Sculpting with fire: celebrating ephemerality at AfrikaBurn 2015 in the Tankwa Karoo, South Africa
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/957 , vital:30075
- Description: Land art, and some installation art, is usually aimed at relatively temporarily manipulating the surface of the earth. AfrikaBurn takes place annually in the near-desert of the Tankwa Karoo, South Africa. It is a communal event unique to Africa, and manifests as a fleeting week-long series of interventions in the natural environment, partially aimed at creating and then actively destroying free-standing public sculptures, some of which are huge and intricate. AfrikaBurn gives any one of the thousands of participants an opportunity to be inspired on any scale to generate artworks that take into account a principle that no debris whatsoever is left behind on the surface of the earth after a week-long celebration of creative energies. Unlike, for instance, an artwork built on the edge of the Indian Ocean in the Eastern Cape, where rough tidal seas would ensure gradual destruction, at AfrikaBurn, the sacrificial method of choice is controlled rapid burning, under the direction of a specified firemaster. This paper seeks to unbundle some aspects of land and installation art in Southern Africa with specific reference to AfrikaBurn 2015 events and anti-fracking initiatives. This is within a context that takes into account recognition that even seemingly durable public sculptures are subject to change and may even physically disappear with the passing of time.
- Full Text:
- Date Issued: 2015
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/957 , vital:30075
- Description: Land art, and some installation art, is usually aimed at relatively temporarily manipulating the surface of the earth. AfrikaBurn takes place annually in the near-desert of the Tankwa Karoo, South Africa. It is a communal event unique to Africa, and manifests as a fleeting week-long series of interventions in the natural environment, partially aimed at creating and then actively destroying free-standing public sculptures, some of which are huge and intricate. AfrikaBurn gives any one of the thousands of participants an opportunity to be inspired on any scale to generate artworks that take into account a principle that no debris whatsoever is left behind on the surface of the earth after a week-long celebration of creative energies. Unlike, for instance, an artwork built on the edge of the Indian Ocean in the Eastern Cape, where rough tidal seas would ensure gradual destruction, at AfrikaBurn, the sacrificial method of choice is controlled rapid burning, under the direction of a specified firemaster. This paper seeks to unbundle some aspects of land and installation art in Southern Africa with specific reference to AfrikaBurn 2015 events and anti-fracking initiatives. This is within a context that takes into account recognition that even seemingly durable public sculptures are subject to change and may even physically disappear with the passing of time.
- Full Text:
- Date Issued: 2015
Seasonal consumption of browse by the African buffalo (Syncerus caffer) in the Thicket Biome of South Africa
- Watermeyer, Jessica P, Carroll, Sarah L, Parker, Daniel M
- Authors: Watermeyer, Jessica P , Carroll, Sarah L , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126096 , vital:35849 , https://doi.org/10.1111/aje.12214
- Description: The African buffalo (Syncerus caffer Sparrman) is both morphologically and physiologically adapted for grazing (Prins, 1996). However, buffalo populations of the Eastern Cape, South Africa, are confined to reserves dominated by thicket vegetation where grass is sparse (Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). Given that the nutritional value of grass deteriorates more rapidly than browse in nonproductive periods (Shipley, 1993), it has been hypothesized that buffalo increase their intake of browse during the dry season (Tshabalala, Dube & Lent, 2009). However, past studies contradict one another (de Graaf, Schulz & van der Walt, 1973; Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). de Graaf, Schulz & van der Walt (1973) analysed the rumen contents of buffalo in the Addo Elephant National Park and suggested that buffalo should be considered browsers because of the high proportion of browse in rumen samples. However, their study was restricted to one site during a drought. Landman & Kerley (2001) later found the opposite (grass comprised ~72% of buffalo dung) and criticized the findings of de Graaf, Schulz amp; van der Walt (1973). However, their study was conducted after a period of exceptionally high rainfall. More recently, Tshabalala, Dube & Lent (2009) recorded significantly more browse in the diet of buffalo during the dry season (33%) than the wet season (28%) at the Great Fish River Nature Reserve. We test the assertion that buffalo increase their intake of browse during dry periods, at another site dominated by thicket. We describe the extent to which grass and browse were consumed by buffalo and whether the proportional occurrence changed monthly.
- Full Text:
- Date Issued: 2015
- Authors: Watermeyer, Jessica P , Carroll, Sarah L , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126096 , vital:35849 , https://doi.org/10.1111/aje.12214
- Description: The African buffalo (Syncerus caffer Sparrman) is both morphologically and physiologically adapted for grazing (Prins, 1996). However, buffalo populations of the Eastern Cape, South Africa, are confined to reserves dominated by thicket vegetation where grass is sparse (Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). Given that the nutritional value of grass deteriorates more rapidly than browse in nonproductive periods (Shipley, 1993), it has been hypothesized that buffalo increase their intake of browse during the dry season (Tshabalala, Dube & Lent, 2009). However, past studies contradict one another (de Graaf, Schulz & van der Walt, 1973; Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). de Graaf, Schulz & van der Walt (1973) analysed the rumen contents of buffalo in the Addo Elephant National Park and suggested that buffalo should be considered browsers because of the high proportion of browse in rumen samples. However, their study was restricted to one site during a drought. Landman & Kerley (2001) later found the opposite (grass comprised ~72% of buffalo dung) and criticized the findings of de Graaf, Schulz amp; van der Walt (1973). However, their study was conducted after a period of exceptionally high rainfall. More recently, Tshabalala, Dube & Lent (2009) recorded significantly more browse in the diet of buffalo during the dry season (33%) than the wet season (28%) at the Great Fish River Nature Reserve. We test the assertion that buffalo increase their intake of browse during dry periods, at another site dominated by thicket. We describe the extent to which grass and browse were consumed by buffalo and whether the proportional occurrence changed monthly.
- Full Text:
- Date Issued: 2015
Seasonality, behaviour and philopatry of spotted ragged tooth sharks Carcharias taurus in Eastern Cape nursery areas, South Africa
- Smale, Malcolm J, Dicken, Matthew L, Booth, Anthony J
- Authors: Smale, Malcolm J , Dicken, Matthew L , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126672 , vital:35910 , https://doi.10.2989/1814232X.2015.1043342
- Description: Spotted ragged-tooth sharks Carcharias taurus occur along the southern and eastern coasts of South Africa. We report on movements of juveniles and adults within a known nursery area on the Eastern Cape coast using acoustic telemetry. The focus area of the study was Algoa Bay, where six VEMCO VR2 ultrasonic receivers were placed at known shark aggregation sites. An additional receiver was placed at Thunderbolt Reef, approximately 2 km southwest of Cape Recife, the south-western tip of Algoa Bay. Single receivers were also deployed at Port Alfred and East London, some 45 and 170 km north-east of Algoa Bay, respectively. VEMCO acoustic V16 tags were either surgically implanted (n = 37) or attached externally using dart heads (n = 6) between January 2003 and March 2006. Surgically implanted tags were recorded over multiple months and years, whereas external tags were probably lost shortly after tagging because they were detected for very short periods. Sharks moved extensively between the sites and revisited monitored reefs over time-periods of months and years, demonstrating philopatry. Departures from and arrivals at reefs were more frequently recorded at sunset and sunrise, respectively. Sharks were detected throughout the year but they spent more time at aggregation sites during summer and autumn, indicating seasonal abundance in agreement with previous findings. Movements away from study reefs were attributed to either foraging or movements to other reefs. Despite extensive movements around the bay and beyond, both juveniles and adults exhibited philopatry to the study area over multiple years.
- Full Text:
- Date Issued: 2015
- Authors: Smale, Malcolm J , Dicken, Matthew L , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126672 , vital:35910 , https://doi.10.2989/1814232X.2015.1043342
- Description: Spotted ragged-tooth sharks Carcharias taurus occur along the southern and eastern coasts of South Africa. We report on movements of juveniles and adults within a known nursery area on the Eastern Cape coast using acoustic telemetry. The focus area of the study was Algoa Bay, where six VEMCO VR2 ultrasonic receivers were placed at known shark aggregation sites. An additional receiver was placed at Thunderbolt Reef, approximately 2 km southwest of Cape Recife, the south-western tip of Algoa Bay. Single receivers were also deployed at Port Alfred and East London, some 45 and 170 km north-east of Algoa Bay, respectively. VEMCO acoustic V16 tags were either surgically implanted (n = 37) or attached externally using dart heads (n = 6) between January 2003 and March 2006. Surgically implanted tags were recorded over multiple months and years, whereas external tags were probably lost shortly after tagging because they were detected for very short periods. Sharks moved extensively between the sites and revisited monitored reefs over time-periods of months and years, demonstrating philopatry. Departures from and arrivals at reefs were more frequently recorded at sunset and sunrise, respectively. Sharks were detected throughout the year but they spent more time at aggregation sites during summer and autumn, indicating seasonal abundance in agreement with previous findings. Movements away from study reefs were attributed to either foraging or movements to other reefs. Despite extensive movements around the bay and beyond, both juveniles and adults exhibited philopatry to the study area over multiple years.
- Full Text:
- Date Issued: 2015
Shifting the priority from giving voice to listening: journalism new
- Garman, Anthea, Malila, Vanessa
- Authors: Garman, Anthea , Malila, Vanessa
- Date: 2015
- Language: English
- Type: text , article
- Identifier: vital:38355 , http://hdl.handle.net/10520/EJC175773
- Description: If, as the critics have argued, the South African media prioritise the voices of elite, middleclass South Africans, then the majority of South Africans are certainly invisible in the mainstream media. Kate Lacey argues that "listening is at the heart of what it means to be in the world, to be active, to be political" (2013: 163), and as such more than just providing a 'voice' for citizens, the media needs to be engaged in active listening to allow audiences to feel 'heard'. Servaes and Malikhao argue that people are 'voiceless' not because they have nothing to say, but because "nobody cares to listen to them" (2005: 91).
- Full Text:
- Date Issued: 2015
- Authors: Garman, Anthea , Malila, Vanessa
- Date: 2015
- Language: English
- Type: text , article
- Identifier: vital:38355 , http://hdl.handle.net/10520/EJC175773
- Description: If, as the critics have argued, the South African media prioritise the voices of elite, middleclass South Africans, then the majority of South Africans are certainly invisible in the mainstream media. Kate Lacey argues that "listening is at the heart of what it means to be in the world, to be active, to be political" (2013: 163), and as such more than just providing a 'voice' for citizens, the media needs to be engaged in active listening to allow audiences to feel 'heard'. Servaes and Malikhao argue that people are 'voiceless' not because they have nothing to say, but because "nobody cares to listen to them" (2005: 91).
- Full Text:
- Date Issued: 2015
Shifting white identities in South Africa: white Africanness and the struggle for racial justice
- Authors: Matthews, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142180 , vital:38056 , DOI: 10.25159/2413-3086/3821
- Description: The end of apartheid predictably caused something of an identity crisis for white South Africans. The sense of uncertainty about what it means to be white has led to much public debate about whiteness in South Africa, as well as a growing body of literature on whites in post-apartheid South Africa. One of the many responses to this need to rethink white identity has been the claim by some that white South Africans can be considered to be African or ought to begin to think of themselves as being African. This paper argues that whites' assertion of an African identity does not necessarily assist in the achievement of racial justice, but that some kind of shift in white identity is required in order for whites to be able to contribute to the achievement of a racially just South Africa. In making this argument, the paper brings contemporary discussions on race and whiteness, and in particular discussions about racial eliminativism, to bear on the question of whether or not white South Africans may rightly claim an African identity.
- Full Text:
- Date Issued: 2015
- Authors: Matthews, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142180 , vital:38056 , DOI: 10.25159/2413-3086/3821
- Description: The end of apartheid predictably caused something of an identity crisis for white South Africans. The sense of uncertainty about what it means to be white has led to much public debate about whiteness in South Africa, as well as a growing body of literature on whites in post-apartheid South Africa. One of the many responses to this need to rethink white identity has been the claim by some that white South Africans can be considered to be African or ought to begin to think of themselves as being African. This paper argues that whites' assertion of an African identity does not necessarily assist in the achievement of racial justice, but that some kind of shift in white identity is required in order for whites to be able to contribute to the achievement of a racially just South Africa. In making this argument, the paper brings contemporary discussions on race and whiteness, and in particular discussions about racial eliminativism, to bear on the question of whether or not white South Africans may rightly claim an African identity.
- Full Text:
- Date Issued: 2015
Siyahluma: a critical health education intervention
- Kelland, Lindsay, Paphitis, Sharli A
- Authors: Kelland, Lindsay , Paphitis, Sharli A
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143638 , vital:38269 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Recent social science research points to various menstruation-related challenges facing women in the global South - most notably for our purposes here, young school-going girls in the global South report a lack of access to (1) reliable and hygienic menstrual products with which to manage their menstruation, as well as (2) the information they need to understand the process of menstruation, how to manage menstruation and how to perceive and treat their menstruating bodies given that menstruation is surrounded by a culture of taboo and silence - menstruation is seen as dirty, impure, contaminating and, importantly, as something to be concealed from others and not spoken about, particularly in relation to male others. This lack of access to information, or in many cases, provision of false, misleading or stigmatised information has a severe negative impact on the management of menstruation for both young girls and women in the global South.
- Full Text:
- Date Issued: 2015
- Authors: Kelland, Lindsay , Paphitis, Sharli A
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143638 , vital:38269 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Recent social science research points to various menstruation-related challenges facing women in the global South - most notably for our purposes here, young school-going girls in the global South report a lack of access to (1) reliable and hygienic menstrual products with which to manage their menstruation, as well as (2) the information they need to understand the process of menstruation, how to manage menstruation and how to perceive and treat their menstruating bodies given that menstruation is surrounded by a culture of taboo and silence - menstruation is seen as dirty, impure, contaminating and, importantly, as something to be concealed from others and not spoken about, particularly in relation to male others. This lack of access to information, or in many cases, provision of false, misleading or stigmatised information has a severe negative impact on the management of menstruation for both young girls and women in the global South.
- Full Text:
- Date Issued: 2015
Socio-spatial dynamics in the use of wild natural resources: Evidence from six rapidly growing medium-sized cities in Africa
- Schlesinger, Johannes, Drescher, Axel W, Shackleton, Charlie M
- Authors: Schlesinger, Johannes , Drescher, Axel W , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180897 , vital:43668 , xlink:href="https://doi.org/10.1016/j.apgeog.2014.11.013"
- Description: Increasing urbanisation in sub-Saharan Africa transforms spatial configurations in and around towns and cities. At the same time wild natural resources play an important role in African livelihoods. Yet, little is known about the impact of urbanisation on the socio-spatial dynamics of the use of wild natural resources. Here we examined the importance of these resources for livelihoods, differences in their use between different locations along the urban-rural continuum, and the respective temporal dynamics. A total of 1158 households were interviewed in six medium-sized cities distributed across five African countries using a standardised questionnaire supplemented by expert interviews and spatial analyses employing Geographic Information Systems. Overall, even though periurban and rural households were more likely to use wild natural resources than those in the urban areas, the use of these resources was generally high along the entire urban-rural continuum. Despite the increasing urban pressure on these resources, they remain an integral part for most households, not only for those lacking access to productive resources, but also for those with a higher standard of living. This trend was found across all study towns, despite the marked differences in their respective socio-spatial as well as environmental settings.
- Full Text:
- Date Issued: 2015
- Authors: Schlesinger, Johannes , Drescher, Axel W , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180897 , vital:43668 , xlink:href="https://doi.org/10.1016/j.apgeog.2014.11.013"
- Description: Increasing urbanisation in sub-Saharan Africa transforms spatial configurations in and around towns and cities. At the same time wild natural resources play an important role in African livelihoods. Yet, little is known about the impact of urbanisation on the socio-spatial dynamics of the use of wild natural resources. Here we examined the importance of these resources for livelihoods, differences in their use between different locations along the urban-rural continuum, and the respective temporal dynamics. A total of 1158 households were interviewed in six medium-sized cities distributed across five African countries using a standardised questionnaire supplemented by expert interviews and spatial analyses employing Geographic Information Systems. Overall, even though periurban and rural households were more likely to use wild natural resources than those in the urban areas, the use of these resources was generally high along the entire urban-rural continuum. Despite the increasing urban pressure on these resources, they remain an integral part for most households, not only for those lacking access to productive resources, but also for those with a higher standard of living. This trend was found across all study towns, despite the marked differences in their respective socio-spatial as well as environmental settings.
- Full Text:
- Date Issued: 2015
Some implications of MetaReality for environmental educators
- Authors: Price, Leigh
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437034 , vital:73325 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter seeks to illuminate the use of dialectical critical realism in a PhD study that was conducted to explore and expand learning processes in sustain able agriculture work-place contexts (Mukute, 2010). The study was conducted in three case study sites in Leso-tho, South Africa and Zimbabwe. About 80 people in three study sites participated in the multiple case study research. In Zimbabwe the study was located in Hwedza District, St Margaret Primary School and its community that learns, practises and facilitates the learn-ing of Permaculture within the Schools and Colleges Permaculture Programme (SCOPE). In South Africa the study took place in Durban urban and peri-urban areas where a communi-ty of organic farmers, facilitators and entrepreneurs co-ordinated the marketing of their produce through Isidore Farm and Earth Mother Organic and support each other to learn and practise organic farming. In Lesotho the study took place in the Mafeteng and Mohale’s Hoek districts where the focus was on farmers who learn and practise the Machobane Farming System (MFS) and were supported in this by the Rural Self Development As-sociation (RSDA) and the Machobane Agricultural Develop-ment Foundation (MADF ). The other research participants were agricultural extension workers who tend to promote high external input agriculture, sustain able agriculture researchers and organic produce marketers.
- Full Text:
- Date Issued: 2015
- Authors: Price, Leigh
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437034 , vital:73325 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter seeks to illuminate the use of dialectical critical realism in a PhD study that was conducted to explore and expand learning processes in sustain able agriculture work-place contexts (Mukute, 2010). The study was conducted in three case study sites in Leso-tho, South Africa and Zimbabwe. About 80 people in three study sites participated in the multiple case study research. In Zimbabwe the study was located in Hwedza District, St Margaret Primary School and its community that learns, practises and facilitates the learn-ing of Permaculture within the Schools and Colleges Permaculture Programme (SCOPE). In South Africa the study took place in Durban urban and peri-urban areas where a communi-ty of organic farmers, facilitators and entrepreneurs co-ordinated the marketing of their produce through Isidore Farm and Earth Mother Organic and support each other to learn and practise organic farming. In Lesotho the study took place in the Mafeteng and Mohale’s Hoek districts where the focus was on farmers who learn and practise the Machobane Farming System (MFS) and were supported in this by the Rural Self Development As-sociation (RSDA) and the Machobane Agricultural Develop-ment Foundation (MADF ). The other research participants were agricultural extension workers who tend to promote high external input agriculture, sustain able agriculture researchers and organic produce marketers.
- Full Text:
- Date Issued: 2015
Spatio-temporal variation in the phytobenthos and phytoplankton community structure and composition of particulate matter along a river-estuary continuum assessed using microscopic and stable isotope analyses
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54416 , vital:26563
- Description: Phytoplankton and phytobenthos communities play an important role in lotic systems as primary producers providing essential biomolecules to higher trophic oganisms and are important indicators for environmental or ecological change. In this thesis, field studies (observational and experimental) along a river–estuary continuum were conducted to assess the spatio-temporal variation and development of phytobenthos and phytoplankton communities using a combination of stable isotope and community analyses in a temperate southern African system across four study periods: September (early spring) and November/December (late spring) 2012, and February (summer) and May/June (winter) 2013. Additionally, the sources and composition of the particulate organic matter were also analysed using stable isotope (δ15N and δ13C) analysis. The effects of substrate type and flood occurrence were assessed through experimental studies at an up- and downstream site of the river after a major flood event that occurred between October and November 2012. Common household tiles were used as artificial substrates to study the development/succession of phytobenthos communities after the flood disturbance. Distinct diatom communities were observed between upstream and downstream sites and at each site, community structure changed with time indicating succession. In addition to recording diatom characteristics on three natural substrates, namely; macrophytes, rocks and sediment, artificial substrates observations were also made on three different types of artificial substrates, namely; brick, brown clay and grey clay tiles. The natural (species richness 78) and artificial substrates (sp. richness 93) had different communities with the latter having greater species richness. Common phytobenthos taxa were not restricted to a single substrate but preference was generally high for the artificial substrates, especially brown tiles (mean sp. richness 47). Results of the redundancy analysis (RDA) analysis indicated that ammonium, conductivity, total dissolved solids, salinity, pH, oxygen reduction potential, phosphate and water depth were the major determinants of the phytobenthos composition at the two sites. The spatio–temporal variation of phytoplankton and phytobenthos communities and allochthonous organic matter along the river–estuary continuum was assessed at 8 sites using a combination of community and stable isotope analyses. A total of 178 species belonging to 78 genera were recorded with diatoms being predominant, accounting for 81.9 % of the total abundance. The total chl-a concentration along the river-estuary continuum increased from spring to a high in summer before decreasing to a low in winter. Periphyton communities were observed to be significantly different across sites (p < 0.05) in terms of species richness, abundances and isotopically The high periphytic δ15N values (range 7.9–15.2 ‰) recorded at the downstream sites compared to the pristine upstream sites (δ15N values range 4–7 ‰) suggest nutrient enrichment most likely derived from anthropogenic sources. Overall, our results reveal general patterns of periphyton communities and stable isotopes and provide improved information in the use of periphyton δ15N as an excellent indicator of anthropogenic nitrogen pollution. Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials traveling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river-estuary continuum varies over space and time, with the upper reaches of a system characterized by allochthonous-dominated material and autochthonous contributions becoming more important in the lower reaches. Samples of the mixed organic pools and allochthonous and autochthonous source materials were collected during the four study periods. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions from the freshwater and terrestrial sources. Stable isotope analysis in R revealed that the contributions of autochthonous organic matter were high in SPM along the entire continuum, and aquatic macrophytes were significant contributors to SPM specifically in the upper reaches. The terrestrial leaves made major contributions to the SPM in the middle regions of the system (i.e. downstream sites of the river, particularly in early and late spring). Bulk detritus had large allochthonous matter components in the lower reaches (estuary), and the contributions of aquatic macrophytes and benthic algae to bulk detritus were high (> 50 %) in the upper to middle reaches (river), but low (< 20 %) in the lower reaches (estuary). The current investigation represents the first attempt to assess the validity of the River Continuum Concept (RCC) in a southern African temperate river. The phytoplankton and phytobenthos communities, and chl-a concentration followed a trend similar to that proposed for the river continuum concept (RCC). The middle reaches based on the phytobenthos or phytoplankton communities and chl-a concentrations which were employed as proxies for primary production, were the most productive, while the upper reaches were the least primary productive. The evaluation of organic matter contributions to the SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different times of the year. Incorporating such spatio-temporal variations in SPM and detritus into food web studies will improve our understanding of the flow of carbon through aquatic systems.
- Full Text:
- Date Issued: 2015
Specialist workforce development through mentoring: comparing collaborative programme evaluation using action research and realist evaluation
- Akhurst, Jacqueline E, Lawson, Sally
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
- Authors: Akhurst, Jacqueline E , Lawson, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143771 , vital:38281 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This Workforce Innovations Programme (WIP) was for healthcare practitioners working in north east England. The innovative mentoring-focused WIP aimed to increase capacity and capability, and to improve services and outcomes for people living with long term neurological conditions. Mentors were matched with practitioners outside of their specialisms and focused on community and partnership working as alternatives to dominant modes of practice. This paper will highlight key outcomes and contextual challenges. It will explore collaborative action research for practitioner development, evidencing the participants’ learning. A medium term realist evaluation then provides data about the value of the WIP; and illustrates ways the programme worked for practitioners and people who used services, to support the drive for improved outcomes. It will compare and contrast the contributions of both forms of programme evaluation, and critique some of the discourses of workforce improvement initiatives.
- Full Text:
- Date Issued: 2015
Specific rewards for tax compliance: responses of small business owners in Ekurhuleni, South Africa
- Bornman, Marina, Stack, Elizabeth M
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145325 , vital:38428 , https://heinonline.org/HOL/Page?handle=hein.journals/ejotaxrs13anddiv=35andg_sent=1andcasa_token=andcollection=journals
- Description: The literature reviewed documents the positive effects of rewards in encouraging desired behaviour, but rewards may have a crowding-in effect, strengthening intrinsic motivation, or a crowding-out effect, weakening it. External interventions may therefore be perceived as supportive, fostering self-esteem and self-determination, while those perceived as controlling may have the opposite effect. A number of countries have adopted a strategy of rewarding tax compliance. The rewards range from certificates awarded to compliant taxpayers, to privilege cards providing opportunities for discounts or special treatment, to lotteries in which compliant taxpayers can participate. The reward strategies are often accompanied by publicity programmes. Two such hypothetical strategies were presented to participants in a survey conducted amongst small business owners in Ekurhuleni, South Africa, to gauge their responses.
- Full Text:
- Date Issued: 2015
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145325 , vital:38428 , https://heinonline.org/HOL/Page?handle=hein.journals/ejotaxrs13anddiv=35andg_sent=1andcasa_token=andcollection=journals
- Description: The literature reviewed documents the positive effects of rewards in encouraging desired behaviour, but rewards may have a crowding-in effect, strengthening intrinsic motivation, or a crowding-out effect, weakening it. External interventions may therefore be perceived as supportive, fostering self-esteem and self-determination, while those perceived as controlling may have the opposite effect. A number of countries have adopted a strategy of rewarding tax compliance. The rewards range from certificates awarded to compliant taxpayers, to privilege cards providing opportunities for discounts or special treatment, to lotteries in which compliant taxpayers can participate. The reward strategies are often accompanied by publicity programmes. Two such hypothetical strategies were presented to participants in a survey conducted amongst small business owners in Ekurhuleni, South Africa, to gauge their responses.
- Full Text:
- Date Issued: 2015
Spectroscopic and nonlinear optical properties of the four positional isomers of 4α-(4-tert-butylphenoxy) phthalocyanine
- Ngubeni, Grace N, Britton, Jonathan, Mack, John, New, Edward, Hancox, Ian, Walker, Marc, Nyokong, Tebello, Jones, Tim S, Khene,Samson M
- Authors: Ngubeni, Grace N , Britton, Jonathan , Mack, John , New, Edward , Hancox, Ian , Walker, Marc , Nyokong, Tebello , Jones, Tim S , Khene,Samson M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241448 , vital:50940 , xlink:href="https://doi.org/10.1039/C5TC01601K"
- Description: The spectroscopic and nonlinear optical properties of the positional isomers of metal free 4α-(4-tert-butylphenoxy) phthalocyanine are presented. Second order nonlinear polarizability (β), imaginary hyperpolarizability (Im(γ)) and imaginary susceptibility (Im[χ(3)]) values were determined for the four positional isomers. The measured β values of the four isomers displayed the following trend, C4h (34.0 × 10−5 m MW−1) > D2h (28.8 × 10−5 m MW−1) > C2v (22.8 × 10−5 m MW−1) > Cs (13.7 × 10−5 m MW−1).
- Full Text:
- Date Issued: 2015
- Authors: Ngubeni, Grace N , Britton, Jonathan , Mack, John , New, Edward , Hancox, Ian , Walker, Marc , Nyokong, Tebello , Jones, Tim S , Khene,Samson M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241448 , vital:50940 , xlink:href="https://doi.org/10.1039/C5TC01601K"
- Description: The spectroscopic and nonlinear optical properties of the positional isomers of metal free 4α-(4-tert-butylphenoxy) phthalocyanine are presented. Second order nonlinear polarizability (β), imaginary hyperpolarizability (Im(γ)) and imaginary susceptibility (Im[χ(3)]) values were determined for the four positional isomers. The measured β values of the four isomers displayed the following trend, C4h (34.0 × 10−5 m MW−1) > D2h (28.8 × 10−5 m MW−1) > C2v (22.8 × 10−5 m MW−1) > Cs (13.7 × 10−5 m MW−1).
- Full Text:
- Date Issued: 2015
Steel Valley and the absence of environmental justice in the new South Africa: Critical realism's kinship with environmental justice
- Authors: Munnik, Victor
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437067 , vital:73328 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: In this chapter I report work with critical realist perspective and tools to examine and review prevailing dispositions on indige-nous and institutional knowledge (Western science) in envi-ronmental learning. I open with a review of some of the macro social processes that have come to inscribe assumptions of incommensur able difference between the two kinds of knowledge. Whilst the previous hegemony of positivism would have resulted in the dismissal of much indigenous knowledge as mere superstition, contemporary intellectual perspectives (poststructural and hermeneutical) have shaped a proliferation of worldview modelling that has resulted in a macro-level ex-emplifying of indigenous knowledge as different from and op-posing Western science (Cobern and Aikenhead, 1998; Ai-kenhead, 2006). Here, the lack of adequate mediating tools has given rise to a problematic inscription of assumed differ-ence between the knowledge of indigenous peoples and that of scientific institutions. Furthermore, despite an overt emanci-patory intention in worldview discourses, the marginalization of indigenous peoples and knowledge remains. I then move into the micro arena with a case study of learning interactions in the South African science curriculum. Specifically, I explore some patterns of exclusion in relation to the manner in which stu-dents are able to gain access to the knowledge of scientific institutions. The experience and evidence reported is of a pre-liminary nature but the insights and emerging models of pro-cess provide a useful perspective on how assumed incom-mensurability of knowledge can be tenuous. The study suggests that a critical engagement with both indigenous knowledge and Western science can reveal integrative synergies.
- Full Text:
- Date Issued: 2015
- Authors: Munnik, Victor
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437067 , vital:73328 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: In this chapter I report work with critical realist perspective and tools to examine and review prevailing dispositions on indige-nous and institutional knowledge (Western science) in envi-ronmental learning. I open with a review of some of the macro social processes that have come to inscribe assumptions of incommensur able difference between the two kinds of knowledge. Whilst the previous hegemony of positivism would have resulted in the dismissal of much indigenous knowledge as mere superstition, contemporary intellectual perspectives (poststructural and hermeneutical) have shaped a proliferation of worldview modelling that has resulted in a macro-level ex-emplifying of indigenous knowledge as different from and op-posing Western science (Cobern and Aikenhead, 1998; Ai-kenhead, 2006). Here, the lack of adequate mediating tools has given rise to a problematic inscription of assumed differ-ence between the knowledge of indigenous peoples and that of scientific institutions. Furthermore, despite an overt emanci-patory intention in worldview discourses, the marginalization of indigenous peoples and knowledge remains. I then move into the micro arena with a case study of learning interactions in the South African science curriculum. Specifically, I explore some patterns of exclusion in relation to the manner in which stu-dents are able to gain access to the knowledge of scientific institutions. The experience and evidence reported is of a pre-liminary nature but the insights and emerging models of pro-cess provide a useful perspective on how assumed incom-mensurability of knowledge can be tenuous. The study suggests that a critical engagement with both indigenous knowledge and Western science can reveal integrative synergies.
- Full Text:
- Date Issued: 2015
Structural and optical properties of alloyed quaternary CdSeTeS core and CdSeTeS/ZnS core–shell quantum dots
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193575 , vital:45349 , xlink:href="https://doi.org/10.1016/j.jallcom.2015.05.083"
- Description: Synthesis of fluorescent alloyed quantum dots (QDs) with unique optical properties suitable for a wide array of chemical, physical and biological applications is of research interest. In this work, highly luminescent and photostable alloyed quaternary CdSeTeS core QDs of two different sizes were fabricated via the organometallic hot-injection synthetic route. Characterization of the nanocrystals were performed using TEM, XRD, UV/vis and fluorescence spectrophotometric techniques. We have demonstrated in this work that the well fabricated alloyed quaternary CdSeTeS core QDs possess unique optical properties that are advantageous over conventional core/shell systems. Formation of the CdSeTeS/ZnS core/shell with the desired optical properties comes with a number of challenges, hence the advantages of the quaternary alloyed core over the core/shell QDs are (i) avoidance of the challenging process of determining the proper shell thickness which can provide the desired optical properties in the core/shell system and (ii) avoidance of the lattice-induced mismatch between the core and the shell material which can either lead to incomplete exciton confinement or dislocation at the core/shell interface.
- Full Text:
- Date Issued: 2015
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193575 , vital:45349 , xlink:href="https://doi.org/10.1016/j.jallcom.2015.05.083"
- Description: Synthesis of fluorescent alloyed quantum dots (QDs) with unique optical properties suitable for a wide array of chemical, physical and biological applications is of research interest. In this work, highly luminescent and photostable alloyed quaternary CdSeTeS core QDs of two different sizes were fabricated via the organometallic hot-injection synthetic route. Characterization of the nanocrystals were performed using TEM, XRD, UV/vis and fluorescence spectrophotometric techniques. We have demonstrated in this work that the well fabricated alloyed quaternary CdSeTeS core QDs possess unique optical properties that are advantageous over conventional core/shell systems. Formation of the CdSeTeS/ZnS core/shell with the desired optical properties comes with a number of challenges, hence the advantages of the quaternary alloyed core over the core/shell QDs are (i) avoidance of the challenging process of determining the proper shell thickness which can provide the desired optical properties in the core/shell system and (ii) avoidance of the lattice-induced mismatch between the core and the shell material which can either lead to incomplete exciton confinement or dislocation at the core/shell interface.
- Full Text:
- Date Issued: 2015
Studies towards the development of novel antimalarial agents
- Authors: Adeyemi, Christiana Modupe
- Date: 2015
- Subjects: Antimalarials , Malaria , Drug resistance , Drug development , Enzyme inhibitors , Plasmodium
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54645 , vital:26596
- Description: Considerable efforts have been made in the modification of existing antimalarial drugs, and the support of incentive programmes have led to a drastic decrease in malaria cases reported by WHO during the past 6 years. However, the development of drug resistance threatens the eradication of this deadly disease and has prompted research on the synthesis of novel antimalarial drugs. Our research has involved the design and synthesis of novel benzylated phosphonate esters as potential 1-deoxy-D-xylose-5-phosphate reductoisomerase (DXR) inhibitors. A series of amidoalkylphosphonate esters were obtained by reacting various 3-subsituted anilines and heterocyclic amines with chloroalkanoyl chlorides and reacting the resulting chloroalkanamides with triethyl phosphite using Michaelis-Arbuzov methodology. Benzylation of the phosphonate esters afforded a series of novel N-benzylated derivatives in good yields and these compounds were fully characterised by NMR and HRMS methods. Several approaches to the introduction of a benzyl group at the C-2 position of the phosphonate ester derivatives have been explored, leading unexpectedly to the isolation of unprecedented tetrahydrofuranyl derivatives. Studies towards the preparation of potential bi-functional PfDXR / HIV-1 RT inhibitors have also been initiated. Preliminary in silico docking studies of selected non-benzylated and benzylated phosphonated derivatives into the Pf-DXR active-site has provided useful insight into the binding potential of these ligands. Bioassays have revealed a very low toxicity for all the synthesised phosphonated compounds and a number of these ligands also exhibit a promising inhibitory activity against the Plasmodium parasite.
- Full Text:
- Date Issued: 2015
- Authors: Adeyemi, Christiana Modupe
- Date: 2015
- Subjects: Antimalarials , Malaria , Drug resistance , Drug development , Enzyme inhibitors , Plasmodium
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54645 , vital:26596
- Description: Considerable efforts have been made in the modification of existing antimalarial drugs, and the support of incentive programmes have led to a drastic decrease in malaria cases reported by WHO during the past 6 years. However, the development of drug resistance threatens the eradication of this deadly disease and has prompted research on the synthesis of novel antimalarial drugs. Our research has involved the design and synthesis of novel benzylated phosphonate esters as potential 1-deoxy-D-xylose-5-phosphate reductoisomerase (DXR) inhibitors. A series of amidoalkylphosphonate esters were obtained by reacting various 3-subsituted anilines and heterocyclic amines with chloroalkanoyl chlorides and reacting the resulting chloroalkanamides with triethyl phosphite using Michaelis-Arbuzov methodology. Benzylation of the phosphonate esters afforded a series of novel N-benzylated derivatives in good yields and these compounds were fully characterised by NMR and HRMS methods. Several approaches to the introduction of a benzyl group at the C-2 position of the phosphonate ester derivatives have been explored, leading unexpectedly to the isolation of unprecedented tetrahydrofuranyl derivatives. Studies towards the preparation of potential bi-functional PfDXR / HIV-1 RT inhibitors have also been initiated. Preliminary in silico docking studies of selected non-benzylated and benzylated phosphonated derivatives into the Pf-DXR active-site has provided useful insight into the binding potential of these ligands. Bioassays have revealed a very low toxicity for all the synthesised phosphonated compounds and a number of these ligands also exhibit a promising inhibitory activity against the Plasmodium parasite.
- Full Text:
- Date Issued: 2015
Study of the biotransformations and microbiological properties of cymbopogon citratus
- Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
Study South Africa
- International Education Association of South Africa (IEASA), Jooste, Nico
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2015
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64911 , vital:28636 , ISBN 9780620672306
- Description: [Editor's Letter]: This, the 15th edition of Study South Africa, continues to provide a platform for South African universities to profile themselves. It also provides highlights from the South African Higher Education system for the past year. This edition will focus on research and the internationalisation of research in the South African context. Study South Africa has established itself as the international mouthpiece for South African universities and without missing a beat has been produced by volunteers who, with enthusiasm, have dedicated their time and intellect to promote Higher Education Internationalisation as well as to promote South Africa as a knowledge destination for students, academics and professional staff. It is a special privilege and honour to write the introductory message for this 15th edition of Study South Africa as President of IEASA and Editor of the publication. In an era where global re-organisation is dominating the Higher Education scene and new alliances are formed to emulate the new geopolitical landscape, we need to take note of all the challenges facing Higher Education Internationalisation. A number of trends can be identified as major influences on Higher Education on a global scale. I will focus on some of those trends affecting Higher Education in emerging economies and the developing world. The first of these trends is the focus on regional and south-south cooperation. South African universities indicated their intent to further develop closer relationships with universities in Africa through their participation in the re-thinking of Africa’s future during the African Higher Education Summit on the Revitalisation of Higher Education for Africa’s future, in Dakar, Senegal during March 2015. The vision agreed upon during the summit is to ‘develop a high quality, massive, vibrant, diverse, differentiated, innovative, autonomous and socially responsible Higher Education sector. This sector will be a driving force to achieving the vision outlined in the Agenda 2063 by the African Union with a commitment to a shared strategic framework for the inclusive growth, sustainable development and global strategy to optimise the use of Africa’s resources for the benefit of all Africans’. The role of universities would be to develop closer cooperation as well as to advance research with a focus on innovation and sustainable economic growth that will integrate African economies as equal partners in the world economy. It is clear from the vision that although the emphasis should be on inter-African collaboration, collaboration with institutions outside the African continent should not be excluded to achieve the knowledge creation needed to achieve Agenda 2063. Another Higher Education Internationalisation trend in South Africa is the development of closer cooperation within the BRICS countries. The agreements reached and strategies agreed to during the BRICS Summit in Ufa, and included in the Ufa Declaration of 17 June 2015, open doors to future collaborations between BRICS universities. It is envisaged that in the next year the constituent meeting of the BRICS University Network and the establishment of the BRICS Universities League will provide the necessary framework for future collaboration amongst universities from the BRICS member countries. It is imperative that organisations like IEASA and the Brazilian FAUBAI play a key role in the establishment and function of the above mentioned networks. We can provide the necessary support and leadership to other member countries where Higher Education Internationalisation is still at the early stages of conceptualisation and organisation. It will be important to make effective use of the occasion of the Global Conference on Higher Education Internationalisation, scheduled to take place in South Africa in August 2016, to debate and set the future agenda for the BRICS University Network in relation to the rest of the world. It is also vital that the BRICS universities as well as the universities in Africa integrate fully with the rest of the world instead of developing a separate grouping. , 15th Edition
- Full Text:
- Date Issued: 2015
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2015
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64911 , vital:28636 , ISBN 9780620672306
- Description: [Editor's Letter]: This, the 15th edition of Study South Africa, continues to provide a platform for South African universities to profile themselves. It also provides highlights from the South African Higher Education system for the past year. This edition will focus on research and the internationalisation of research in the South African context. Study South Africa has established itself as the international mouthpiece for South African universities and without missing a beat has been produced by volunteers who, with enthusiasm, have dedicated their time and intellect to promote Higher Education Internationalisation as well as to promote South Africa as a knowledge destination for students, academics and professional staff. It is a special privilege and honour to write the introductory message for this 15th edition of Study South Africa as President of IEASA and Editor of the publication. In an era where global re-organisation is dominating the Higher Education scene and new alliances are formed to emulate the new geopolitical landscape, we need to take note of all the challenges facing Higher Education Internationalisation. A number of trends can be identified as major influences on Higher Education on a global scale. I will focus on some of those trends affecting Higher Education in emerging economies and the developing world. The first of these trends is the focus on regional and south-south cooperation. South African universities indicated their intent to further develop closer relationships with universities in Africa through their participation in the re-thinking of Africa’s future during the African Higher Education Summit on the Revitalisation of Higher Education for Africa’s future, in Dakar, Senegal during March 2015. The vision agreed upon during the summit is to ‘develop a high quality, massive, vibrant, diverse, differentiated, innovative, autonomous and socially responsible Higher Education sector. This sector will be a driving force to achieving the vision outlined in the Agenda 2063 by the African Union with a commitment to a shared strategic framework for the inclusive growth, sustainable development and global strategy to optimise the use of Africa’s resources for the benefit of all Africans’. The role of universities would be to develop closer cooperation as well as to advance research with a focus on innovation and sustainable economic growth that will integrate African economies as equal partners in the world economy. It is clear from the vision that although the emphasis should be on inter-African collaboration, collaboration with institutions outside the African continent should not be excluded to achieve the knowledge creation needed to achieve Agenda 2063. Another Higher Education Internationalisation trend in South Africa is the development of closer cooperation within the BRICS countries. The agreements reached and strategies agreed to during the BRICS Summit in Ufa, and included in the Ufa Declaration of 17 June 2015, open doors to future collaborations between BRICS universities. It is envisaged that in the next year the constituent meeting of the BRICS University Network and the establishment of the BRICS Universities League will provide the necessary framework for future collaboration amongst universities from the BRICS member countries. It is imperative that organisations like IEASA and the Brazilian FAUBAI play a key role in the establishment and function of the above mentioned networks. We can provide the necessary support and leadership to other member countries where Higher Education Internationalisation is still at the early stages of conceptualisation and organisation. It will be important to make effective use of the occasion of the Global Conference on Higher Education Internationalisation, scheduled to take place in South Africa in August 2016, to debate and set the future agenda for the BRICS University Network in relation to the rest of the world. It is also vital that the BRICS universities as well as the universities in Africa integrate fully with the rest of the world instead of developing a separate grouping. , 15th Edition
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- Date Issued: 2015
Subjective well-being in Africa
- Botha, Ferdi, Snowball, Jeanette D
- Authors: Botha, Ferdi , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61084 , vital:27946
- Description: Research on quality of life and subjective well-being (SWB) has witnessed a remarkable growth over the past four decades or so. Since Easterlin’s (1974) seminal contribution on the relationship between happiness and income, thousands of studies have followed that examine the intricacies of subjective well-being (for reviews, see Frey and Stutzer, 2002; Dolan et al., 2008; MacKerron, 2012). These studies have uncovered some very important aspects of individual well-being and have pointed to the fact that money or income is not always (as is often assumed) the most important determinant of SWB.
- Full Text:
- Date Issued: 2015
- Authors: Botha, Ferdi , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61084 , vital:27946
- Description: Research on quality of life and subjective well-being (SWB) has witnessed a remarkable growth over the past four decades or so. Since Easterlin’s (1974) seminal contribution on the relationship between happiness and income, thousands of studies have followed that examine the intricacies of subjective well-being (for reviews, see Frey and Stutzer, 2002; Dolan et al., 2008; MacKerron, 2012). These studies have uncovered some very important aspects of individual well-being and have pointed to the fact that money or income is not always (as is often assumed) the most important determinant of SWB.
- Full Text:
- Date Issued: 2015
Surface modification of silica-coated gadolinium oxide nanoparticles with zinc tetracarboxyphenoxy phthalocyanine for the photodegradation of Orange G
- Ledwaba, Mpho, Masilela, Nkosiphile, Nyokong, Tebello, Antunes, Edith M
- Authors: Ledwaba, Mpho , Masilela, Nkosiphile , Nyokong, Tebello , Antunes, Edith M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193621 , vital:45353 , xlink:href="https://doi.org/10.1016/j.molcata.2015.03.023"
- Description: Zinc tetracarboxyphenoxy phthalocyanine was covalently linked to Gd2O3 nanoparticles for the photocatalytic degradation of Orange G. Characterization of the composite was carried out using XRD, TEM, XPS, UV–vis spectroscopy and FT-IR spectroscopy. The composite showed improved photophysical properties over the phthalocyanine alone and the catalyst was found to be reusable. Analyses of the photodegradation rates of the azo dye indicated pseudo first-order kinetics.
- Full Text:
- Date Issued: 2015
- Authors: Ledwaba, Mpho , Masilela, Nkosiphile , Nyokong, Tebello , Antunes, Edith M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193621 , vital:45353 , xlink:href="https://doi.org/10.1016/j.molcata.2015.03.023"
- Description: Zinc tetracarboxyphenoxy phthalocyanine was covalently linked to Gd2O3 nanoparticles for the photocatalytic degradation of Orange G. Characterization of the composite was carried out using XRD, TEM, XPS, UV–vis spectroscopy and FT-IR spectroscopy. The composite showed improved photophysical properties over the phthalocyanine alone and the catalyst was found to be reusable. Analyses of the photodegradation rates of the azo dye indicated pseudo first-order kinetics.
- Full Text:
- Date Issued: 2015
Survival of bifidobacteria and their usefulness in faecal source tracking
- Luyt, Catherine D, Khamanga, Sandile M, Muller, Wilhelmine J, Tandlich, Roman
- Authors: Luyt, Catherine D , Khamanga, Sandile M , Muller, Wilhelmine J , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76117 , vital:30508 , https://doi.org/10.1515/lwr-2015-0001
- Description: Bifidobacteria have long since been recommended as indicators of human and animal pollution. Concentration ratio (tracking ratio) of the sorbitol-utilising bifidobacteria (SUB) and the total bifidobacteria (TB) can be used to distinguish between animal and human sources of faecal water contamination. The cut-off value needs to be calibrated in a given geographical area. Seven sites with permanent faecal contamination were selected in South Africa. Concentrations of SUB ranged from 10-50000 cells/100 mL, while TB ranged from 0-8000 cells/100 mL. The tracking ratio ranged from 0.10 to 6.25, but no clear cut-off value could be established. The YN-17 agar was replaced for TB with the modified Beerens medium with pH = 5.70, to suppress the growth of faecal streptococci. Tracking ratios observed are most likely the results of different survival rates of SUB and TB. Bifidobacteria die-off due to nutrients was not found to be significant using design of experiment. Thus a lack of continuous input or oxygen levels in water may be major factors. This would limit the ratios used as a faecal source tracking method.
- Full Text:
- Date Issued: 2015
- Authors: Luyt, Catherine D , Khamanga, Sandile M , Muller, Wilhelmine J , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76117 , vital:30508 , https://doi.org/10.1515/lwr-2015-0001
- Description: Bifidobacteria have long since been recommended as indicators of human and animal pollution. Concentration ratio (tracking ratio) of the sorbitol-utilising bifidobacteria (SUB) and the total bifidobacteria (TB) can be used to distinguish between animal and human sources of faecal water contamination. The cut-off value needs to be calibrated in a given geographical area. Seven sites with permanent faecal contamination were selected in South Africa. Concentrations of SUB ranged from 10-50000 cells/100 mL, while TB ranged from 0-8000 cells/100 mL. The tracking ratio ranged from 0.10 to 6.25, but no clear cut-off value could be established. The YN-17 agar was replaced for TB with the modified Beerens medium with pH = 5.70, to suppress the growth of faecal streptococci. Tracking ratios observed are most likely the results of different survival rates of SUB and TB. Bifidobacteria die-off due to nutrients was not found to be significant using design of experiment. Thus a lack of continuous input or oxygen levels in water may be major factors. This would limit the ratios used as a faecal source tracking method.
- Full Text:
- Date Issued: 2015