The role of eutrophication in the biological control of water hyacinth, Eichhornia crassipes, in South Africa
- Coetzee, Julie A, Hill, Martin P
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
'I want to tell the story again': re-telling in selected novels by Jeanette Winterson and Alan Warner
- Authors: Collett, Jenna Lara
- Date: 2011
- Subjects: Warner, Alan Criticism and interpretation Winterson, Jeanette, 1959- -- Criticism and interpretation English fiction -- 20th century -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2248 , http://hdl.handle.net/10962/d1002291
- Description: This thesis investigates acts of ‘re-telling’ in four selected novels by Jeanette Winterson and Alan Warner.Re-telling, as I have defined it, refers to the re-imagining and re-writing of existing narratives from mythology, fairy tale, and folktale, as well as the re-visioning of scientific discourses and historiography. I argue that this re-telling is representative of a contemporary cultural phenomenon, and is evidence of a postmodern genre that some literary theorists have termed re-visionary fiction. Despite the prevalent re-telling of canonical stories throughout literary history, there is much evidence for the emergence of a specifically contemporary trend of re-visionary literature. Part One of this thesis comprises two chapters which deal with Winterson’s Sexing the Cherry (1989) and Weight (2005) respectively. In these chapters, I argue that, although the feminist and historiographic elements of her work are significant, there exist further motivations for Winterson’s acts of re-telling in both Sexing the Cherry and Weight. In Chapter One, I analyse Winterson’s subversion and re-imagining of historiography, as well as her re-telling of fairy tale, in Sexing the Cherry. Chapter Two provides a discussion of Winterson’s re-telling of the myth of Atlas from Greek mythology, in which she draws on the discourses of science, technology, and autobiography, in Weight. Part Two focuses on Warner’s first two novels, Morvern Callar (1995) and These Demented Lands (1997). In both novels, Warner re-imagines aspects of Christian, Celtic and pagan mythology in order to debunk the validity of biblical archetypes and narratives in a contemporary working-class setting, as well as to endow his protagonist with goddess-like or mythical sensibilities. Chapter Three deals predominantly with Warner’s use of language, which I argue is central to his blending of mythological and contemporary content, while Chapter Four analyses his use of myth in these two novels. This thesis argues that while both Winterson and Warner share many of the aims associated with contemporary re-visionary fiction, their novels also exceed the boundaries of the genre in various ways. Winterson and Warner may, therefore, represent a new class of re-visionary writers, whose aim is not solely to subvert the pre-text but to draw on its generic discourses and thematic conventions in order to demonstrate the generic and discursive possibilities inherent in the act of re-telling.
- Full Text:
- Date Issued: 2011
- Authors: Collett, Jenna Lara
- Date: 2011
- Subjects: Warner, Alan Criticism and interpretation Winterson, Jeanette, 1959- -- Criticism and interpretation English fiction -- 20th century -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2248 , http://hdl.handle.net/10962/d1002291
- Description: This thesis investigates acts of ‘re-telling’ in four selected novels by Jeanette Winterson and Alan Warner.Re-telling, as I have defined it, refers to the re-imagining and re-writing of existing narratives from mythology, fairy tale, and folktale, as well as the re-visioning of scientific discourses and historiography. I argue that this re-telling is representative of a contemporary cultural phenomenon, and is evidence of a postmodern genre that some literary theorists have termed re-visionary fiction. Despite the prevalent re-telling of canonical stories throughout literary history, there is much evidence for the emergence of a specifically contemporary trend of re-visionary literature. Part One of this thesis comprises two chapters which deal with Winterson’s Sexing the Cherry (1989) and Weight (2005) respectively. In these chapters, I argue that, although the feminist and historiographic elements of her work are significant, there exist further motivations for Winterson’s acts of re-telling in both Sexing the Cherry and Weight. In Chapter One, I analyse Winterson’s subversion and re-imagining of historiography, as well as her re-telling of fairy tale, in Sexing the Cherry. Chapter Two provides a discussion of Winterson’s re-telling of the myth of Atlas from Greek mythology, in which she draws on the discourses of science, technology, and autobiography, in Weight. Part Two focuses on Warner’s first two novels, Morvern Callar (1995) and These Demented Lands (1997). In both novels, Warner re-imagines aspects of Christian, Celtic and pagan mythology in order to debunk the validity of biblical archetypes and narratives in a contemporary working-class setting, as well as to endow his protagonist with goddess-like or mythical sensibilities. Chapter Three deals predominantly with Warner’s use of language, which I argue is central to his blending of mythological and contemporary content, while Chapter Four analyses his use of myth in these two novels. This thesis argues that while both Winterson and Warner share many of the aims associated with contemporary re-visionary fiction, their novels also exceed the boundaries of the genre in various ways. Winterson and Warner may, therefore, represent a new class of re-visionary writers, whose aim is not solely to subvert the pre-text but to draw on its generic discourses and thematic conventions in order to demonstrate the generic and discursive possibilities inherent in the act of re-telling.
- Full Text:
- Date Issued: 2011
Entrepreneurship education at a FET college
- Authors: Cook, Vania Saretta
- Date: 2011
- Subjects: Entrepreneurship -- Study and teaching , Business education
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8637 , http://hdl.handle.net/10948/d1008071 , Entrepreneurship -- Study and teaching , Business education
- Description: The previous economic structure in South Africa was well served by the FET College institutions in that they provided a resource pool for large companies and organisations. This however, developed a student mindset of becoming an employee instead of the employer of an organisation. With an economy in transition, privately owned companies or organisations now account for an increasing proportion of economic development. Hence, FET Colleges need to redefine their role in the economy and society, specifically in the type of entrepreneurship courses they offer. This study examines the provision of entrepreneurship education at a FET College in the Eastern Cape with special reference to the levels of provision, support mechanisms, course objectives, contents, teaching and assessment methods to ascertain whether they are appropriately developed to prepare students for entrepreneurship as a career option. This study followed a qualitative research paradigm, implementing a case study approach during the research. In order to analyse the above, the New Venture Creation and Entrepreneurship and Business Management students were selected for this study. Data were collected by handing out questionnaires to a sample of 200 students to assess entrepreneurship courses and pedagogies. The results of this study, indicate that entrepreneurship education at a specific FET College is not enabling the students with sufficient knowledge and skills to start their own business. The results indicate a low level of entrepreneurship education and a weak standing of entrepreneurship courses, which tend to only be part of the Finance course offered within the Business Studies Department at a FET College. Contributing factors to this low level of entrepreneurship education have been identified by lack of support mechanisms by management, the theoretical orientation of entrepreneurship curriculum, teaching methods and assessment of tasks. Based on these findings, it is strongly suggested that this FET College should: (1) develop specialised entrepreneurship programmes for all students; (2) receive special funding for entrepreneurship education; (3) integrate experiential learning in the curriculum; and (4) give special consideration to training entrepreneurship educators.
- Full Text:
- Date Issued: 2011
- Authors: Cook, Vania Saretta
- Date: 2011
- Subjects: Entrepreneurship -- Study and teaching , Business education
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8637 , http://hdl.handle.net/10948/d1008071 , Entrepreneurship -- Study and teaching , Business education
- Description: The previous economic structure in South Africa was well served by the FET College institutions in that they provided a resource pool for large companies and organisations. This however, developed a student mindset of becoming an employee instead of the employer of an organisation. With an economy in transition, privately owned companies or organisations now account for an increasing proportion of economic development. Hence, FET Colleges need to redefine their role in the economy and society, specifically in the type of entrepreneurship courses they offer. This study examines the provision of entrepreneurship education at a FET College in the Eastern Cape with special reference to the levels of provision, support mechanisms, course objectives, contents, teaching and assessment methods to ascertain whether they are appropriately developed to prepare students for entrepreneurship as a career option. This study followed a qualitative research paradigm, implementing a case study approach during the research. In order to analyse the above, the New Venture Creation and Entrepreneurship and Business Management students were selected for this study. Data were collected by handing out questionnaires to a sample of 200 students to assess entrepreneurship courses and pedagogies. The results of this study, indicate that entrepreneurship education at a specific FET College is not enabling the students with sufficient knowledge and skills to start their own business. The results indicate a low level of entrepreneurship education and a weak standing of entrepreneurship courses, which tend to only be part of the Finance course offered within the Business Studies Department at a FET College. Contributing factors to this low level of entrepreneurship education have been identified by lack of support mechanisms by management, the theoretical orientation of entrepreneurship curriculum, teaching methods and assessment of tasks. Based on these findings, it is strongly suggested that this FET College should: (1) develop specialised entrepreneurship programmes for all students; (2) receive special funding for entrepreneurship education; (3) integrate experiential learning in the curriculum; and (4) give special consideration to training entrepreneurship educators.
- Full Text:
- Date Issued: 2011
The lived experience of meaning in life and satisfaction with life among older adults
- Authors: Cooper, Holly
- Date: 2011
- Subjects: Meaning (Psychology) , Satisfaction , Old age , Old age homes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4398 , vital:20595
- Description: The purpose of the study was to explore and describe the meaning in life and satisfaction with life of the elderly living in the old age institutions.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Holly
- Date: 2011
- Subjects: Meaning (Psychology) , Satisfaction , Old age , Old age homes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4398 , vital:20595
- Description: The purpose of the study was to explore and describe the meaning in life and satisfaction with life of the elderly living in the old age institutions.
- Full Text:
- Date Issued: 2011
Hsp90α/β associates with the GSK3β/axin1/phospho-β-catenin complex in the human MCF-7 epithelial breast cancer model:
- Cooper, Leanne C, Prinsloo, Earl, Edkins, Adrienne L, Blatch, Gregory L
- Authors: Cooper, Leanne C , Prinsloo, Earl , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165096 , vital:41208 , DOI: 10.1016/j.bbrc.2011.08.136
- Description: Hsp90α/β, the signal transduction chaperone, maintains intracellular communication in normal, stem, and cancer cells. The well characterised association of Hsp90α/β with its client kinases form the framework of multiple signalling networks. GSK3β, a known Hsp90α/β client, mediates β-catenin phosphorylation as part of a cytoplasmic destruction complex which targets phospho-β-catenin to the 26S proteasome. The canonical Wnt/β-catenin pathway promotes stem cell self-renewal as well as oncogenesis. The degree of Hsp90α/β involvement in Wnt/β-catenin signalling needs clarification. Here, we describe the association of Hsp90α/β with GSK3β, β-catenin, phospho-β-catenin and the molecular scaffold, axin1, in the human MCF-7 epithelial breast cancer cell model using selective inhibition of Hsp90α/β, confocal laser scanning microscopy and immunoprecipitation. Our findings suggest that Hsp90α/β modulates the phosphorylation of β-catenin by interaction in common complex with GSK3β/axin1/β-catenin.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Leanne C , Prinsloo, Earl , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165096 , vital:41208 , DOI: 10.1016/j.bbrc.2011.08.136
- Description: Hsp90α/β, the signal transduction chaperone, maintains intracellular communication in normal, stem, and cancer cells. The well characterised association of Hsp90α/β with its client kinases form the framework of multiple signalling networks. GSK3β, a known Hsp90α/β client, mediates β-catenin phosphorylation as part of a cytoplasmic destruction complex which targets phospho-β-catenin to the 26S proteasome. The canonical Wnt/β-catenin pathway promotes stem cell self-renewal as well as oncogenesis. The degree of Hsp90α/β involvement in Wnt/β-catenin signalling needs clarification. Here, we describe the association of Hsp90α/β with GSK3β, β-catenin, phospho-β-catenin and the molecular scaffold, axin1, in the human MCF-7 epithelial breast cancer cell model using selective inhibition of Hsp90α/β, confocal laser scanning microscopy and immunoprecipitation. Our findings suggest that Hsp90α/β modulates the phosphorylation of β-catenin by interaction in common complex with GSK3β/axin1/β-catenin.
- Full Text:
- Date Issued: 2011
The role of Hsp90 in the Wnt pathway of MCF7 breast cancer cells
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Leanne Claire
- Date: 2011
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3985 , http://hdl.handle.net/10962/d1004044 , Cancer -- Treatment , Heat shock proteins , Cancer cells , Molecular chaperones
- Description: Breast cancer is one of the most common forms of cancer in not only South African women, but women all over the world. The molecular chaperone heat shock protein 90 (HSP90) is upregulated in cancer and is almost exclusively associated with proteins involved in intracellular signal transduction, thus it plays an important role in signalling pathways within the cell. In cancer, there is an aberrant activation of the Wnt signaling pathway, which results in stabilized β-catenin being able to translocate to the nucleus where it can trigger the transcription of oncogenes found to be involved in the self-renewal of cells. The level of β-catenin is usually kept in check by a destruction complex comprising glycogen synthase kinase 3-beta (GSK-3β), axin1, adenomatous polyposis coli (APC) which phosphorylate β-catenin, resulting in its ubiquitination and degradation. HSP90 has been found to be associated with GSK-3β, but whether this association is only transient is debatable. Very little is known about the association of HSP90 with other members of the Wnt pathway in breast cancer. In this study, we have attempted to further identify the direct associations between HSP90 and GSK-3β, β-catenin, p-β-catenin and axin1. Immunofluorescence and confocal microscopy co-localization studies suggested a potential association between HSP90 and these proteins. Treatment with HSP90 inhibitors, 17-AAG and novobiocin resulted in a shift of axin1 to what appeared to be the plasma membrane. The associations of HSP90 with GSK-3β, β-catenin, p-β-catenin and axin1 were confirmed biochemically by co-immunoprecipitation and inhibition using 17-AAG, geldanamycin and novobiocin. We showed, for the first time that HSP90 is associated in a possible complex with β-catenin, p-β-catenin and axin1 therefore is potentially involved in the modulation of p-β-catenin in the Wnt pathway through the stabilization of the destruction complex.
- Full Text:
- Date Issued: 2011
Comfortably numb: Crump unveiled—a review of the 2011 Alan Crump retrospective exhibitio
- Authors: Cooper, Paul S
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147924 , vital:38685 , DOI:10.1080/00043389.2011.11877152
- Description: Writing can at times be difficult. It is not without considerable anxiety that I undertake to write this particular review. Perhaps I should offer a short qualifier: this is not strictly a review but rather a collection of ideas around the works and their arrangement, as well as my own musings and reflections on Crump. I want to pick up on what I identify to be an approach that personalises Crump as a professor, colleague and artist (we find this tone embedded throughout the accompanying exhibition catalogue). 1 I have chosen to structure this essay using a series of trigger headings, some provocative and possibly even inflammatory, others more neutral and concerned with getting to the core of what this retrospective and posthumous show is all about. All the while my thinking is to channel a sense (or lack thereof, as it may turn out) of my own experience of his work and person.
- Full Text:
- Date Issued: 2011
- Authors: Cooper, Paul S
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147924 , vital:38685 , DOI:10.1080/00043389.2011.11877152
- Description: Writing can at times be difficult. It is not without considerable anxiety that I undertake to write this particular review. Perhaps I should offer a short qualifier: this is not strictly a review but rather a collection of ideas around the works and their arrangement, as well as my own musings and reflections on Crump. I want to pick up on what I identify to be an approach that personalises Crump as a professor, colleague and artist (we find this tone embedded throughout the accompanying exhibition catalogue). 1 I have chosen to structure this essay using a series of trigger headings, some provocative and possibly even inflammatory, others more neutral and concerned with getting to the core of what this retrospective and posthumous show is all about. All the while my thinking is to channel a sense (or lack thereof, as it may turn out) of my own experience of his work and person.
- Full Text:
- Date Issued: 2011
An integrated maintenance management system model for the pharmaceutical industry
- Authors: Coopoosamy, Kribban
- Date: 2011
- Subjects: Pharmaceutical industry -- Management , Pharmaceutical services
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8609 , http://hdl.handle.net/10948/1583 , Pharmaceutical industry -- Management , Pharmaceutical services
- Description: Organisations are continuously seeking for strategies to improve operations and gain competitive advantage. Maintenance tends to be a key management issue for many industrial companies. Maintenance management, being an integral part of manufacturing, can influence competitive companys‟ priorities, such as cost, quality and flexibility, and, hence, business strategy directly. The pharmaceutical industry also faces some unique challenges such as increasingly stringent safety and quality regulations, the effect of innovations in medical science and healthcare and a complex and costly design-to-market process (from product concept and development to market delivery). The industry is also going through turbulent times as it has to cope with challenges common to many other industries, how to deal with increasing competition, hold down costs, and expand. Regulatory compliance is one of the significant industry drivers for pharmaceutical companies. Regulations are enacted by government authorities to ensure public health and safety. The focus of regulation is on quality assurance and control in all areas such as receiving, manufacturing, storing, packaging, despatching and delivering. Apart from the required quality and safety checks, the regulations also mandate extensive record keeping of procedures, processes and systems. This treatise will investigate the maintenance management system of a pharmaceutical company and compare it to best practices. The true name of the pharmaceutical company that will be researched will not be disclosed for confidentiality reasons, instead it will be called My Pharmaceuticals. The company is based in Port Elizabeth. The research consists of a preliminary study to identify the problem areas in the maintenance management system within the company. A literature review of best practices in maintenance management systems combined with an investigation into the best pharmaceutical practices in maintenance management systems and regulatory controls are investigated and a model will be proposed to improve the current situation at the company.
- Full Text:
- Date Issued: 2011
- Authors: Coopoosamy, Kribban
- Date: 2011
- Subjects: Pharmaceutical industry -- Management , Pharmaceutical services
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8609 , http://hdl.handle.net/10948/1583 , Pharmaceutical industry -- Management , Pharmaceutical services
- Description: Organisations are continuously seeking for strategies to improve operations and gain competitive advantage. Maintenance tends to be a key management issue for many industrial companies. Maintenance management, being an integral part of manufacturing, can influence competitive companys‟ priorities, such as cost, quality and flexibility, and, hence, business strategy directly. The pharmaceutical industry also faces some unique challenges such as increasingly stringent safety and quality regulations, the effect of innovations in medical science and healthcare and a complex and costly design-to-market process (from product concept and development to market delivery). The industry is also going through turbulent times as it has to cope with challenges common to many other industries, how to deal with increasing competition, hold down costs, and expand. Regulatory compliance is one of the significant industry drivers for pharmaceutical companies. Regulations are enacted by government authorities to ensure public health and safety. The focus of regulation is on quality assurance and control in all areas such as receiving, manufacturing, storing, packaging, despatching and delivering. Apart from the required quality and safety checks, the regulations also mandate extensive record keeping of procedures, processes and systems. This treatise will investigate the maintenance management system of a pharmaceutical company and compare it to best practices. The true name of the pharmaceutical company that will be researched will not be disclosed for confidentiality reasons, instead it will be called My Pharmaceuticals. The company is based in Port Elizabeth. The research consists of a preliminary study to identify the problem areas in the maintenance management system within the company. A literature review of best practices in maintenance management systems combined with an investigation into the best pharmaceutical practices in maintenance management systems and regulatory controls are investigated and a model will be proposed to improve the current situation at the company.
- Full Text:
- Date Issued: 2011
The influence of 1950s fashion photographers, Richard Avedon and Irving Penn, on photographers Matthew Rolston and Steven Meisel
- Authors: Cordier, Astrid
- Date: 2011
- Subjects: Fashion photpgraphy , Photographers -- United States
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8496 , http://hdl.handle.net/10948/d1008112 , Fashion photpgraphy , Photographers -- United States
- Description: Photography has been used to record and document periods in time, which Wells (2001:19) acknowledges by stating that, “…photographs are records and documents which pin down the changing world of appearance”. Richard Avedon and Irving Penn made a significant contribution to fashion photography during the 1950s but this has seldom been explored in a scholarly way. By defining the characteristics of Avedon and Penn’s work, a possible understanding of their influence on contemporary fashion photographers, Matthew Rolston and Steven Meisel may be determined and so expand on the understanding of the contribution of Avedon and Penn to contemporary fashion photography. Avedon, Penn, Rolston and Meisel’s fashion photographs will be visually analysed to show the similarities and the relevance of 1950s fashion photography to contemporary fashion photography. Paul Martin Lester’s (2003) method of visual analysis will be used as the basis for this analysis. The reason for choosing Lester’s methods of visual analysis is that it can be applied to all fields of visual art and design. Contemporary fashion photography draws on many different stylistic devices and periods in history for its re-invention, so it is important to understand what constitutes the defining characteristics of a stylistic period in history to be able to revisit it in contemporary photography.
- Full Text:
- Date Issued: 2011
- Authors: Cordier, Astrid
- Date: 2011
- Subjects: Fashion photpgraphy , Photographers -- United States
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8496 , http://hdl.handle.net/10948/d1008112 , Fashion photpgraphy , Photographers -- United States
- Description: Photography has been used to record and document periods in time, which Wells (2001:19) acknowledges by stating that, “…photographs are records and documents which pin down the changing world of appearance”. Richard Avedon and Irving Penn made a significant contribution to fashion photography during the 1950s but this has seldom been explored in a scholarly way. By defining the characteristics of Avedon and Penn’s work, a possible understanding of their influence on contemporary fashion photographers, Matthew Rolston and Steven Meisel may be determined and so expand on the understanding of the contribution of Avedon and Penn to contemporary fashion photography. Avedon, Penn, Rolston and Meisel’s fashion photographs will be visually analysed to show the similarities and the relevance of 1950s fashion photography to contemporary fashion photography. Paul Martin Lester’s (2003) method of visual analysis will be used as the basis for this analysis. The reason for choosing Lester’s methods of visual analysis is that it can be applied to all fields of visual art and design. Contemporary fashion photography draws on many different stylistic devices and periods in history for its re-invention, so it is important to understand what constitutes the defining characteristics of a stylistic period in history to be able to revisit it in contemporary photography.
- Full Text:
- Date Issued: 2011
Biomechanical, physiological and perceptual responses of three different athlete groups to the cycle-run transition
- Authors: Cripwell, Devin Matthew
- Date: 2011
- Subjects: Biomechanics -- Research , Human mechanics -- Research , Cycling -- Physiological aspects -- Research , Running -- Physiological aspects -- Research , Exercise -- Physiological aspects -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5106 , http://hdl.handle.net/10962/d1005184 , Biomechanics -- Research , Human mechanics -- Research , Cycling -- Physiological aspects -- Research , Running -- Physiological aspects -- Research , Exercise -- Physiological aspects -- Research
- Description: The transition from cycling to running has been identified as one of the key determinants of success in triathlon, as it has been suggested that the cycle may affect subsequent running efficiency such that running performance is significantly altered or reduced. It is also suggested that athletes more adapted to the transition itself, rather than purely running or cycling, may be more efficient during the post-cycle running bout. The current study sought to investigate the effects of prior cycling on subsequent selected biomechanical, physiological and perceptual responses of three different athlete groups. Subjects were selected on the basis of their sporting background, and were divided into three groups – triathletes, cyclists and runners. Experimentation required subjects to perform a seven minute treadmill running protocol at 15km.h⁻¹, during which biomechanical (EMG, Stride rate, Stride length, Vertical acceleration), physiological (HR, VO₂, EE) and perceptual (RPE) responses were recorded. After resting, subjects were required to perform a twenty minute stationary cycle at 70% of maximal aerobic power (previously determined), immediately followed by a second seven minute treadmill running protocol during which the same data were collected and compared to those collected during the first run. Biomechanical responses indicate that the cycle protocol had no effect on the muscle activity or vertical acceleration responses of any of the three subject groups, while the triathlete group significantly altered their gait responses in order to preserve running economy. The triathlete group was the least affected when considering the physiological responses, as running economy was preserved for this group. The runner and cyclist groups were significantly affected by the transition, as running economy decreased significantly for these groups. Perceptual responses indicate that athletes more experienced with the transition may find the transition from cycling to running to be easier than those inexperienced in this transition. It is apparent that a high intensity cycle protocol has limited statistical impact on selected biomechanical responses, while physiological and perceptual responses were altered, during a subsequent run, regardless of athlete type. That said, the ability of transition-trained athletes to transition comfortably between disciplines was highlighted, which may have important performance implications.
- Full Text:
- Date Issued: 2011
- Authors: Cripwell, Devin Matthew
- Date: 2011
- Subjects: Biomechanics -- Research , Human mechanics -- Research , Cycling -- Physiological aspects -- Research , Running -- Physiological aspects -- Research , Exercise -- Physiological aspects -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5106 , http://hdl.handle.net/10962/d1005184 , Biomechanics -- Research , Human mechanics -- Research , Cycling -- Physiological aspects -- Research , Running -- Physiological aspects -- Research , Exercise -- Physiological aspects -- Research
- Description: The transition from cycling to running has been identified as one of the key determinants of success in triathlon, as it has been suggested that the cycle may affect subsequent running efficiency such that running performance is significantly altered or reduced. It is also suggested that athletes more adapted to the transition itself, rather than purely running or cycling, may be more efficient during the post-cycle running bout. The current study sought to investigate the effects of prior cycling on subsequent selected biomechanical, physiological and perceptual responses of three different athlete groups. Subjects were selected on the basis of their sporting background, and were divided into three groups – triathletes, cyclists and runners. Experimentation required subjects to perform a seven minute treadmill running protocol at 15km.h⁻¹, during which biomechanical (EMG, Stride rate, Stride length, Vertical acceleration), physiological (HR, VO₂, EE) and perceptual (RPE) responses were recorded. After resting, subjects were required to perform a twenty minute stationary cycle at 70% of maximal aerobic power (previously determined), immediately followed by a second seven minute treadmill running protocol during which the same data were collected and compared to those collected during the first run. Biomechanical responses indicate that the cycle protocol had no effect on the muscle activity or vertical acceleration responses of any of the three subject groups, while the triathlete group significantly altered their gait responses in order to preserve running economy. The triathlete group was the least affected when considering the physiological responses, as running economy was preserved for this group. The runner and cyclist groups were significantly affected by the transition, as running economy decreased significantly for these groups. Perceptual responses indicate that athletes more experienced with the transition may find the transition from cycling to running to be easier than those inexperienced in this transition. It is apparent that a high intensity cycle protocol has limited statistical impact on selected biomechanical responses, while physiological and perceptual responses were altered, during a subsequent run, regardless of athlete type. That said, the ability of transition-trained athletes to transition comfortably between disciplines was highlighted, which may have important performance implications.
- Full Text:
- Date Issued: 2011
Probing the biocompatibility of biomedical interfaces using the Quartz Crystal Microbalance with Dissipation
- Authors: Cromhout, Mary
- Date: 2011
- Subjects: Biomedical materials , Nanostructured materials , Biomedical engineering , Quartz crystal microbalances , Blood proteins , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4102 , http://hdl.handle.net/10962/d1010660
- Description: The biomedical application of nanotechnology has come into the spotlight, with the promise of ‘personalised’ therapeutics that couple early diagnosis with targeted therapeutic activity. Due to the rapid growth of the biomedical applications of nanoparticles, along with the lack of understanding concerning their interactions with biomolecules, there is a pressing need for the development of standard methods directed at investigating the effect of introducing these unique particles into the human body. The central aim of this research is to establish a platform directed at assessing the biological fate of pioneering therapeutic particulate agents, such as metallophthalocyanines (MPcs) and multi-walled carbon nanotubes (FMWCNTs). In particular, we proposed, that Quartz Crystal Microbalance with Dissipation (QCM-D) technology may be employed to assess the composition of blood protein corona deposited on the therapeutic surface, and subsequently assess the biocompatibility of such particles. The proposed method of protein detection utilises the nanogram sensitivity of QCM-D technology to monitor highly specific antibody-antigen interactions. In particular those interactions which occur when probe antibodies are used to detect adsorbed blood proteins deposited on target particle-modified sensor surfaces. Protein detection analysis was directed toward identification of surface bound human serum albumin, complement factor C3c, and human plasma fibrinogen. Preliminary analysis of generic biomedical surfaces indicated human serum albumin demonstrates a higher binding affinity towards positively charged surfaces (i.e. cysteamine self-assembled monolayer), followed by hydrophobic surfaces. Detection of complement C3c, corresponded with literature, where lower levels were detected on negatively charged surfaces (i.e. mercapto undecanoic acid self-assembled monolayer), and higher levels of more hydrophobic surfaces (i.e. 11-amino undecane thiol self-assembled monolayer). Human plasma fibrinogen was observed to favour hydrophilic over hydrophobic self-assembled monolayer surfaces, which was in accordance with literature. Application of the proposed protein detection method for biocompatibility analysis of target therapeutic molecules, namely metallophthalocyanines and acid functionalised multi-walled carbon nanotubes, demonstrated a dependence on modified-surface film characteristics, such as surface charge and topography with regards to human serum albumin and human plasma fibrinogen analysis representing new insights into their potential biomolecular interactions The highest levels of detected human serum albumin and complement C3c were detected on the GePcSmix-modified surfaces. AlPcSmix-modified surfaces analysis suggested the highest levels of human plasma fibrinogen. Two methods of acid functionalisation were employed, using both nitric and sulphuric acid, and pure nitric acid. A general increase in detected human serum albumin, corresponding with an increase in functionalisation time, was observed. Complement C3c detection suggested an increase in deposited complement C3c, with increasing functionalisation time, when assessing nitric acid functionalised multi-walled carbon nanotubes, and a decrease, with increasing functionalisation time, when assessing nitric and sulphuric acid functionalised multi-walled carbon nanotubes. Analysis of human plasma fibrinogen was inconclusive, as were cytotoxicity experiments utilising MCF-7 cells in the presence of metallophthalocyanine complexes, raising simultaneously important considerations for their application and study. In the first such detailed examination of its kind it was concluded that the proposed method of protein detection, using QCM-D, allows for the rudimentary but rapid means of analysis of select protein corona deposited on particulate biomedical surfaces.
- Full Text:
- Date Issued: 2011
- Authors: Cromhout, Mary
- Date: 2011
- Subjects: Biomedical materials , Nanostructured materials , Biomedical engineering , Quartz crystal microbalances , Blood proteins , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4102 , http://hdl.handle.net/10962/d1010660
- Description: The biomedical application of nanotechnology has come into the spotlight, with the promise of ‘personalised’ therapeutics that couple early diagnosis with targeted therapeutic activity. Due to the rapid growth of the biomedical applications of nanoparticles, along with the lack of understanding concerning their interactions with biomolecules, there is a pressing need for the development of standard methods directed at investigating the effect of introducing these unique particles into the human body. The central aim of this research is to establish a platform directed at assessing the biological fate of pioneering therapeutic particulate agents, such as metallophthalocyanines (MPcs) and multi-walled carbon nanotubes (FMWCNTs). In particular, we proposed, that Quartz Crystal Microbalance with Dissipation (QCM-D) technology may be employed to assess the composition of blood protein corona deposited on the therapeutic surface, and subsequently assess the biocompatibility of such particles. The proposed method of protein detection utilises the nanogram sensitivity of QCM-D technology to monitor highly specific antibody-antigen interactions. In particular those interactions which occur when probe antibodies are used to detect adsorbed blood proteins deposited on target particle-modified sensor surfaces. Protein detection analysis was directed toward identification of surface bound human serum albumin, complement factor C3c, and human plasma fibrinogen. Preliminary analysis of generic biomedical surfaces indicated human serum albumin demonstrates a higher binding affinity towards positively charged surfaces (i.e. cysteamine self-assembled monolayer), followed by hydrophobic surfaces. Detection of complement C3c, corresponded with literature, where lower levels were detected on negatively charged surfaces (i.e. mercapto undecanoic acid self-assembled monolayer), and higher levels of more hydrophobic surfaces (i.e. 11-amino undecane thiol self-assembled monolayer). Human plasma fibrinogen was observed to favour hydrophilic over hydrophobic self-assembled monolayer surfaces, which was in accordance with literature. Application of the proposed protein detection method for biocompatibility analysis of target therapeutic molecules, namely metallophthalocyanines and acid functionalised multi-walled carbon nanotubes, demonstrated a dependence on modified-surface film characteristics, such as surface charge and topography with regards to human serum albumin and human plasma fibrinogen analysis representing new insights into their potential biomolecular interactions The highest levels of detected human serum albumin and complement C3c were detected on the GePcSmix-modified surfaces. AlPcSmix-modified surfaces analysis suggested the highest levels of human plasma fibrinogen. Two methods of acid functionalisation were employed, using both nitric and sulphuric acid, and pure nitric acid. A general increase in detected human serum albumin, corresponding with an increase in functionalisation time, was observed. Complement C3c detection suggested an increase in deposited complement C3c, with increasing functionalisation time, when assessing nitric acid functionalised multi-walled carbon nanotubes, and a decrease, with increasing functionalisation time, when assessing nitric and sulphuric acid functionalised multi-walled carbon nanotubes. Analysis of human plasma fibrinogen was inconclusive, as were cytotoxicity experiments utilising MCF-7 cells in the presence of metallophthalocyanine complexes, raising simultaneously important considerations for their application and study. In the first such detailed examination of its kind it was concluded that the proposed method of protein detection, using QCM-D, allows for the rudimentary but rapid means of analysis of select protein corona deposited on particulate biomedical surfaces.
- Full Text:
- Date Issued: 2011
Cross-border tourism planning and development: the case of the Lake Gariep Initiative
- Authors: Crozier, Marguerite Nicole
- Date: 2011
- Subjects: Tourism -- South Africa -- Gariep Dam -- Case studies , Gariep Dam (South Africa) -- Tourism -- Case studies , Central-local government relations -- South Africa -- Gariep Dam , Globalization -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9034 , http://hdl.handle.net/10948/1668 , Tourism -- South Africa -- Gariep Dam -- Case studies , Gariep Dam (South Africa) -- Tourism -- Case studies , Central-local government relations -- South Africa -- Gariep Dam , Globalization -- Economic aspects -- South Africa
- Description: The concept of cross-border tourism planning and cooperation is investigated in reference to the Lake !Gariep Initiative. The field of cross-border economic planning and integration is an area of increasing interest in regional development studies. The Lake Gariep Initiative is an initiative to promote cross-border planning and development around nature conservation, water resource management, economic development, poverty alleviation and tourism in the three municipalities that surround the Gariep Dam. The Gariep Dam, which is largest dam in South Africa, is surrounded by three provinces. The region is also economically and politically marginalised as it has a small, dispersed population and a marginal contribution to the broader regional economy. Under these circumstances the coordination of resources between municipalities to develop and promote the region has been identified as a key success factor for the region. The Lake Gariep Initiative although strongly supported locally has over ten years failed to be institutionalised. This study examines the Lake Gariep Initiative in terms of the origins of the concept and the key challenges that have been faced in establishing a cross-border, development entity. Findings are based on an assessment of documents on the formation of the LGI, interviews with stakeholders involved in the process and an assessment of critical success factors in reference to national and international case studies. This study provides a review of the key challenges, benefits and critical success factors for cross-border tourism development in relation to the Lake !Gariep Initiative.
- Full Text:
- Date Issued: 2011
- Authors: Crozier, Marguerite Nicole
- Date: 2011
- Subjects: Tourism -- South Africa -- Gariep Dam -- Case studies , Gariep Dam (South Africa) -- Tourism -- Case studies , Central-local government relations -- South Africa -- Gariep Dam , Globalization -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9034 , http://hdl.handle.net/10948/1668 , Tourism -- South Africa -- Gariep Dam -- Case studies , Gariep Dam (South Africa) -- Tourism -- Case studies , Central-local government relations -- South Africa -- Gariep Dam , Globalization -- Economic aspects -- South Africa
- Description: The concept of cross-border tourism planning and cooperation is investigated in reference to the Lake !Gariep Initiative. The field of cross-border economic planning and integration is an area of increasing interest in regional development studies. The Lake Gariep Initiative is an initiative to promote cross-border planning and development around nature conservation, water resource management, economic development, poverty alleviation and tourism in the three municipalities that surround the Gariep Dam. The Gariep Dam, which is largest dam in South Africa, is surrounded by three provinces. The region is also economically and politically marginalised as it has a small, dispersed population and a marginal contribution to the broader regional economy. Under these circumstances the coordination of resources between municipalities to develop and promote the region has been identified as a key success factor for the region. The Lake Gariep Initiative although strongly supported locally has over ten years failed to be institutionalised. This study examines the Lake Gariep Initiative in terms of the origins of the concept and the key challenges that have been faced in establishing a cross-border, development entity. Findings are based on an assessment of documents on the formation of the LGI, interviews with stakeholders involved in the process and an assessment of critical success factors in reference to national and international case studies. This study provides a review of the key challenges, benefits and critical success factors for cross-border tourism development in relation to the Lake !Gariep Initiative.
- Full Text:
- Date Issued: 2011
Textual representations of migrants and the process of migration in selected South African media a combined critical discourse analysis and corpus linguistics study
- Authors: Crymble, Leigh
- Date: 2011
- Subjects: Immigrants in mass media -- South Africa Mass media and foreign workers -- South Africa Refugees -- Press coverage -- South Africa Xenophobia in mass media -- South Africa Critical discourse analysis Corpora (Linguistics) Sunday Times (Johannesburg, South Africa) City Press (Johannesburg, South Africa) Mail & Guardian
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2342 , http://hdl.handle.net/10962/d1002624
- Description: South Africa has long been associated with racial and ethnic issues surrounding prejudice and discrimination and despite a move post-1994 to a democratic ‘rainbow nation’ society, the country has remained plagued by unequal power relations. One such instance of inequality relates to the marginalisation of migrants which has been realised through xenophobic attitudes and actions, most notably the violence that swept across the country in 2008. Several reasons have been suggested in an attempt to explain the cause of the violence, including claims that migrants are taking ‘our jobs and our women’, migrants are ‘illegal and criminal’ and bringing ‘disease and contamination’ with them from their countries of origin. Although widely accepted that many, if not all, of these beliefs are based on ignorance and hearsay, these extensive generalisations shape and reinforce prejudiced ideologies about migrant communities. It is thus only when confronted with evidence that challenges this dominant discourse, that South Africans are able to reconsider their views. Williams (2008) suggests that for many South Africans, Africa continues to be the ‘dark continent’ that is seen as an ominous, threatening force of which they have very little knowledge. For this reason, anti-immigrant sentiment in a South African context has traditionally been directed at African foreigners. In this study I examine the ways in which African migrants and migrant communities, as well as the overall processes of migration, are depicted by selected South African print media: City Press, Mail & Guardian and Sunday Times. Using a combined Corpus Linguistics and Critical Discourse Analysis approach, I investigate the following questions: How are migrants and the process of migration into South Africa represented by these established newspapers between 2006 and 2010? Are there any differences or similarities between these representations? In particular, what ideologies regarding migrants and migrant communities underlie these representations? My analysis focuses on the landscape of public discourse about migration with an exploration of the rise and fall of the terminologies used to categorise migrants and the social implications of these classifications. Additionally, I analyse the expansive occurrences of negative representations of migrants, particularly through the use of ‘othering’ pronouns ‘us’ versus ‘them’ and through the use of metaphorical language which largely depicts these individuals as en masse natural disasters. I conclude that these discursive elements play a crucial role in contributing to an overall xenophobic rhetoric. Despite subtle differences between the three newspapers which can be accounted for based on their political persuasions and agendas, it is surprising to note how aligned these publications are with regard to their portrayal of migrants. With a few exceptions, this representation positions these individuals as powerless and disenfranchised and maintains the status quo view of migrants as burdens on the South African economy and resources. Overall, the newspaper articles contribute to mainstream dominant discourse on migrants and migration with the underlying ideology that migrants are responsible for the hardships suffered by South African citizens. Thus, this study contributes significantly to existing bodies of research detailing discourse on migrants and emphasises the intrinsic links between language, ideology and society.
- Full Text:
- Date Issued: 2011
- Authors: Crymble, Leigh
- Date: 2011
- Subjects: Immigrants in mass media -- South Africa Mass media and foreign workers -- South Africa Refugees -- Press coverage -- South Africa Xenophobia in mass media -- South Africa Critical discourse analysis Corpora (Linguistics) Sunday Times (Johannesburg, South Africa) City Press (Johannesburg, South Africa) Mail & Guardian
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2342 , http://hdl.handle.net/10962/d1002624
- Description: South Africa has long been associated with racial and ethnic issues surrounding prejudice and discrimination and despite a move post-1994 to a democratic ‘rainbow nation’ society, the country has remained plagued by unequal power relations. One such instance of inequality relates to the marginalisation of migrants which has been realised through xenophobic attitudes and actions, most notably the violence that swept across the country in 2008. Several reasons have been suggested in an attempt to explain the cause of the violence, including claims that migrants are taking ‘our jobs and our women’, migrants are ‘illegal and criminal’ and bringing ‘disease and contamination’ with them from their countries of origin. Although widely accepted that many, if not all, of these beliefs are based on ignorance and hearsay, these extensive generalisations shape and reinforce prejudiced ideologies about migrant communities. It is thus only when confronted with evidence that challenges this dominant discourse, that South Africans are able to reconsider their views. Williams (2008) suggests that for many South Africans, Africa continues to be the ‘dark continent’ that is seen as an ominous, threatening force of which they have very little knowledge. For this reason, anti-immigrant sentiment in a South African context has traditionally been directed at African foreigners. In this study I examine the ways in which African migrants and migrant communities, as well as the overall processes of migration, are depicted by selected South African print media: City Press, Mail & Guardian and Sunday Times. Using a combined Corpus Linguistics and Critical Discourse Analysis approach, I investigate the following questions: How are migrants and the process of migration into South Africa represented by these established newspapers between 2006 and 2010? Are there any differences or similarities between these representations? In particular, what ideologies regarding migrants and migrant communities underlie these representations? My analysis focuses on the landscape of public discourse about migration with an exploration of the rise and fall of the terminologies used to categorise migrants and the social implications of these classifications. Additionally, I analyse the expansive occurrences of negative representations of migrants, particularly through the use of ‘othering’ pronouns ‘us’ versus ‘them’ and through the use of metaphorical language which largely depicts these individuals as en masse natural disasters. I conclude that these discursive elements play a crucial role in contributing to an overall xenophobic rhetoric. Despite subtle differences between the three newspapers which can be accounted for based on their political persuasions and agendas, it is surprising to note how aligned these publications are with regard to their portrayal of migrants. With a few exceptions, this representation positions these individuals as powerless and disenfranchised and maintains the status quo view of migrants as burdens on the South African economy and resources. Overall, the newspaper articles contribute to mainstream dominant discourse on migrants and migration with the underlying ideology that migrants are responsible for the hardships suffered by South African citizens. Thus, this study contributes significantly to existing bodies of research detailing discourse on migrants and emphasises the intrinsic links between language, ideology and society.
- Full Text:
- Date Issued: 2011
The photophysical properties of low symmetry phthalocyanines in conjunction with quantum dots
- Authors: D'Souza, Sarah
- Date: 2011
- Subjects: Phthalocyanines , Photochemistry , Zinc , Quantum dots , Spectrum analysis , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4331 , http://hdl.handle.net/10962/d1004992 , Phthalocyanines , Photochemistry , Zinc , Quantum dots , Spectrum analysis , Nanoparticles
- Description: he synthesis, extensive spectroscopic characterization and photophysical studies of low symmetry zinc phthalocyanine have been conducted. Comparisons have been made taking into consideration the influence of the solvent properties as well as substituent type and position. Photosensitizing properties of the zinc phthalocyanine derivatives in the presence of thiol capped CdTe quantum dots (QDs) were compared. The QDs were used as energy transfer donors and to facilitate with energy transfer through Förster resonance energy transfer (FRET) from the QDs to the MPcs. The linkage of unsymmetrically substituted 4-monoaminophenoxy zinc phthalocyanine (ZnAPPc) to CdTe quantum dots capped with mercaptopropionic acid (MPA), L-cysteine (L-cys) or thioglycolic acid (TGA) has been achieved using the coupling agents ethyl-N3 dimethylaminopropyl)carbodiimide (EDC) and N-hydroxy succinimide (NHS), which facilitate formation of an amide bond to form the QD-ZnAPPc-linked complex. The formation of the amide bond was confirmed using UV-Vis, Raman and IR spectroscopies, as well as AFM (atomic force microscopy). Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnAPPc in both the linked (QDZnAPPc-linked) and mixed (QD:ZnAPPc-mixed) conjugates for MPA only. The linked L-cys and TGA complexes (QD-ZnAPPc-linked) gave the largest FRET efficiencies hence showing the advantages of covalent linking. Fluorescence quantum yields of QDs were decreased in QD:ZnAPPc-mixed and QD:ZnAPPc-linked. High triplet state quantum yields were obtained for the linked QD-phthalocyanine derivatives (ZnAPPc)and monoaminozinc phthalocyanine (ZnAPc) compared to when ZnAPPc and ZnAPc were mixed with MPA QDs without a chemical bond.
- Full Text:
- Date Issued: 2011
- Authors: D'Souza, Sarah
- Date: 2011
- Subjects: Phthalocyanines , Photochemistry , Zinc , Quantum dots , Spectrum analysis , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4331 , http://hdl.handle.net/10962/d1004992 , Phthalocyanines , Photochemistry , Zinc , Quantum dots , Spectrum analysis , Nanoparticles
- Description: he synthesis, extensive spectroscopic characterization and photophysical studies of low symmetry zinc phthalocyanine have been conducted. Comparisons have been made taking into consideration the influence of the solvent properties as well as substituent type and position. Photosensitizing properties of the zinc phthalocyanine derivatives in the presence of thiol capped CdTe quantum dots (QDs) were compared. The QDs were used as energy transfer donors and to facilitate with energy transfer through Förster resonance energy transfer (FRET) from the QDs to the MPcs. The linkage of unsymmetrically substituted 4-monoaminophenoxy zinc phthalocyanine (ZnAPPc) to CdTe quantum dots capped with mercaptopropionic acid (MPA), L-cysteine (L-cys) or thioglycolic acid (TGA) has been achieved using the coupling agents ethyl-N3 dimethylaminopropyl)carbodiimide (EDC) and N-hydroxy succinimide (NHS), which facilitate formation of an amide bond to form the QD-ZnAPPc-linked complex. The formation of the amide bond was confirmed using UV-Vis, Raman and IR spectroscopies, as well as AFM (atomic force microscopy). Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnAPPc in both the linked (QDZnAPPc-linked) and mixed (QD:ZnAPPc-mixed) conjugates for MPA only. The linked L-cys and TGA complexes (QD-ZnAPPc-linked) gave the largest FRET efficiencies hence showing the advantages of covalent linking. Fluorescence quantum yields of QDs were decreased in QD:ZnAPPc-mixed and QD:ZnAPPc-linked. High triplet state quantum yields were obtained for the linked QD-phthalocyanine derivatives (ZnAPPc)and monoaminozinc phthalocyanine (ZnAPc) compared to when ZnAPPc and ZnAPc were mixed with MPA QDs without a chemical bond.
- Full Text:
- Date Issued: 2011
Synthesis and photophysical studies of CdTe quantum dot-monosubstituted zinc phthalocyanine conjugates
- D'Souza, Sarah, Antunes, Edith M, Nyokong, Tebello
- Authors: D'Souza, Sarah , Antunes, Edith M , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247825 , vital:51621 , xlink:href="https://doi.org/10.1016/j.ica.2010.12.027"
- Description: The linkage of unsymmetrically monosubstituted 4-aminophenoxy zinc phthalocyanine (ZnAPPc, 5) to CdTe quantum dots capped with mercaptopropionic acid (MPA), L-cysteine (L-cys) or thioglycolic acid (TGA) has been achieved using the coupling agents ethyl-N(3-dimethylaminopropyl) carbodiimide and N-hydroxy succinimide, which facilitate formation of an amide bond to form the QD–ZnAPPc-linked conjugate. The formation of the amide bond was confirmed using Raman and IR spectroscopies. Atomic force microscopy (AFM) and UV–Vis spectroscopy were used further to characterise the conjugate. Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnAPPc in both the linked (QD–ZnAPPc-linked) and mixed (QD:ZnAPPc-mixed) conjugates. The linked L-cys and TGA QDs conjugates (QD–ZnAPPc-linked) gave the largest FRET efficiencies hence showing the advantages of covalent linking. Fluorescence quantum yields of QDs were decreased in QD:ZnAPPc-mixed and QD:ZnAPPc-linked.
- Full Text:
- Date Issued: 2011
- Authors: D'Souza, Sarah , Antunes, Edith M , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247825 , vital:51621 , xlink:href="https://doi.org/10.1016/j.ica.2010.12.027"
- Description: The linkage of unsymmetrically monosubstituted 4-aminophenoxy zinc phthalocyanine (ZnAPPc, 5) to CdTe quantum dots capped with mercaptopropionic acid (MPA), L-cysteine (L-cys) or thioglycolic acid (TGA) has been achieved using the coupling agents ethyl-N(3-dimethylaminopropyl) carbodiimide and N-hydroxy succinimide, which facilitate formation of an amide bond to form the QD–ZnAPPc-linked conjugate. The formation of the amide bond was confirmed using Raman and IR spectroscopies. Atomic force microscopy (AFM) and UV–Vis spectroscopy were used further to characterise the conjugate. Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnAPPc in both the linked (QD–ZnAPPc-linked) and mixed (QD:ZnAPPc-mixed) conjugates. The linked L-cys and TGA QDs conjugates (QD–ZnAPPc-linked) gave the largest FRET efficiencies hence showing the advantages of covalent linking. Fluorescence quantum yields of QDs were decreased in QD:ZnAPPc-mixed and QD:ZnAPPc-linked.
- Full Text:
- Date Issued: 2011
Photophysical behavior of zinc monoaminophthalocyanines linked to mercaptopropionic acid-capped CdTe quantum dots
- D'Souza, Sarah, Antunes, Edith M, Litwinski, Christian, Nyokong, Tebello
- Authors: D'Souza, Sarah , Antunes, Edith M , Litwinski, Christian , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247634 , vital:51602 , xlink:href="https://doi.org/10.1016/j.jphotochem.2011.03.005"
- Description: Photosensitizing properties of zinc monoaminophthalocyanine (2) {in the absence or presence of mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs)} were compared with those of mono-aminophenoxy zinc phthalocyanine (3), zinc tetrasulfonated phthalocyanine and zinc phthalocyanine. Complexes 2 and 3 were also linked to the MPA capped CdTe quantum dots through the formation of an amide bond. High triplet state quantum yields were obtained for the linked QD–phthalocyanine derivatives (complexes 2 and 3) compared to when complexes 2 and 3 were mixed with MPA QDs without a chemical bond.
- Full Text:
- Date Issued: 2011
- Authors: D'Souza, Sarah , Antunes, Edith M , Litwinski, Christian , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247634 , vital:51602 , xlink:href="https://doi.org/10.1016/j.jphotochem.2011.03.005"
- Description: Photosensitizing properties of zinc monoaminophthalocyanine (2) {in the absence or presence of mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs)} were compared with those of mono-aminophenoxy zinc phthalocyanine (3), zinc tetrasulfonated phthalocyanine and zinc phthalocyanine. Complexes 2 and 3 were also linked to the MPA capped CdTe quantum dots through the formation of an amide bond. High triplet state quantum yields were obtained for the linked QD–phthalocyanine derivatives (complexes 2 and 3) compared to when complexes 2 and 3 were mixed with MPA QDs without a chemical bond.
- Full Text:
- Date Issued: 2011
Adequacy of the advanced certificate in education to develop the work-intergrated learning competencies of principals: a case study
- Authors: Dali, Christopher Malizo
- Date: 2011
- Subjects: School principals -- Training of -- South Africa -- Eastern Cape , Emotional intelligence -- Study and teaching -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9472 , http://hdl.handle.net/10948/1342 , School principals -- Training of -- South Africa -- Eastern Cape , Emotional intelligence -- Study and teaching -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape
- Description: The aim of this study was to explore the adequacy of the Advanced Certificate in Education (School Leadership) programme to develop the school principals’ workintegrated learning competencies (WILCs) at the Higher Education Institutions (HEIs). One of the objectives of this study was therefore to determine the extent to which the Advanced Certificate in Education (ACE) – School Leadership (SL) programme could utilise emotional intelligence (EI) to develop the principals’ intrapersonal and interpersonal competencies for collegial leadership. Another objective was to explore the school principals’ perceptions of their emotional competencies that could link their theoretical studies at the Nelson Mandela Metropolitan University (NMMU) with their practical learning experiences in their schools. Presently, one of the major programmes that could use EI in the development of school principals’ WILCs is the ACE (SL) programme offered by HEIs. The challenge for HEIs, such as the NMMU, is to offer an ACE (SL) programme that is capable of empowering principals from divergent school backgrounds. This would enable them to better understand and interpret the contextual evironments in their schools and their emotional relationships with their teachers as colleagues. The purposively selected research participants for this study comprised of school principals from one hundred and thirty rural, urban, township and farm schools. These schools are located in areas such as Lusikisiki, Bizana, Kokstad, Maluti, Mount Frere, Mount Fletcher, Cradock, Graaff-Reinet, Uitenhage and Port Elizabeth. For the purposes of triangulation, forty-two semi-structured questionnaire responses, five focus group interviews, ten in-depth interviews, and the school principals’ portfolio reflections, were used in the collection and analysis of the data. The findings of this interpretive, explorative, descriptive, and phenomenological study revealed that generally, the school principals had satisfactory levels of EI, firstly especially in terms of their intrapersonal competencies such as adaptability, v achievement drive, commitment, initiative and optimism. The school principals valued the opportunity afforded to them by the ACE (SL) programme to discuss their individual emotions and experiences with principals from similar and different school contexts. The ACE (SL) programme helped them to interrogate and express their own perceptions and experiences and the WILCs required in their leadership positions in schools. Secondly, the findings on the effectiveness of the interpersonal WILCs revealed that most of the school principals were adept at inducing desirable feelings and actions in their teachers. The feedback from the semi-structured questionnaire, the in-depth interviews, the focus group interviews, and the principals’ reflection portfolios indicated that EI could strongly influence the development of the WILCs of school principals. Politically astute principals know how to collaborate with teachers to achieve school goals. They create a culture of trust and achievement as they collaborate as colleagues in their schools. In conceptualising the development of the WILCs of school principals, one of the major recommendations emanating from this study is the utilisation of the WILCs model to develop the school principals’ collegial leadership abilities. The WILCs model was developed as a recommendation to provide a common language for discussing emotional capabilities and guidance for a host of WILCs such as self-awareness, selfregulation, empathy, conflict management, building bonds, enabling and inspiring others to develop in a collaborative and collegial manner. Underpinning the WILCs model are five major assumptions. The first assumption is that although the intrapersonal and interpersonal competencies are essential, generic and could be applied to any organisational context, the focus in this study is on school principals and their school environments. The second assumption of this model is that the WILCs are the result of rigorous research and represent a way of describing the effective leadership abilities of principals within their school contexts. The third assumption is that the WILCs are interrelated, complex, and serve to highlight key elements of effective leadership in the school environment without privileging one over another. Fourthly, the conceptual basis for the construction of the WILCs model is the vi empowerment of principals and their interpersonal relationships with the wider school community. Fifthly, and a highly relevant assumption for school principals, this WILCs model brings together the social constructivist essence of the two epistemic sites of learning discussed in this study – the schools and the HEIs – and the interconnectedness between EI and IQ in the development of principals’ WILCs for collegial leadership. Evidently, principals cannot solely depend on their experiences only to hone their leadership competencies. Formal programmes, such as the ACE (SL) programme, are essential to develop the WILCs of school principals. Nothing less should be contemplated to develop their collegial leadership competencies.
- Full Text:
- Date Issued: 2011
- Authors: Dali, Christopher Malizo
- Date: 2011
- Subjects: School principals -- Training of -- South Africa -- Eastern Cape , Emotional intelligence -- Study and teaching -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9472 , http://hdl.handle.net/10948/1342 , School principals -- Training of -- South Africa -- Eastern Cape , Emotional intelligence -- Study and teaching -- South Africa -- Eastern Cape , Educational leadership -- South Africa -- Eastern Cape , School management and organization -- South Africa -- Eastern Cape
- Description: The aim of this study was to explore the adequacy of the Advanced Certificate in Education (School Leadership) programme to develop the school principals’ workintegrated learning competencies (WILCs) at the Higher Education Institutions (HEIs). One of the objectives of this study was therefore to determine the extent to which the Advanced Certificate in Education (ACE) – School Leadership (SL) programme could utilise emotional intelligence (EI) to develop the principals’ intrapersonal and interpersonal competencies for collegial leadership. Another objective was to explore the school principals’ perceptions of their emotional competencies that could link their theoretical studies at the Nelson Mandela Metropolitan University (NMMU) with their practical learning experiences in their schools. Presently, one of the major programmes that could use EI in the development of school principals’ WILCs is the ACE (SL) programme offered by HEIs. The challenge for HEIs, such as the NMMU, is to offer an ACE (SL) programme that is capable of empowering principals from divergent school backgrounds. This would enable them to better understand and interpret the contextual evironments in their schools and their emotional relationships with their teachers as colleagues. The purposively selected research participants for this study comprised of school principals from one hundred and thirty rural, urban, township and farm schools. These schools are located in areas such as Lusikisiki, Bizana, Kokstad, Maluti, Mount Frere, Mount Fletcher, Cradock, Graaff-Reinet, Uitenhage and Port Elizabeth. For the purposes of triangulation, forty-two semi-structured questionnaire responses, five focus group interviews, ten in-depth interviews, and the school principals’ portfolio reflections, were used in the collection and analysis of the data. The findings of this interpretive, explorative, descriptive, and phenomenological study revealed that generally, the school principals had satisfactory levels of EI, firstly especially in terms of their intrapersonal competencies such as adaptability, v achievement drive, commitment, initiative and optimism. The school principals valued the opportunity afforded to them by the ACE (SL) programme to discuss their individual emotions and experiences with principals from similar and different school contexts. The ACE (SL) programme helped them to interrogate and express their own perceptions and experiences and the WILCs required in their leadership positions in schools. Secondly, the findings on the effectiveness of the interpersonal WILCs revealed that most of the school principals were adept at inducing desirable feelings and actions in their teachers. The feedback from the semi-structured questionnaire, the in-depth interviews, the focus group interviews, and the principals’ reflection portfolios indicated that EI could strongly influence the development of the WILCs of school principals. Politically astute principals know how to collaborate with teachers to achieve school goals. They create a culture of trust and achievement as they collaborate as colleagues in their schools. In conceptualising the development of the WILCs of school principals, one of the major recommendations emanating from this study is the utilisation of the WILCs model to develop the school principals’ collegial leadership abilities. The WILCs model was developed as a recommendation to provide a common language for discussing emotional capabilities and guidance for a host of WILCs such as self-awareness, selfregulation, empathy, conflict management, building bonds, enabling and inspiring others to develop in a collaborative and collegial manner. Underpinning the WILCs model are five major assumptions. The first assumption is that although the intrapersonal and interpersonal competencies are essential, generic and could be applied to any organisational context, the focus in this study is on school principals and their school environments. The second assumption of this model is that the WILCs are the result of rigorous research and represent a way of describing the effective leadership abilities of principals within their school contexts. The third assumption is that the WILCs are interrelated, complex, and serve to highlight key elements of effective leadership in the school environment without privileging one over another. Fourthly, the conceptual basis for the construction of the WILCs model is the vi empowerment of principals and their interpersonal relationships with the wider school community. Fifthly, and a highly relevant assumption for school principals, this WILCs model brings together the social constructivist essence of the two epistemic sites of learning discussed in this study – the schools and the HEIs – and the interconnectedness between EI and IQ in the development of principals’ WILCs for collegial leadership. Evidently, principals cannot solely depend on their experiences only to hone their leadership competencies. Formal programmes, such as the ACE (SL) programme, are essential to develop the WILCs of school principals. Nothing less should be contemplated to develop their collegial leadership competencies.
- Full Text:
- Date Issued: 2011
Initial investigations into dynamics of mesozooplankton community structure in Algoa Bay, South Africa
- Authors: Dali, Luzuko O'Brian
- Date: 2011
- Subjects: Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5715 , http://hdl.handle.net/10962/d1005401 , Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Description: As part of a long-term monitoring programme initiated by the South African Environmental Observation Network (SAEON) Elwandle Node, the spatio-temporal dynamics of mesozooplankton (200–2000 μm) community structure in Algoa Bay, on the Eastern Cape coastline of southern Africa, was investigated in summer and winter of 2008. Physical-chemical and biological variables were measured at selected sites in the eastern and western sectors of the Bay. During summer, nutrient rich waters upwelling into the eastern sector of the Bay contributed to significant spatial variation in selected physical-chemical variables. During winter, virtually no significant spatial patterns in the physical-chemical variables were observed (P>0.05 in all cases). For the majority of physical-chemical variables, no significant seasonal patterns in values were detected (P>0.05 in all cases). Notable exceptions were water column stability and water temperatures which were highest during summer, and seston, turbidity and ammonium concentrations which attained the highest values in winter. The striking seasonal pattern observed in the water column stability, coupled with the upwelling event, coincided with a strong seasonal pattern in the total surface and integrated chlorophyll-a concentrations within the Bay. During summer, the total surface phytoplankton biomass ranged from 1.87–3.11 μg.L⁻¹ and the integrated biomass values between 44.6 and 89.1 mg chl-a m⁻². In winter, surface chl-a concentrations ranged from 0.49 to 0.55 μg.L⁻¹ and integrated biomass from 13.5 to 13.8 mg chl-a m⁻². During both seasons, the large microphytoplankton (>20 μm) fraction contributed the most (>80%) to the total phytoplankton biomass suggesting that phytoplankton growth is not nutrient limited within the Bay. The total mesozooplankton abundance and biomass values during summer varied between 10088.92 and 28283.21 ind.m⁻³ and between 76.59 and 161.94 mg.m⁻³, respectively. During winter, total abundance and biomass of mesozooplankton within the Bay were significantly lower, ranging from 2392.49 to 11145.29 ind.m⁻³, and from 34.49 to 42.49 mg.m⁻³, respectively (P<0.05). During both seasons, cosmopolitan copepod species 200–500μm in size dominated the total mesozooplankton counts, numerically and in biomass. Hierarchical cluster analyses identified distinct zooplankton groupings within the Bay during both the summer (three groupings) and winter (four groupings) surveys. The different groupings identified during the two seasons were not associated with any specific geographic region or hydrological feature. Nonetheless, a distinct seasonal pattern in the mesozooplankton community was evident, largely reflecting the increased abundance of mesozooplankton during the summer survey. Canonical Correspondence Analyses (CCA) indicated that the zooplankton community structure within Algoa Bay reflected a complex interaction between physical-chemical (e.g. temperature, water column stability, turbidity, and nitrate, dissolved oxygen and nitrite concentrations) and biological factors (e.g. microphytoplankton and picophytoplankton concentrations). These data provide baseline information towards long-term monitoring programs that will be conducted in Algoa Bay, as part of the South African Environmental Observation Network (SAEON), in the near future.
- Full Text:
- Date Issued: 2011
- Authors: Dali, Luzuko O'Brian
- Date: 2011
- Subjects: Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5715 , http://hdl.handle.net/10962/d1005401 , Zooplankton -- Research -- Indian Ocean -- South Africa , Phytoplankton -- Research -- Indian Ocean -- South Africa
- Description: As part of a long-term monitoring programme initiated by the South African Environmental Observation Network (SAEON) Elwandle Node, the spatio-temporal dynamics of mesozooplankton (200–2000 μm) community structure in Algoa Bay, on the Eastern Cape coastline of southern Africa, was investigated in summer and winter of 2008. Physical-chemical and biological variables were measured at selected sites in the eastern and western sectors of the Bay. During summer, nutrient rich waters upwelling into the eastern sector of the Bay contributed to significant spatial variation in selected physical-chemical variables. During winter, virtually no significant spatial patterns in the physical-chemical variables were observed (P>0.05 in all cases). For the majority of physical-chemical variables, no significant seasonal patterns in values were detected (P>0.05 in all cases). Notable exceptions were water column stability and water temperatures which were highest during summer, and seston, turbidity and ammonium concentrations which attained the highest values in winter. The striking seasonal pattern observed in the water column stability, coupled with the upwelling event, coincided with a strong seasonal pattern in the total surface and integrated chlorophyll-a concentrations within the Bay. During summer, the total surface phytoplankton biomass ranged from 1.87–3.11 μg.L⁻¹ and the integrated biomass values between 44.6 and 89.1 mg chl-a m⁻². In winter, surface chl-a concentrations ranged from 0.49 to 0.55 μg.L⁻¹ and integrated biomass from 13.5 to 13.8 mg chl-a m⁻². During both seasons, the large microphytoplankton (>20 μm) fraction contributed the most (>80%) to the total phytoplankton biomass suggesting that phytoplankton growth is not nutrient limited within the Bay. The total mesozooplankton abundance and biomass values during summer varied between 10088.92 and 28283.21 ind.m⁻³ and between 76.59 and 161.94 mg.m⁻³, respectively. During winter, total abundance and biomass of mesozooplankton within the Bay were significantly lower, ranging from 2392.49 to 11145.29 ind.m⁻³, and from 34.49 to 42.49 mg.m⁻³, respectively (P<0.05). During both seasons, cosmopolitan copepod species 200–500μm in size dominated the total mesozooplankton counts, numerically and in biomass. Hierarchical cluster analyses identified distinct zooplankton groupings within the Bay during both the summer (three groupings) and winter (four groupings) surveys. The different groupings identified during the two seasons were not associated with any specific geographic region or hydrological feature. Nonetheless, a distinct seasonal pattern in the mesozooplankton community was evident, largely reflecting the increased abundance of mesozooplankton during the summer survey. Canonical Correspondence Analyses (CCA) indicated that the zooplankton community structure within Algoa Bay reflected a complex interaction between physical-chemical (e.g. temperature, water column stability, turbidity, and nitrate, dissolved oxygen and nitrite concentrations) and biological factors (e.g. microphytoplankton and picophytoplankton concentrations). These data provide baseline information towards long-term monitoring programs that will be conducted in Algoa Bay, as part of the South African Environmental Observation Network (SAEON), in the near future.
- Full Text:
- Date Issued: 2011
Effects of colours, shapes and icons on performance and familiarity
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
- Date Issued: 2011
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
- Date Issued: 2011
Energy versus angular momentum in black hole binaries
- Damour, T, Nagar, A, Pollney, D, Reisswig, C
- Authors: Damour, T , Nagar, A , Pollney, D , Reisswig, C
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6792 , http://hdl.handle.net/10962/d1006946
- Description: Using accurate numerical-relativity simulations of (nonspinning) black-hole binaries with mass ratios 1∶1, 2∶1, and 3∶1, we compute the gauge-invariant relation between the (reduced) binding energy E and the (reduced) angular momentum j of the system. We show that the relation E(j) is an accurate diagnostic of the dynamics of a black-hole binary in a highly relativistic regime. By comparing the numerical-relativity ENR(j) curve with the predictions of several analytic approximation schemes, we find that, while the canonically defined, nonresummed post-Newtonian–expanded EPN(j) relation exhibits large and growing deviations from ENR(j), the prediction of the effective one body formalism, based purely on known analytical results (without any calibration to numerical relativity), agrees strikingly well with the numerical-relativity results.
- Full Text:
- Date Issued: 2011
- Authors: Damour, T , Nagar, A , Pollney, D , Reisswig, C
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6792 , http://hdl.handle.net/10962/d1006946
- Description: Using accurate numerical-relativity simulations of (nonspinning) black-hole binaries with mass ratios 1∶1, 2∶1, and 3∶1, we compute the gauge-invariant relation between the (reduced) binding energy E and the (reduced) angular momentum j of the system. We show that the relation E(j) is an accurate diagnostic of the dynamics of a black-hole binary in a highly relativistic regime. By comparing the numerical-relativity ENR(j) curve with the predictions of several analytic approximation schemes, we find that, while the canonically defined, nonresummed post-Newtonian–expanded EPN(j) relation exhibits large and growing deviations from ENR(j), the prediction of the effective one body formalism, based purely on known analytical results (without any calibration to numerical relativity), agrees strikingly well with the numerical-relativity results.
- Full Text:
- Date Issued: 2011