“As soon as the four sides are all equal, then the angles must be 90° each”: children's misconceptions in geometry
- Atebe, Humphrey U, Schäfer, Marc
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140983 , vital:37934 , DOI: 10.1080/10288457.2008.10740634
- Description: This study describes Nigerian and South African students' conceptual understanding in high school geometry based on the van Hiele model of geometric thinking levels. The study further highlights students' misconceptions in school geometry. Concepts of triangles and quadrilaterals were investigated among 36 mathematics learners drawn from grades 10 through 12 who participated in this study. The tasks included identifying and naming shapes, sorting of shapes, stating the properties of shapes, defining of shapes and establishing class inclusions of shapes. The results indicated that many Nigerian and South African high school learners in Grade 10, 11 and 12 hold a number of misconceptions about geometric concepts of triangles and quadrilaterals.
- Full Text:
- Date Issued: 2013
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140983 , vital:37934 , DOI: 10.1080/10288457.2008.10740634
- Description: This study describes Nigerian and South African students' conceptual understanding in high school geometry based on the van Hiele model of geometric thinking levels. The study further highlights students' misconceptions in school geometry. Concepts of triangles and quadrilaterals were investigated among 36 mathematics learners drawn from grades 10 through 12 who participated in this study. The tasks included identifying and naming shapes, sorting of shapes, stating the properties of shapes, defining of shapes and establishing class inclusions of shapes. The results indicated that many Nigerian and South African high school learners in Grade 10, 11 and 12 hold a number of misconceptions about geometric concepts of triangles and quadrilaterals.
- Full Text:
- Date Issued: 2013
'Rich man poor man': inter-household and community factors influencing the use of wild plant resources amongst rural households in South Africa
- Cocks, Michelle L, Bangay, Lindsey, Shackleton, Charlie M, Wiersum, K Freerk
- Authors: Cocks, Michelle L , Bangay, Lindsey , Shackleton, Charlie M , Wiersum, K Freerk
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141211 , vital:37953 , DOI: 10.3843/SusDev.15.3:3
- Description: Biodiversity is recognised as an integral part of people's daily livelihoods. This study therefore aims to understand the use of NTFPs at an intricate level by determining what role these resources fulfil in six rural villages and 1011 households' livelihoods. It examines how the use of NTFPs are influenced by intra-household variables, such as wealth and gender, and inter-community variables, such as accessibility to the natural resource. The results reveal that approximately 4453 kg of wild material is used annually per household, of which 1598 kg is used for cultural purposes. The influence of vegetation type and differences between villages are statistically more significant than inter-household variables. At an inter-household level, an increase in the financial status of households did not result in a decrease in the use of natural resources, nor in the quantity of material used.
- Full Text:
- Date Issued: 2010
- Authors: Cocks, Michelle L , Bangay, Lindsey , Shackleton, Charlie M , Wiersum, K Freerk
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141211 , vital:37953 , DOI: 10.3843/SusDev.15.3:3
- Description: Biodiversity is recognised as an integral part of people's daily livelihoods. This study therefore aims to understand the use of NTFPs at an intricate level by determining what role these resources fulfil in six rural villages and 1011 households' livelihoods. It examines how the use of NTFPs are influenced by intra-household variables, such as wealth and gender, and inter-community variables, such as accessibility to the natural resource. The results reveal that approximately 4453 kg of wild material is used annually per household, of which 1598 kg is used for cultural purposes. The influence of vegetation type and differences between villages are statistically more significant than inter-household variables. At an inter-household level, an increase in the financial status of households did not result in a decrease in the use of natural resources, nor in the quantity of material used.
- Full Text:
- Date Issued: 2010
Estuarine use by spotted grunter Pomadasys commersonnii in a South African estuary, as determined by acoustic telemetry
- Childs, Amber-Robyn, Cowley, Paul D, Næsje, T F, Booth, Anthony J, Potts, Warren M, Thorstad, Eva B, Økland, F
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
- Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
- Full Text:
- Date Issued: 2010
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
- Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
- Full Text:
- Date Issued: 2010
Does reservoir trophic status influence the feeding and growth of the sharptooth catfish, Clarias gariepinus (Teleostei: Clariidae)?
- Potts, Warren M, Hecht, Thomas, Andrew, Timothy G
- Authors: Potts, Warren M , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124309 , vital:35591 , https://doi.org/10.2989/A JAS.2008.33.2.6.503
- Description: The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a waterbody had an effect on the growth rate of the species. In order of importance, the diet of catfish in Kat River Reservoir consisted of fish, insects, zooplankton, plant material and other items, while the diet of catfish in Laing Reservoir consisted of fish, plant material, zooplankton, other vertebrates and insects. The diets of catfish in the two reservoirs had a similarity index of 68.1% and there was no significant difference in their nutritional value. Fish prey was the most important dietary component in both reservoirs. Temperature regime and zooplankton and zoobenthos density were similar in both systems. However, fish prey density was significantly higher in the eutrophic Laing Reservoir and catfish grew significantly faster in that system. The slower growth rate in Kat River Reservoir was attributed to the higher energy costs associated with the capture of fish prey, which was less abundant than in Laing Reservoir. Trophic status therefore had an indirect effect on catfish growth by influencing the availability of fish prey.
- Full Text:
- Date Issued: 2010
- Authors: Potts, Warren M , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124309 , vital:35591 , https://doi.org/10.2989/A JAS.2008.33.2.6.503
- Description: The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a waterbody had an effect on the growth rate of the species. In order of importance, the diet of catfish in Kat River Reservoir consisted of fish, insects, zooplankton, plant material and other items, while the diet of catfish in Laing Reservoir consisted of fish, plant material, zooplankton, other vertebrates and insects. The diets of catfish in the two reservoirs had a similarity index of 68.1% and there was no significant difference in their nutritional value. Fish prey was the most important dietary component in both reservoirs. Temperature regime and zooplankton and zoobenthos density were similar in both systems. However, fish prey density was significantly higher in the eutrophic Laing Reservoir and catfish grew significantly faster in that system. The slower growth rate in Kat River Reservoir was attributed to the higher energy costs associated with the capture of fish prey, which was less abundant than in Laing Reservoir. Trophic status therefore had an indirect effect on catfish growth by influencing the availability of fish prey.
- Full Text:
- Date Issued: 2010
Institutions and economic research: a case of location externalities on agricultural resource allocation in the Kat River basin, South Africa
- Mbatha, Cyril N, Antrobus, Geoffrey G
- Authors: Mbatha, Cyril N , Antrobus, Geoffrey G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142991 , vital:38183 , DOI: 10.1080/03031853.2013.798069
- Description: The Physical Externality Model is used to illustrate the potential limitations of blindly adopting formal models for economic investigation and explanation in varied geographical contexts. As argued by institutional economists for the last hundred years the practice limits the value and relevance of most general economic inquiry. This model postulates that the geographical location of farmers along a given watercourse, in which water is diverted individually, leads to structural inefficiencies that negatively affect the whole farming community. These effects are felt more severely at downstream sites and lead to a status quo where upstream farmers possess relative economic and political advantages over their counterparts elsewhere. In the study of the Kat River basin these predictions appear to be true only in as far as they relate to legal and political allocations and use of water resources.
- Full Text:
- Date Issued: 2010
- Authors: Mbatha, Cyril N , Antrobus, Geoffrey G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142991 , vital:38183 , DOI: 10.1080/03031853.2013.798069
- Description: The Physical Externality Model is used to illustrate the potential limitations of blindly adopting formal models for economic investigation and explanation in varied geographical contexts. As argued by institutional economists for the last hundred years the practice limits the value and relevance of most general economic inquiry. This model postulates that the geographical location of farmers along a given watercourse, in which water is diverted individually, leads to structural inefficiencies that negatively affect the whole farming community. These effects are felt more severely at downstream sites and lead to a status quo where upstream farmers possess relative economic and political advantages over their counterparts elsewhere. In the study of the Kat River basin these predictions appear to be true only in as far as they relate to legal and political allocations and use of water resources.
- Full Text:
- Date Issued: 2010
Establishment of translocated populations of smallmouth yellowfish, Labeobarbus aeneus (Pisces: Cyprinidae), in lentic and lotic habitats in the Great Fish River system, South Africa
- Weyl, Olaf L F, Stadtlander, Timo, Booth, Anthony J
- Authors: Weyl, Olaf L F , Stadtlander, Timo , Booth, Anthony J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124418 , vital:35607 , https://doi.org/10.3377/004.044.0109
- Description: As a result of numerous introductions and translocations of fishes, South Africa has recently been identified as a fish invasion hotspot (Leprieur et al. 2008). In freshwater ecosystems invasion by alien species is considered a leading mechanism driving environmental change (Clavero & Garcia- Berthou 2005; Garcia-Berthou et al. 2005). In South Africa, documented effects of fish invasions include the extirpation of indigenous fishes through predation (Cambray 2003), changes in invertebrate community structure (Lowe et al. 2008) and hybridization (Canonico et al. 2005). As a result, the management of alien species is a high national priority (National Environmental Management: Biodiversity Act 2004). Such management requires an understanding of the biology, ecology and establishment success of fishes outside their native range.
- Full Text:
- Date Issued: 2009
- Authors: Weyl, Olaf L F , Stadtlander, Timo , Booth, Anthony J
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124418 , vital:35607 , https://doi.org/10.3377/004.044.0109
- Description: As a result of numerous introductions and translocations of fishes, South Africa has recently been identified as a fish invasion hotspot (Leprieur et al. 2008). In freshwater ecosystems invasion by alien species is considered a leading mechanism driving environmental change (Clavero & Garcia- Berthou 2005; Garcia-Berthou et al. 2005). In South Africa, documented effects of fish invasions include the extirpation of indigenous fishes through predation (Cambray 2003), changes in invertebrate community structure (Lowe et al. 2008) and hybridization (Canonico et al. 2005). As a result, the management of alien species is a high national priority (National Environmental Management: Biodiversity Act 2004). Such management requires an understanding of the biology, ecology and establishment success of fishes outside their native range.
- Full Text:
- Date Issued: 2009
Sustainability assessment using a unit-based sustainability assessment tool: The case of three teaching departments at Rhodes University, South Africa
- Authors: Togo, Muchaiteyi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386863 , vital:68182 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122776"
- Description: A sustainability assessment study was performed with three teaching departments at Rhodes University – Ichthyology and Fisheries Science, Anthropology, and Accounting. The assessment used a Unit-based Sustainability Assessment Tool (USAT) and was guided by systems thinking and the ontological framework provided by critical realism. Results of the study showed that the Department of Ichthyology and Fisheries Science had a higher integration of sustainability issues in its activities than the other departments sampled, with Accounting having the lowest integration. Interviews conducted with departmental heads and content analyses of documents revealed differences in sustainability issues addressed and in approaches used in tackling them among these departments. The study is intended to inform the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership, which promotes mainstreaming environment and sustainability in universities during the United Nations Decade of Education for Sustainable Development. The study does not provide answers to mainstreaming activities, but opens up space to debate and deliberate how to deal with the mainstreaming of sustainability in universities. It identified some of the challenges to be addressed in university-wide mainstreaming work, and affirmed the need for systems thinking in bringing about change at institutional level to extend changes taking place in individual teaching contexts.
- Full Text:
- Date Issued: 2008
- Authors: Togo, Muchaiteyi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386863 , vital:68182 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122776"
- Description: A sustainability assessment study was performed with three teaching departments at Rhodes University – Ichthyology and Fisheries Science, Anthropology, and Accounting. The assessment used a Unit-based Sustainability Assessment Tool (USAT) and was guided by systems thinking and the ontological framework provided by critical realism. Results of the study showed that the Department of Ichthyology and Fisheries Science had a higher integration of sustainability issues in its activities than the other departments sampled, with Accounting having the lowest integration. Interviews conducted with departmental heads and content analyses of documents revealed differences in sustainability issues addressed and in approaches used in tackling them among these departments. The study is intended to inform the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership, which promotes mainstreaming environment and sustainability in universities during the United Nations Decade of Education for Sustainable Development. The study does not provide answers to mainstreaming activities, but opens up space to debate and deliberate how to deal with the mainstreaming of sustainability in universities. It identified some of the challenges to be addressed in university-wide mainstreaming work, and affirmed the need for systems thinking in bringing about change at institutional level to extend changes taking place in individual teaching contexts.
- Full Text:
- Date Issued: 2008
When commercial can also be community:
- Authors: du Toit, Peter , Rau, Asta
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159322 , vital:40287 , https://hdl.handle.net/10520/EJC140094
- Description: Questions of ownership, control and profit distribution are widely used to distinguish between commercial and community media ventures, but an over-reliance on such distinctions may eclipse other important considerations in a way that impacts negatively on media diversity.
- Full Text:
- Date Issued: 2008
- Authors: du Toit, Peter , Rau, Asta
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159322 , vital:40287 , https://hdl.handle.net/10520/EJC140094
- Description: Questions of ownership, control and profit distribution are widely used to distinguish between commercial and community media ventures, but an over-reliance on such distinctions may eclipse other important considerations in a way that impacts negatively on media diversity.
- Full Text:
- Date Issued: 2008
Electrocatalytic and photosensitizing behavior of metallophthalocyanine complexes
- Authors: Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265908 , vital:53899 , xlink:href="https://doi.org/10.1142/S1088424608000388"
- Description: Electrocatalytic or photosensitizing (photocatalytic) properties of metallophthalocyanine (MPc) complexes are dependent on the central metal. Electrocatalytic behavior is observed for electroactive central metals such as Co, Mn and Fe, whereas photosensitizing behavior is observed for diamagnetic metals such as Al, Zn and Si. In the presence of nanoparticles such as quantum dots, the photosensitizing behavior of MPc complexes is improved. Carbon nanotubes enhance the electrocatalytic behavior of MPc complexes.
- Full Text:
- Date Issued: 2008
- Authors: Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265908 , vital:53899 , xlink:href="https://doi.org/10.1142/S1088424608000388"
- Description: Electrocatalytic or photosensitizing (photocatalytic) properties of metallophthalocyanine (MPc) complexes are dependent on the central metal. Electrocatalytic behavior is observed for electroactive central metals such as Co, Mn and Fe, whereas photosensitizing behavior is observed for diamagnetic metals such as Al, Zn and Si. In the presence of nanoparticles such as quantum dots, the photosensitizing behavior of MPc complexes is improved. Carbon nanotubes enhance the electrocatalytic behavior of MPc complexes.
- Full Text:
- Date Issued: 2008
Dungamanzi/stirring waters: Tsonga and Shangaan art from southern Africa, Nessa Leibhammer (Ed.): book reviews
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
Synthesis and electrochemical characterisation of a near infrared absorbing oxo vanadium (IV) octapentylthio-phthalocyanine
- Mbambisa, Gcineka, Nyokong, Tebello
- Authors: Mbambisa, Gcineka , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/266008 , vital:53909 , xlink:href="https://doi.org/10.1016/j.poly.2008.06.004"
- Description: The synthesis of an α-substituted phthalocyanine oxo vanadium(IV) 1,4,8,11,15,18,22,25-octapentathiophthalocyanine (4) which absorbs at 850 nm in dichloromethane is reported. The complex is purple in colour and becomes green on reduction. The cyclic and square wave voltammetries of the complex show five redox couples. The spectroelectrochemical data showed only ring based processes. The ring reduced species is observed at wavelengths greater than 680 nm rather than the usual 500–600 nm range typical of ring reduced phthalocyanine complexes.
- Full Text:
- Date Issued: 2008
- Authors: Mbambisa, Gcineka , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/266008 , vital:53909 , xlink:href="https://doi.org/10.1016/j.poly.2008.06.004"
- Description: The synthesis of an α-substituted phthalocyanine oxo vanadium(IV) 1,4,8,11,15,18,22,25-octapentathiophthalocyanine (4) which absorbs at 850 nm in dichloromethane is reported. The complex is purple in colour and becomes green on reduction. The cyclic and square wave voltammetries of the complex show five redox couples. The spectroelectrochemical data showed only ring based processes. The ring reduced species is observed at wavelengths greater than 680 nm rather than the usual 500–600 nm range typical of ring reduced phthalocyanine complexes.
- Full Text:
- Date Issued: 2008
Interaction of water-soluble thiol capped CdTe quantum dots and bovine serum albumin
- Idowu, Mopelola, Lamprecht, Emmanuel, Nyokong, Tebello
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Date Issued: 2008
Communicating across cultures in South African law courts: towards an information technology solution*
- Kaschula, Russell H, Mostert, André
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2008
- Subjects: Language policy -- South Africa , Courts interpreting and translating -- South Africa , Translating and interpreting -- Technological innovations , Intercultural communication -- South Africa , Conduct of court proceedings -- South Africa , Linguistic rights -- South Africa , Multilingualism -- South Africa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59423 , vital:27599 , doi: 10.5842/36-0-39
- Description: Language rights in South Africa are entrenched in the Constitution of South Africa (Chapter 1, Section 6, Constitution of the Republic of South Africa, 1996). However, the concomitant infrastructure and organisational realities make this policy difficult to implement, especially in law courts (Kaschula and Ralarala 2004). Creating effective communicative environments has historically been constrained by lack of effective training of legal practitioners and by the lack of capacity for building translation structures. With the advancement of technology, potential solutions are becoming more apparent and it is incumbent upon the academic community to embark on a rigorous investigation into possible solutions and how these Information Communication Technology (ICT) solutions could be applied to the execution of justice in South African law courts. This article aims to open the discourse of possible solutions, via assessments of computer based translation solutions, ICT context simulations and other potential opportunities. The authors hope to initiate the interest of other language and legal practitioners to explore how the new technological capabilities could be harnessed to support the entrenchment of language rights in our law courts.
- Full Text:
- Date Issued: 2008
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2008
- Subjects: Language policy -- South Africa , Courts interpreting and translating -- South Africa , Translating and interpreting -- Technological innovations , Intercultural communication -- South Africa , Conduct of court proceedings -- South Africa , Linguistic rights -- South Africa , Multilingualism -- South Africa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59423 , vital:27599 , doi: 10.5842/36-0-39
- Description: Language rights in South Africa are entrenched in the Constitution of South Africa (Chapter 1, Section 6, Constitution of the Republic of South Africa, 1996). However, the concomitant infrastructure and organisational realities make this policy difficult to implement, especially in law courts (Kaschula and Ralarala 2004). Creating effective communicative environments has historically been constrained by lack of effective training of legal practitioners and by the lack of capacity for building translation structures. With the advancement of technology, potential solutions are becoming more apparent and it is incumbent upon the academic community to embark on a rigorous investigation into possible solutions and how these Information Communication Technology (ICT) solutions could be applied to the execution of justice in South African law courts. This article aims to open the discourse of possible solutions, via assessments of computer based translation solutions, ICT context simulations and other potential opportunities. The authors hope to initiate the interest of other language and legal practitioners to explore how the new technological capabilities could be harnessed to support the entrenchment of language rights in our law courts.
- Full Text:
- Date Issued: 2008
Sing a swansong for the SABC as we know it : keep public broadcasting, redistribute the broadcaster
- Authors: Berger, Guy
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159326 , vital:40288 , https://hdl.handle.net/10520/EJC140098
- Description: Behind the dragged-out confrontations around the SABC are a politics of paralysis. That's not necessarily a bad thing if the alternative is the broadcaster being a tool of a single particular force. But it's also not exactly first prize for South Africans. Power is divided across so many centres that no single force has been able to easily prevail on SABC during the year.
- Full Text:
- Date Issued: 2008
- Authors: Berger, Guy
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159326 , vital:40288 , https://hdl.handle.net/10520/EJC140098
- Description: Behind the dragged-out confrontations around the SABC are a politics of paralysis. That's not necessarily a bad thing if the alternative is the broadcaster being a tool of a single particular force. But it's also not exactly first prize for South Africans. Power is divided across so many centres that no single force has been able to easily prevail on SABC during the year.
- Full Text:
- Date Issued: 2008
Tracing and erasure in Kathryn Smith's Psychogeographies: the washing away of wrongs
- Authors: de Jager, Maureen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147413 , vital:38634 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31057
- Description: Kathryn Smith's Psychogeographies: The Washing Away of Wrongs is a series of twelve prints comprising photographs and handwritten text, wherein she records her 'pilgrimage' to the former homes of British serial killer Dennis Nilsen. As such, it utilises photographic and autographic traces to 'track' the elusive traces left by Nilsen. Given the lapse of two decades between Nilsen's arrest and Smith's visit, the traces of Nilsen's 'wrongs' seem all but erased by the banal façade of suburban living which has continued on, regardless. In taking this as a starting point, the following article considers the motif of absence that characterises Smith's work as intrinsic to traces per se.
- Full Text:
- Date Issued: 2008
- Authors: de Jager, Maureen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147413 , vital:38634 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31057
- Description: Kathryn Smith's Psychogeographies: The Washing Away of Wrongs is a series of twelve prints comprising photographs and handwritten text, wherein she records her 'pilgrimage' to the former homes of British serial killer Dennis Nilsen. As such, it utilises photographic and autographic traces to 'track' the elusive traces left by Nilsen. Given the lapse of two decades between Nilsen's arrest and Smith's visit, the traces of Nilsen's 'wrongs' seem all but erased by the banal façade of suburban living which has continued on, regardless. In taking this as a starting point, the following article considers the motif of absence that characterises Smith's work as intrinsic to traces per se.
- Full Text:
- Date Issued: 2008
Energy transfer in zinc porphyrin–phthalocyanine heterotrimer and heterononamer studied by fluorescence resonance energy transfer (FRET)
- Durmus, Mahmut, Chen, Jiyao Y, Zhao, Zhixin X, Nyokong, Tebello
- Authors: Durmus, Mahmut , Chen, Jiyao Y , Zhao, Zhixin X , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268599 , vital:54213 , xlink:href="https://doi.org/10.1016/j.saa.2007.07.010"
- Description: Two or eight zinc triphenyl porphyrins were conjugated with Zn-phthalocyanine or H2-phthalocyanine to form ZnPc–(ZnTPP)2, ZnPc–(ZnTPP)8, H2Pc–(ZnTPP)2 and H2Pc–(ZnTPP)8. Energy transfers from the porphyrin moiety to phthalocyanine part were quantitatively studied with the modality of fluorescence resonance energy transfer (FRET). By measuring the fluorescence increment from the phthalocyanine moiety and the decrease from porphyrin part under selective excitation at the B band of the porphyrin part in those conjugated compounds and their equimolar mixture of compositions, energy transfer efficiencies were estimated to be 90% for H2Pc–(ZnTPP)8 and ZnPc–(ZnTPP)8, and 60%, 30% for ZnPc–(ZnTPP)2 and H2Pc–(ZnTPP)2, respectively.
- Full Text:
- Date Issued: 2008
- Authors: Durmus, Mahmut , Chen, Jiyao Y , Zhao, Zhixin X , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268599 , vital:54213 , xlink:href="https://doi.org/10.1016/j.saa.2007.07.010"
- Description: Two or eight zinc triphenyl porphyrins were conjugated with Zn-phthalocyanine or H2-phthalocyanine to form ZnPc–(ZnTPP)2, ZnPc–(ZnTPP)8, H2Pc–(ZnTPP)2 and H2Pc–(ZnTPP)8. Energy transfers from the porphyrin moiety to phthalocyanine part were quantitatively studied with the modality of fluorescence resonance energy transfer (FRET). By measuring the fluorescence increment from the phthalocyanine moiety and the decrease from porphyrin part under selective excitation at the B band of the porphyrin part in those conjugated compounds and their equimolar mixture of compositions, energy transfer efficiencies were estimated to be 90% for H2Pc–(ZnTPP)8 and ZnPc–(ZnTPP)8, and 60%, 30% for ZnPc–(ZnTPP)2 and H2Pc–(ZnTPP)2, respectively.
- Full Text:
- Date Issued: 2008
Pragmatic research design
- Amos, Trevor L, Pearse, Noel J
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
Ecological thinking: Schopenhauer, J M Coetzee and who we are in the world
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7031 , http://hdl.handle.net/10962/d1007362 , https://doi.org/10.5848/CSP.0926.00001
- Description: preprint , For the ecological agenda to make substantive progress, we will have to see powerful people and social agencies turning away from the ecological insanity that threatens us all, and for this to happen, people need to embrace voluntary renunciation, on the understanding that this is not self-sacrifice, but a different and more satisfying way of being in the world. The paper offers some thought, provoked by reading J.M. Coetzee and Arthur Schopenhauer, about what would make this change possible, what might enable it; and secondly why it is implausible that any such ideal might actually come to pass.
- Full Text:
- Date Issued: 2008
Tuning the redox properties of Co-N4 macrocyclic complexes for the catalytic electrooxidation of glucose
- Villagra, Evelyn, Bedioui, Fethi, Nyokong, Tebello, Canales, J Carlos, Sancy, Mamie, Páez, Maritza A, Costamagna, Juan, Zagal, Jose H
- Authors: Villagra, Evelyn , Bedioui, Fethi , Nyokong, Tebello , Canales, J Carlos , Sancy, Mamie , Páez, Maritza A , Costamagna, Juan , Zagal, Jose H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268675 , vital:54221 , xlink:href="https://doi.org/10.1016/j.electacta.2008.02.006"
- Description: Graphite electrodes modified with four different cobalt N4 macrocyclics, namely Co tetrapentapyridinophthalocyanine, (CoTPenPyrPc), Co tetrapyridinoporphyrazine (CoTPyPz), Co octa(hydroxyethylthio)phthalocyanine (CoOEHTPc) and Co tetranitrophthalocyanine (CoTNPc) exhibit catalytic activity for the oxidation of glucose in alkaline media. The purpose of this work is to establish correlations between the catalytic activity of these complexes and their redox potential. The activity of the different modified electrodes was tested by linear voltammetry under hydrodynamic conditions using the rotating disk technique. Tafel plots constructed from mass-transport corrected currents give slopes ranging from 0.080 to 0.160 V/decade for the different catalysts which suggests that a first one-electron step is rate controlling with the symmetry of the energy barrier depending on the nature of the ligand of the Co complex. A plot of log I versus the Co(II)/(I) formal potential gives a volcano curve that also includes catalysts studied previously. This illustrates the concept that the formal potential of the catalyst needs to be tuned to a certain value for achieving maximum activity. A theoretical interpretation of these results is given in terms of Langmuir isotherms for the adsorption of glucose on the Co sites of the surface-confined metal complexes.
- Full Text:
- Date Issued: 2008
- Authors: Villagra, Evelyn , Bedioui, Fethi , Nyokong, Tebello , Canales, J Carlos , Sancy, Mamie , Páez, Maritza A , Costamagna, Juan , Zagal, Jose H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268675 , vital:54221 , xlink:href="https://doi.org/10.1016/j.electacta.2008.02.006"
- Description: Graphite electrodes modified with four different cobalt N4 macrocyclics, namely Co tetrapentapyridinophthalocyanine, (CoTPenPyrPc), Co tetrapyridinoporphyrazine (CoTPyPz), Co octa(hydroxyethylthio)phthalocyanine (CoOEHTPc) and Co tetranitrophthalocyanine (CoTNPc) exhibit catalytic activity for the oxidation of glucose in alkaline media. The purpose of this work is to establish correlations between the catalytic activity of these complexes and their redox potential. The activity of the different modified electrodes was tested by linear voltammetry under hydrodynamic conditions using the rotating disk technique. Tafel plots constructed from mass-transport corrected currents give slopes ranging from 0.080 to 0.160 V/decade for the different catalysts which suggests that a first one-electron step is rate controlling with the symmetry of the energy barrier depending on the nature of the ligand of the Co complex. A plot of log I versus the Co(II)/(I) formal potential gives a volcano curve that also includes catalysts studied previously. This illustrates the concept that the formal potential of the catalyst needs to be tuned to a certain value for achieving maximum activity. A theoretical interpretation of these results is given in terms of Langmuir isotherms for the adsorption of glucose on the Co sites of the surface-confined metal complexes.
- Full Text:
- Date Issued: 2008
A Bernsteinian analysis of the integration of natural resource management in the curriculum of a rural disadvantaged school
- Authors: Nsubuga, Yvonne
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386415 , vital:68139 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122771"
- Description: Knowledge integration is one of the key principles that underpin curriculum reform in post-apartheid South Africa. One form of teacher support that has been adopted in South Africa is to provide schools throughout the country with samples of pedagogic texts such as curriculum documents and examination exemplars to act as guidelines to teachers as they implement this new curriculum requirement. In the isolated and under-resourced rural schools of South Africa, these texts are the main form of curriculum guidance to teachers. Hence the knowledge integration principles and messages conveyed within these texts are of crucial importance. One contributory factor to the lack of information on knowledge integration at rural underresourced schools is the lack of simple and effective research tools by which to analyse and compare the extent of knowledge integration within pedagogic texts and classroom practices. This article reports on a Bernstein informed analysis that was carried out on three different Grade 10 Life Sciences pedagogic texts in order to assess the extent to which they integrate natural resource management (NRM). The study involved the construction of two indicator frameworks as the research tools with which the analysis was conducted. Results from the analysis showed that although the official Grade 10 Life Sciences pedagogic texts contained very high levels of NRM integration, this was not the case for the Grade 10 Life Sciences text that was produced at the school level. The study provides useful insight into curriculum recontextualisation at a rural under-resourced school through the lens of NRM integration within the Grade 10 Life Sciences pedagogic texts. Such insight has the potential to contribute to better curriculum design and implementation strategies to service schools. This will hopefully help to narrow the gap that currently exists between the official and enacted curricula.
- Full Text:
- Date Issued: 2008
- Authors: Nsubuga, Yvonne
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386415 , vital:68139 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122771"
- Description: Knowledge integration is one of the key principles that underpin curriculum reform in post-apartheid South Africa. One form of teacher support that has been adopted in South Africa is to provide schools throughout the country with samples of pedagogic texts such as curriculum documents and examination exemplars to act as guidelines to teachers as they implement this new curriculum requirement. In the isolated and under-resourced rural schools of South Africa, these texts are the main form of curriculum guidance to teachers. Hence the knowledge integration principles and messages conveyed within these texts are of crucial importance. One contributory factor to the lack of information on knowledge integration at rural underresourced schools is the lack of simple and effective research tools by which to analyse and compare the extent of knowledge integration within pedagogic texts and classroom practices. This article reports on a Bernstein informed analysis that was carried out on three different Grade 10 Life Sciences pedagogic texts in order to assess the extent to which they integrate natural resource management (NRM). The study involved the construction of two indicator frameworks as the research tools with which the analysis was conducted. Results from the analysis showed that although the official Grade 10 Life Sciences pedagogic texts contained very high levels of NRM integration, this was not the case for the Grade 10 Life Sciences text that was produced at the school level. The study provides useful insight into curriculum recontextualisation at a rural under-resourced school through the lens of NRM integration within the Grade 10 Life Sciences pedagogic texts. Such insight has the potential to contribute to better curriculum design and implementation strategies to service schools. This will hopefully help to narrow the gap that currently exists between the official and enacted curricula.
- Full Text:
- Date Issued: 2008