Physicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanine-nanoparticle conjugates
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
Phytochemical, anti-inflammatory and anti-trypanosomal properties of Anthocleista vogelii Planch (Loganiaceae) stem bark
- Eze, Fabian I, Siwe-Noundou, Xavier, Osadebe, Patience, Krause, Rui W M
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Osadebe, Patience , Krause, Rui W M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194059 , vital:45419 , xlink:href="https://doi.org/10.1016/j.jep.2019.111851"
- Description: Ethnopharmacological relevance: Anthocleista vogelii Planch (Loganiaceae) is used in African Traditional Medicine for the treatment of pain and inflammatory disorders as well as sleeping sickness. Aim of the study: To determine the in vivo anti-inflammatory and in vitro anti-trypanosomal activities of the extracts of A. vogelii stem bark and identify the phytochemical classes of the fractions responsible for the activities. Materials and methods: The in vivo anti-inflammatory activity of the extracts was evaluated using the egg albumin-induced rat paw oedema model while the in vitro anti-trypanosomal activity was assessed on Trypanosoma brucei brucei. The in vitro cytotoxicity was assessed on HeLa (human cervix adenocarcinoma) cell line. Results: The methanolic extract of A. vogelii stem bark, with 11.2% yield, gave LD50 > 5000 mg/kg. The n-hexane fraction of the extract contains steroids, terpenes and fatty acids and yielded non-cytotoxic terpenoidal column fraction with anti-trypanosomal IC50 of 3.0 μg/mL. The ethylacetate fraction at 100 mg/kg dose significantly (p less than 0.05) provoked 37.8, 62.5 and 69.7% inhibition of oedema induced by egg-albumin at the second, fourth and sixth hours respectively. Conclusion: The study demonstrated that the anti-inflammatory and anti-trypanosomal activities of A. vogelii are probably due to non-cytotoxic terpenoids and validated the traditional use of A. vogelii in the treatment of inflammation and sleeping sickness.
- Full Text:
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Osadebe, Patience , Krause, Rui W M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194059 , vital:45419 , xlink:href="https://doi.org/10.1016/j.jep.2019.111851"
- Description: Ethnopharmacological relevance: Anthocleista vogelii Planch (Loganiaceae) is used in African Traditional Medicine for the treatment of pain and inflammatory disorders as well as sleeping sickness. Aim of the study: To determine the in vivo anti-inflammatory and in vitro anti-trypanosomal activities of the extracts of A. vogelii stem bark and identify the phytochemical classes of the fractions responsible for the activities. Materials and methods: The in vivo anti-inflammatory activity of the extracts was evaluated using the egg albumin-induced rat paw oedema model while the in vitro anti-trypanosomal activity was assessed on Trypanosoma brucei brucei. The in vitro cytotoxicity was assessed on HeLa (human cervix adenocarcinoma) cell line. Results: The methanolic extract of A. vogelii stem bark, with 11.2% yield, gave LD50 > 5000 mg/kg. The n-hexane fraction of the extract contains steroids, terpenes and fatty acids and yielded non-cytotoxic terpenoidal column fraction with anti-trypanosomal IC50 of 3.0 μg/mL. The ethylacetate fraction at 100 mg/kg dose significantly (p less than 0.05) provoked 37.8, 62.5 and 69.7% inhibition of oedema induced by egg-albumin at the second, fourth and sixth hours respectively. Conclusion: The study demonstrated that the anti-inflammatory and anti-trypanosomal activities of A. vogelii are probably due to non-cytotoxic terpenoids and validated the traditional use of A. vogelii in the treatment of inflammation and sleeping sickness.
- Full Text:
Pigs vs people: the use of pigs as analogues for humans in forensic entomology and taphonomy research
- Matuszewski, Szymon, Hall, Martin J R, Moreau, Gaétan, Schoenly, Kenneth G, Tarone, Aaron M, Villet, Martin H
- Authors: Matuszewski, Szymon , Hall, Martin J R , Moreau, Gaétan , Schoenly, Kenneth G , Tarone, Aaron M , Villet, Martin H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140557 , vital:37898 , DOI: 10.1007/s00414-019-02074-5
- Description: Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.
- Full Text:
- Authors: Matuszewski, Szymon , Hall, Martin J R , Moreau, Gaétan , Schoenly, Kenneth G , Tarone, Aaron M , Villet, Martin H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140557 , vital:37898 , DOI: 10.1007/s00414-019-02074-5
- Description: Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.
- Full Text:
Plant disease detection and classification for farmers and everyday gardeners
- Poole, Louise C, Brown, Dane L
- Authors: Poole, Louise C , Brown, Dane L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465722 , vital:76635 , xlink:href="https://www.researchgate.net/profile/Dane-Brown-2/publication/335378684_Plant_Disease_Detection_and_Classification_for_Farmers_and_Everyday_Gardeners/links/5d611905299bf1f70b090b54/Plant-Disease-Detection-and-Classification-for-Farmers-and-Everyday-Gardeners.pdf"
- Description: Identifying and rating diseases by hand is an expensive, time consuming, subjective and unreliable method as compared to what computers can provide. Image processing and machine learning enable automated disease identification. Research has proven that automated disease identification systems can be used as a preventative measure against plant rot and death. This paper narrows down the best techniques to segment images of leaves toward improved classification of diseases found on those leaves. An investigation is conducted on image segmentation and machine learning techniques, including state-of-the-art systems, to determine the most appropriate approach to prevent death and rot in plants. Promising results were observed during testing, and show that a system can be implemented to assist with plant health that is relevant to both home gardeners and farmers.
- Full Text:
- Authors: Poole, Louise C , Brown, Dane L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465722 , vital:76635 , xlink:href="https://www.researchgate.net/profile/Dane-Brown-2/publication/335378684_Plant_Disease_Detection_and_Classification_for_Farmers_and_Everyday_Gardeners/links/5d611905299bf1f70b090b54/Plant-Disease-Detection-and-Classification-for-Farmers-and-Everyday-Gardeners.pdf"
- Description: Identifying and rating diseases by hand is an expensive, time consuming, subjective and unreliable method as compared to what computers can provide. Image processing and machine learning enable automated disease identification. Research has proven that automated disease identification systems can be used as a preventative measure against plant rot and death. This paper narrows down the best techniques to segment images of leaves toward improved classification of diseases found on those leaves. An investigation is conducted on image segmentation and machine learning techniques, including state-of-the-art systems, to determine the most appropriate approach to prevent death and rot in plants. Promising results were observed during testing, and show that a system can be implemented to assist with plant health that is relevant to both home gardeners and farmers.
- Full Text:
Plants, people, and place: complex, mutualistic, and co-evolving global patterns through time
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
Plaxenone A and B: Cytotoxic halogenated monoterpenes from the South African red seaweed Plocamium maxillosum
- Knott, Michael G, de la Mare, Jo-Anne, Edkins, Adrienne L, Zhang, Angel, Stillman, Martin J, Bolton, John J, Antunes, Edith M, Beukes, Denzil R
- Authors: Knott, Michael G , de la Mare, Jo-Anne , Edkins, Adrienne L , Zhang, Angel , Stillman, Martin J , Bolton, John J , Antunes, Edith M , Beukes, Denzil R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164446 , vital:41119 , https://doi.org/10.1016/j.phytol.2018.12.009
- Description: The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.
- Full Text:
- Authors: Knott, Michael G , de la Mare, Jo-Anne , Edkins, Adrienne L , Zhang, Angel , Stillman, Martin J , Bolton, John J , Antunes, Edith M , Beukes, Denzil R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164446 , vital:41119 , https://doi.org/10.1016/j.phytol.2018.12.009
- Description: The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.
- Full Text:
Poacher detection and wildlife counting system
- Brown, Dane L, Schormann, Daniel
- Authors: Brown, Dane L , Schormann, Daniel
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465733 , vital:76636 , xlink:href="https://www.researchgate.net/profile/Dane-Brown-2/publication/335378767_Poacher_Detection_and_Wildlife_Counting_System/links/5d6117c7a6fdccc32ccd2cac/Poacher-Detection-and-Wildlife-Counting-System.pdf"
- Description: The illegal hunting of wildlife is a serious problem, causing a large number of animals to approach extinction or worse. Drones provide a viable option for constant surveillance and multiple instances of using drones for this purpose have been tried. However, existing methods predominantly rely on manual surveillance from camera feeds. This paper shows that using either visible or thermal cameras, with modern image processing and machine learning techniques, enables a system to autonomously detect humans, while tracking animals by their identity number (id). The thermal characteristics of special but inexpensive cameras are used for object detection with centroid tracking, and convolutional neural networks are used to classify humans and wildlife. Classification also enables the counting of wildlife by id, which can help game reserves keep track of wildlife.
- Full Text:
- Authors: Brown, Dane L , Schormann, Daniel
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465733 , vital:76636 , xlink:href="https://www.researchgate.net/profile/Dane-Brown-2/publication/335378767_Poacher_Detection_and_Wildlife_Counting_System/links/5d6117c7a6fdccc32ccd2cac/Poacher-Detection-and-Wildlife-Counting-System.pdf"
- Description: The illegal hunting of wildlife is a serious problem, causing a large number of animals to approach extinction or worse. Drones provide a viable option for constant surveillance and multiple instances of using drones for this purpose have been tried. However, existing methods predominantly rely on manual surveillance from camera feeds. This paper shows that using either visible or thermal cameras, with modern image processing and machine learning techniques, enables a system to autonomously detect humans, while tracking animals by their identity number (id). The thermal characteristics of special but inexpensive cameras are used for object detection with centroid tracking, and convolutional neural networks are used to classify humans and wildlife. Classification also enables the counting of wildlife by id, which can help game reserves keep track of wildlife.
- Full Text:
Political constellations: an analysis of the use of language in positioning South African political parties in the Daily Sun
- Authors: Siebörger, Ian
- Date: 2019
- Subjects: Knowledge, Theory of , Political culture South Africa , Systemic grammar , Political parties South Africa , Functionalism (Linguistics) , Mass media and language South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/113934 , vital:33846 , http://doi.org/10.21504/10962/113934
- Description: As a young democracy, post-apartheid South Africa has both a complex and rapidly changing political landscape, and a developing system of interconnected public spheres in which ordinary citizens engage in political discourses. In this context, this thesis examines the ways in which language is used to position South Africa's political parties in the Daily Sun, the country's most widely-read tabloid newspaper. It uses a complex, multi-stage method of analysis to develop tools for describing how different policy positions and moral evaluations are associated with political parties. This is accomplished through complementary analyses using Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). The study describes current political discourses in South Africa as the products of a long process of historical development extending through the segregationist and apartheid eras to the post-apartheid present. It also situates the Daily Sun within South Africa's current media landscape and argues that the newspaper is to some extent successful in facilitating a vibrant alternative public sphere in which readers engage with the news. The study's multi-stage method of analysis begins with a corpus analysis of all political news articles from the Daily Sun dating from January to June 2015. This analysis reveals various tendencies in the positioning of South Africa's three largest political parties that are investigated further in later stages of analysis. Three selected individual articles are subjected to _ne-grained analysis in an exploratory analysis stage, and three others in a targeted analysis stage. The exploratory analyses are designed to investigate the contribution of various linguistic and discursive resources to political positioning in the data, while the targeted analyses demonstrate the contribution of these resources to positioning in articles that were carefully selected to reflect as many of the trends found in the corpus analysis as possible. These analyses enact the concept of axiological-semantic density from LCT to show the ways in which political knowledge is condensed in the articles. This condensation produces constellations of people, policy positions and moral evaluations in each article. These constellations, in turn, give indications of the cosmologies, or organizing principles, behind the Daily Sun's political news coverage. On the basis of the exploratory analyses, a multi-level translation device for axiological-semantic density is developed to describe the ways in which this concept is enacted in the analysis. The use of this translation device is then demonstrated using the targeted analyses. This study adapts the concepts of iconization, aggregation and technicality from SFL, collectively referred to as 'mass', to show how language works to position political parties. It finds that the use of intertextual references and lexical strings makes a considerable contribution toward political positioning in the data. Repeated couplings of the abovementioned resources in complexes (also known as syndromes) drive the process of political positioning. The Daily Sun is found to report primarily on concrete actions by individual politicians, and contains little to no information on policy decisions. No one political party is favoured, but coverage tends to emphasize accusations against politicians. This may reinforce distrust in politics and a withdrawal from engagement in political processes among readers. By contrast, this study shows that engagement in South Africa's public discourses can be encouraged through stronger promotion of critical language awareness in education, the growth of civil society organizations as vehicles for dialogue and social action on matters of public interest, and a variety of initiatives by the media designed to show the relevance of policy decisions to individuals' lives and increase participation in the news-making process. , Thesis (PhD) -- Faculty of Humanities, English Language and Linguistics, 2019
- Full Text: false
- Authors: Siebörger, Ian
- Date: 2019
- Subjects: Knowledge, Theory of , Political culture South Africa , Systemic grammar , Political parties South Africa , Functionalism (Linguistics) , Mass media and language South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/113934 , vital:33846 , http://doi.org/10.21504/10962/113934
- Description: As a young democracy, post-apartheid South Africa has both a complex and rapidly changing political landscape, and a developing system of interconnected public spheres in which ordinary citizens engage in political discourses. In this context, this thesis examines the ways in which language is used to position South Africa's political parties in the Daily Sun, the country's most widely-read tabloid newspaper. It uses a complex, multi-stage method of analysis to develop tools for describing how different policy positions and moral evaluations are associated with political parties. This is accomplished through complementary analyses using Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). The study describes current political discourses in South Africa as the products of a long process of historical development extending through the segregationist and apartheid eras to the post-apartheid present. It also situates the Daily Sun within South Africa's current media landscape and argues that the newspaper is to some extent successful in facilitating a vibrant alternative public sphere in which readers engage with the news. The study's multi-stage method of analysis begins with a corpus analysis of all political news articles from the Daily Sun dating from January to June 2015. This analysis reveals various tendencies in the positioning of South Africa's three largest political parties that are investigated further in later stages of analysis. Three selected individual articles are subjected to _ne-grained analysis in an exploratory analysis stage, and three others in a targeted analysis stage. The exploratory analyses are designed to investigate the contribution of various linguistic and discursive resources to political positioning in the data, while the targeted analyses demonstrate the contribution of these resources to positioning in articles that were carefully selected to reflect as many of the trends found in the corpus analysis as possible. These analyses enact the concept of axiological-semantic density from LCT to show the ways in which political knowledge is condensed in the articles. This condensation produces constellations of people, policy positions and moral evaluations in each article. These constellations, in turn, give indications of the cosmologies, or organizing principles, behind the Daily Sun's political news coverage. On the basis of the exploratory analyses, a multi-level translation device for axiological-semantic density is developed to describe the ways in which this concept is enacted in the analysis. The use of this translation device is then demonstrated using the targeted analyses. This study adapts the concepts of iconization, aggregation and technicality from SFL, collectively referred to as 'mass', to show how language works to position political parties. It finds that the use of intertextual references and lexical strings makes a considerable contribution toward political positioning in the data. Repeated couplings of the abovementioned resources in complexes (also known as syndromes) drive the process of political positioning. The Daily Sun is found to report primarily on concrete actions by individual politicians, and contains little to no information on policy decisions. No one political party is favoured, but coverage tends to emphasize accusations against politicians. This may reinforce distrust in politics and a withdrawal from engagement in political processes among readers. By contrast, this study shows that engagement in South Africa's public discourses can be encouraged through stronger promotion of critical language awareness in education, the growth of civil society organizations as vehicles for dialogue and social action on matters of public interest, and a variety of initiatives by the media designed to show the relevance of policy decisions to individuals' lives and increase participation in the news-making process. , Thesis (PhD) -- Faculty of Humanities, English Language and Linguistics, 2019
- Full Text: false
Popular politics in the rural Western Cape, South Africa: a case study of Ruiterbos
- Authors: Ghedi Alasow, Jonis
- Date: 2019
- Subjects: Political participation -- South Africa -- Cape Town , South Africa -- Politics and government -- 1994- , Land tenure -- Political aspects -- South Africa , Land use, Rural -- Political aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96165 , vital:31246
- Description: This thesis argues that the philosophical foundations upon which human beings have been engaged have, across various schools of thought, made the mistake of presuming that some people are more modern than others. This suggestion is refuted throughout this thesis. To do this, intellectual traditions that take the fundamental rationality of all human beings as an indispensable starting point are engaged to argue for the need to acknowledge that everyone in the ‘now’ is indeed, of the ‘now’. This thesis connects these debates about modernity, rationality and humanity to the contemporary discussions around rural politics with particular reference to Ruiterbos in the Western Cape province of South Africa. By means of detailed empirical and ethnographic research, this thesis illustrates the issues around which people in Ruiterbos are politicised. Via this case study, the a priori assumption that rural politics will necessarily manifest itself only with respect to questions of land and agrarian reform or labour relations is complicated. The two issues around which people in Ruiterbos, during the time of this research, seem to be politicised – housing and education – are surfaced throughout this thesis. The thesis argues that the findings in this case study call for an expansion of the issues that are traditionally considered when the question of rural politics is raised. The often historicist approach that limits the possibilities for politics in rural areas should be suspended for an approach that takes popular politics and political agents in rural areas seriously. The thesis finally argues that the conclusions that are reached with respect to questions of modernity and rural politics ought to be adopted to allow for more detailed and thorough explanations of popular politics in places like Ruiterbos.
- Full Text:
- Authors: Ghedi Alasow, Jonis
- Date: 2019
- Subjects: Political participation -- South Africa -- Cape Town , South Africa -- Politics and government -- 1994- , Land tenure -- Political aspects -- South Africa , Land use, Rural -- Political aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96165 , vital:31246
- Description: This thesis argues that the philosophical foundations upon which human beings have been engaged have, across various schools of thought, made the mistake of presuming that some people are more modern than others. This suggestion is refuted throughout this thesis. To do this, intellectual traditions that take the fundamental rationality of all human beings as an indispensable starting point are engaged to argue for the need to acknowledge that everyone in the ‘now’ is indeed, of the ‘now’. This thesis connects these debates about modernity, rationality and humanity to the contemporary discussions around rural politics with particular reference to Ruiterbos in the Western Cape province of South Africa. By means of detailed empirical and ethnographic research, this thesis illustrates the issues around which people in Ruiterbos are politicised. Via this case study, the a priori assumption that rural politics will necessarily manifest itself only with respect to questions of land and agrarian reform or labour relations is complicated. The two issues around which people in Ruiterbos, during the time of this research, seem to be politicised – housing and education – are surfaced throughout this thesis. The thesis argues that the findings in this case study call for an expansion of the issues that are traditionally considered when the question of rural politics is raised. The often historicist approach that limits the possibilities for politics in rural areas should be suspended for an approach that takes popular politics and political agents in rural areas seriously. The thesis finally argues that the conclusions that are reached with respect to questions of modernity and rural politics ought to be adopted to allow for more detailed and thorough explanations of popular politics in places like Ruiterbos.
- Full Text:
Post-release evaluation of Megamelus scutellaris Berg. (hemiptera: delphacidae): a biological control agent of water hyacinth Eichhornia crassipes (Mart.) Solms-Laub (Pontederiaceae) in South Africa
- Authors: Miller, Benjamin Erich
- Date: 2019
- Subjects: Megamelus scutellaris Berg. , Delphacidae , Noxious weeds -- Biological control -- South Africa , Aquatic weeds -- Biological control -- South Africa , Water hyacinth -- Biological control -- South Africa , Biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92330 , vital:30710
- Description: Water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub. (Pontederiaceae) is a free-floating aquatic macrophyte from South America that was introduced to South Africa in the 1900s for its attractive ornamental flowers. The plant was classified as a serious invader in the country in the 1970s, eventually becoming the worst invasive aquatic plant in South Africa. Biological control is widely regarded as the most effective method of managing water hyacinth, as it is ecologically safe, cost-effective, and self-sustaining. To date, nine biological control agents have been released in South Africa against water hyacinth, including eight arthropods and a pathogen. Due to the cumulative effects of highly eutrophic waterbodies, which mitigate the damage caused by biological control, and the cold winters which inhibit the rate of biological control agent population build up, South Africa currently has more biological control agents released on water hyacinth than anywhere else in the world. The need for a cold-tolerant agent that can reproduce and develop quickly, while still being damaging to water hyacinth in eutrophic systems, led to the introduction of the most recently released water hyacinth biological control agent, the planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae), which was initially collected from Argentina. This thesis formed the first post-release evaluation of M. scutellaris since its release in South Africa in 2013. It included a greenhouse experiment to measure the agent’s feeding damage in relation to different nutrient levels and stocking rates, as well as a field component to evaluate both the post-winter recovery of M. scutellaris, and a nationwide survey to measure the establishment of the agent around the country in relation to climate, water quality, and plant health. In the greenhouse experiment, the feeding damage was quantified using measurements of plant growth parameters and chlorophyll fluorometry. It was found that, like other biological control agents of water hyacinth, M. scutellaris was most damaging when released in high numbers on plants grown at medium nutrient levels, and less effective on plants grown at elevated nutrient levels. A water hyacinth infestation on the Kubusi River was selected for the evaluation of the post-winter recovery of M. scutellaris. The Kubusi River is both the first site where M. scutellaris was released, and the coldest site where water hyacinth biological control agents have established successfully in South Africa. Monthly visits tracking seasonal plant health characteristics and agent population densities indicated that the populations of M. scutellaris were impacted most significantly by the season. Low temperatures led to the water hyacinth plants being of poor quality during the winter, which had a subsequent negative effect on the agent populations. The agents could only fully recover by late summer, which meant that the plants were without any significant biological control through the initial phases of the growing season, when they were most vulnerable, and a significant lag-phase occurred between the recovery of the plants and the recovery of the agent population after the winter bottleneck. A survey of all sites where M. scutellaris had been released in South Africa yielded 16 sites where the agents had successfully established, having survived at least one full winter. Among these sites were four sites where the agents were found without them having been released, indicating that they can disperse unaided to new sites. The temperature was a major factor responsible for the success or failure of establishment, with very few agents surviving in the hot areas of South Africa or in areas with a high frost incidence. The density of M. scutellaris was higher in nutrient-rich water, and on plants with more leaves, suggesting that the quality of the plants also contributed to establishment. The results of this thesis showed that M. scutellaris is able to establish successfully in South Africa, and that the agents are capable of causing significant damage to water hyacinth, making it a promising addition to the biological control programme. Novel methods of measuring subtle insect feeding damage in plants and quantifying agent populations are also discussed, along with suggestions for the future implementation of M. scutellaris in South Africa.
- Full Text:
- Authors: Miller, Benjamin Erich
- Date: 2019
- Subjects: Megamelus scutellaris Berg. , Delphacidae , Noxious weeds -- Biological control -- South Africa , Aquatic weeds -- Biological control -- South Africa , Water hyacinth -- Biological control -- South Africa , Biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92330 , vital:30710
- Description: Water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub. (Pontederiaceae) is a free-floating aquatic macrophyte from South America that was introduced to South Africa in the 1900s for its attractive ornamental flowers. The plant was classified as a serious invader in the country in the 1970s, eventually becoming the worst invasive aquatic plant in South Africa. Biological control is widely regarded as the most effective method of managing water hyacinth, as it is ecologically safe, cost-effective, and self-sustaining. To date, nine biological control agents have been released in South Africa against water hyacinth, including eight arthropods and a pathogen. Due to the cumulative effects of highly eutrophic waterbodies, which mitigate the damage caused by biological control, and the cold winters which inhibit the rate of biological control agent population build up, South Africa currently has more biological control agents released on water hyacinth than anywhere else in the world. The need for a cold-tolerant agent that can reproduce and develop quickly, while still being damaging to water hyacinth in eutrophic systems, led to the introduction of the most recently released water hyacinth biological control agent, the planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae), which was initially collected from Argentina. This thesis formed the first post-release evaluation of M. scutellaris since its release in South Africa in 2013. It included a greenhouse experiment to measure the agent’s feeding damage in relation to different nutrient levels and stocking rates, as well as a field component to evaluate both the post-winter recovery of M. scutellaris, and a nationwide survey to measure the establishment of the agent around the country in relation to climate, water quality, and plant health. In the greenhouse experiment, the feeding damage was quantified using measurements of plant growth parameters and chlorophyll fluorometry. It was found that, like other biological control agents of water hyacinth, M. scutellaris was most damaging when released in high numbers on plants grown at medium nutrient levels, and less effective on plants grown at elevated nutrient levels. A water hyacinth infestation on the Kubusi River was selected for the evaluation of the post-winter recovery of M. scutellaris. The Kubusi River is both the first site where M. scutellaris was released, and the coldest site where water hyacinth biological control agents have established successfully in South Africa. Monthly visits tracking seasonal plant health characteristics and agent population densities indicated that the populations of M. scutellaris were impacted most significantly by the season. Low temperatures led to the water hyacinth plants being of poor quality during the winter, which had a subsequent negative effect on the agent populations. The agents could only fully recover by late summer, which meant that the plants were without any significant biological control through the initial phases of the growing season, when they were most vulnerable, and a significant lag-phase occurred between the recovery of the plants and the recovery of the agent population after the winter bottleneck. A survey of all sites where M. scutellaris had been released in South Africa yielded 16 sites where the agents had successfully established, having survived at least one full winter. Among these sites were four sites where the agents were found without them having been released, indicating that they can disperse unaided to new sites. The temperature was a major factor responsible for the success or failure of establishment, with very few agents surviving in the hot areas of South Africa or in areas with a high frost incidence. The density of M. scutellaris was higher in nutrient-rich water, and on plants with more leaves, suggesting that the quality of the plants also contributed to establishment. The results of this thesis showed that M. scutellaris is able to establish successfully in South Africa, and that the agents are capable of causing significant damage to water hyacinth, making it a promising addition to the biological control programme. Novel methods of measuring subtle insect feeding damage in plants and quantifying agent populations are also discussed, along with suggestions for the future implementation of M. scutellaris in South Africa.
- Full Text:
Poverty reduction strategies and non-timber forest products
- Pullanikkatil, Deepa, Shackleton, Charlie M
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433583 , vital:72985 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_1
- Description: The first of the 17 Global Goals that make up the 2030 Agenda for Sustainable Development is to end poverty in all its forms everywhere. Although the numbers of poor people in the world has declined over the last few decades, it is still alarmingly high, being approximately 770 million in 2013 (Fig. 1) (World Bank in Understanding Poverty 2017). Currently the majority of the world’s poor live in rural areas, and their livelihoods are dominated by land-based activities including gathering of Non-Timber Forest Products (NTFPs). There were rela tively few studies offering more socially orientated perspectives and insights on the links between NTFP use, dependency and poverty. The ordinary people using NTFPs, their reasons for doing so and their experiences are given in this book.
- Full Text:
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433583 , vital:72985 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_1
- Description: The first of the 17 Global Goals that make up the 2030 Agenda for Sustainable Development is to end poverty in all its forms everywhere. Although the numbers of poor people in the world has declined over the last few decades, it is still alarmingly high, being approximately 770 million in 2013 (Fig. 1) (World Bank in Understanding Poverty 2017). Currently the majority of the world’s poor live in rural areas, and their livelihoods are dominated by land-based activities including gathering of Non-Timber Forest Products (NTFPs). There were rela tively few studies offering more socially orientated perspectives and insights on the links between NTFP use, dependency and poverty. The ordinary people using NTFPs, their reasons for doing so and their experiences are given in this book.
- Full Text:
Poverty reduction through non-timber forest products
- Pullanikkatil, Deepa, Shackleton, Charlie M
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433598 , vital:72986 , ISBN 978-3-319-75580-9 , https://doi.org/10.1007/978-3-319-75580-9
- Description: This book narrates personal stories of people from around the world who have used natural products, in particular Non Timber Forest Products (NTFPs) as a means to come out of poverty. Ending poverty remains a major worldwide challenge and is the number one goal under the UN Sustainable Development Goals. The book fills an important knowledge gap; that of personal stories of NTFP users. This has not been part of past publications on NTFPs which tend to focus on statistics and analysis of numbers, thus, the human faces of NTFP users are missing. Narrative stories provide a wealth of data about people and their experiences rather than aggregated classifications, categories and characteristics of poverty. The objective of this book is to illustrate the poverty alleviation potential of NTFPs through documenting the personal life stories of individuals and households that lifted themselves out of poverty through trade of NTFPs. This book is for all who are interested in poverty alleviation and NTFPs.
- Full Text:
- Authors: Pullanikkatil, Deepa , Shackleton, Charlie M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433598 , vital:72986 , ISBN 978-3-319-75580-9 , https://doi.org/10.1007/978-3-319-75580-9
- Description: This book narrates personal stories of people from around the world who have used natural products, in particular Non Timber Forest Products (NTFPs) as a means to come out of poverty. Ending poverty remains a major worldwide challenge and is the number one goal under the UN Sustainable Development Goals. The book fills an important knowledge gap; that of personal stories of NTFP users. This has not been part of past publications on NTFPs which tend to focus on statistics and analysis of numbers, thus, the human faces of NTFP users are missing. Narrative stories provide a wealth of data about people and their experiences rather than aggregated classifications, categories and characteristics of poverty. The objective of this book is to illustrate the poverty alleviation potential of NTFPs through documenting the personal life stories of individuals and households that lifted themselves out of poverty through trade of NTFPs. This book is for all who are interested in poverty alleviation and NTFPs.
- Full Text:
Pregnancy Decision Making: Abortion and Adoption
- Mavuso, Jabulile M-J J, Macleod, Catriona I
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434145 , vital:73034 , ISBN 9781119161899 , https://onlinelibrary.wiley.com/doi/book/10.1002/9781119171492
- Description: Pregnancy decision making encompasses a large range of interactions, including decisions and actions to avoid pregnancy or to become pregnant. This entry addresses the question of decision making regarding the outcome of a pregnancy: abortion or taking the pregnancy to term, with the latter resulting in parenting or adoption placement. Adolescents' pregnancy decision making has been a special area of focus for some decades now, particularly regarding whether adolescents are capable of making termination-of-pregnancy decisions. This entry highlights controversies concerning, first, teenage pregnancy as a social problem; second, risk research that seeks to outline the consequences of various reproductive decisions; third, questions around adolescents' maturity regarding making reproductive decisions; fourth, the reasons provided for various reproductive decisions; and, finally, issues surrounding the autonomy of young pregnant women in their reproductive decisions.
- Full Text:
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434145 , vital:73034 , ISBN 9781119161899 , https://onlinelibrary.wiley.com/doi/book/10.1002/9781119171492
- Description: Pregnancy decision making encompasses a large range of interactions, including decisions and actions to avoid pregnancy or to become pregnant. This entry addresses the question of decision making regarding the outcome of a pregnancy: abortion or taking the pregnancy to term, with the latter resulting in parenting or adoption placement. Adolescents' pregnancy decision making has been a special area of focus for some decades now, particularly regarding whether adolescents are capable of making termination-of-pregnancy decisions. This entry highlights controversies concerning, first, teenage pregnancy as a social problem; second, risk research that seeks to outline the consequences of various reproductive decisions; third, questions around adolescents' maturity regarding making reproductive decisions; fourth, the reasons provided for various reproductive decisions; and, finally, issues surrounding the autonomy of young pregnant women in their reproductive decisions.
- Full Text:
Preparation of NIR absorbing axial substituted tin (iv) porphyrins and their photocytotoxic properties
- Babu, Balaji, Amuhaya, Edith K, Oluwole, David O, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
Prime time geographies: dancehall performance, visual communication and the philosophy of ‘Boundarylessness'
- Authors: Stanley Niaah, Sonjah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145930 , vital:38479 , https://0-doi.org.wam.seals.ac.za/10.1080/00086495.2019.1565218
- Description: What is Dancehall, and how does it employ visual technologies? Dancehall is not just a musical genre. It is Jamaica’s premier popular street theatre, a celebration of the entire spectrum of life from birth to death, expressed at events that combine dance and music, where consenting adults leave their troubles behind just for a moment to revel in the deep and old rhythmic structures that transport them into scape beyond the urban, beyond the inner city, into spaces of fulfilment.
- Full Text:
- Authors: Stanley Niaah, Sonjah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145930 , vital:38479 , https://0-doi.org.wam.seals.ac.za/10.1080/00086495.2019.1565218
- Description: What is Dancehall, and how does it employ visual technologies? Dancehall is not just a musical genre. It is Jamaica’s premier popular street theatre, a celebration of the entire spectrum of life from birth to death, expressed at events that combine dance and music, where consenting adults leave their troubles behind just for a moment to revel in the deep and old rhythmic structures that transport them into scape beyond the urban, beyond the inner city, into spaces of fulfilment.
- Full Text:
Privately protected areas provide key opportunities for the regional persistence of large- and medium-sized mammals
- Clements, Hayley S, Kerley, Graham I H, Cumming, Graeme S, de Vos, Alta, Cook, Carly N
- Authors: Clements, Hayley S , Kerley, Graham I H , Cumming, Graeme S , de Vos, Alta , Cook, Carly N
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416383 , vital:71344 , xlink:href="https://doi.org/10.1111/1365-2664.13300"
- Description: Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., low -land habitats on fertile soils, coastal zones), land is often privately owned and state-owned PAs tend to be under-represented. Despite the potentially disproportionate contribution that privately protected areas (PPAs) could make to representing biodiversity and supporting its persistence across regional PA estates, this contribution is poorly understood.
- Full Text:
- Authors: Clements, Hayley S , Kerley, Graham I H , Cumming, Graeme S , de Vos, Alta , Cook, Carly N
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416383 , vital:71344 , xlink:href="https://doi.org/10.1111/1365-2664.13300"
- Description: Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., low -land habitats on fertile soils, coastal zones), land is often privately owned and state-owned PAs tend to be under-represented. Despite the potentially disproportionate contribution that privately protected areas (PPAs) could make to representing biodiversity and supporting its persistence across regional PA estates, this contribution is poorly understood.
- Full Text:
Probing the potential of social ecosystemic skills approaches for green skills planning: Perspectives from Expanded Public Works Programme studies
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392924 , vital:68812 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: The Expanded Public Works Programme (EPWP) in South Africa is an extensive governmental intervention to provide work opportunities. The EPWP context is a significant site of green skills emergence in South Africa, especially at the elementary occupation level. The training associated with these programmes has, to date, been largely top down, and little nuanced understanding exists on the training and learning pathways potential development for these green skills. There is a paradox between the top down approach to training, and the primarily regional implementation platforms of EPWP job opportunities and their developmental intent. To reconcile this paradox, I draw on social ecosystemic skills research to probe the potential for such a conceptual and theoretical framework for guiding green skills research for the EPWP. I share some methodologies and insights developed in EPWP green skills research projects that offer potential for providing insight into a social ecosystemic model for green skills research in EPWP programmes. Social ecosystemic models in skills research seek to develop skills development approaches that forge stronger connections between working, living and learning, foregrounding regional, place-based models for skills planning that require interfacing with vertical facilitatory mechanisms and horizontal connectivities.
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392924 , vital:68812 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: The Expanded Public Works Programme (EPWP) in South Africa is an extensive governmental intervention to provide work opportunities. The EPWP context is a significant site of green skills emergence in South Africa, especially at the elementary occupation level. The training associated with these programmes has, to date, been largely top down, and little nuanced understanding exists on the training and learning pathways potential development for these green skills. There is a paradox between the top down approach to training, and the primarily regional implementation platforms of EPWP job opportunities and their developmental intent. To reconcile this paradox, I draw on social ecosystemic skills research to probe the potential for such a conceptual and theoretical framework for guiding green skills research for the EPWP. I share some methodologies and insights developed in EPWP green skills research projects that offer potential for providing insight into a social ecosystemic model for green skills research in EPWP programmes. Social ecosystemic models in skills research seek to develop skills development approaches that forge stronger connections between working, living and learning, foregrounding regional, place-based models for skills planning that require interfacing with vertical facilitatory mechanisms and horizontal connectivities.
- Full Text:
Probing the potential of social ecosystemic skills approaches for green skills planning: Perspectives from Expanded Public Works Programme studies
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436064 , vital:73224 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: The Expanded Public Works Programme (EPWP) in South Af-rica is an extensive governmental intervention to provide work opportunities. The EPWP context is a significant site of green skills emergence in South Africa, especially at the elementary occupation level. The training associated with these pro-grammes has, to date, been largely top down, and little nu-anced understanding exists on the training and learning path-ways potential development for these green skills. There is a paradox between the top down approach to training, and the primarily regional implementation platforms of EPWP job op-portunities and their developmental intent. To reconcile this paradox, I draw on social ecosystemic skills research to probe the potential for such a conceptual and theoretical framework for guiding green skills research for the EPWP. I share some methodologies and insights developed in EPWP green skills research projects that offer potential for providing insight into a social ecosystemic model for green skills research in EPWP programmes. Social ecosystemic models in skills research seek to develop skills development approaches that forge stronger connections between working, living and learning, foregrounding regional, place-based models for skills planning that require interfacing with vertical facilitatory mechanisms and horizontal connectivities.
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436064 , vital:73224 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: The Expanded Public Works Programme (EPWP) in South Af-rica is an extensive governmental intervention to provide work opportunities. The EPWP context is a significant site of green skills emergence in South Africa, especially at the elementary occupation level. The training associated with these pro-grammes has, to date, been largely top down, and little nu-anced understanding exists on the training and learning path-ways potential development for these green skills. There is a paradox between the top down approach to training, and the primarily regional implementation platforms of EPWP job op-portunities and their developmental intent. To reconcile this paradox, I draw on social ecosystemic skills research to probe the potential for such a conceptual and theoretical framework for guiding green skills research for the EPWP. I share some methodologies and insights developed in EPWP green skills research projects that offer potential for providing insight into a social ecosystemic model for green skills research in EPWP programmes. Social ecosystemic models in skills research seek to develop skills development approaches that forge stronger connections between working, living and learning, foregrounding regional, place-based models for skills planning that require interfacing with vertical facilitatory mechanisms and horizontal connectivities.
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Protected nearshore shallow and deep subtidal rocky reef communities differ in their trophic diversity but not their nutritional condition
- Heyns-Veale, Elodie R, Richoux, Nicole B, Bernard, Anthony T F, Götz, Albrecht
- Authors: Heyns-Veale, Elodie R , Richoux, Nicole B , Bernard, Anthony T F , Götz, Albrecht
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454362 , vital:75338 , xlink:href="https://doi.org/10.2989/1814232X.2019.1580614"
- Description: Large physical changes that alter reef macrobenthos and fish assemblages occur with increasing depth, so the biological processes that regulate communities at different depths are expected to diverge. We used analyses of stable isotopes (δ13C and δ15N) and fatty acids to establish whether shallow (11–25 m) and deep (45–75 m) warm-temperate reef communities within a South African marine protected area differ in their trophic organisation and nutritional condition. We found evidence of enhanced nutritional condition in plankton from the deeper reef as compared with the shallow reef based on the essential fatty acid content, but this effect was generally not observed in the macrobenthos or the fish communities. Community-based indices derived from the stable isotope data indicated that the shallow-reef community had significantly greater niche diversification (greater diversity of carbon sources at the base of the food web) and more niche space occupied than the deep-reef community. One obvious difference in available carbon sources between reef communities was the absence of benthic primary production on the deep reef, where light is limiting. Our results highlight that the decreased trophic diversity, and to an extent functional redundancy, associated with the simplification of food webs at depth may translate into greater vulnerability of deep reefs to disturbance.
- Full Text:
- Authors: Heyns-Veale, Elodie R , Richoux, Nicole B , Bernard, Anthony T F , Götz, Albrecht
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454362 , vital:75338 , xlink:href="https://doi.org/10.2989/1814232X.2019.1580614"
- Description: Large physical changes that alter reef macrobenthos and fish assemblages occur with increasing depth, so the biological processes that regulate communities at different depths are expected to diverge. We used analyses of stable isotopes (δ13C and δ15N) and fatty acids to establish whether shallow (11–25 m) and deep (45–75 m) warm-temperate reef communities within a South African marine protected area differ in their trophic organisation and nutritional condition. We found evidence of enhanced nutritional condition in plankton from the deeper reef as compared with the shallow reef based on the essential fatty acid content, but this effect was generally not observed in the macrobenthos or the fish communities. Community-based indices derived from the stable isotope data indicated that the shallow-reef community had significantly greater niche diversification (greater diversity of carbon sources at the base of the food web) and more niche space occupied than the deep-reef community. One obvious difference in available carbon sources between reef communities was the absence of benthic primary production on the deep reef, where light is limiting. Our results highlight that the decreased trophic diversity, and to an extent functional redundancy, associated with the simplification of food webs at depth may translate into greater vulnerability of deep reefs to disturbance.
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Psychological knowledge production about abortion: the politics of location and representation
- Macleod, Catriona I, Mavuso, Jabulile M-J J, Chiweshe, Malvern T, du Toit, Ryan
- Authors: Macleod, Catriona I , Mavuso, Jabulile M-J J , Chiweshe, Malvern T , du Toit, Ryan
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443734 , vital:74148 , xlink:href="https://doi.org/10.1136/bmjsrh-2018-200208"
- Description: Despite considerable psychology research being conducted on abortion, there has been no study of the history of psychological knowledge production on the topic. The aim of our research was to analyse journal articles published in English language psychology journals using a politics of location and of representation analytical lens.
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- Authors: Macleod, Catriona I , Mavuso, Jabulile M-J J , Chiweshe, Malvern T , du Toit, Ryan
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443734 , vital:74148 , xlink:href="https://doi.org/10.1136/bmjsrh-2018-200208"
- Description: Despite considerable psychology research being conducted on abortion, there has been no study of the history of psychological knowledge production on the topic. The aim of our research was to analyse journal articles published in English language psychology journals using a politics of location and of representation analytical lens.
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