also often seen as “old Afrikaner history”: at best, an episode of limited relevance to the many South Africans effectively written out of this narrative; at worst, a platform for nostalgic hankering by a conservative few.
- Full Text:
- Date Issued: 2017
A framework for implementing bring your own device in higher education institutions in South Africa
- Authors: De Kock, Ryan
- Date: 2017
- Subjects: Educational technology -- South Africa , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/7191 , vital:21300
- Description: Although the concept of Bring Your Own Device (BYOD) was only first introduced in 2009, organisations and higher education institutions have shown an increasing interest in and tolerance for employees and students using their own mobile devices for work and academic purposes, to such an extent that it is predicted that BYOD will become the leading practice for all educational environments by the year 2017. Although mobile device usage is increasing in higher education institutions, it has been found that currently no generally recognised framework exists to aid South African higher education institutions with the implementation of BYOD. The problem is further worsened as research suggests that the number of new mobile vulnerabilities reported each year has increased. The primary objective of this study is to develop a framework for implementing BYOD in higher education institutions in South Africa. This primary objective is divided into several secondary objectives, which collectively aim to address the proposed problem. Therefore, the secondary objectives are to understand BYOD in organisations and the challenges it brings; to determine how BYOD challenges differ in higher education institutions; to determine the key components for implementing BYOD in higher education institutions; to determine the extent to which the BYOD key components relate to a higher education institution in South Africa; and to validate the proposed BYOD framework, verifying its quality, efficacy and utility. At first, a comprehensive literature study is used to determine and understand the benefits, challenges and key components for the implementation of BYOD in both organisations and higher education institutions. Thereafter, a case study is used to determine the extent to which the components, identified in the literature study, relate to an educational institution in South Africa. The findings from the case study, in combination with the key components, are then triangulated and a preliminary framework for implementing BYOD in higher education institutions in South Africa is argued. Furthermore, elite interviews are used to determine the quality, efficacy and utility of the proposed BYOD framework. To address the proposed problem, this research proposes a stepby- step holistic framework to aid South African higher education institutions with the implementation of BYOD. This framework adds a significant contribution to the work on this topic, as it provides a foundation upon which further such research can build. It is believed that such a framework would be useful for higher education institutions in South Africa and would result in the improved implementation of BYOD.
- Full Text:
- Date Issued: 2017
- Authors: De Kock, Ryan
- Date: 2017
- Subjects: Educational technology -- South Africa , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/7191 , vital:21300
- Description: Although the concept of Bring Your Own Device (BYOD) was only first introduced in 2009, organisations and higher education institutions have shown an increasing interest in and tolerance for employees and students using their own mobile devices for work and academic purposes, to such an extent that it is predicted that BYOD will become the leading practice for all educational environments by the year 2017. Although mobile device usage is increasing in higher education institutions, it has been found that currently no generally recognised framework exists to aid South African higher education institutions with the implementation of BYOD. The problem is further worsened as research suggests that the number of new mobile vulnerabilities reported each year has increased. The primary objective of this study is to develop a framework for implementing BYOD in higher education institutions in South Africa. This primary objective is divided into several secondary objectives, which collectively aim to address the proposed problem. Therefore, the secondary objectives are to understand BYOD in organisations and the challenges it brings; to determine how BYOD challenges differ in higher education institutions; to determine the key components for implementing BYOD in higher education institutions; to determine the extent to which the BYOD key components relate to a higher education institution in South Africa; and to validate the proposed BYOD framework, verifying its quality, efficacy and utility. At first, a comprehensive literature study is used to determine and understand the benefits, challenges and key components for the implementation of BYOD in both organisations and higher education institutions. Thereafter, a case study is used to determine the extent to which the components, identified in the literature study, relate to an educational institution in South Africa. The findings from the case study, in combination with the key components, are then triangulated and a preliminary framework for implementing BYOD in higher education institutions in South Africa is argued. Furthermore, elite interviews are used to determine the quality, efficacy and utility of the proposed BYOD framework. To address the proposed problem, this research proposes a stepby- step holistic framework to aid South African higher education institutions with the implementation of BYOD. This framework adds a significant contribution to the work on this topic, as it provides a foundation upon which further such research can build. It is believed that such a framework would be useful for higher education institutions in South Africa and would result in the improved implementation of BYOD.
- Full Text:
- Date Issued: 2017
Extracellular Hsp90 and TGFP regulate adhesion, migration and anchorage independent growth in a paired colon cancer cell line model
- de la Mare, Jo-Anne, Jurgens, Tamarin, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Jurgens, Tamarin , Edkins, Adrienne L
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59920 , vital:27710 , https://doi.org/10.1186/s12885-017-3190-z
- Description: Tumour metastasis remains the major cause of death in cancer patients and, to date, the mechanism and signalling pathways governing this process are not completely understood. The TGF-ß pathway is the most commonly mutated pathway in cancer, however its role in cancer progression is controversial as it can function as both a promoter and a suppressor of metastasis. Although previous studies have suggested a role for the molecular chaperone Hsp90 in regulating the TGF-ß pathway, the level at which this occurs as well as the consequences in terms of colon cancer metastasis are unknown.
- Full Text:
- Date Issued: 2017
- Authors: de la Mare, Jo-Anne , Jurgens, Tamarin , Edkins, Adrienne L
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59920 , vital:27710 , https://doi.org/10.1186/s12885-017-3190-z
- Description: Tumour metastasis remains the major cause of death in cancer patients and, to date, the mechanism and signalling pathways governing this process are not completely understood. The TGF-ß pathway is the most commonly mutated pathway in cancer, however its role in cancer progression is controversial as it can function as both a promoter and a suppressor of metastasis. Although previous studies have suggested a role for the molecular chaperone Hsp90 in regulating the TGF-ß pathway, the level at which this occurs as well as the consequences in terms of colon cancer metastasis are unknown.
- Full Text:
- Date Issued: 2017
Woody plant species richness, composition and structure in urban sacred sites, Grahamstown, South Africa
- De Lacy, Peter J G, Shackleton, Charlie M
- Authors: De Lacy, Peter J G , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180079 , vital:43307 , xlink:href="https://doi.org/10.1007/s11252-017-0669-y"
- Description: Sacred sites are important not only for their traditional, spiritual or religious significance, but may also potentially be valuable for biodiversity conservation in human transformed landscapes. Yet, there has been little consideration of sacred sites in urban areas in this respect. Consequently, to better understand the ecosystem service and conservation value of urban sacred sites, inventories of their floral communities are needed. We examined the richness, composition and structure of the trees and shrubs in 35 urban churchyards and cemeteries in the City of Saints (Grahamstown). The combined area of urban sacred sites (38.7 ha) represented 2.2% of the city area and 13.6% of the public green space area. Species richness of woody plants was high, albeit dominated by non-native species. Levels of similarity among sites were low, indicating the effects of individual management regimens. There was no relationship between age of the site and measured attributes of the vegetation, nor were there any significant differences in vegetation among different religious denominations. However, the basal area and number of woody plants was significantly related to site size. These results indicate the significant heterogeneity of urban sacred sites as green spaces within the urban matrix. The significance of this heterogeneity in providing ecosystem services to users of sacred sites and the broader urban communities requires further investigation.
- Full Text:
- Date Issued: 2017
- Authors: De Lacy, Peter J G , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180079 , vital:43307 , xlink:href="https://doi.org/10.1007/s11252-017-0669-y"
- Description: Sacred sites are important not only for their traditional, spiritual or religious significance, but may also potentially be valuable for biodiversity conservation in human transformed landscapes. Yet, there has been little consideration of sacred sites in urban areas in this respect. Consequently, to better understand the ecosystem service and conservation value of urban sacred sites, inventories of their floral communities are needed. We examined the richness, composition and structure of the trees and shrubs in 35 urban churchyards and cemeteries in the City of Saints (Grahamstown). The combined area of urban sacred sites (38.7 ha) represented 2.2% of the city area and 13.6% of the public green space area. Species richness of woody plants was high, albeit dominated by non-native species. Levels of similarity among sites were low, indicating the effects of individual management regimens. There was no relationship between age of the site and measured attributes of the vegetation, nor were there any significant differences in vegetation among different religious denominations. However, the basal area and number of woody plants was significantly related to site size. These results indicate the significant heterogeneity of urban sacred sites as green spaces within the urban matrix. The significance of this heterogeneity in providing ecosystem services to users of sacred sites and the broader urban communities requires further investigation.
- Full Text:
- Date Issued: 2017
Aesthetic and spiritual ecosystem services provided by urban sacred sites
- De Lacy, Peter J G, Shackleton, Charlie M
- Authors: De Lacy, Peter J G , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60919 , vital:27891 , http://dx.doi.org/10.3390/su9091628
- Description: The range and use of ecosystem services provided by urban sacred sites has hardly been considered in studies of urban ecology, sustainability and human wellbeing. This paper examines the perceived ecosystem services supplied by green spaces or gardens associated with places of religious worship and appreciated by worshippers in a mid-sized town in South Africa. A questionnaire with open, closed and Likert scale questions was administered at 30 places of worship (25 with gardens and five without). Respondents identified a wide diversity of ecosystem services provided by gardens, with social ones being more recognized than ecological, and economic services the least. Approximately two-thirds of respondents visited a sacred site garden weekly or more often. The majority of respondents (96%) felt that a garden was necessary because it added to their feelings of connection with God, or helped them relax and so be better able to concentrate, and 54% stated that a garden enhanced their overall spiritual experience. Regression analysis revealed that aesthetic appreciation of a garden was significantly related to woody plant species richness, number and basal area in the garden. On the other hand, spiritual experience was positively related to woody plant basal area, but not species richness nor tree number. Neither size of the garden, nor number of years the respondents had been vising a particular sacred site had any influence on the rated spiritual or aesthetic experiences. These results reveal the widely appreciated ecosystem services provided by urban sacred spaces and their centrality in enhancing spiritual satisfaction for some.
- Full Text:
- Date Issued: 2017
- Authors: De Lacy, Peter J G , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60919 , vital:27891 , http://dx.doi.org/10.3390/su9091628
- Description: The range and use of ecosystem services provided by urban sacred sites has hardly been considered in studies of urban ecology, sustainability and human wellbeing. This paper examines the perceived ecosystem services supplied by green spaces or gardens associated with places of religious worship and appreciated by worshippers in a mid-sized town in South Africa. A questionnaire with open, closed and Likert scale questions was administered at 30 places of worship (25 with gardens and five without). Respondents identified a wide diversity of ecosystem services provided by gardens, with social ones being more recognized than ecological, and economic services the least. Approximately two-thirds of respondents visited a sacred site garden weekly or more often. The majority of respondents (96%) felt that a garden was necessary because it added to their feelings of connection with God, or helped them relax and so be better able to concentrate, and 54% stated that a garden enhanced their overall spiritual experience. Regression analysis revealed that aesthetic appreciation of a garden was significantly related to woody plant species richness, number and basal area in the garden. On the other hand, spiritual experience was positively related to woody plant basal area, but not species richness nor tree number. Neither size of the garden, nor number of years the respondents had been vising a particular sacred site had any influence on the rated spiritual or aesthetic experiences. These results reveal the widely appreciated ecosystem services provided by urban sacred spaces and their centrality in enhancing spiritual satisfaction for some.
- Full Text:
- Date Issued: 2017
A framework for information security management in local government
- Authors: De Lange, Joshua
- Date: 2017
- Subjects: Computer security -- Management , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/7588 , vital:21932
- Description: Information has become so pervasive within enterprises and everyday life, that it is almost indispensable. This is clear as information has become core to the business operations of any enterprise. Information and communication technology (ICT) systems are heavily relied upon to store, process and transmit this valuable commodity. Due to its immense value, information and related ICT resources have to be adequately protected. This protection of information is commonly referred to as information security.
- Full Text:
- Date Issued: 2017
- Authors: De Lange, Joshua
- Date: 2017
- Subjects: Computer security -- Management , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/7588 , vital:21932
- Description: Information has become so pervasive within enterprises and everyday life, that it is almost indispensable. This is clear as information has become core to the business operations of any enterprise. Information and communication technology (ICT) systems are heavily relied upon to store, process and transmit this valuable commodity. Due to its immense value, information and related ICT resources have to be adequately protected. This protection of information is commonly referred to as information security.
- Full Text:
- Date Issued: 2017