Halogen substituted A2B type Co (III) triarylcorroles
- Niu, Yingjie, Li, Minzhi, Zhang, Qianchong, Zhu, Weihua, Mack, John, Fomo, Gertrude, Nyokong, Tebello, Liang, Xu
- Authors: Niu, Yingjie , Li, Minzhi , Zhang, Qianchong , Zhu, Weihua , Mack, John , Fomo, Gertrude , Nyokong, Tebello , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233048 , vital:50051 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.02.049"
- Description: Seven low symmetry A2B type Co(III)triarylcorroles with electron withdrawing meso-aryl substituents have been synthesized and characterized. A detailed analysis of the optical and redox properties has been carried out by comparing their optical spectroscopy, electrochemistry and spectroelectrochemistry to trends predicted in a series of DFT and TD-DFT calculations. The results demonstrate that Co(III)corroles are highly effective catalysts for hydrogen evolution reactions (HERs). Moreover, there is a marked enhancement in their homogenous catalytic ability when halogen atoms are introduced at the B position, which demonstrates that facile modifying the meso-aryl rings is a effective strategy for developing new HER catalysts. The electrochemical results demonstrate that an unusual two step modulation of HER reactions can be achieved by using singly and doubly electrochemical reduced cobalt triarylcorroles anions.
- Full Text:
- Authors: Niu, Yingjie , Li, Minzhi , Zhang, Qianchong , Zhu, Weihua , Mack, John , Fomo, Gertrude , Nyokong, Tebello , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233048 , vital:50051 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.02.049"
- Description: Seven low symmetry A2B type Co(III)triarylcorroles with electron withdrawing meso-aryl substituents have been synthesized and characterized. A detailed analysis of the optical and redox properties has been carried out by comparing their optical spectroscopy, electrochemistry and spectroelectrochemistry to trends predicted in a series of DFT and TD-DFT calculations. The results demonstrate that Co(III)corroles are highly effective catalysts for hydrogen evolution reactions (HERs). Moreover, there is a marked enhancement in their homogenous catalytic ability when halogen atoms are introduced at the B position, which demonstrates that facile modifying the meso-aryl rings is a effective strategy for developing new HER catalysts. The electrochemical results demonstrate that an unusual two step modulation of HER reactions can be achieved by using singly and doubly electrochemical reduced cobalt triarylcorroles anions.
- Full Text:
Happiness is somebody’s name
- Authors: Jijana, Thabo
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7268 , vital:21237
- Description: This collection of loosely interlinked short stories is a “book of imaginary beings”. It draws its influence from amaXhosa history, religion and mythology. Written in a fluid blend of isiXhosa and English, the stories make use of innovative forms and an inventive, pared-down language to create new and strange perspectives on our past, present and future. Ranging in length from brief mini-sagas to longer vignettes, the collection touches on such diverse subjects as the lore and superstitions surrounding the mythical being of tokoloshe, sorcery in the black community, and other fantastical elements of amaXhosa folklore. Literary influences include the Syrian writer Osama Olamar, whose writing about inanimate and everyday objects is both interesting and rare; Amos Tutuola, whose appropriation of Yoruba mythology I have learned much from; the Argentinian writer Julio Cortazar who has the facility to articulate the fantastical in a straightforward narrative; and Taban Lo Liyong, the Ugandan writer, whose fabulist work has served as stimulus for many of these stories.
- Full Text:
- Authors: Jijana, Thabo
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7268 , vital:21237
- Description: This collection of loosely interlinked short stories is a “book of imaginary beings”. It draws its influence from amaXhosa history, religion and mythology. Written in a fluid blend of isiXhosa and English, the stories make use of innovative forms and an inventive, pared-down language to create new and strange perspectives on our past, present and future. Ranging in length from brief mini-sagas to longer vignettes, the collection touches on such diverse subjects as the lore and superstitions surrounding the mythical being of tokoloshe, sorcery in the black community, and other fantastical elements of amaXhosa folklore. Literary influences include the Syrian writer Osama Olamar, whose writing about inanimate and everyday objects is both interesting and rare; Amos Tutuola, whose appropriation of Yoruba mythology I have learned much from; the Argentinian writer Julio Cortazar who has the facility to articulate the fantastical in a straightforward narrative; and Taban Lo Liyong, the Ugandan writer, whose fabulist work has served as stimulus for many of these stories.
- Full Text:
Health promotion: approaches to dietary salt reduction
- Authors: Mushoriwa, Fadzai
- Date: 2017
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/44761 , vital:25439
- Description: Background Globally, non-communicable diseases are the leading causes of mortality and morbidity, with the majority of these occurring in low-middle income countries. The devastating consequences of non-communicable diseases could be curtailed through better management of four modifiable factors: physical inactivity; tobacco use; harmful use of alcohol; and unhealthy diets. The World Health Organisation has recommended dietary salt reduction as a cost-effective strategy in combatting the burden of NCDs. Consumer awareness and education is one of three primary strategies that have been identified by the World Health Organisation to achieve population-wide salt reduction. It involves the provision of salt reduction knowledge and the promotion of healthy salt related practices. These campaigns are a necessity in populations with high discretionary salt use such as South Africa. For these health promotion activities to succeed, they need to be developed with consideration of factors such as the environment, culture, and socio-economic standing of the intended target population. This two-phase health promotion study was conducted at St Mary’s Development and Care Centre and the Assumption Sisters Nutrition Centre. These are two community based organisations located in Grahamstown, South Africa. A needs assessment was conducted to identify the knowledge and practices of cooks and guardians from these centres on dietary salt reduction. The aim of the second phase of the study was to conduct an educational intervention and to develop a culturally appropriate and contextually specific health information intervention through a participatory process. Method: This was a qualitative study that was supported by elements of quantitative research.. The first phase of the current study was a needs assessment. The first step involved an observational phase with cooks from the centres. The aim was to observe their discretionary salt use during food preparation and to document the salt content in the processed foods available at each centre. Semi-structured interviews were then conducted, with 3 cooks and 16 guardians1 from the centres, to assess their knowledge and practices regarding salt reduction.Parents or the people responsible for the care of the children attending both centres. Guided by findings from the needs assessment phase, an educational intervention was developed. This phase involved the participatory development of three health information leaflets and a series of educational interactive sessions were conducted. Quantitative tests to assess the readability, suitability, and actionability were conducted on the leaflets. Qualitative assessment of the leaflets involved formative evaluations conducted by health care professionals, phase 1 participants, Rhodes University peer educators, an African languages and cultural expert, and a Rhodes University student wellness manager. This step was included to assess the content validity, context specificity, acceptability, and cultural appropriateness of the materials. Educational interactive sessions were guided by constructs of the Social Cognitive Theory and were conducted on three main topics: ‘Salt and my health’, ‘Reducing salt in my diet’, and ‘Reading food labels’. Results: The majority of the processed foods available at both centres contained low to medium levels of salt. Children at the centres were not provided with salt shakers on the tables during meal times. Cooks did not use measuring utensils when adding salt during meal preparation. Semistructured interviews revealed that participants lacked both declarative and procedural knowledge. In terms of declarative knowledge, they were unaware of the daily salt intake recommendations and the relationship between salt and sodium. Participants were able to identify hypertension as one of the health related consequences of high salt consumption. Most participants were responsible for purchasing groceries in their households. Their selfreported food label reading behaviours and inability to read food labels highlighted their lack of procedural knowledge. Most participants reported that they added salt during meal preparation and at mealtimes, highlighting high discretionary salt use. Some participants were also aware of cultural or religious uses of salt. The developed health information leaflets were considered to be written at a readability level appropriate for the target audience. The leaflets were also deemed to be actionable, culturally appropriate, and contextually specific and suitable materials. The educational interactive sessions were found to be interesting and informative. Conclusions: Findings from the needs assessment revealed the need for an educational intervention to address the identified gaps in the participants’ knowledge and practices regarding dietary salt reduction. The developed health information leaflets were found to be informative, culturally appropriate, and contextually specific, as planned. Interactive sessions provided an excellent platform to supply participants with concise and accurate information, increasing the possibility of improving their salt reduction related knowledge.
- Full Text:
- Authors: Mushoriwa, Fadzai
- Date: 2017
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/44761 , vital:25439
- Description: Background Globally, non-communicable diseases are the leading causes of mortality and morbidity, with the majority of these occurring in low-middle income countries. The devastating consequences of non-communicable diseases could be curtailed through better management of four modifiable factors: physical inactivity; tobacco use; harmful use of alcohol; and unhealthy diets. The World Health Organisation has recommended dietary salt reduction as a cost-effective strategy in combatting the burden of NCDs. Consumer awareness and education is one of three primary strategies that have been identified by the World Health Organisation to achieve population-wide salt reduction. It involves the provision of salt reduction knowledge and the promotion of healthy salt related practices. These campaigns are a necessity in populations with high discretionary salt use such as South Africa. For these health promotion activities to succeed, they need to be developed with consideration of factors such as the environment, culture, and socio-economic standing of the intended target population. This two-phase health promotion study was conducted at St Mary’s Development and Care Centre and the Assumption Sisters Nutrition Centre. These are two community based organisations located in Grahamstown, South Africa. A needs assessment was conducted to identify the knowledge and practices of cooks and guardians from these centres on dietary salt reduction. The aim of the second phase of the study was to conduct an educational intervention and to develop a culturally appropriate and contextually specific health information intervention through a participatory process. Method: This was a qualitative study that was supported by elements of quantitative research.. The first phase of the current study was a needs assessment. The first step involved an observational phase with cooks from the centres. The aim was to observe their discretionary salt use during food preparation and to document the salt content in the processed foods available at each centre. Semi-structured interviews were then conducted, with 3 cooks and 16 guardians1 from the centres, to assess their knowledge and practices regarding salt reduction.Parents or the people responsible for the care of the children attending both centres. Guided by findings from the needs assessment phase, an educational intervention was developed. This phase involved the participatory development of three health information leaflets and a series of educational interactive sessions were conducted. Quantitative tests to assess the readability, suitability, and actionability were conducted on the leaflets. Qualitative assessment of the leaflets involved formative evaluations conducted by health care professionals, phase 1 participants, Rhodes University peer educators, an African languages and cultural expert, and a Rhodes University student wellness manager. This step was included to assess the content validity, context specificity, acceptability, and cultural appropriateness of the materials. Educational interactive sessions were guided by constructs of the Social Cognitive Theory and were conducted on three main topics: ‘Salt and my health’, ‘Reducing salt in my diet’, and ‘Reading food labels’. Results: The majority of the processed foods available at both centres contained low to medium levels of salt. Children at the centres were not provided with salt shakers on the tables during meal times. Cooks did not use measuring utensils when adding salt during meal preparation. Semistructured interviews revealed that participants lacked both declarative and procedural knowledge. In terms of declarative knowledge, they were unaware of the daily salt intake recommendations and the relationship between salt and sodium. Participants were able to identify hypertension as one of the health related consequences of high salt consumption. Most participants were responsible for purchasing groceries in their households. Their selfreported food label reading behaviours and inability to read food labels highlighted their lack of procedural knowledge. Most participants reported that they added salt during meal preparation and at mealtimes, highlighting high discretionary salt use. Some participants were also aware of cultural or religious uses of salt. The developed health information leaflets were considered to be written at a readability level appropriate for the target audience. The leaflets were also deemed to be actionable, culturally appropriate, and contextually specific and suitable materials. The educational interactive sessions were found to be interesting and informative. Conclusions: Findings from the needs assessment revealed the need for an educational intervention to address the identified gaps in the participants’ knowledge and practices regarding dietary salt reduction. The developed health information leaflets were found to be informative, culturally appropriate, and contextually specific, as planned. Interactive sessions provided an excellent platform to supply participants with concise and accurate information, increasing the possibility of improving their salt reduction related knowledge.
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Hearing the citizens: inequality, access to journalists and the prospects for inclusively mediated spaces of political deliberation in South Africa
- Authors: Oelofsen, Marietjie
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/35030 , vital:24309
- Description: This study examines the extent to which material and social inequality in post-apartheid South Africa affect possibilities for poor citizens to gain access to mainstream spaces of mediated political deliberation. Access is problematized in terms of the possibilities that exist for poor citizens to ‘appear’ in these spaces as emancipated citizens with political agency. The study is motivated by a perception that South Africa’s middle-class and privileged citizens have more access to political deliberation because mainstream journalists pay more attention to their political concerns. Because mediated political deliberation provides a space for articulating the political will of citizens it is important that it reflects the multiple, and diverse range of voices that make up South Africa’s polity. If the experience of socioeconomically marginalised citizens is not registered in the same way as the experience of citizens with economic and political power, the balance of political decision-making continues to be skewed against the interests of the poor. Rather than a media-centric approach, the study centres on perceptions and views of poor citizens about their relationship with mainstream journalists. The study combines information from group interviews with citizens from Hangberg, Cape Town with 410 news reports in 18 mainstream newspapers about Hangberg citizens over a 20-year period. The interviews show that poor citizens feel largely excluded from mediated political deliberation; not because they do not appear in the news but because of how they appear in the news. The news reports confirm that mainstream journalists pay more attention to voices with political and economic power than to the voices of poor citizens. Even in news reports about Hangberg citizens, political leaders and non-governmental experts often talk about the problems in Hangberg more than the citizens of Hangberg themselves talk about these problems. Building on a relatively new scholarly interest in ‘active’ and ‘political’ listening in media studies and democratic theory (Bickford 1996, Dreher 2009, Couldry 2009, Dobson 2014, Wasserman 2013, Garman and Malila 2014), I consider listening as a constitutive element of the way in which journalists engage with poor citizens in mediated deliberative spaces. I ask whether different practices of listening can enable journalists to construct narratives that provide marginalised groups with different possibilities for equal access to, and participation in these spaces?
- Full Text:
- Authors: Oelofsen, Marietjie
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/35030 , vital:24309
- Description: This study examines the extent to which material and social inequality in post-apartheid South Africa affect possibilities for poor citizens to gain access to mainstream spaces of mediated political deliberation. Access is problematized in terms of the possibilities that exist for poor citizens to ‘appear’ in these spaces as emancipated citizens with political agency. The study is motivated by a perception that South Africa’s middle-class and privileged citizens have more access to political deliberation because mainstream journalists pay more attention to their political concerns. Because mediated political deliberation provides a space for articulating the political will of citizens it is important that it reflects the multiple, and diverse range of voices that make up South Africa’s polity. If the experience of socioeconomically marginalised citizens is not registered in the same way as the experience of citizens with economic and political power, the balance of political decision-making continues to be skewed against the interests of the poor. Rather than a media-centric approach, the study centres on perceptions and views of poor citizens about their relationship with mainstream journalists. The study combines information from group interviews with citizens from Hangberg, Cape Town with 410 news reports in 18 mainstream newspapers about Hangberg citizens over a 20-year period. The interviews show that poor citizens feel largely excluded from mediated political deliberation; not because they do not appear in the news but because of how they appear in the news. The news reports confirm that mainstream journalists pay more attention to voices with political and economic power than to the voices of poor citizens. Even in news reports about Hangberg citizens, political leaders and non-governmental experts often talk about the problems in Hangberg more than the citizens of Hangberg themselves talk about these problems. Building on a relatively new scholarly interest in ‘active’ and ‘political’ listening in media studies and democratic theory (Bickford 1996, Dreher 2009, Couldry 2009, Dobson 2014, Wasserman 2013, Garman and Malila 2014), I consider listening as a constitutive element of the way in which journalists engage with poor citizens in mediated deliberative spaces. I ask whether different practices of listening can enable journalists to construct narratives that provide marginalised groups with different possibilities for equal access to, and participation in these spaces?
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Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective
- Edkins, Adrienne L, Price, John T, Pockley, A Graham, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Price, John T , Pockley, A Graham , Blatch, Gregory L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164332 , vital:41109 , DOI: 10.1098/rstb.2016.0521
- Description: Many heat shock proteins (HSPs) are essential to survival as a consequence of their role as molecular chaperones, and play a critical role in maintaining cellular proteostasis by integrating the fundamental processes of protein folding and degradation. HSPs are arguably among the most prominent classes of proteins that have been broadly linked to many human disorders, with changes in their expression profile and/or intracellular/extracellular location now being described as contributing to the pathogenesis of a number of different diseases. Although the concept was initially controversial, it is now widely accepted that HSPs have additional biological functions over and above their role in proteostasis (so-called ‘protein moonlighting’).
- Full Text:
- Authors: Edkins, Adrienne L , Price, John T , Pockley, A Graham , Blatch, Gregory L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164332 , vital:41109 , DOI: 10.1098/rstb.2016.0521
- Description: Many heat shock proteins (HSPs) are essential to survival as a consequence of their role as molecular chaperones, and play a critical role in maintaining cellular proteostasis by integrating the fundamental processes of protein folding and degradation. HSPs are arguably among the most prominent classes of proteins that have been broadly linked to many human disorders, with changes in their expression profile and/or intracellular/extracellular location now being described as contributing to the pathogenesis of a number of different diseases. Although the concept was initially controversial, it is now widely accepted that HSPs have additional biological functions over and above their role in proteostasis (so-called ‘protein moonlighting’).
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Help or hindrance? a critical analysis of the agreement on sanitary and phytosanitary measures, and its effects on developing countries
- Authors: Waterworth, Tayla
- Date: 2017
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10962/7090 , vital:21216
- Description: WHILE it is accepted that the category of "developing country" is a broad one, it can nevertheless be acknowledged that the countries which fall within this categorisation share several common features. Such common features include their lack of financial resources and scientific capacity, and their reliance on trade in primary agricultural goods. The Agreement on Sanitary and Phytosanitary Measures was originally created to regulate trade in primary agricultural goods, and so its provisions are of great significance to developing countries. In its Preamble the Agreement acknowledges both the unique circumstances of developing countries and its desire to assist them in entering into and expanding within the international trading markets. As part of this endeavour, several provisions were included in the Agreement which purport to protect and provide for the interests of developing countries. In its inception, its Preamble, and the very nature of its content, the Agreement shows a desire to assist developing countries wherever possible. Unfortunately, a close analysis of the provisions of the Agreement shows that this desire has not been fulfilled. Many of the provisions of the Agreement are heavily skewed toward the interests of importing Members, often at the expense of developing Members - particularly those that export primary agricultural goods. Even the provisions of the Agreement which purport to provide protection and special and differential treatment specifically for developing countries frequently fall short, either as a result of ambiguous phrasing or poor textual interpretation by the dispute settlement bodies of the World Trade Organization. As a result, there exists a potential within the Agreement to have a significant detrimental impact on the international trading opportunities of exporting developing countries. In this thesis I analyse the provisions of the Agreement to determine where, why and how they are likely to have, or are having, a detrimental impact on developing countries (particularly exporting developing countries). After identifying these problems I examine and discuss several potential solutions and how they may be implemented to minimise - or even remove - the negative impact on developing countries and their international trading markets.
- Full Text:
- Authors: Waterworth, Tayla
- Date: 2017
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10962/7090 , vital:21216
- Description: WHILE it is accepted that the category of "developing country" is a broad one, it can nevertheless be acknowledged that the countries which fall within this categorisation share several common features. Such common features include their lack of financial resources and scientific capacity, and their reliance on trade in primary agricultural goods. The Agreement on Sanitary and Phytosanitary Measures was originally created to regulate trade in primary agricultural goods, and so its provisions are of great significance to developing countries. In its Preamble the Agreement acknowledges both the unique circumstances of developing countries and its desire to assist them in entering into and expanding within the international trading markets. As part of this endeavour, several provisions were included in the Agreement which purport to protect and provide for the interests of developing countries. In its inception, its Preamble, and the very nature of its content, the Agreement shows a desire to assist developing countries wherever possible. Unfortunately, a close analysis of the provisions of the Agreement shows that this desire has not been fulfilled. Many of the provisions of the Agreement are heavily skewed toward the interests of importing Members, often at the expense of developing Members - particularly those that export primary agricultural goods. Even the provisions of the Agreement which purport to provide protection and special and differential treatment specifically for developing countries frequently fall short, either as a result of ambiguous phrasing or poor textual interpretation by the dispute settlement bodies of the World Trade Organization. As a result, there exists a potential within the Agreement to have a significant detrimental impact on the international trading opportunities of exporting developing countries. In this thesis I analyse the provisions of the Agreement to determine where, why and how they are likely to have, or are having, a detrimental impact on developing countries (particularly exporting developing countries). After identifying these problems I examine and discuss several potential solutions and how they may be implemented to minimise - or even remove - the negative impact on developing countries and their international trading markets.
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Highly efficient CCl bond cleavage and unprecedented CC bond cleavage of environmentally toxic DDT through molecular electrochemical catalysis
- Liang, Xu, Huang, Tingting, Li, Minzhi, Mack, John, Wildervanck, Martijn, Nyokong, Tebello, Zhu, Weihua
- Authors: Liang, Xu , Huang, Tingting , Li, Minzhi , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Zhu, Weihua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188921 , vital:44798 , xlink:href="https://doi.org/10.1016/j.apcata.2017.07.026"
- Description: The electrocatalytic properties of a Co(II)octaalkoxyphthalocyanine complex (Co(II)Pc) with eight strongly electron-donating substituents provide the first example of the complete dechlorination of DDT through molecular electrocatalysis, rather than the use of metal electrodes which had been achieved previously. Interaction with a highly nucleophilic [Co(I)Pc]2− species results in rapid cleavage of the C(sp3) Cl, C(sp2) Cl and aromatic C(sp2) Cl bonds. Bis(p-chlorophenyl)methanone (BPCl2) is detected in high yield along with its full dechlorination product, diphenylmethanone (BP) and the conventional C Cl bond cleavage products, due to an unprecedented C C bond cleavage reaction that is followed by the formation of a C−O bond. Theoretical calculations are used to analyze trends in the electronic structure of the Co(II)octaalkoxyphthalocyanine complex that account for the efficiency of the C Cl bond cleavage reactions, and the reaction process and mechanism are analyzed in depth.
- Full Text:
- Authors: Liang, Xu , Huang, Tingting , Li, Minzhi , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Zhu, Weihua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188921 , vital:44798 , xlink:href="https://doi.org/10.1016/j.apcata.2017.07.026"
- Description: The electrocatalytic properties of a Co(II)octaalkoxyphthalocyanine complex (Co(II)Pc) with eight strongly electron-donating substituents provide the first example of the complete dechlorination of DDT through molecular electrocatalysis, rather than the use of metal electrodes which had been achieved previously. Interaction with a highly nucleophilic [Co(I)Pc]2− species results in rapid cleavage of the C(sp3) Cl, C(sp2) Cl and aromatic C(sp2) Cl bonds. Bis(p-chlorophenyl)methanone (BPCl2) is detected in high yield along with its full dechlorination product, diphenylmethanone (BP) and the conventional C Cl bond cleavage products, due to an unprecedented C C bond cleavage reaction that is followed by the formation of a C−O bond. Theoretical calculations are used to analyze trends in the electronic structure of the Co(II)octaalkoxyphthalocyanine complex that account for the efficiency of the C Cl bond cleavage reactions, and the reaction process and mechanism are analyzed in depth.
- Full Text:
Homecoming
- Authors: Mazwai, Nontsikelelo
- Date: 2017
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/164930 , vital:41185
- Description: Thesis (MA)--Rhodes University, Faculty of Humanities, School of Languages, 2017
- Full Text:
- Authors: Mazwai, Nontsikelelo
- Date: 2017
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/164930 , vital:41185
- Description: Thesis (MA)--Rhodes University, Faculty of Humanities, School of Languages, 2017
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How compatible are urban livestock and urban green spaces and trees?: An assessment in a medium-sized South African town
- Shackleton, Charlie M, Guild, Jenny, Bromham, B, Impey, S, Jarrett, Mitchell, Ngubane, S, Steijl, K
- Authors: Shackleton, Charlie M , Guild, Jenny , Bromham, B , Impey, S , Jarrett, Mitchell , Ngubane, S , Steijl, K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181048 , vital:43694 , xlink:href="https://doi.org/10.1080/19463138.2017.1314968"
- Description: Urban green spaces and trees provide multiple benefits to urban residents and the sustainability of cities. A poorly examined benefit is the provision of fodder to urban livestock. However, the presence and activities of livestock may be incompatible with other uses, although this has been little studied. We examined the impacts of livestock on trees and parks along a gradient of declining livestock density, complemented with a tree planting experiment to monitor damage. Neighbouring residents and park managers were interviewed regarding their perceptions of damage caused by livestock. The negative impacts on soil compaction, tree damage and death increased with increasing livestock densities. Thorny tree species were damaged significantly less (13 %) than non-thorny species (77 %), as were protected trees (25 %) relative to unprotected ones (65 %). There was more tree damage in public green spaces (PUGS) (54 %) than control sites (38 %). The majority of local residents felt that livestock should not be allowed in formal PUGS, and most urban park managers regarded livestock damage as a strong disincentive to plant trees. These results show the need for management of the trade-offs caused by livestock and greater appreciation of livestock as agents shaping aspects of PUGS.
- Full Text:
- Authors: Shackleton, Charlie M , Guild, Jenny , Bromham, B , Impey, S , Jarrett, Mitchell , Ngubane, S , Steijl, K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181048 , vital:43694 , xlink:href="https://doi.org/10.1080/19463138.2017.1314968"
- Description: Urban green spaces and trees provide multiple benefits to urban residents and the sustainability of cities. A poorly examined benefit is the provision of fodder to urban livestock. However, the presence and activities of livestock may be incompatible with other uses, although this has been little studied. We examined the impacts of livestock on trees and parks along a gradient of declining livestock density, complemented with a tree planting experiment to monitor damage. Neighbouring residents and park managers were interviewed regarding their perceptions of damage caused by livestock. The negative impacts on soil compaction, tree damage and death increased with increasing livestock densities. Thorny tree species were damaged significantly less (13 %) than non-thorny species (77 %), as were protected trees (25 %) relative to unprotected ones (65 %). There was more tree damage in public green spaces (PUGS) (54 %) than control sites (38 %). The majority of local residents felt that livestock should not be allowed in formal PUGS, and most urban park managers regarded livestock damage as a strong disincentive to plant trees. These results show the need for management of the trade-offs caused by livestock and greater appreciation of livestock as agents shaping aspects of PUGS.
- Full Text:
I did not die
- Authors: Mzamo, Tebello
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7246 , vital:21232
- Description: My novella is about a mine worker and his family. Set in both Lesotho and South Africa, it engages the effects of migrant labour on families in post-apartheid South Africa. Told through the eyes of the different family members, the narrative uses shifting points of view and moves fluidly through time to present an intimate but complex view of the lives of ordinary working class people. It incorporates witchcraft and ghosts to reveal the blurred lines between the realms of life and death. This collection is inspired by my own father who is a former mine worker. I am influenced by Joyce Carol Oates and Chibundu Onuzo's darkly realistic style, Veronique Tadjo’s explorations of migration and death, the family chronicles of Chimamanda Ngozi Adichie and Yvonne Adhiambo Owuor. I am also inspired by female fantasy and horror writers such as those collected in Ann and Jeff VanderMeer’s anthology, Sisters of the Revolution: A Feminist Speculative Fiction Anthology.
- Full Text:
- Authors: Mzamo, Tebello
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7246 , vital:21232
- Description: My novella is about a mine worker and his family. Set in both Lesotho and South Africa, it engages the effects of migrant labour on families in post-apartheid South Africa. Told through the eyes of the different family members, the narrative uses shifting points of view and moves fluidly through time to present an intimate but complex view of the lives of ordinary working class people. It incorporates witchcraft and ghosts to reveal the blurred lines between the realms of life and death. This collection is inspired by my own father who is a former mine worker. I am influenced by Joyce Carol Oates and Chibundu Onuzo's darkly realistic style, Veronique Tadjo’s explorations of migration and death, the family chronicles of Chimamanda Ngozi Adichie and Yvonne Adhiambo Owuor. I am also inspired by female fantasy and horror writers such as those collected in Ann and Jeff VanderMeer’s anthology, Sisters of the Revolution: A Feminist Speculative Fiction Anthology.
- Full Text:
I want to believe there is a girl here under the table
- Authors: Asfour, Fouad-Martin
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7190 , vital:21227
- Description: Written in non-linear fragments, my thesis is what Audre Lorde in her novel Zami calls a "biomythography" - the weaving together of myth, history and biography in epic narrative form, a style of composition that represents all the ways in which we perceive the world. Using repetition and shifting memories, I draw from my bicultural upbringing in Offenbach, a city in Germany populated mostly by migrants, as well as my experience of working in art and culture internationally, travelling and living in different countries. Interrogating objects, buildings, family photographs, books and movies, and listening to the silences of the unvoiced, I upset and play with experiences of othering, assumptions and expectations about identity and ask questions about home, belonging and migration, mother tongue and translation. I draw inspiration from Korean American artist Theresa Hak Kyung Cha's use of texts, documents and images to explore dislocation and memory, as well as authors who engage language, translation and belonging such as Mikhail Shishkin, Yoko Tawada, Gloria Anzaldua and Mohammed Khair-Eddine.
- Full Text:
- Authors: Asfour, Fouad-Martin
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7190 , vital:21227
- Description: Written in non-linear fragments, my thesis is what Audre Lorde in her novel Zami calls a "biomythography" - the weaving together of myth, history and biography in epic narrative form, a style of composition that represents all the ways in which we perceive the world. Using repetition and shifting memories, I draw from my bicultural upbringing in Offenbach, a city in Germany populated mostly by migrants, as well as my experience of working in art and culture internationally, travelling and living in different countries. Interrogating objects, buildings, family photographs, books and movies, and listening to the silences of the unvoiced, I upset and play with experiences of othering, assumptions and expectations about identity and ask questions about home, belonging and migration, mother tongue and translation. I draw inspiration from Korean American artist Theresa Hak Kyung Cha's use of texts, documents and images to explore dislocation and memory, as well as authors who engage language, translation and belonging such as Mikhail Shishkin, Yoko Tawada, Gloria Anzaldua and Mohammed Khair-Eddine.
- Full Text:
Identification of SNPs within the CYP2A6 enzyme of TNBC cell lines and the resulting change in activity
- Dingle, Laura Margaret Kirkpatrick
- Authors: Dingle, Laura Margaret Kirkpatrick
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64349 , vital:28536
- Description: Expected release date-May 2019
- Full Text:
- Authors: Dingle, Laura Margaret Kirkpatrick
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64349 , vital:28536
- Description: Expected release date-May 2019
- Full Text:
Identifying growth criteria and sediment movement mechanisms of needle ice using high-frequency environmental and visual monitoring
- Authors: Borg, Carl-Johan
- Date: 2017
- Subjects: Frazil ice , Sediment transport , Ice mechanics , Photography -- Digital techniques , Environmental monitoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/17656 , vital:22268
- Description: Environmental growth conditions and mechanisms involved in sediment transport by needle ice have historically been difficult to assess and are poorly documented. The spatial and temporal dynamics that relate to the environment, growth and decay of needle ice are not fully understood. This study monitored needle ice growth, melt and visually identified sediment displacement mechanisms by needle ice, with the aim of revealing environmental growth criteria, timing of growth/melt, ground-surface-air energy balance and sediment displacement mechanisms. Furthermore, the impact of needle ice displacement on vegetation and patterned ground formation was analysed. High-frequency visual monitoring, using three cameras, supplemented by high-frequency measurements of air temperature, soil moisture and wind speed was used to investigate needle ice growth and decay dynamics. Results from visual and environmental monitoring of needle ice growth, showed that the needle ice growing environment was more dynamic, especially in terms of surface temperature, than previously argued. Needle ice growth was observed to occur during surface temperatures from -2.0°C to 2.2°C, soil moisture levels from 0.4% to 37.4% and in winds speeds of 0 m/s to 12.6 m/s. Needle ice initiation was documented a few minutes to hours before or after the onset of surface temperature dropping to below 0°C. Imagery displayed that the depth of ice nucleation was variable within the soil column, possibly relating to the energy balance of radiative cooling, convective heat loss, ground conductivity and latent heat release at the air-surface-ground boundary. Heaving and resettling, toppling and rolling were identified as slope displacement mechanisms when needle ice decayed. Animal trampling and hail were additionally documented as substantial surface altering processes. Furthermore, no impact of needle ice reducing vegetation stability was identified, although a tendency to hinder vegetation expansion was noted. Also, no creation of patterned ground was observed as a result of needle ice decay.
- Full Text:
- Authors: Borg, Carl-Johan
- Date: 2017
- Subjects: Frazil ice , Sediment transport , Ice mechanics , Photography -- Digital techniques , Environmental monitoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/17656 , vital:22268
- Description: Environmental growth conditions and mechanisms involved in sediment transport by needle ice have historically been difficult to assess and are poorly documented. The spatial and temporal dynamics that relate to the environment, growth and decay of needle ice are not fully understood. This study monitored needle ice growth, melt and visually identified sediment displacement mechanisms by needle ice, with the aim of revealing environmental growth criteria, timing of growth/melt, ground-surface-air energy balance and sediment displacement mechanisms. Furthermore, the impact of needle ice displacement on vegetation and patterned ground formation was analysed. High-frequency visual monitoring, using three cameras, supplemented by high-frequency measurements of air temperature, soil moisture and wind speed was used to investigate needle ice growth and decay dynamics. Results from visual and environmental monitoring of needle ice growth, showed that the needle ice growing environment was more dynamic, especially in terms of surface temperature, than previously argued. Needle ice growth was observed to occur during surface temperatures from -2.0°C to 2.2°C, soil moisture levels from 0.4% to 37.4% and in winds speeds of 0 m/s to 12.6 m/s. Needle ice initiation was documented a few minutes to hours before or after the onset of surface temperature dropping to below 0°C. Imagery displayed that the depth of ice nucleation was variable within the soil column, possibly relating to the energy balance of radiative cooling, convective heat loss, ground conductivity and latent heat release at the air-surface-ground boundary. Heaving and resettling, toppling and rolling were identified as slope displacement mechanisms when needle ice decayed. Animal trampling and hail were additionally documented as substantial surface altering processes. Furthermore, no impact of needle ice reducing vegetation stability was identified, although a tendency to hinder vegetation expansion was noted. Also, no creation of patterned ground was observed as a result of needle ice decay.
- Full Text:
Impact of an introduced predator (Micropterus salmoides, Centrarchidae) on native estuarine fish elucidated through fatty acid analyses
- Carassou, Laure, Magoro, Mandla L, Whitfield, Alan K, Richoux, Nicole B
- Authors: Carassou, Laure , Magoro, Mandla L , Whitfield, Alan K , Richoux, Nicole B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456247 , vital:75496 , xlink:href="https://hal.inrae.fr/hal-04177984/document"
- Description: The introduction of alien fish species can have contrasting impacts on local aquatic communities. The largemouth bass Micropterus salmoides (Centrarchidae; Fig.1) was introduced in 1928 in South Africa for recreational anglers. Concerns about its impact on local indigenous freshwater and estuarine fish populations are raised (Gratwicke and Marshall, 2001; Weyl and Lewis, 2006; Wasserman et al., 2011). In particular, the predatory impact of M. salmoides on estuary-associated juveniles of marine fish species must be elucidated.
- Full Text:
- Authors: Carassou, Laure , Magoro, Mandla L , Whitfield, Alan K , Richoux, Nicole B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456247 , vital:75496 , xlink:href="https://hal.inrae.fr/hal-04177984/document"
- Description: The introduction of alien fish species can have contrasting impacts on local aquatic communities. The largemouth bass Micropterus salmoides (Centrarchidae; Fig.1) was introduced in 1928 in South Africa for recreational anglers. Concerns about its impact on local indigenous freshwater and estuarine fish populations are raised (Gratwicke and Marshall, 2001; Weyl and Lewis, 2006; Wasserman et al., 2011). In particular, the predatory impact of M. salmoides on estuary-associated juveniles of marine fish species must be elucidated.
- Full Text:
Implementing the annual national assessment at an ordinary public primary school in the Eastern Cape: a case study analysis
- Authors: Lascelles, Philippa Anne
- Date: 2017
- Subjects: Educational tests and measurements -- South Africa , Educational tests and measurements -- South Africa -- Case studies , Education, Elementary -- South Africa , Elementary schools -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7713 , vital:21288
- Description: This empirical study describes in rich detail five teachers’ perceptions of the Annual National Assessment [ANA] at one level of the school system (Grade Three of the Foundation Phase [FP]) at an ordinary public primary school in an urban area of the Eastern Cape. Secondly, the study described the process of preparing for, implementing and assessing the 2014 ANA at the selected school. In order to generate insights for a deep understanding of how teachers perceive, prepare for and implement the ANA, the challenges that arise, and how the ANA is impacting on curriculum and pedagogy, an interpretive qualitative research approach and case study method were adopted. The researcher, a participant observer operating from an insider position, used ethnographic techniques to describe, document and analyse teachers’ perceptions and experiences of implementing the 2014 ANA tests in a specific context (one school) and at one level of the school system (Grade 3). Data gathered through observations, semi-structured interviews and document analysis were coded and analysed in order to identify emerging themes. These are compared to trends and developments in contemporary literature on educational assessment. The findings revealed that while the teachers were compliant and efficient in their implementation and administration of the ANA, they have a narrow perception of the ANA as a summative assessment serving systemic purposes. There was little, if any, evidence of them using the ANA for the formative assessment purposes intended by policy. As a result, opportunities for using the ANA to enhance teaching and learning were lost. The study illuminated the roles and responsibilities of the teachers, the school management team and Eastern Cape [EC] Department of Education [DoE] in the ANA preparation and implementation process, and the need for strengthening the support provided by the EC DoE. Although context specific, the study sheds light on how Grade 3 teachers in an ordinary public school perceive and implement the ANA. The insights afforded and lessons that can be learned from this case study may be relevant to other Foundation Phase school contexts.
- Full Text:
- Authors: Lascelles, Philippa Anne
- Date: 2017
- Subjects: Educational tests and measurements -- South Africa , Educational tests and measurements -- South Africa -- Case studies , Education, Elementary -- South Africa , Elementary schools -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7713 , vital:21288
- Description: This empirical study describes in rich detail five teachers’ perceptions of the Annual National Assessment [ANA] at one level of the school system (Grade Three of the Foundation Phase [FP]) at an ordinary public primary school in an urban area of the Eastern Cape. Secondly, the study described the process of preparing for, implementing and assessing the 2014 ANA at the selected school. In order to generate insights for a deep understanding of how teachers perceive, prepare for and implement the ANA, the challenges that arise, and how the ANA is impacting on curriculum and pedagogy, an interpretive qualitative research approach and case study method were adopted. The researcher, a participant observer operating from an insider position, used ethnographic techniques to describe, document and analyse teachers’ perceptions and experiences of implementing the 2014 ANA tests in a specific context (one school) and at one level of the school system (Grade 3). Data gathered through observations, semi-structured interviews and document analysis were coded and analysed in order to identify emerging themes. These are compared to trends and developments in contemporary literature on educational assessment. The findings revealed that while the teachers were compliant and efficient in their implementation and administration of the ANA, they have a narrow perception of the ANA as a summative assessment serving systemic purposes. There was little, if any, evidence of them using the ANA for the formative assessment purposes intended by policy. As a result, opportunities for using the ANA to enhance teaching and learning were lost. The study illuminated the roles and responsibilities of the teachers, the school management team and Eastern Cape [EC] Department of Education [DoE] in the ANA preparation and implementation process, and the need for strengthening the support provided by the EC DoE. Although context specific, the study sheds light on how Grade 3 teachers in an ordinary public school perceive and implement the ANA. The insights afforded and lessons that can be learned from this case study may be relevant to other Foundation Phase school contexts.
- Full Text:
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
Improved nonlinear optical behaviour of ball type indium (III) phthalocyanine linked to glutathione capped nanoparticles
- Nwaji, Njemuwa, Oluwole, David O, Mack, John, Louzada, Marcel, Khene, Samson M, Britton, Jonathan, Nyokong, Tebello
- Authors: Nwaji, Njemuwa , Oluwole, David O , Mack, John , Louzada, Marcel , Khene, Samson M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239654 , vital:50752 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.01.066"
- Description: The synthesis of ball–type indium phthalocyanine (complex 4) and its covalent attachment to glutathione (GSH–) capped (Ag, Au, CdTeSe, CdTeSe/ZnO) nanoparticles are reported in this work. Furthermore, their photophysical and nonlinear optical behaviour were investigated. We observed a decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield of the nanoconjugates in comparison to complex 4 alone. The reverse saturable absorption was found to be dependent on excited state absorption. The optical limiting threshold ranges from 0.40–0.78 (J/cm2). The nanoconjugate of the complex 4 with GSH–CdTeSe/ZnO (QD1) accounted for the most improved triplet state parameters and nonlinear optical behaviour in comparison to complex 4 and the other nanoconjugates studied in this work.
- Full Text:
- Authors: Nwaji, Njemuwa , Oluwole, David O , Mack, John , Louzada, Marcel , Khene, Samson M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239654 , vital:50752 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.01.066"
- Description: The synthesis of ball–type indium phthalocyanine (complex 4) and its covalent attachment to glutathione (GSH–) capped (Ag, Au, CdTeSe, CdTeSe/ZnO) nanoparticles are reported in this work. Furthermore, their photophysical and nonlinear optical behaviour were investigated. We observed a decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield of the nanoconjugates in comparison to complex 4 alone. The reverse saturable absorption was found to be dependent on excited state absorption. The optical limiting threshold ranges from 0.40–0.78 (J/cm2). The nanoconjugate of the complex 4 with GSH–CdTeSe/ZnO (QD1) accounted for the most improved triplet state parameters and nonlinear optical behaviour in comparison to complex 4 and the other nanoconjugates studied in this work.
- Full Text:
Improved photocatalytic degradation of Orange G using hybrid nanofibers
- Ledwaba, Mpho, Masilela, Nkosiphile, Nyokong, Tebello, Antunes, Edith M
- Authors: Ledwaba, Mpho , Masilela, Nkosiphile , Nyokong, Tebello , Antunes, Edith M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239632 , vital:50750 , xlink:href="https://doi.org/10.1007/s11051-017-3853-3"
- Description: Functionalised electrospun polyamide-6 (PA-6) nanofibres incorporating gadolinium oxide nanoparticles conjugated to zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc) as the sensitizer were prepared for the photocatalytic degradation of Orange G. Fibres incorporating the phthalocyanine alone or a mixture of the nanoparticles and phthalocyanine were also generated. The singlet oxygen-generating ability of the sensitizer was shown to be maintained within the fibre mat, with the singlet oxygen quantum yields increasing upon incorporation of the magnetic nanoparticles. Consequently, the rate of the photodegradation of Orange G was observed to increase with an increase in singlet oxygen quantum yield. A reduction in the half-lives for the functionalised nanofibres was recorded in the presence of the magnetic nanoparticles, indicating an improvement in the efficiency of the degradation process.
- Full Text:
- Authors: Ledwaba, Mpho , Masilela, Nkosiphile , Nyokong, Tebello , Antunes, Edith M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239632 , vital:50750 , xlink:href="https://doi.org/10.1007/s11051-017-3853-3"
- Description: Functionalised electrospun polyamide-6 (PA-6) nanofibres incorporating gadolinium oxide nanoparticles conjugated to zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc) as the sensitizer were prepared for the photocatalytic degradation of Orange G. Fibres incorporating the phthalocyanine alone or a mixture of the nanoparticles and phthalocyanine were also generated. The singlet oxygen-generating ability of the sensitizer was shown to be maintained within the fibre mat, with the singlet oxygen quantum yields increasing upon incorporation of the magnetic nanoparticles. Consequently, the rate of the photodegradation of Orange G was observed to increase with an increase in singlet oxygen quantum yield. A reduction in the half-lives for the functionalised nanofibres was recorded in the presence of the magnetic nanoparticles, indicating an improvement in the efficiency of the degradation process.
- Full Text:
Improvement of the pharmacological activity of menthol via enzymatic β-anomer-selective glycosylation
- Choi, Ha-Young, Kim, Bo-Min, Morgan, Abubaker M A, Kim, Joong Su, Kim, Won-Gon
- Authors: Choi, Ha-Young , Kim, Bo-Min , Morgan, Abubaker M A , Kim, Joong Su , Kim, Won-Gon
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67515 , vital:29106 , http://dx.doi.org/10.1186/s13568-017-0468-0
- Description: Publisher version , Menthol has a considerable cooling effect, but the use range of menthol is limited because of its extremely low solubility in water and inherent flavor. (−)-Menthol β-glucoside was determined to be more soluble in water (>27 times) than (−)-menthol α-glucoside; hence, β-anomer-selective glucosylation of menthol is necessary. The in vitro glycosylation of (−)-menthol by uridine diphosphate glycosyltransferase (BLC) from Bacillus licheniformis generated (−)-menthol β-glucoside and new (−)-menthol β-galactoside and (−)-menthol N-acetylglucosamine. The maximum conversion rate of menthol to (−)-menthol β-D-glucoside by BLC was found to be 58.9%. Importantly, (−)-menthol β-D-glucoside had a higher cooling effect and no flavor compared with menthol. In addition, (−)-menthol β-D-glucoside was determined to be a non-sensitizer in a skin allergy test in the human cell line activation test, whereas menthol was a sensitizer.
- Full Text:
- Authors: Choi, Ha-Young , Kim, Bo-Min , Morgan, Abubaker M A , Kim, Joong Su , Kim, Won-Gon
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67515 , vital:29106 , http://dx.doi.org/10.1186/s13568-017-0468-0
- Description: Publisher version , Menthol has a considerable cooling effect, but the use range of menthol is limited because of its extremely low solubility in water and inherent flavor. (−)-Menthol β-glucoside was determined to be more soluble in water (>27 times) than (−)-menthol α-glucoside; hence, β-anomer-selective glucosylation of menthol is necessary. The in vitro glycosylation of (−)-menthol by uridine diphosphate glycosyltransferase (BLC) from Bacillus licheniformis generated (−)-menthol β-glucoside and new (−)-menthol β-galactoside and (−)-menthol N-acetylglucosamine. The maximum conversion rate of menthol to (−)-menthol β-D-glucoside by BLC was found to be 58.9%. Importantly, (−)-menthol β-D-glucoside had a higher cooling effect and no flavor compared with menthol. In addition, (−)-menthol β-D-glucoside was determined to be a non-sensitizer in a skin allergy test in the human cell line activation test, whereas menthol was a sensitizer.
- Full Text: