MRSA pyruvate kinase inhibitory activity of synthetically derived thiazole containing deoxytopsentin analogues
- Veale, Clinton G L, Zoraghi, Roya, Lobb, Kevin A, Reiner, Neil E, Andersen, Raymond J, Davies-Coleman, Michael T
- Authors: Veale, Clinton G L , Zoraghi, Roya , Lobb, Kevin A , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448923 , vital:74771 , xlink:href="https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0034-1382365"
- Description: The health care crisis caused by methicillin resistant Staphylococcus aureus (MRSA) is due in part to a lack of fundamental drug discovery research into new antibiotics with novel modes of action. Marine bis-indole alkaloids have proved to be effective in vitro antibacterials. We present the synthesis of thiazole containing analogues of the marine natural product MRSA pyruvate kinase (PK) inhibitor, 6-bromodeoxytopsenin. The synthetic analogues showed moderate activity compared to the marine natural product against MRSA PK, an evolutionary conserved hub protein critical for bacterial survival. Our synthesis, via a Hantzsch thiazole condensation of α-oxo-1H-indole-3-thioacetamides with 2-bromo-1-(1H-indol-3-yl)-ethanones provided several challenges.
- Full Text:
- Authors: Veale, Clinton G L , Zoraghi, Roya , Lobb, Kevin A , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448923 , vital:74771 , xlink:href="https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0034-1382365"
- Description: The health care crisis caused by methicillin resistant Staphylococcus aureus (MRSA) is due in part to a lack of fundamental drug discovery research into new antibiotics with novel modes of action. Marine bis-indole alkaloids have proved to be effective in vitro antibacterials. We present the synthesis of thiazole containing analogues of the marine natural product MRSA pyruvate kinase (PK) inhibitor, 6-bromodeoxytopsenin. The synthetic analogues showed moderate activity compared to the marine natural product against MRSA PK, an evolutionary conserved hub protein critical for bacterial survival. Our synthesis, via a Hantzsch thiazole condensation of α-oxo-1H-indole-3-thioacetamides with 2-bromo-1-(1H-indol-3-yl)-ethanones provided several challenges.
- Full Text:
Multilingual repertoires and strategic rapport management: a comparative study of South African and Dutch small business discourse.
- Authors: Lauriks, Sanne
- Date: 2014
- Subjects: Discourse analysis , Business communication -- South Africa , Business communication -- Netherlands , Multilingual communication -- South Africa , Multilingual communication -- Netherlands , Communication in management -- South Africa , Communication in management -- Netherlands , Sociolinguistics -- South Africa , Sociolinguistics -- Netherlands , Language and culture -- South Africa , Language and culture -- Netherlands
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2382 , http://hdl.handle.net/10962/d1013162
- Description: In this era of globalisation and the consequent increase in social, economic and physical mobility, small businesses are transforming into sites of increasing language contact (Harris and Bargiela-Chiappini 2003). This study explores situated language practices within two small multilingual businesses. The first is a bicycle rental and repair shop located in Amsterdam (the Netherlands), which is a city with a dynamic multilingual society. The second is a tyre fitment centre in Grahamstown (South Africa), which is a city characterised by a stable triglossia of English, Xhosa and Afrikaans. Using Linguistic Ethnography (Rampton 2007) as my data collection method, I spent a total of eight weeks in these businesses. For the analysis I draw on Spencer-Oatey’s (2000b; 2011) Rapport Management Framework and sociolinguistics of globalisation (Blommaert 2010). This combination allowed me to explore situated language practices in relation to a contemporary context of increased globalisation. The analysis is structured using Spencer-Oatey’s (2000b) concept of rapport orientations. The orientations are presented as one of the key factors that influence the choice for a certain strategy. The orientations thus seemed a constructive way of showing how the observed strategies were employed by the participants of this study and what function they fulfilled in a certain context. However, difficulties emerged during the analysis with applying this concept to some of the more elaborate and complex data. As a result my argument developed into two different strands. The first demonstrates how individuals turn to their multilingual repertoires to negotiate agency and power relationships in small business discourse. The analysis reveals that people at times deliberately promote and maintains discordant relations, which can be understood as a rational response to the individual’s social and economic context. The second discusses the problems that emerged during my analysis with applying rapport management orientations to my data. I propose theoretical developments, warranted by my data, to create an Enhanced Rapport Management Framework suitable for the analysis of complex small business discourse.
- Full Text:
- Authors: Lauriks, Sanne
- Date: 2014
- Subjects: Discourse analysis , Business communication -- South Africa , Business communication -- Netherlands , Multilingual communication -- South Africa , Multilingual communication -- Netherlands , Communication in management -- South Africa , Communication in management -- Netherlands , Sociolinguistics -- South Africa , Sociolinguistics -- Netherlands , Language and culture -- South Africa , Language and culture -- Netherlands
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2382 , http://hdl.handle.net/10962/d1013162
- Description: In this era of globalisation and the consequent increase in social, economic and physical mobility, small businesses are transforming into sites of increasing language contact (Harris and Bargiela-Chiappini 2003). This study explores situated language practices within two small multilingual businesses. The first is a bicycle rental and repair shop located in Amsterdam (the Netherlands), which is a city with a dynamic multilingual society. The second is a tyre fitment centre in Grahamstown (South Africa), which is a city characterised by a stable triglossia of English, Xhosa and Afrikaans. Using Linguistic Ethnography (Rampton 2007) as my data collection method, I spent a total of eight weeks in these businesses. For the analysis I draw on Spencer-Oatey’s (2000b; 2011) Rapport Management Framework and sociolinguistics of globalisation (Blommaert 2010). This combination allowed me to explore situated language practices in relation to a contemporary context of increased globalisation. The analysis is structured using Spencer-Oatey’s (2000b) concept of rapport orientations. The orientations are presented as one of the key factors that influence the choice for a certain strategy. The orientations thus seemed a constructive way of showing how the observed strategies were employed by the participants of this study and what function they fulfilled in a certain context. However, difficulties emerged during the analysis with applying this concept to some of the more elaborate and complex data. As a result my argument developed into two different strands. The first demonstrates how individuals turn to their multilingual repertoires to negotiate agency and power relationships in small business discourse. The analysis reveals that people at times deliberately promote and maintains discordant relations, which can be understood as a rational response to the individual’s social and economic context. The second discusses the problems that emerged during my analysis with applying rapport management orientations to my data. I propose theoretical developments, warranted by my data, to create an Enhanced Rapport Management Framework suitable for the analysis of complex small business discourse.
- Full Text:
Multilingualism at work in South African Higher Education: From policy to practice
- Authors: Maseko, Pamela
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/468426 , vital:77053 , ISBN 9781783091669 , https://doi.org/10.21832/9781783091669
- Description: Language policies published after the attainment of democracy in 1994, which are particularly applicable to HEIs, seek to guard against the use of language to perpetuate the inequalities and inequities of South African society in the past. The main goal of these policies is to promote linguistic and cultural diversity in HEIs as well as to prepare students to participate fully in our multilingual society, where multilingual proficiency is critical. English and Afrikaans are acknowledged as languages of research and scholarship in HE at present, but legislative policies applicable to language use and practices in HE make provision for preventing these languages from being used as a barrier to the access, retention and success of previously disadvantaged people (see Kotzé’s detailed discussion in Chapter 2). The indigenous African languages, which have, until now, had a minimal role in HE, are seen as critical for the attainment of the goals of the language policies. As a consequence, legislation on language in HE recommends that HEIs should rethink the place of these languages and, in line with national policy, should develop their own policies and implementation plans on the advancement, promotion and use of these languages.
- Full Text:
- Authors: Maseko, Pamela
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/468426 , vital:77053 , ISBN 9781783091669 , https://doi.org/10.21832/9781783091669
- Description: Language policies published after the attainment of democracy in 1994, which are particularly applicable to HEIs, seek to guard against the use of language to perpetuate the inequalities and inequities of South African society in the past. The main goal of these policies is to promote linguistic and cultural diversity in HEIs as well as to prepare students to participate fully in our multilingual society, where multilingual proficiency is critical. English and Afrikaans are acknowledged as languages of research and scholarship in HE at present, but legislative policies applicable to language use and practices in HE make provision for preventing these languages from being used as a barrier to the access, retention and success of previously disadvantaged people (see Kotzé’s detailed discussion in Chapter 2). The indigenous African languages, which have, until now, had a minimal role in HE, are seen as critical for the attainment of the goals of the language policies. As a consequence, legislation on language in HE recommends that HEIs should rethink the place of these languages and, in line with national policy, should develop their own policies and implementation plans on the advancement, promotion and use of these languages.
- Full Text:
Multilingualism for teaching and learning
- Authors: Maseko, Pamela
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/468436 , vital:77054 , ISBN 9781920677565
- Description: This chapter will address a number of issues pertaining to multilingualism for teaching and learning in South African higher education during the SANTED II Programme. It will provide the national and institutional language policy context for the SANTED multilingualism projects, the challenges of implementation, the strategies used for implementation and monitoring, and the institutional uptake of the programmes at the end of the SANTED II Programme in 2010. The discussion will illustrate how the pilot projects introduced through SANTED provided a springboard for implementation of multilingual learning and teaching. The chapter will further demonstrate that while some universities had policies that supported multilingualism, in most cases these policies were largely dormant. The pilot projects provided the means for activating them and institutionalising practices conceptualised therein. The process itself provided impetus for robust debates on the value of bilingual and multilingual education for effective learning in higher education, as well as the importance of linguistic and cultural diversity in building national unity.
- Full Text:
- Authors: Maseko, Pamela
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/468436 , vital:77054 , ISBN 9781920677565
- Description: This chapter will address a number of issues pertaining to multilingualism for teaching and learning in South African higher education during the SANTED II Programme. It will provide the national and institutional language policy context for the SANTED multilingualism projects, the challenges of implementation, the strategies used for implementation and monitoring, and the institutional uptake of the programmes at the end of the SANTED II Programme in 2010. The discussion will illustrate how the pilot projects introduced through SANTED provided a springboard for implementation of multilingual learning and teaching. The chapter will further demonstrate that while some universities had policies that supported multilingualism, in most cases these policies were largely dormant. The pilot projects provided the means for activating them and institutionalising practices conceptualised therein. The process itself provided impetus for robust debates on the value of bilingual and multilingual education for effective learning in higher education, as well as the importance of linguistic and cultural diversity in building national unity.
- Full Text:
My enemy's enemies: recruiting hemipteran-tending generalist ants for biological control in citrus orchards by spatial partitioning of foraging webs
- Bownes, Angela, Moore, Sean D, Villet, Martin H
- Authors: Bownes, Angela , Moore, Sean D , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442075 , vital:73953 , https://hdl.handle.net/10520/EJC160247
- Description: Generalist predators are contentious biocontrol agents, especially ants that protect pestilent hemipterans from specialist predators and parasitoids. We attempted to force generalist, hemipteran-tending ants into a degree of dietary specificity by spatially partitioning and simplifying their trophic web. Pupae of Helicoverpa armigera, Thaumatotibia leucotreta and Ceratitis capitata introduced into a citrus orchard survived significantly better in plots where all nests of two pestilent, generalist ant species namely Anoplolepis custodiens and Pheidole megacephala had been poisoned compared with untreated control plots. In some plots the ants' foraging environments were partitioned into arboreal and epigaeic trophic webs using sticky barriers to prevent ground-nesting ants from ascending the trees. Plots partitioned this way showed suppressed levels of survival of emplaced pest pupae that were similar to those in unpartitioned control plots. Pest survival was significantly lower for T. leucotreta than for H. armigera and C. capitata, implicating prey body size or life cycle duration as factors in predation by ants. Pheidole megacephala and the predator complex as a whole can be valuable agents in the natural control of soil-pupating citrus pests if they are restricted to the ground. Trunk banding, rather than poisoning, is therefore recommended as part of managing ecologically mercenary ants in citrus orchards.
- Full Text:
- Authors: Bownes, Angela , Moore, Sean D , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442075 , vital:73953 , https://hdl.handle.net/10520/EJC160247
- Description: Generalist predators are contentious biocontrol agents, especially ants that protect pestilent hemipterans from specialist predators and parasitoids. We attempted to force generalist, hemipteran-tending ants into a degree of dietary specificity by spatially partitioning and simplifying their trophic web. Pupae of Helicoverpa armigera, Thaumatotibia leucotreta and Ceratitis capitata introduced into a citrus orchard survived significantly better in plots where all nests of two pestilent, generalist ant species namely Anoplolepis custodiens and Pheidole megacephala had been poisoned compared with untreated control plots. In some plots the ants' foraging environments were partitioned into arboreal and epigaeic trophic webs using sticky barriers to prevent ground-nesting ants from ascending the trees. Plots partitioned this way showed suppressed levels of survival of emplaced pest pupae that were similar to those in unpartitioned control plots. Pest survival was significantly lower for T. leucotreta than for H. armigera and C. capitata, implicating prey body size or life cycle duration as factors in predation by ants. Pheidole megacephala and the predator complex as a whole can be valuable agents in the natural control of soil-pupating citrus pests if they are restricted to the ground. Trunk banding, rather than poisoning, is therefore recommended as part of managing ecologically mercenary ants in citrus orchards.
- Full Text:
My grandmother breaks her hip
- Authors: Bamjee, Saaleha
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Poetry , South African poetry (English) -- Study and teaching (Higher) , South African poetry (English) -- 21st century , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5998 , http://hdl.handle.net/10962/d1020881
- Description: A collection of narrative and confessional poems. The poems are mostly short, cinematic, physical, imagistic: moments in time. They explore the poet’s own life, body, memories, and family relationships, and the tensions between power, duty, love and faith. Several poems concern the navigation of meaning and belonging in a time when international urban culture often clashes with tradition.
- Full Text:
- Authors: Bamjee, Saaleha
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Poetry , South African poetry (English) -- Study and teaching (Higher) , South African poetry (English) -- 21st century , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5998 , http://hdl.handle.net/10962/d1020881
- Description: A collection of narrative and confessional poems. The poems are mostly short, cinematic, physical, imagistic: moments in time. They explore the poet’s own life, body, memories, and family relationships, and the tensions between power, duty, love and faith. Several poems concern the navigation of meaning and belonging in a time when international urban culture often clashes with tradition.
- Full Text:
Narrative/therapy and an apartheid story: audiences, ethical witnessing
- Authors: Sutherland, Alexandra
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/469601 , vital:77271 , ISBN 9781443862363
- Description: This book explores the use of drama or theatre texts about, as ap-proaches to, or methodologies for, interventions in conflict and post-conflict contexts. It maps the role of drama/theatre in the centre and in the aftermath of overt and direct conflict, traces how the relation-ship between drama/theatre and conflict is shaping the socio-cultural, political, and aesthetic landscapes of these contexts, and engages with drama/theatre as methodologies to address or forge new rela-tionships around conflict. As such, it deals with the transformative abilities of drama/theatre in contexts where conflict or violence is overt or covert in its effects, expressions and modes of social control in a range of geographical constituencies. It includes chapters pre-dominantly from South Africa, but also from rural Nigeria and New Zealand, reflecting work on conflict in prisons, tertiary and secondary education, cities, villages and families. It also contains two new origi-nal play scripts, both resulting in acclaimed performances: Hush, on family violence in New Zealand, and The Line, on xenophobia in South Africa.
- Full Text:
- Authors: Sutherland, Alexandra
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/469601 , vital:77271 , ISBN 9781443862363
- Description: This book explores the use of drama or theatre texts about, as ap-proaches to, or methodologies for, interventions in conflict and post-conflict contexts. It maps the role of drama/theatre in the centre and in the aftermath of overt and direct conflict, traces how the relation-ship between drama/theatre and conflict is shaping the socio-cultural, political, and aesthetic landscapes of these contexts, and engages with drama/theatre as methodologies to address or forge new rela-tionships around conflict. As such, it deals with the transformative abilities of drama/theatre in contexts where conflict or violence is overt or covert in its effects, expressions and modes of social control in a range of geographical constituencies. It includes chapters pre-dominantly from South Africa, but also from rural Nigeria and New Zealand, reflecting work on conflict in prisons, tertiary and secondary education, cities, villages and families. It also contains two new origi-nal play scripts, both resulting in acclaimed performances: Hush, on family violence in New Zealand, and The Line, on xenophobia in South Africa.
- Full Text:
Narratives that shape the professional identities of mathematics teachers
- Felix, Clyde Benedict Aurelius
- Authors: Felix, Clyde Benedict Aurelius
- Date: 2014
- Subjects: Mathematics teachers -- South Africa -- Port Elizabeth , Mathematics teachers -- South Africa -- Grahamstown , Mathematics teachers -- Professional relationships , Mathematics teachers -- Training of , Mathematics -- Study and teaching -- South Africa -- Eastern Cape , Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1995 , http://hdl.handle.net/10962/d1013547
- Description: The central position in this study is that the professional identities, and consequently the classroom practices, of mathematics teachers are continuously being shaped by their narratives of past and present experiences. The primary research question explores the narratives that shape the professional identities of seven mathematics teachers; and the secondary research question, how their narratives shape their professional identities. Furthermore, the potential implications of this study for the design and implementation of pre-service teacher education programmes and in-service teacher development initiatives are considered. This study is framed by Socioculturalism; a theoretical perspective of human thinking as social in origin and of learning as participation in social practices. Futhermore, in line with Situated Learning Theory, the key theoretical notions are: identity (or learning as becoming); community (or learning as belonging); practice (or learning as doing); and meaning (or learning as experience). Identity is construed here as a conceptual bridge between learning and its cultural settings; and also between the individual and the social. In this study, the identity-shaping narratives of seven mathematics teachers, all purposively sampled from schools in the Port Elizabeth and Grahamstown education districts of the Eastern Cape Province of South Africa, were accessed via a narrative inquiry; followed by a horizontal analysis to identify common patterns or recurring themes in the narratives of all seven participants; and, a vertical analysis of the narratives of four of the participants to determine how their narratives shape their professional identities. Recurring themes that emerged during the horizontal analysis include the influence of: family support; role models; changing work environments; continuous professional development; professional recognition; religion; and, micro-politics. The vertical analysis demonstrated how, through a process of interpreting the narratives and restorying them into a meaningful core narrative; it is possible to gain insights into how personal narratives shape a professional identity. This study highlights the importance of listening to the narratives of mathematics teachers; because their professional identities, and consequently their teaching practices, are continuously being shaped by their narratives. It is anticipated that this research will be of interest and benefit to researchers, policy-makers, and teachers; especially in the area of Mathematics Education, where both narrative inquiry as a research method and research into teachers’ professional identities are relatively new.
- Full Text:
- Authors: Felix, Clyde Benedict Aurelius
- Date: 2014
- Subjects: Mathematics teachers -- South Africa -- Port Elizabeth , Mathematics teachers -- South Africa -- Grahamstown , Mathematics teachers -- Professional relationships , Mathematics teachers -- Training of , Mathematics -- Study and teaching -- South Africa -- Eastern Cape , Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1995 , http://hdl.handle.net/10962/d1013547
- Description: The central position in this study is that the professional identities, and consequently the classroom practices, of mathematics teachers are continuously being shaped by their narratives of past and present experiences. The primary research question explores the narratives that shape the professional identities of seven mathematics teachers; and the secondary research question, how their narratives shape their professional identities. Furthermore, the potential implications of this study for the design and implementation of pre-service teacher education programmes and in-service teacher development initiatives are considered. This study is framed by Socioculturalism; a theoretical perspective of human thinking as social in origin and of learning as participation in social practices. Futhermore, in line with Situated Learning Theory, the key theoretical notions are: identity (or learning as becoming); community (or learning as belonging); practice (or learning as doing); and meaning (or learning as experience). Identity is construed here as a conceptual bridge between learning and its cultural settings; and also between the individual and the social. In this study, the identity-shaping narratives of seven mathematics teachers, all purposively sampled from schools in the Port Elizabeth and Grahamstown education districts of the Eastern Cape Province of South Africa, were accessed via a narrative inquiry; followed by a horizontal analysis to identify common patterns or recurring themes in the narratives of all seven participants; and, a vertical analysis of the narratives of four of the participants to determine how their narratives shape their professional identities. Recurring themes that emerged during the horizontal analysis include the influence of: family support; role models; changing work environments; continuous professional development; professional recognition; religion; and, micro-politics. The vertical analysis demonstrated how, through a process of interpreting the narratives and restorying them into a meaningful core narrative; it is possible to gain insights into how personal narratives shape a professional identity. This study highlights the importance of listening to the narratives of mathematics teachers; because their professional identities, and consequently their teaching practices, are continuously being shaped by their narratives. It is anticipated that this research will be of interest and benefit to researchers, policy-makers, and teachers; especially in the area of Mathematics Education, where both narrative inquiry as a research method and research into teachers’ professional identities are relatively new.
- Full Text:
National substantive agreement on wages and conditions of employment concluded between Pioneer Foods (Pty) Ltd t/a Essential Foods: Bakeries and Food and Allied Workers Union.
- Pioneer Foods (Pty) Ltd, Essential Foods: Bakeries, Food and Allied Workers Union
- Authors: Pioneer Foods (Pty) Ltd , Essential Foods: Bakeries , Food and Allied Workers Union
- Date: 2014
- Subjects: Pioneer Foods (Pty) Ltd , Essential Foods: Bakeries , Food and Allied Workers Union , Collective bargaining -- South Africa , Wages -- South Africa
- Language: English
- Type: collective labor agreements , text
- Identifier: http://hdl.handle.net/10962/96130 , vital:31240 , Labour Research Service (LRS)
- Description: National substantive agreement on wages and conditions of employment concluded between Pioneer Foods (Pty) Ltd t/a Essential Foods: Bakeries and Food and Allied Workers Union.
- Full Text:
- Authors: Pioneer Foods (Pty) Ltd , Essential Foods: Bakeries , Food and Allied Workers Union
- Date: 2014
- Subjects: Pioneer Foods (Pty) Ltd , Essential Foods: Bakeries , Food and Allied Workers Union , Collective bargaining -- South Africa , Wages -- South Africa
- Language: English
- Type: collective labor agreements , text
- Identifier: http://hdl.handle.net/10962/96130 , vital:31240 , Labour Research Service (LRS)
- Description: National substantive agreement on wages and conditions of employment concluded between Pioneer Foods (Pty) Ltd t/a Essential Foods: Bakeries and Food and Allied Workers Union.
- Full Text:
Natural resource products contribute to poverty mitigation amongst urbanising communities in sub-saharan Africa
- Shackleton, Charlie M, Schlesinger, Johannes, Kaoma, Humphrey, Davenport, N I, Ward, Catherine D, Evans, Michelle L, Drescher, Axel W
- Authors: Shackleton, Charlie M , Schlesinger, Johannes , Kaoma, Humphrey , Davenport, N I , Ward, Catherine D , Evans, Michelle L , Drescher, Axel W
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:6624 , http://hdl.handle.net/10962/d1016232
- Description: [From Introduction] Urbanisation in sub-Saharan Africa: changing the locus of poverty. Urbanisation is a global phenomenon that is changing the face of the Earth, as well as how people earn a living and secure their livelihoods. In 2006 the number of urban people in the world surpassed the number of rural people, and this gap will continue to grow. In only 16 years (by 2030) just under two-thirds of the world's people will be urban dwellers. Whilst most of the developed world and large parts of Latin America already have more than threequarters of their populations living in cities and towns, most countries in Asia and sub-Saharan Africa are still catching up. This means that they are experiencing massive migrations from rural to urban areas as rural people wish to swap the insecurities of rural living for the allure of secure employment and better services for health, education, sanitation and transport in towns and cities. Sub-Saharan Africa (SSA) is the most rapidly urbanising region of the globe. According to UN-Habitat, in 1990, only 28 % of the region's inhabitants lived in towns and cities; that increased to approximately 32 % in 2001 and 41 % in 2010. The size of the urban population is likely to surpass the rural one around 2025. Contrary to popular belief, most urban residents in SSA (and globally) live in small towns rather than massive megacities; with just over half living in towns of less than 200,000 people and 78 % living in towns of less than 500,000 residents. Only 14 % of urban dwellers live in cities of more than one million people. Many new urban households maintain strong links to relatives and clans in rural areas, with circular migration patterns emerging as the urban transition takes place over several decades. The implications of this extremely rapid urbanisation in SSA countries for livelihoods and poverty are widely debated. UN-Habitat highlights a relatively unique aspect of urbanisation in SSA as being the accompanying high rate of growth in informal settlements or slums. In other words, not all rural migrants to towns and cities find secure incomes or shelter. Some slum areas have become permanent features where inter-generational poverty is reproduced. Although urban areas are producing an increasing share of national wealth in SSA countries, some argue that slowly the nexus of poverty is shifting towards urban areas. Rates of poverty are high in rural areas of SSA, but migration and internal population growth means that in some countries the number of urban poor almost matches the number of rural poor, and it is likely to grow. The informal economy contributes an average of 40 – 45 % of total urban GDP, which is higher than any other region of the world.
- Full Text:
- Authors: Shackleton, Charlie M , Schlesinger, Johannes , Kaoma, Humphrey , Davenport, N I , Ward, Catherine D , Evans, Michelle L , Drescher, Axel W
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:6624 , http://hdl.handle.net/10962/d1016232
- Description: [From Introduction] Urbanisation in sub-Saharan Africa: changing the locus of poverty. Urbanisation is a global phenomenon that is changing the face of the Earth, as well as how people earn a living and secure their livelihoods. In 2006 the number of urban people in the world surpassed the number of rural people, and this gap will continue to grow. In only 16 years (by 2030) just under two-thirds of the world's people will be urban dwellers. Whilst most of the developed world and large parts of Latin America already have more than threequarters of their populations living in cities and towns, most countries in Asia and sub-Saharan Africa are still catching up. This means that they are experiencing massive migrations from rural to urban areas as rural people wish to swap the insecurities of rural living for the allure of secure employment and better services for health, education, sanitation and transport in towns and cities. Sub-Saharan Africa (SSA) is the most rapidly urbanising region of the globe. According to UN-Habitat, in 1990, only 28 % of the region's inhabitants lived in towns and cities; that increased to approximately 32 % in 2001 and 41 % in 2010. The size of the urban population is likely to surpass the rural one around 2025. Contrary to popular belief, most urban residents in SSA (and globally) live in small towns rather than massive megacities; with just over half living in towns of less than 200,000 people and 78 % living in towns of less than 500,000 residents. Only 14 % of urban dwellers live in cities of more than one million people. Many new urban households maintain strong links to relatives and clans in rural areas, with circular migration patterns emerging as the urban transition takes place over several decades. The implications of this extremely rapid urbanisation in SSA countries for livelihoods and poverty are widely debated. UN-Habitat highlights a relatively unique aspect of urbanisation in SSA as being the accompanying high rate of growth in informal settlements or slums. In other words, not all rural migrants to towns and cities find secure incomes or shelter. Some slum areas have become permanent features where inter-generational poverty is reproduced. Although urban areas are producing an increasing share of national wealth in SSA countries, some argue that slowly the nexus of poverty is shifting towards urban areas. Rates of poverty are high in rural areas of SSA, but migration and internal population growth means that in some countries the number of urban poor almost matches the number of rural poor, and it is likely to grow. The informal economy contributes an average of 40 – 45 % of total urban GDP, which is higher than any other region of the world.
- Full Text:
Necrophiliac Narration and the Business of Friends: Damon Galgut’s The Good Doctor
- Authors: Marais, Mike
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144159 , vital:38316 , DOI: 10.1080/17533171.2014.918406
- Description: Set in the period following South Africa’s first democratic elections, Damon Galgut’s The Good Doctor traces the friendship that develops between two doctors working at a rural hospital. While it does not deal overtly with the politics of the “new” South Africa, the novel’s treatment of friendship, which cuts across the distinction between the private and the public, reflects obliquely on the nature of the emerging democratic dispensation. In this paper, I explore the link that Galgut constructs between friendship and community, and argue that his portrayal of the former points to the possibility of a form of community that is premised on a “common strangeness.”
- Full Text:
- Authors: Marais, Mike
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144159 , vital:38316 , DOI: 10.1080/17533171.2014.918406
- Description: Set in the period following South Africa’s first democratic elections, Damon Galgut’s The Good Doctor traces the friendship that develops between two doctors working at a rural hospital. While it does not deal overtly with the politics of the “new” South Africa, the novel’s treatment of friendship, which cuts across the distinction between the private and the public, reflects obliquely on the nature of the emerging democratic dispensation. In this paper, I explore the link that Galgut constructs between friendship and community, and argue that his portrayal of the former points to the possibility of a form of community that is premised on a “common strangeness.”
- Full Text:
Nectar feeding by weavers (Ploceidae) and their role as pollinators
- Authors: Craig, Adrian J F K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449445 , vital:74822 , https://doi.org/10.2989/00306525.2014.900828
- Description: Reviews of nectar-feeding by birds initially focused on specialist nectarivores and ignored the role that more generalist feeders may play in plant pollination. Recent work has emphasised the range of bird species, both specialist and opportunistic, that feed on nectar. In this review, I collate published information on nectar-feeding by weavers, highlight known weaver–plant relationships, and suggest areas for future research. There are published records of nectar feeding for Plocepasser superciliosus, Amblyospiza albifrons, Anaplectes rubriceps, two Quelea spp., four Euplectes spp., all six Foudia spp., two Malimbus spp. and 22 Ploceus spp. To date, there have been no unambiguous reports of other genera feeding on nectar. The role of Ploceus species as pollinators of Strelitzia reginae, proposed by ornithologists decades ago, has recently been confirmed by botanists. Current studies of Aloe species in South Africa suggest that opportunistic avian nectarivores such as ploceids may be the chief pollinators of bird-pollinated plants in this genus, whereas specialist nectar feeders (sunbirds) may be ‘nectar robbers’ in many cases. Particularly for winter-flowering plants, weaver species are potential pollinators, but exclusion experiments are needed to establish their role, while the dietary importance of nectar, and its impact on the birds’ physiology, has not been critically studied.
- Full Text:
- Authors: Craig, Adrian J F K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449445 , vital:74822 , https://doi.org/10.2989/00306525.2014.900828
- Description: Reviews of nectar-feeding by birds initially focused on specialist nectarivores and ignored the role that more generalist feeders may play in plant pollination. Recent work has emphasised the range of bird species, both specialist and opportunistic, that feed on nectar. In this review, I collate published information on nectar-feeding by weavers, highlight known weaver–plant relationships, and suggest areas for future research. There are published records of nectar feeding for Plocepasser superciliosus, Amblyospiza albifrons, Anaplectes rubriceps, two Quelea spp., four Euplectes spp., all six Foudia spp., two Malimbus spp. and 22 Ploceus spp. To date, there have been no unambiguous reports of other genera feeding on nectar. The role of Ploceus species as pollinators of Strelitzia reginae, proposed by ornithologists decades ago, has recently been confirmed by botanists. Current studies of Aloe species in South Africa suggest that opportunistic avian nectarivores such as ploceids may be the chief pollinators of bird-pollinated plants in this genus, whereas specialist nectar feeders (sunbirds) may be ‘nectar robbers’ in many cases. Particularly for winter-flowering plants, weaver species are potential pollinators, but exclusion experiments are needed to establish their role, while the dietary importance of nectar, and its impact on the birds’ physiology, has not been critically studied.
- Full Text:
New geochemical constraints on the genesis of the Gamsberg zinc deposit, Namaqualand Metamorphic Province, South Africa
- Authors: Foulkes, Susan Elizabeth
- Date: 2014
- Subjects: Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5054 , http://hdl.handle.net/10962/d1012084 , Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Description: The base metal massive sulfide deposits of the Aggeneys-Gamsberg (A-G) District are hosted within the Mesoproterozoic Bushmanland Group of the Namaqua-Natal Metamorphic Complex in the Northern Cape Province of South Africa. The district displays an apparent eastward trend in the economic concentration of base metals (+ barite) from relatively Cu-Pb-rich, Ba-poor mineralisation at Black Mountain to Zn- and Ba-rich ores at Gamsberg. Base metal sulfides at Gamsberg are restricted to the so called Gams (Iron) Formation which comprises a sulfidic mineralized unit (“B”) enveloped within a sequence of meta-sedimentary units (“A” and “C”). The aim of the study was to shed further light on the genesis and chemical evolution of the sulfide mineralisation at Gamsberg in the context of the entire A-G District, by interrogating further the apparent district-wide trend in base metal distribution. The Gams Iron Formation was sampled and studied from one key drill core intersection (“G1”) which intersects the largest part of it as described elsewhere; a small number of additional samples from a second drill core (“G2”) complemented the main sample suite. Minerals that make up the silicate assemblages across the studied section include quartz, garnet, pyroxene, pyroxenoid, phyllosilicates, carbonates, amphiboles, oxides (chiefly magnetite) and graphite. In a stratigraphic context, the mineralogical variations conform directly to those documented in the relevant literature from the Gamsberg locality. These are coupled, where possible, with mineral-chemical profiles of selected silicate species which replicate those of bulk-rock compositions, particularly with respect to Mn, Fe and Ca in the upper C Unit of the studied section. These signals collectively track the characteristic transition from a terrigenous, siliciclastic sediment-dominated footwall to an exhalative sediment-dominated hanging wall to the sulfide mineralisation as also seen in similar deposits elsewhere, particularly with respect to the characteristic Mn-rich signature increasingly observed in the hanging wall C Unit. The foregoing suggests that the examined section faithfully records the interpreted primary stratigraphy of the deposits, despite the complex structural and metamorphic overprint that characterises the region. This facilitates a stratigraphic analytical approach on the sulfidic Unit B, through a combination of mineral-chemical and stable isotope analyses. Dominant sulfides in Unit B are sphalerite and pyrite, with lesser pyrrhotite and minor galena. Sphalerite shows high and generally invariant contents of Fe (mean 12.18wt%, as FeS) whereas Zn anti-correlates with Mn (mean 5.58wt%, as MnS). Isotopic analyses for S, Fe and Zn in hand-picked sphalerite and pyrite separates were used with a view to providing new evidence for chemical and isotopic variation within the sulfide ore-body in a vertical (i.e. stratigraphic) sense, discuss the implications thereof, and ultimately interpret the new data in light of similar existing data from the A-G District and elsewhere. The δ³⁴S data for pyrite (plus a single pyrrhotite grain) and sphalerite from both cores G1 and G2 show comparable compositional ranges between 22.9 and 30.4‰ and between 27 and 30.1‰ respectively. The δ⁵⁶Fe data for pyrite show a range between -1.85 and 0.19‰, whereas seven sphalerite separates have a very narrow range of δ⁶⁶Zn from 0.06 to 0.20‰. The atypically high sulfur isotope data reported in this study are interpreted to reflect sedimentary deposition of primary sulfide ore at Gamsberg from an isotopically highly evolved seawater sulfate source through large-scale Rayleigh fractionation processes. Thermogenic sulfate reduction is proposed to have been the main reductive mechanism from seawater sulfate to sulfide, given the absence of very low δ³⁴S data for sulfides anywhere in the A-G District. By contrast, the δ⁶⁶Zn values for sphalerite are for all intents and purposes invariant and very close to 0‰, and therefore suggest little Zn isotope fractionation from an original exhalative fluid source. On this evidence alone, Zn isotopes therefore appear to hold little promise as a proxy of the chemical and isotopic evolution of SEDEX deposits in space and time, although this can only be verified through further application in the broader A-G District and similar deposits elsewhere. The apparent decoupling of Zn and S isotopes in the Gamsberg sulfide deposit, however, points towards diverse sources of these two components, i.e. ascending metalliferous brines versus seawater respectively. Finally, pyrite δ⁵⁶Fe data do show a stratigraphic trend of generally declining values up-section, which are interpreted to reflect the influence of broadly coeval precipitation of isotopically heavy Fe-oxides on a broader-scale – now preserved as abundant magnetite through metamorphism. Further work on the iron isotope composition of silicate-and oxide-hosted Fe on a local-to-district scale will assist in testing this interpretation.
- Full Text:
- Authors: Foulkes, Susan Elizabeth
- Date: 2014
- Subjects: Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5054 , http://hdl.handle.net/10962/d1012084 , Zinc ores -- South Africa -- Gamsberg , Mines and mineral resources -- South Africa -- Gamsberg , Mineralogy -- South Africa -- Gamsberg , Molecular evolution , Geology -- South Africa -- Namaqualand
- Description: The base metal massive sulfide deposits of the Aggeneys-Gamsberg (A-G) District are hosted within the Mesoproterozoic Bushmanland Group of the Namaqua-Natal Metamorphic Complex in the Northern Cape Province of South Africa. The district displays an apparent eastward trend in the economic concentration of base metals (+ barite) from relatively Cu-Pb-rich, Ba-poor mineralisation at Black Mountain to Zn- and Ba-rich ores at Gamsberg. Base metal sulfides at Gamsberg are restricted to the so called Gams (Iron) Formation which comprises a sulfidic mineralized unit (“B”) enveloped within a sequence of meta-sedimentary units (“A” and “C”). The aim of the study was to shed further light on the genesis and chemical evolution of the sulfide mineralisation at Gamsberg in the context of the entire A-G District, by interrogating further the apparent district-wide trend in base metal distribution. The Gams Iron Formation was sampled and studied from one key drill core intersection (“G1”) which intersects the largest part of it as described elsewhere; a small number of additional samples from a second drill core (“G2”) complemented the main sample suite. Minerals that make up the silicate assemblages across the studied section include quartz, garnet, pyroxene, pyroxenoid, phyllosilicates, carbonates, amphiboles, oxides (chiefly magnetite) and graphite. In a stratigraphic context, the mineralogical variations conform directly to those documented in the relevant literature from the Gamsberg locality. These are coupled, where possible, with mineral-chemical profiles of selected silicate species which replicate those of bulk-rock compositions, particularly with respect to Mn, Fe and Ca in the upper C Unit of the studied section. These signals collectively track the characteristic transition from a terrigenous, siliciclastic sediment-dominated footwall to an exhalative sediment-dominated hanging wall to the sulfide mineralisation as also seen in similar deposits elsewhere, particularly with respect to the characteristic Mn-rich signature increasingly observed in the hanging wall C Unit. The foregoing suggests that the examined section faithfully records the interpreted primary stratigraphy of the deposits, despite the complex structural and metamorphic overprint that characterises the region. This facilitates a stratigraphic analytical approach on the sulfidic Unit B, through a combination of mineral-chemical and stable isotope analyses. Dominant sulfides in Unit B are sphalerite and pyrite, with lesser pyrrhotite and minor galena. Sphalerite shows high and generally invariant contents of Fe (mean 12.18wt%, as FeS) whereas Zn anti-correlates with Mn (mean 5.58wt%, as MnS). Isotopic analyses for S, Fe and Zn in hand-picked sphalerite and pyrite separates were used with a view to providing new evidence for chemical and isotopic variation within the sulfide ore-body in a vertical (i.e. stratigraphic) sense, discuss the implications thereof, and ultimately interpret the new data in light of similar existing data from the A-G District and elsewhere. The δ³⁴S data for pyrite (plus a single pyrrhotite grain) and sphalerite from both cores G1 and G2 show comparable compositional ranges between 22.9 and 30.4‰ and between 27 and 30.1‰ respectively. The δ⁵⁶Fe data for pyrite show a range between -1.85 and 0.19‰, whereas seven sphalerite separates have a very narrow range of δ⁶⁶Zn from 0.06 to 0.20‰. The atypically high sulfur isotope data reported in this study are interpreted to reflect sedimentary deposition of primary sulfide ore at Gamsberg from an isotopically highly evolved seawater sulfate source through large-scale Rayleigh fractionation processes. Thermogenic sulfate reduction is proposed to have been the main reductive mechanism from seawater sulfate to sulfide, given the absence of very low δ³⁴S data for sulfides anywhere in the A-G District. By contrast, the δ⁶⁶Zn values for sphalerite are for all intents and purposes invariant and very close to 0‰, and therefore suggest little Zn isotope fractionation from an original exhalative fluid source. On this evidence alone, Zn isotopes therefore appear to hold little promise as a proxy of the chemical and isotopic evolution of SEDEX deposits in space and time, although this can only be verified through further application in the broader A-G District and similar deposits elsewhere. The apparent decoupling of Zn and S isotopes in the Gamsberg sulfide deposit, however, points towards diverse sources of these two components, i.e. ascending metalliferous brines versus seawater respectively. Finally, pyrite δ⁵⁶Fe data do show a stratigraphic trend of generally declining values up-section, which are interpreted to reflect the influence of broadly coeval precipitation of isotopically heavy Fe-oxides on a broader-scale – now preserved as abundant magnetite through metamorphism. Further work on the iron isotope composition of silicate-and oxide-hosted Fe on a local-to-district scale will assist in testing this interpretation.
- Full Text:
New possibilities for research on reef fish across the continental shelf of South Africa
- Bernard, Anthony T F, Götz, Albrecht, Parker, Daniel M, Heyns, Elodie R, Halse, Sarah J, Riddin, N A, Smith, M K S, Paterson, Angus W, Winker, A Henning, Fullwood, L, Langlois, T J, Harvey, E S
- Authors: Bernard, Anthony T F , Götz, Albrecht , Parker, Daniel M , Heyns, Elodie R , Halse, Sarah J , Riddin, N A , Smith, M K S , Paterson, Angus W , Winker, A Henning , Fullwood, L , Langlois, T J , Harvey, E S
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6971 , http://hdl.handle.net/10962/d1014566
- Description: [From introduction] Subtidal research presents numerous challenges that restrict the ability to answer fundamental ecological questions related to reef systems. These challenges are closely associated with traditional monitoring methods and include depth restrictions (e.g. safe diving depths for underwater visual census), habitat destruction (e.g. trawling), mortality of target species (e.g. controlled angling and fish traps), and high operating costs (e.g. remotely operated vehicles and large research vessels. Whereas many of these challenges do not apply or are avoidable in the shallow subtidal environment, the difficulties grow as one attempts to sample deeper benthic habitats. This situation has resulted in a paucity of knowledge on the structure and ecology of deep water reef habitats around the coast of South Africa and in most marine areas around the world. Furthermore, the inability to effectively survey deep water benthic environments has limited the capacity of researchers to investigate connectivity between shallow and deep water habitats in a standardised and comparable fashion.
- Full Text:
- Authors: Bernard, Anthony T F , Götz, Albrecht , Parker, Daniel M , Heyns, Elodie R , Halse, Sarah J , Riddin, N A , Smith, M K S , Paterson, Angus W , Winker, A Henning , Fullwood, L , Langlois, T J , Harvey, E S
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6971 , http://hdl.handle.net/10962/d1014566
- Description: [From introduction] Subtidal research presents numerous challenges that restrict the ability to answer fundamental ecological questions related to reef systems. These challenges are closely associated with traditional monitoring methods and include depth restrictions (e.g. safe diving depths for underwater visual census), habitat destruction (e.g. trawling), mortality of target species (e.g. controlled angling and fish traps), and high operating costs (e.g. remotely operated vehicles and large research vessels. Whereas many of these challenges do not apply or are avoidable in the shallow subtidal environment, the difficulties grow as one attempts to sample deeper benthic habitats. This situation has resulted in a paucity of knowledge on the structure and ecology of deep water reef habitats around the coast of South Africa and in most marine areas around the world. Furthermore, the inability to effectively survey deep water benthic environments has limited the capacity of researchers to investigate connectivity between shallow and deep water habitats in a standardised and comparable fashion.
- Full Text:
Nine lives of William Shakespeare
- Authors: Wright, Laurence
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468650 , vital:77108 , https://doi.org/10.1080/10137548.2014.901647
- Description: Shakespearean biography inhabits a curious zone of the hypothetical perfective: a few solid but scanty facts are teased this way and that at the behest of biographers to produce a convincing fictive life-story of refulgent and satisfying fullness. Yawning lacunae are sutured by means of ‘possibly’, ‘probably’, ‘conceivably’, ‘likely’, ‘reasonably’ and similar pleas for indulgence. It may be a failing in me, but this frank acknowledgment of abject ignorance, followed by bold authorial extrapolation, daintily hedged about by anxious gestures of caution and intellectual responsibility, gives me the willies. In fact, multiple ‘Willies’, Willies beyond all reason. That's one sure readerly consequence of a superfluity of biographical bardolatry, which Holderness's book both diagnoses and adds to. If Anne Barton is correct, at least one formal biography of Shakespeare has appeared each year since 1996.
- Full Text:
- Authors: Wright, Laurence
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468650 , vital:77108 , https://doi.org/10.1080/10137548.2014.901647
- Description: Shakespearean biography inhabits a curious zone of the hypothetical perfective: a few solid but scanty facts are teased this way and that at the behest of biographers to produce a convincing fictive life-story of refulgent and satisfying fullness. Yawning lacunae are sutured by means of ‘possibly’, ‘probably’, ‘conceivably’, ‘likely’, ‘reasonably’ and similar pleas for indulgence. It may be a failing in me, but this frank acknowledgment of abject ignorance, followed by bold authorial extrapolation, daintily hedged about by anxious gestures of caution and intellectual responsibility, gives me the willies. In fact, multiple ‘Willies’, Willies beyond all reason. That's one sure readerly consequence of a superfluity of biographical bardolatry, which Holderness's book both diagnoses and adds to. If Anne Barton is correct, at least one formal biography of Shakespeare has appeared each year since 1996.
- Full Text:
Nonlinear optical studies of metallophtalocyanines and hemiporphyrazines in solution
- Authors: Britton, Jonathan
- Date: 2014
- Subjects: Phthalocyanines Photochemistry Nanoparticles Nanostructured materials Polymers Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4464 , http://hdl.handle.net/10962/d1011608
- Description: This thesis presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (5-12) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tertbutylphenoxy and amino groups in solution and in poly (methyl methacrylate) (PMMA) films. The optical limiting parameters of Pcs were higher for tertbutylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ⁽³⁾]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10⁻¹² to 10⁻¹° esu cm range. Hyperpolarizabilities (γ) ranged from 10⁻³¹ to 10⁻²⁹ esu L for Pc alone or in mixture with QDs. The effect on the optical limiting abilities of twelve embedded phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films was also examined. The effect of forming a covalent link zinc tetraamino phthalocyanine (12) with poly (methyl acrylic acid) (PMAA) and Zn (13) and OHAl (14) octacarboxy phthalocyanines to polyethylenimine (PEI) was also studied. The hyperpolarizability of the twelve phthalocyanines in polymer was found to be in the range of 10⁻²⁶ to 10⁻²⁴ esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution. Non-linear optical (NLO) parameters were determined for phthalocyanine complexes containing In, Ga and Zn as central metals when embedded in PMMA polymer in the presence of quantum dots (QDs). The QDs mainly employed were CdTe-TGA (TGA = thioglylcolic acid). Triplet lifetimes increased as k (excited state (σex) to ground state (σg) absorption cross section ratio) values decreased with the addition of the CdTe-TGA to the phthalocyanines. The saturation energy density (Fsat) values were smaller in the films when compared to the solutions. Complex 7 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS-TGA, CdSe-TGA, fullerenes and single walled carbon nanotubes. There is a general improvement in optical limiting ability of Pc complexes in the presence of nanomaterials (NMs). Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation. 3(4), 15(16)-Bis-(4 -tert-butyl-phenoxy)-10, 22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1, 3, 5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
- Full Text:
- Authors: Britton, Jonathan
- Date: 2014
- Subjects: Phthalocyanines Photochemistry Nanoparticles Nanostructured materials Polymers Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4464 , http://hdl.handle.net/10962/d1011608
- Description: This thesis presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (5-12) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tertbutylphenoxy and amino groups in solution and in poly (methyl methacrylate) (PMMA) films. The optical limiting parameters of Pcs were higher for tertbutylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ⁽³⁾]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10⁻¹² to 10⁻¹° esu cm range. Hyperpolarizabilities (γ) ranged from 10⁻³¹ to 10⁻²⁹ esu L for Pc alone or in mixture with QDs. The effect on the optical limiting abilities of twelve embedded phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films was also examined. The effect of forming a covalent link zinc tetraamino phthalocyanine (12) with poly (methyl acrylic acid) (PMAA) and Zn (13) and OHAl (14) octacarboxy phthalocyanines to polyethylenimine (PEI) was also studied. The hyperpolarizability of the twelve phthalocyanines in polymer was found to be in the range of 10⁻²⁶ to 10⁻²⁴ esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution. Non-linear optical (NLO) parameters were determined for phthalocyanine complexes containing In, Ga and Zn as central metals when embedded in PMMA polymer in the presence of quantum dots (QDs). The QDs mainly employed were CdTe-TGA (TGA = thioglylcolic acid). Triplet lifetimes increased as k (excited state (σex) to ground state (σg) absorption cross section ratio) values decreased with the addition of the CdTe-TGA to the phthalocyanines. The saturation energy density (Fsat) values were smaller in the films when compared to the solutions. Complex 7 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS-TGA, CdSe-TGA, fullerenes and single walled carbon nanotubes. There is a general improvement in optical limiting ability of Pc complexes in the presence of nanomaterials (NMs). Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation. 3(4), 15(16)-Bis-(4 -tert-butyl-phenoxy)-10, 22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1, 3, 5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
- Full Text:
Normative self-perceptions of journalists in Nigeria : the case of the Guardian newspaper
- Authors: Tiri, Judith
- Date: 2014
- Subjects: Guardian (Nigeria) , Nigeria -- In mass media , Nigeria -- Politics and government -- In mass media , Newspapers -- Nigeria , Journalism -- Political aspects -- Nigeria , Journalists -- Nigeria -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3523
- Description: The study aims at interrogating the self - perceptions of journalists in Nigeria. The study is an attempt to answer some questions as: what contributions have journalists made to the democratization of Nigeria from 1960 to date? What role(s) did the media play during and after the transition to democracy? To what extent have the activities of politicians and the business class affected t he media’s social responsibility? What are the self-perceptions of journalists working in Nigeria’s The Guardian newspaper? The studies on normative theories of the press, Journalism Culture, and the perceived influences on journalism practice in a democra cy were adapted to answer the afore-listed questions. The works on how elite continuity and transitology models affect the perceptions of journalists in new democracies were also used to answer the questions posed. Since the field of research of the preced ing works is the West, the Nigerian experience points to issues that were not addressed in the prior studies because of the latter’s unique socio-political, historical, economic and ethno-religious structures . The data were collected and analyzed according to the QualitaQualitative paradigm, using in-depth semi-structured individual interviews with journalists working at The Guardian newspaper. The findings suggest that the journalists have made positive contributions to Nigeria’s democratization. The journalists that support this thesis claim that the self-perceptions of their role have changed from an adversarial position to a democratically-defined social responsibility role. This is because journalists ensure that government policies are implemented and the iss ues that affect the masses are reported. The findings show that in spite of the shift to democratization some challenges have remained, for example the journalists’ lives are not safe ; they collect bribes which are popularly called brown envelopes in Nigeria, write biased stories, and hold partisan relationships with the politicians and entrepreneurial elites and so on. The study acknowledges that democratization is in a continuum and that (the stakeholders or) civil society, journalists, the state and the entrepreneurial elites must contribute to deepen Nigeria’s democracy. The study suggests a self-perception theory that uses individual structures and institutions of a country to guide the stakeholders to play roles that will deepen democracy.
- Full Text:
- Authors: Tiri, Judith
- Date: 2014
- Subjects: Guardian (Nigeria) , Nigeria -- In mass media , Nigeria -- Politics and government -- In mass media , Newspapers -- Nigeria , Journalism -- Political aspects -- Nigeria , Journalists -- Nigeria -- Psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3523
- Description: The study aims at interrogating the self - perceptions of journalists in Nigeria. The study is an attempt to answer some questions as: what contributions have journalists made to the democratization of Nigeria from 1960 to date? What role(s) did the media play during and after the transition to democracy? To what extent have the activities of politicians and the business class affected t he media’s social responsibility? What are the self-perceptions of journalists working in Nigeria’s The Guardian newspaper? The studies on normative theories of the press, Journalism Culture, and the perceived influences on journalism practice in a democra cy were adapted to answer the afore-listed questions. The works on how elite continuity and transitology models affect the perceptions of journalists in new democracies were also used to answer the questions posed. Since the field of research of the preced ing works is the West, the Nigerian experience points to issues that were not addressed in the prior studies because of the latter’s unique socio-political, historical, economic and ethno-religious structures . The data were collected and analyzed according to the QualitaQualitative paradigm, using in-depth semi-structured individual interviews with journalists working at The Guardian newspaper. The findings suggest that the journalists have made positive contributions to Nigeria’s democratization. The journalists that support this thesis claim that the self-perceptions of their role have changed from an adversarial position to a democratically-defined social responsibility role. This is because journalists ensure that government policies are implemented and the iss ues that affect the masses are reported. The findings show that in spite of the shift to democratization some challenges have remained, for example the journalists’ lives are not safe ; they collect bribes which are popularly called brown envelopes in Nigeria, write biased stories, and hold partisan relationships with the politicians and entrepreneurial elites and so on. The study acknowledges that democratization is in a continuum and that (the stakeholders or) civil society, journalists, the state and the entrepreneurial elites must contribute to deepen Nigeria’s democracy. The study suggests a self-perception theory that uses individual structures and institutions of a country to guide the stakeholders to play roles that will deepen democracy.
- Full Text:
Occurrence of larval fishes in a rocky shore-associated nursery area in temperate South Africa, with emphasis on temperature-related growth in dominant Sparidae
- Strydom, Nadine A, Booth, Anthony J, McLachlan, A
- Authors: Strydom, Nadine A , Booth, Anthony J , McLachlan, A
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125342 , vital:35774 , https://doi.10.2989/1814232X.2014.899269
- Description: Larval fishes were studied in Shark Bay on the warm, temperate south-east coast of South Africa. The bay is a small, shallow, subtidal area associated with a rocky shore. Sampling took place fortnightly for a period of one year (September 2004–August 2005) to assess composition, abundance and growth of fishes. The objectives of the study were to assess the extent of use of this habitat type by larvae throughout the year and to ascertain what temperature advantages this relatively warm habitat could have on growth of dominant species. A total of 10 fish families, represented by 16 taxa, was collected using a specially modified beach seine net (mesh aperture 500 μm). Shark Bay was utilised extensively by Diplodus capensis and Sarpa salpa and to a lesser extent by Clinus supercilious, Liza spp. and Mugil cephalus. Mean catch per unit effort (CPUE) of larvae was high (>500 larvae per net haul), peaking at ~7 500 larvae in a single haul that consisted mostly of postflexion-stage Sparidae. There was a weak, negative correlation (−0.24) between temperature and overall CPUE, which reflected either the seasonality or protracted nature of spawning by the species occurring in the bay. There was no significant difference in CPUE between the moon phases sampled on the spring tides in this study. Shark Bay was dominated by postflexionstage larvae, consisting in particular of species common to tide pools during the juvenile stage. Certain species were sampled for only short periods during the year. The year-round occurrence and high abundance of the two dominant species indicate that Shark Bay represents an important nursery habitat for the completion of the larval phase. These species exhibited exponential growth that lagged behind small increases in temperature, highlighting the importance of access to shallow, warm habitat that allows larval growth to increase, leading to earlier settlement into juvenile habitat and thereby reducing the pelagic larval duration.
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- Authors: Strydom, Nadine A , Booth, Anthony J , McLachlan, A
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125342 , vital:35774 , https://doi.10.2989/1814232X.2014.899269
- Description: Larval fishes were studied in Shark Bay on the warm, temperate south-east coast of South Africa. The bay is a small, shallow, subtidal area associated with a rocky shore. Sampling took place fortnightly for a period of one year (September 2004–August 2005) to assess composition, abundance and growth of fishes. The objectives of the study were to assess the extent of use of this habitat type by larvae throughout the year and to ascertain what temperature advantages this relatively warm habitat could have on growth of dominant species. A total of 10 fish families, represented by 16 taxa, was collected using a specially modified beach seine net (mesh aperture 500 μm). Shark Bay was utilised extensively by Diplodus capensis and Sarpa salpa and to a lesser extent by Clinus supercilious, Liza spp. and Mugil cephalus. Mean catch per unit effort (CPUE) of larvae was high (>500 larvae per net haul), peaking at ~7 500 larvae in a single haul that consisted mostly of postflexion-stage Sparidae. There was a weak, negative correlation (−0.24) between temperature and overall CPUE, which reflected either the seasonality or protracted nature of spawning by the species occurring in the bay. There was no significant difference in CPUE between the moon phases sampled on the spring tides in this study. Shark Bay was dominated by postflexionstage larvae, consisting in particular of species common to tide pools during the juvenile stage. Certain species were sampled for only short periods during the year. The year-round occurrence and high abundance of the two dominant species indicate that Shark Bay represents an important nursery habitat for the completion of the larval phase. These species exhibited exponential growth that lagged behind small increases in temperature, highlighting the importance of access to shallow, warm habitat that allows larval growth to increase, leading to earlier settlement into juvenile habitat and thereby reducing the pelagic larval duration.
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Ocean warming affects the distribution and abundance of resident fishes by changing their reproductive scope
- Potts, Warren M, Booth, Anthony J, Richardson, Timothy J, Sauer, Warwick H H
- Authors: Potts, Warren M , Booth, Anthony J , Richardson, Timothy J , Sauer, Warwick H H
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125352 , vital:35775 , https://doi.10.1007/s11160-013-9329-3
- Description: With ocean warming predicted globally, one of the mechanisms driving distributional shifts and changes in the abundance of resident fishes is reproductive output. The relationship between sea surface temperature and the reproductive activity of a eurythermic, resident coastal species, blacktail seabream Diplodus sargus capensis, was examined in the ‘‘ocean warming’’ hotspot of the northern Benguela. Reproductive activity was found to be restricted to periods when the water temperature dropped below 20 _C. A metadata analysis conducted on the D. sargus sub-species complex similarly showed that reproductive activity was restricted to temperatures between 15 and 20 _C, regardless of the range in ambient water temperature. Based on these findings and using satellite derived SST information, we examined D. s. capensis’s total and seasonal ‘‘reproductive scope’’ that is defined as either the area suitable for spawning each year or the duration of its potential spawning season at a fixed geographical locality, respectively. Trends were examined over the last three decades. Reproductive scope by area was found to be shrinking at a rate of 7 % per decade in southern Angola and expanding at a rate of 6 % per decade in northern Namibia. Reproductive scope by season decreased by 1.05 months per decade in Namibe, southern Angola and increased by 0.76 months per decade in Hentiesbaai, northern Namibia. Changes in reproductive scope may be a driving mechanism of distributional shifts in resident fishes, although the rate of the shifts is likely to be slow. More importantly, changes in reproductive scope will not be uniform throughout fish distributions and will most likely result in heterogeneous variations in fish abundance.
- Full Text:
- Authors: Potts, Warren M , Booth, Anthony J , Richardson, Timothy J , Sauer, Warwick H H
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125352 , vital:35775 , https://doi.10.1007/s11160-013-9329-3
- Description: With ocean warming predicted globally, one of the mechanisms driving distributional shifts and changes in the abundance of resident fishes is reproductive output. The relationship between sea surface temperature and the reproductive activity of a eurythermic, resident coastal species, blacktail seabream Diplodus sargus capensis, was examined in the ‘‘ocean warming’’ hotspot of the northern Benguela. Reproductive activity was found to be restricted to periods when the water temperature dropped below 20 _C. A metadata analysis conducted on the D. sargus sub-species complex similarly showed that reproductive activity was restricted to temperatures between 15 and 20 _C, regardless of the range in ambient water temperature. Based on these findings and using satellite derived SST information, we examined D. s. capensis’s total and seasonal ‘‘reproductive scope’’ that is defined as either the area suitable for spawning each year or the duration of its potential spawning season at a fixed geographical locality, respectively. Trends were examined over the last three decades. Reproductive scope by area was found to be shrinking at a rate of 7 % per decade in southern Angola and expanding at a rate of 6 % per decade in northern Namibia. Reproductive scope by season decreased by 1.05 months per decade in Namibe, southern Angola and increased by 0.76 months per decade in Hentiesbaai, northern Namibia. Changes in reproductive scope may be a driving mechanism of distributional shifts in resident fishes, although the rate of the shifts is likely to be slow. More importantly, changes in reproductive scope will not be uniform throughout fish distributions and will most likely result in heterogeneous variations in fish abundance.
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Ocean warming hotspots provide early warning laboratories for climate change impacts
- Pecl, Gretta T, Hobday, Alistair J, Frusher, Stewart, Sauer, Warwick H H, Bates, Amanda E
- Authors: Pecl, Gretta T , Hobday, Alistair J , Frusher, Stewart , Sauer, Warwick H H , Bates, Amanda E
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125363 , vital:35776 , https://doi.10.1007/s11160-014-9355-9
- Description: A growing literature describes a wide range of negative impacts of climate change on marine resources and the people and communities they support, including species range changes, changes in productivity of fisheries and declines in economic performance (Doney et al. 2012; Poloczanska et al. 2013). These impacts, many of which are projected to increase in future, are compounded by growing pressures on marine resources (Halpern et al. 2008; Maxwell et al. 2013). An estimated 260 million people are involved directly or indirectly in global marine fisheries (Teh and Sumaila 2013) with many of the resources for capture fisheries already fully (&57 % in 2009) or over exploited (30 %) (FAO 2012). Nevertheless, production of marine resources will need to increase to accommodate the demands of a growing population, and the impacts of climate change on food security will need to be minimised (FAO 2009). Identifying opportunities and threats, and developing adaptation options in response to climate change impacts in the marine realm, is essential for optimising the benefits that society can continue to derive from the goods and services provided by marine resources.
- Full Text:
- Authors: Pecl, Gretta T , Hobday, Alistair J , Frusher, Stewart , Sauer, Warwick H H , Bates, Amanda E
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125363 , vital:35776 , https://doi.10.1007/s11160-014-9355-9
- Description: A growing literature describes a wide range of negative impacts of climate change on marine resources and the people and communities they support, including species range changes, changes in productivity of fisheries and declines in economic performance (Doney et al. 2012; Poloczanska et al. 2013). These impacts, many of which are projected to increase in future, are compounded by growing pressures on marine resources (Halpern et al. 2008; Maxwell et al. 2013). An estimated 260 million people are involved directly or indirectly in global marine fisheries (Teh and Sumaila 2013) with many of the resources for capture fisheries already fully (&57 % in 2009) or over exploited (30 %) (FAO 2012). Nevertheless, production of marine resources will need to increase to accommodate the demands of a growing population, and the impacts of climate change on food security will need to be minimised (FAO 2009). Identifying opportunities and threats, and developing adaptation options in response to climate change impacts in the marine realm, is essential for optimising the benefits that society can continue to derive from the goods and services provided by marine resources.
- Full Text: