A Case Study of Two Selected Teachers as they Integrated Dynamic Geometry Software as a Visualisation Tool in Teaching Geometry:
- Mavani, Deepak, Mavani, Beena, Schäfer, Marc
- Authors: Mavani, Deepak , Mavani, Beena , Schäfer, Marc
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141076 , vital:37942 , https://doi.org/10.1080/18117295.2018.1522716
- Description: This paper reports on an aspect of a larger research study conceptualised within a teacher development project in Mthatha, Eastern Cape Province. The project was initiated with the objective to develop appropriate skills to use dynamic geometry software (DGS) effectively and strategically as a teaching and learning tool for mathematics. The study reported in this paper aims specifically to ascertain how selected mathematics teachers integrated co-developed technologically aided visualisation tools in the observed lessons. The case study involved two teachers from different schools. The data sources were the classroom observations followed by stimulated reflective interviews with the teachers. The data were analysed to study the use of DGS visualisation tools in relation to Kilpatrick’s framework of teaching proficiency.
- Full Text:
- Authors: Mavani, Deepak , Mavani, Beena , Schäfer, Marc
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141076 , vital:37942 , https://doi.org/10.1080/18117295.2018.1522716
- Description: This paper reports on an aspect of a larger research study conceptualised within a teacher development project in Mthatha, Eastern Cape Province. The project was initiated with the objective to develop appropriate skills to use dynamic geometry software (DGS) effectively and strategically as a teaching and learning tool for mathematics. The study reported in this paper aims specifically to ascertain how selected mathematics teachers integrated co-developed technologically aided visualisation tools in the observed lessons. The case study involved two teachers from different schools. The data sources were the classroom observations followed by stimulated reflective interviews with the teachers. The data were analysed to study the use of DGS visualisation tools in relation to Kilpatrick’s framework of teaching proficiency.
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Biological control of Salvinia molesta in South Africa revisited
- Martin, Grant D, Coetzee, Julie A, Weyl, Philip S R, Parkinson, Matthew C, Hill, Martin P
- Authors: Martin, Grant D , Coetzee, Julie A , Weyl, Philip S R , Parkinson, Matthew C , Hill, Martin P
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/103878 , vital:32318 , https://doi.org/10.1016/j.biocontrol.2018.06.011
- Description: The aquatic weed Salvinia molesta D.S. Mitch. (Salviniaceae) was first recorded in South Africa in the early 1900s, and by the 1960s was regarded as one of South Africa’s worst aquatic weeds. Following the release of the weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) in 1985, the weed is now considered under successful biological control. However, the post-release evaluation of this biological control programme has been ad hoc, therefore, to assess the efficacy of the agent, annual quantitative surveys of South African freshwater systems have been undertaken since 2008. Over the last ten years, of the 57 S. molesta sites visited annually in South Africa, the weevil has established at all of them. Eighteen sites are under successful biological control, where the weed no longer poses a threat to the system and 19 are under substantial biological control, where biological control has reduced the impact of the weed. Since 2008, the average percentage weed cover at sites has declined significantly from 51–100% cover to 0–5% cover in 2017 (R2 = 0.78; P < 0.05). Observations of site-specific characteristics suggest that biological control is most effective at small sites and more difficult at larger and shaded sites. Our findings show that S. molesta remains under good biological control in South Africa, however, some sites require intermittent strategic management, such as augmentative releases of C. salviniae.
- Full Text:
- Authors: Martin, Grant D , Coetzee, Julie A , Weyl, Philip S R , Parkinson, Matthew C , Hill, Martin P
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/103878 , vital:32318 , https://doi.org/10.1016/j.biocontrol.2018.06.011
- Description: The aquatic weed Salvinia molesta D.S. Mitch. (Salviniaceae) was first recorded in South Africa in the early 1900s, and by the 1960s was regarded as one of South Africa’s worst aquatic weeds. Following the release of the weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) in 1985, the weed is now considered under successful biological control. However, the post-release evaluation of this biological control programme has been ad hoc, therefore, to assess the efficacy of the agent, annual quantitative surveys of South African freshwater systems have been undertaken since 2008. Over the last ten years, of the 57 S. molesta sites visited annually in South Africa, the weevil has established at all of them. Eighteen sites are under successful biological control, where the weed no longer poses a threat to the system and 19 are under substantial biological control, where biological control has reduced the impact of the weed. Since 2008, the average percentage weed cover at sites has declined significantly from 51–100% cover to 0–5% cover in 2017 (R2 = 0.78; P < 0.05). Observations of site-specific characteristics suggest that biological control is most effective at small sites and more difficult at larger and shaded sites. Our findings show that S. molesta remains under good biological control in South Africa, however, some sites require intermittent strategic management, such as augmentative releases of C. salviniae.
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Gender and popular imaginaries in Africa:
- Spencer, Lynda G, Ligaga, Dina, Musila, Grace
- Authors: Spencer, Lynda G , Ligaga, Dina , Musila, Grace
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138860 , vital:37679 , DOI: 10.1080/10130950.2018.1526467
- Description: If we accept that many Africans’ social perceptions on a range of questions, including gender, are shaped by popular cultural productions which retain a keen pulse on the everyday, then it is important to reflect on the interface between gender and popular imaginaries. The debate on the definition of the ‘popular’ remains an open one with multiple interpretations and categories. This contestation in itself gestures towards popular culture’s inclination for ambiguity and slipperiness. As Karin Barber (2018:13) reminds us, the popular constitutes “expressive forms that are constantly emergent, ephemeral, embedded in daily life, given to extraordinary bursts of activity and rapid transformation”. For George Ogola, popular cultural forms “engage with and subject the polity to constant critique through informal but widely recognised forms of censure” (2017:2). In this special issue, we use popular imaginaries to mean the range of cultural productions, platforms, and interactions between consumers and producers - which are often interchangeable - that capture the material, the affective, as inflected and refracted in different texts, contexts and platforms.
- Full Text:
- Authors: Spencer, Lynda G , Ligaga, Dina , Musila, Grace
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138860 , vital:37679 , DOI: 10.1080/10130950.2018.1526467
- Description: If we accept that many Africans’ social perceptions on a range of questions, including gender, are shaped by popular cultural productions which retain a keen pulse on the everyday, then it is important to reflect on the interface between gender and popular imaginaries. The debate on the definition of the ‘popular’ remains an open one with multiple interpretations and categories. This contestation in itself gestures towards popular culture’s inclination for ambiguity and slipperiness. As Karin Barber (2018:13) reminds us, the popular constitutes “expressive forms that are constantly emergent, ephemeral, embedded in daily life, given to extraordinary bursts of activity and rapid transformation”. For George Ogola, popular cultural forms “engage with and subject the polity to constant critique through informal but widely recognised forms of censure” (2017:2). In this special issue, we use popular imaginaries to mean the range of cultural productions, platforms, and interactions between consumers and producers - which are often interchangeable - that capture the material, the affective, as inflected and refracted in different texts, contexts and platforms.
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The effect of pre-dose on thermally and optically stimulated luminescence from α-Al2O3C, Mg and α-Al2O3: C
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/111011 , vital:33363 , https://doi.org/10.1016/j.apradiso.2018.06.012
- Description: We report the effect of pre-dose on the thermoluminescence (TL) and optically stimulated luminescence (OSL) dose response of α-Al2O3:C,Mg and α-Al2O3:C. Before any luminescence measurement, the samples were irradiated with different doses, namely 100, 500 and 1000 Gy to populate the deep electron traps. This is the pre-dose. The results from TL and OSL studies are compared with results from samples used without any pre-measurement dose. The TL glow curves and OSL decay curves of α-Al2O3:C,Mg recorded after pre-doses of 100, 500 and 1000 Gy are identical to those from a sample used without any pre-dose. Further, the TL and OSL dose response of all α-Al2O3:C,Mg samples are similar regardless of pre-dose. In comparison, the TL glow curves and OSL decay curves of α-Al2O3:C are influenced by pre-dose. We conclude that the differences in the TL and OSL dose response of various pre-dosed samples of α-Al2O3:C are due to the concentration of charge in the deep traps. On the other hand, owing to the lower concentration of such deep traps in α-Al2O3:C,Mg, the TL or OSL dose responses are not affected by pre-dose in this material.
- Full Text: false
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/111011 , vital:33363 , https://doi.org/10.1016/j.apradiso.2018.06.012
- Description: We report the effect of pre-dose on the thermoluminescence (TL) and optically stimulated luminescence (OSL) dose response of α-Al2O3:C,Mg and α-Al2O3:C. Before any luminescence measurement, the samples were irradiated with different doses, namely 100, 500 and 1000 Gy to populate the deep electron traps. This is the pre-dose. The results from TL and OSL studies are compared with results from samples used without any pre-measurement dose. The TL glow curves and OSL decay curves of α-Al2O3:C,Mg recorded after pre-doses of 100, 500 and 1000 Gy are identical to those from a sample used without any pre-dose. Further, the TL and OSL dose response of all α-Al2O3:C,Mg samples are similar regardless of pre-dose. In comparison, the TL glow curves and OSL decay curves of α-Al2O3:C are influenced by pre-dose. We conclude that the differences in the TL and OSL dose response of various pre-dosed samples of α-Al2O3:C are due to the concentration of charge in the deep traps. On the other hand, owing to the lower concentration of such deep traps in α-Al2O3:C,Mg, the TL or OSL dose responses are not affected by pre-dose in this material.
- Full Text: false
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