Development and validation of a stability-indicating method for the quantitation of paclitaxel in pharmaceutical dosage forms
- Mohammadi, Ali, Esimaeili, Farnaz, Dinarvand, Rasoul, Atyabi, Fatemeh, Walker, Roderick B
- Authors: Mohammadi, Ali , Esimaeili, Farnaz , Dinarvand, Rasoul , Atyabi, Fatemeh , Walker, Roderick B
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184278 , vital:44196 , xlink:href="https://doi.org/10.1093/chromsci/47.7.599"
- Description: A simple, rapid stability-indicating isocratic assay has been developed and validated for the determination of Paclitaxel (PTX) in commercial injection formulations. The assay is performed using a Nucleosil RP-18 (5 µm, 250 × 4.0 mm i.d) column protected by a Nucleosil C18 precolumn (5 µm, 4.0 × 4.0 mm i.d.) with a mobile phase of methanol–water (80:20) and UV detection at 230 nm. The method was found to be specific for PTX in the presence of degradation products with an overall analytical run time of ~ 9 min. Accuracy reported as % bias was found to be 0.1–2.5% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22–2.65% RSD, while inter-day precision (intermediate precision) was found to be 1.0–3.0% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 29.78x + 7.65, and a linear regression coefficient of 0.9994 over the concentration range 0.05–20 µg/mL. The limits of quantitation and detection were 0.05 and 0.02 µg/mL, respectively. Taxol (30 mg/5 mL), a commercially available dosage form of PTX, was assayed and 100.6–103.6% of the label claim was recovered.
- Full Text:
- Date Issued: 2009
- Authors: Mohammadi, Ali , Esimaeili, Farnaz , Dinarvand, Rasoul , Atyabi, Fatemeh , Walker, Roderick B
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184278 , vital:44196 , xlink:href="https://doi.org/10.1093/chromsci/47.7.599"
- Description: A simple, rapid stability-indicating isocratic assay has been developed and validated for the determination of Paclitaxel (PTX) in commercial injection formulations. The assay is performed using a Nucleosil RP-18 (5 µm, 250 × 4.0 mm i.d) column protected by a Nucleosil C18 precolumn (5 µm, 4.0 × 4.0 mm i.d.) with a mobile phase of methanol–water (80:20) and UV detection at 230 nm. The method was found to be specific for PTX in the presence of degradation products with an overall analytical run time of ~ 9 min. Accuracy reported as % bias was found to be 0.1–2.5% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22–2.65% RSD, while inter-day precision (intermediate precision) was found to be 1.0–3.0% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 29.78x + 7.65, and a linear regression coefficient of 0.9994 over the concentration range 0.05–20 µg/mL. The limits of quantitation and detection were 0.05 and 0.02 µg/mL, respectively. Taxol (30 mg/5 mL), a commercially available dosage form of PTX, was assayed and 100.6–103.6% of the label claim was recovered.
- Full Text:
- Date Issued: 2009
Development of Thanatophilus micans (Fabricius 1794)(Coleoptera: Silphidae) at constant temperatures
- Midgley, John M, Villet, Martin H
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441904 , vital:73933 , https://doi.org/10.1007/s00414-008-0280-0
- Description: Thanatophilus micans is capable of finding corpses at least as quickly as most fly species and, as the most widespread species of the Silphidae in Africa, offers a useful model for estimating post-mortem interval. Larvae were reared at ten constant temperatures from 15°C to 35°C and their length measured at 4, 8, or 12-h intervals depending on their instar. Length generally increased with increased rearing temperature, but decreased at extremely high temperatures. Note was made of the age at which individuals progressed past developmental milestones. Development took longer at lower temperatures. These results are presented as a combined isomegalen and isomorphen diagram. Developmental constants were generated for each milestone using major axis regression. Developmental threshold values did not differ significantly between milestones. Development took longer than in blow flies, but was faster than in Dermestidae. The three models presented here, therefore, cover an important time frame in estimating minimum PMI once fly larvae have matured to the point of leaving a corpse, and, therefore, provide a tool that was not previously available to forensic entomologists.
- Full Text:
- Date Issued: 2009
Development of Thanatophilus micans (Fabricius 1794)(Coleoptera: Silphidae) at constant temperatures
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441904 , vital:73933 , https://doi.org/10.1007/s00414-008-0280-0
- Description: Thanatophilus micans is capable of finding corpses at least as quickly as most fly species and, as the most widespread species of the Silphidae in Africa, offers a useful model for estimating post-mortem interval. Larvae were reared at ten constant temperatures from 15°C to 35°C and their length measured at 4, 8, or 12-h intervals depending on their instar. Length generally increased with increased rearing temperature, but decreased at extremely high temperatures. Note was made of the age at which individuals progressed past developmental milestones. Development took longer at lower temperatures. These results are presented as a combined isomegalen and isomorphen diagram. Developmental constants were generated for each milestone using major axis regression. Developmental threshold values did not differ significantly between milestones. Development took longer than in blow flies, but was faster than in Dermestidae. The three models presented here, therefore, cover an important time frame in estimating minimum PMI once fly larvae have matured to the point of leaving a corpse, and, therefore, provide a tool that was not previously available to forensic entomologists.
- Full Text:
- Date Issued: 2009
Diffraction efficiency and I–V characteristics of metal-free phthalocyanine doped nematic liquid crystals
- Köysal, Oguz, Okutan, Mustafa, San, S Eren, Nyokong, Tebello, Durmus, Mahmut
- Authors: Köysal, Oguz , Okutan, Mustafa , San, S Eren , Nyokong, Tebello , Durmus, Mahmut
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263511 , vital:53634 , xlink:href="https://doi.org/10.1016/j.matchemphys.2008.10.056"
- Description: The synthesis and characterization of the tetra-4-benzyloxyphenoxy substituted metal-free phthalocyanine (H2Pc) is reported for the first time. Formation of the photoinduced gratings has been experienced in a metal-free phthalocyanine doped nematic liquid crystal (LC) system and its I–V properties are characterized by electrical measurements. Four samples are prepared at different doping percentages and in homogenously aligned sandwiched geometry. We report the results of two set of experiments on these samples. One of them is the grating diffraction experiment for the analysis of optically induced reorientation process which is a basis for possible holographic applications. Accessible diffraction efficiency is found to be linearly increasing as the amount of the phthalocyanine doping rises. In the scope of the other set of measurements I–V peculiarity of the system is also found to be enhanced and linearly dependent on doping.
- Full Text:
- Date Issued: 2009
- Authors: Köysal, Oguz , Okutan, Mustafa , San, S Eren , Nyokong, Tebello , Durmus, Mahmut
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263511 , vital:53634 , xlink:href="https://doi.org/10.1016/j.matchemphys.2008.10.056"
- Description: The synthesis and characterization of the tetra-4-benzyloxyphenoxy substituted metal-free phthalocyanine (H2Pc) is reported for the first time. Formation of the photoinduced gratings has been experienced in a metal-free phthalocyanine doped nematic liquid crystal (LC) system and its I–V properties are characterized by electrical measurements. Four samples are prepared at different doping percentages and in homogenously aligned sandwiched geometry. We report the results of two set of experiments on these samples. One of them is the grating diffraction experiment for the analysis of optically induced reorientation process which is a basis for possible holographic applications. Accessible diffraction efficiency is found to be linearly increasing as the amount of the phthalocyanine doping rises. In the scope of the other set of measurements I–V peculiarity of the system is also found to be enhanced and linearly dependent on doping.
- Full Text:
- Date Issued: 2009
Discourses around abortion in a low-income community in the Western Cape
- Authors: Bowes, Tanya-Ann
- Date: 2009
- Subjects: Abortion -- Moral and ethical aspects , Abortion -- Religious aspects -- Christianity , Patriarchy -- South Africa , Abortion -- South Africa -- Western Cape , Male domination (Social structure)
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: vital:2939 , http://hdl.handle.net/10962/d1002448
- Description: Since the introduction of the Choice on Termination of Pregnancy Act in 1996, research concerning abortion has primarily focused on public health issues or on the personal experience of women. The cultural and social context within which women experience a termination of pregnancy and in which services are offered has received less attention. The purpose of this study was to analyse public discourses around abortion in a low-income community in the Western Cape. Focus groups were used to gather data from three women’s and three men’s groups. The findings suggest that the agenda of pro-life discourses in this community is not always to defend the life of the fetus. Rather these discourses serve to protect, preserve and maintain the power of the traditional nuclear family, headed by the husband, over women’s reproduction and sexuality. Religious and moral arguments serve to disguise the gender issues at stake. However, instances also occurred where TOP was supported if the husband participated in the decision-making process. Therefore, his presence normalised abortion. Thus, the prevailing public discourses around abortion in this community either support or negate abortion in order to further the agenda of patriarchy.
- Full Text:
- Date Issued: 2009
- Authors: Bowes, Tanya-Ann
- Date: 2009
- Subjects: Abortion -- Moral and ethical aspects , Abortion -- Religious aspects -- Christianity , Patriarchy -- South Africa , Abortion -- South Africa -- Western Cape , Male domination (Social structure)
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: vital:2939 , http://hdl.handle.net/10962/d1002448
- Description: Since the introduction of the Choice on Termination of Pregnancy Act in 1996, research concerning abortion has primarily focused on public health issues or on the personal experience of women. The cultural and social context within which women experience a termination of pregnancy and in which services are offered has received less attention. The purpose of this study was to analyse public discourses around abortion in a low-income community in the Western Cape. Focus groups were used to gather data from three women’s and three men’s groups. The findings suggest that the agenda of pro-life discourses in this community is not always to defend the life of the fetus. Rather these discourses serve to protect, preserve and maintain the power of the traditional nuclear family, headed by the husband, over women’s reproduction and sexuality. Religious and moral arguments serve to disguise the gender issues at stake. However, instances also occurred where TOP was supported if the husband participated in the decision-making process. Therefore, his presence normalised abortion. Thus, the prevailing public discourses around abortion in this community either support or negate abortion in order to further the agenda of patriarchy.
- Full Text:
- Date Issued: 2009
Disjunctions in the Diptera (Insecta) fauna of the Mediterranean Province and southern Africa and a discussion of biogeographical considerations : ecological overview article
- Kirk-Spriggs, A H, McGregor, Gillian K
- Authors: Kirk-Spriggs, A H , McGregor, Gillian K
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6880 , http://hdl.handle.net/10962/d1011636
- Description: This paper explores disjunctions in the Diptera fauna of the Mediterranean Province and southern Africa, drawing from eight families of Diptera, the more ancient Psychodidae and Vermileonidae, and the more recent Acroceridae, Asilidae, Bombyliidae, Dolichopodidae, Pipunculidae and Sciomyzidae. Information from recent published revisions is geo-referenced and plotted onto maps using GIS software. These distribution patterns are interpreted and probable means and routes of dispersal between the two regions are discussed. The concept of an Afrotropical sub-Saharan boundary is outlined and it is argued that although the vast, arid and virtually abiotic Sahara acts as a barrier to dispersal today, relict floral and faunal populations of Mediterranean provincial origin still occur on the Hoggar and Tibesti Mountains of the central Sahara, indicating that the aridification of the Sahara is a very recent event. The presence of extensive palaeolakes formerly covering ca 10% of the present-day Sahara is regarded as evidence in support of this hypothesis. These lakes and their associated catchments, situated in basins between the central Saharan mountains, could clearly have acted as a humid route of dispersal as recently as 4000 BP, when these lakes began to recede, and this route is here regarded as a "central high Africa corridor"; a filter-bridge between the Mediterranean Province and southern Africa. Examples of Mediterranean provincial species of Ephydridae and the muscid genus Lispe Latreille, 1796, occurring as far south as the AÏr Massif in northern Niger are cited as examples of relict montane Diptera of Mediterranean provincial origin in the southern Hoggar Mountains; these groups being associated with the margins of standing water. Balinsky's (1962) concept of an "arid corridor" is also re-examined, using examples from the larger, less mobile Diptera, and it is concluded that such a pattern may not be the result of aridity, but represent an "eastern high Africa corridor", broadly corresponding to the "African Supers well". Other perceived distribution pathways between the Holarctic and Afrotropical Regions are mapped. Anemochore dispersal is considered, and the extent of the Afrotropical Region is discussed. Mediterranean tectonic evolution on both a globe of constant size and on a smaller Jurassic globe is also considered. It is concluded that if all the transitional zones between the zoogeographical regions are to be given more-or-less equivalent treatment, we must avoid setting boundaries based on earlier faunal distributions. For this reason the current boundary between the Palaearctic and Afrotropical Regions, arbitrary as it is, should be retained, despite evidence suggesting recent continuity between sub-Saharan Africa, North Africa and the Arabian Peninsula, corresponding broadly to the African and Arabian lithospheric plates.
- Full Text:
- Date Issued: 2009
- Authors: Kirk-Spriggs, A H , McGregor, Gillian K
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6880 , http://hdl.handle.net/10962/d1011636
- Description: This paper explores disjunctions in the Diptera fauna of the Mediterranean Province and southern Africa, drawing from eight families of Diptera, the more ancient Psychodidae and Vermileonidae, and the more recent Acroceridae, Asilidae, Bombyliidae, Dolichopodidae, Pipunculidae and Sciomyzidae. Information from recent published revisions is geo-referenced and plotted onto maps using GIS software. These distribution patterns are interpreted and probable means and routes of dispersal between the two regions are discussed. The concept of an Afrotropical sub-Saharan boundary is outlined and it is argued that although the vast, arid and virtually abiotic Sahara acts as a barrier to dispersal today, relict floral and faunal populations of Mediterranean provincial origin still occur on the Hoggar and Tibesti Mountains of the central Sahara, indicating that the aridification of the Sahara is a very recent event. The presence of extensive palaeolakes formerly covering ca 10% of the present-day Sahara is regarded as evidence in support of this hypothesis. These lakes and their associated catchments, situated in basins between the central Saharan mountains, could clearly have acted as a humid route of dispersal as recently as 4000 BP, when these lakes began to recede, and this route is here regarded as a "central high Africa corridor"; a filter-bridge between the Mediterranean Province and southern Africa. Examples of Mediterranean provincial species of Ephydridae and the muscid genus Lispe Latreille, 1796, occurring as far south as the AÏr Massif in northern Niger are cited as examples of relict montane Diptera of Mediterranean provincial origin in the southern Hoggar Mountains; these groups being associated with the margins of standing water. Balinsky's (1962) concept of an "arid corridor" is also re-examined, using examples from the larger, less mobile Diptera, and it is concluded that such a pattern may not be the result of aridity, but represent an "eastern high Africa corridor", broadly corresponding to the "African Supers well". Other perceived distribution pathways between the Holarctic and Afrotropical Regions are mapped. Anemochore dispersal is considered, and the extent of the Afrotropical Region is discussed. Mediterranean tectonic evolution on both a globe of constant size and on a smaller Jurassic globe is also considered. It is concluded that if all the transitional zones between the zoogeographical regions are to be given more-or-less equivalent treatment, we must avoid setting boundaries based on earlier faunal distributions. For this reason the current boundary between the Palaearctic and Afrotropical Regions, arbitrary as it is, should be retained, despite evidence suggesting recent continuity between sub-Saharan Africa, North Africa and the Arabian Peninsula, corresponding broadly to the African and Arabian lithospheric plates.
- Full Text:
- Date Issued: 2009
Drawing Lines in the Sand: AM v RM 2010 2 SA 223 (ECP)
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54107 , vital:26391 , http://www.ufh.ac.za/speculumjuris/files/pdf/SpeculumJuris_2009_Part_2.pdf
- Description: Judge Elna Revelas’s decision in the case of Mohamed v Mohamed 1 may be described as one of those run-of-the-mill applications in terms of rule 43 which are routinely heard on motion court days in any one of our high courts across the country. This case note suggests that her decision belies such a description. Instead, this note suggests that her decision marks a move away from existing jurisprudence on Muslim marriages in a way which may undermine, rather than promote, the recognition and respect for the marriage institutions of different religious systems and beliefs. I tentatively suggest that by granting the rule 43 application the court may have effectively imposed civil marriage obligations on a religious marriage even though the parties had not concluded a marriage in terms of the Marriage Act.2 As such, the decision has potentially radical consequences for parties in Muslim marriages and highlights the complex issues that courts have had to face in the last two decades without any guiding legislation. In order to understand the judgment properly, its context has to be considered. This context includes (1) the numerous judgments extending protection to women in Muslim marriages in the last two decades against the backdrop of the coming into effect of the Constitution of the Republic of South Africa, 1996; and (2) the application by the Women’s Legal Centre Trust (hereafter “WLCT”) to the Constitutional Court to force the President and Parliament to enact legislation to recognise and protect Muslim marriages.
- Full Text:
- Date Issued: 2009
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54107 , vital:26391 , http://www.ufh.ac.za/speculumjuris/files/pdf/SpeculumJuris_2009_Part_2.pdf
- Description: Judge Elna Revelas’s decision in the case of Mohamed v Mohamed 1 may be described as one of those run-of-the-mill applications in terms of rule 43 which are routinely heard on motion court days in any one of our high courts across the country. This case note suggests that her decision belies such a description. Instead, this note suggests that her decision marks a move away from existing jurisprudence on Muslim marriages in a way which may undermine, rather than promote, the recognition and respect for the marriage institutions of different religious systems and beliefs. I tentatively suggest that by granting the rule 43 application the court may have effectively imposed civil marriage obligations on a religious marriage even though the parties had not concluded a marriage in terms of the Marriage Act.2 As such, the decision has potentially radical consequences for parties in Muslim marriages and highlights the complex issues that courts have had to face in the last two decades without any guiding legislation. In order to understand the judgment properly, its context has to be considered. This context includes (1) the numerous judgments extending protection to women in Muslim marriages in the last two decades against the backdrop of the coming into effect of the Constitution of the Republic of South Africa, 1996; and (2) the application by the Women’s Legal Centre Trust (hereafter “WLCT”) to the Constitutional Court to force the President and Parliament to enact legislation to recognise and protect Muslim marriages.
- Full Text:
- Date Issued: 2009
Editorial: environmental-education research in the year of COP 15
- Lotz-Sisitka, Heila, Kronlid, David O
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
Effect of laundry activities on in-stream concentrations of linear alkylbenzene sulfonate in a small rural South African river
- Gordon, Andrew K, Muller, Wilhelmine J, Gysman, N, Marshall, S J, Sparham, C J, O'Connor, S M, Whelan, M J
- Authors: Gordon, Andrew K , Muller, Wilhelmine J , Gysman, N , Marshall, S J , Sparham, C J , O'Connor, S M , Whelan, M J
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7094 , http://hdl.handle.net/10962/d1012427
- Description: In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 µg L− 1) but were generally very low (< 11 µg L− 1) at downstream monitoring stations, suggesting that LAS was rapidly dissipated by a combination of degradation, hydrodynamic dispersion and dilution. Concentrations in the immediate vicinity of the washing site were lower than expected on the basis of the household survey because most waste water was disposed of on the river bank rather than directly in the river. No ecological effects are expected from LAS emissions at this site.
- Full Text:
- Date Issued: 2009
- Authors: Gordon, Andrew K , Muller, Wilhelmine J , Gysman, N , Marshall, S J , Sparham, C J , O'Connor, S M , Whelan, M J
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7094 , http://hdl.handle.net/10962/d1012427
- Description: In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 µg L− 1) but were generally very low (< 11 µg L− 1) at downstream monitoring stations, suggesting that LAS was rapidly dissipated by a combination of degradation, hydrodynamic dispersion and dilution. Concentrations in the immediate vicinity of the washing site were lower than expected on the basis of the household survey because most waste water was disposed of on the river bank rather than directly in the river. No ecological effects are expected from LAS emissions at this site.
- Full Text:
- Date Issued: 2009
Effect of peripheral fused ring substitution on the optical spectroscopy and electronic structure of metal phthalocyanine complexes
- Chidawanyika, Wadzanai J U, Mack, John, Shimizu, Soji, Kobayashi, Nagao, Nyokong, Tebello
- Authors: Chidawanyika, Wadzanai J U , Mack, John , Shimizu, Soji , Kobayashi, Nagao , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263353 , vital:53620 , xlink:href="https://doi.org/10.1142/S1088424609001339"
- Description: In this paper the impact of peripheral substitution with a strongly withdrawing fused ring group on the optical spectroscopy of a metal phthalocyanine complex is analyzed. We report the synthesis of [9 (or 10), 16 (or 17), 23 (or 24)-tri-tert-butylimidophthalocyaninato]zinc(II) (ZnttbIPc), which should eventually prove to be a useful precursor for forming dimeric compounds. The electronic structure is analyzed through a detailed analysis of the UV-visible absorption and magnetic circular dichroism spectra and time-dependent density functional theory calculations. Other than a marked splitting of the Q band, the spectrum is broadly similar to that of ZnPc in terms of the main π → π* electronic bands. The vibrational bands differ markedly in the Q band region when an imido group is added to ligand periphery, relative to what is observed in the case of zinc mononaphthotribenzotetraazaporphyrin (Zn3B1N) with an additional fused benzene ring. The absorption and emission spectra lack mirror symmetry as is the case with ZnPc and thus provide possible evidence for a second set of electronic origins in the Q band region arising from n → π* rather then π → π* transitions.
- Full Text:
- Date Issued: 2009
- Authors: Chidawanyika, Wadzanai J U , Mack, John , Shimizu, Soji , Kobayashi, Nagao , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263353 , vital:53620 , xlink:href="https://doi.org/10.1142/S1088424609001339"
- Description: In this paper the impact of peripheral substitution with a strongly withdrawing fused ring group on the optical spectroscopy of a metal phthalocyanine complex is analyzed. We report the synthesis of [9 (or 10), 16 (or 17), 23 (or 24)-tri-tert-butylimidophthalocyaninato]zinc(II) (ZnttbIPc), which should eventually prove to be a useful precursor for forming dimeric compounds. The electronic structure is analyzed through a detailed analysis of the UV-visible absorption and magnetic circular dichroism spectra and time-dependent density functional theory calculations. Other than a marked splitting of the Q band, the spectrum is broadly similar to that of ZnPc in terms of the main π → π* electronic bands. The vibrational bands differ markedly in the Q band region when an imido group is added to ligand periphery, relative to what is observed in the case of zinc mononaphthotribenzotetraazaporphyrin (Zn3B1N) with an additional fused benzene ring. The absorption and emission spectra lack mirror symmetry as is the case with ZnPc and thus provide possible evidence for a second set of electronic origins in the Q band region arising from n → π* rather then π → π* transitions.
- Full Text:
- Date Issued: 2009
Effect of the killing method on post-mortem change in length of larvae of Thanatophilus micans (Fabricius, 1794) (Coleoptera: Silphidae) stored in 70% ethanol
- Midgley, John M, Villet, Martin H
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6857 , http://hdl.handle.net/10962/d1011140
- Description: It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable.
- Full Text:
- Date Issued: 2009
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6857 , http://hdl.handle.net/10962/d1011140
- Description: It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable.
- Full Text:
- Date Issued: 2009
Effects of food quality on tissue-specific isotope ratios in the mussel Perna perna
- Hill, Jaclyn M, McQuaid, Christopher D
- Authors: Hill, Jaclyn M , McQuaid, Christopher D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444563 , vital:74251 , https://doi.org/10.1007/s10750-009-9865-y
- Description: Investigations into trophic ecology and aquatic food web resolution are increasingly accomplished through stable isotope analysis. The incorporation of dietary and metabolic changes over time results in variations in isotope signatures and turnover rates of producers and consumers at tissue, individual, population and species levels. Consequently, the elucidation of trophic relationships in aquatic systems depends on establishing standard isotope values and tissue turnover rates for the level in question. This study investigated the effect of diet and food quality on isotopic signatures of four mussel tissues: adductor muscle, gonad, gill and mantle tissue from the brown mussel Perna perna. In the laboratory, mussels were fed one of the two isotopically distinct diets for 3 months.
- Full Text:
- Date Issued: 2009
- Authors: Hill, Jaclyn M , McQuaid, Christopher D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444563 , vital:74251 , https://doi.org/10.1007/s10750-009-9865-y
- Description: Investigations into trophic ecology and aquatic food web resolution are increasingly accomplished through stable isotope analysis. The incorporation of dietary and metabolic changes over time results in variations in isotope signatures and turnover rates of producers and consumers at tissue, individual, population and species levels. Consequently, the elucidation of trophic relationships in aquatic systems depends on establishing standard isotope values and tissue turnover rates for the level in question. This study investigated the effect of diet and food quality on isotopic signatures of four mussel tissues: adductor muscle, gonad, gill and mantle tissue from the brown mussel Perna perna. In the laboratory, mussels were fed one of the two isotopically distinct diets for 3 months.
- Full Text:
- Date Issued: 2009
Effects of the number of ring substituents of cobalt carboxyphthalocyanines on the electrocatalytic detection of nitrite, cysteine and melatonin
- Matemadombo, Fungisai, Sehlotho, Nthapo, Nyokong, Tebello
- Authors: Matemadombo, Fungisai , Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263408 , vital:53625 , xlink:href="https://doi.org/10.1142/S108842460900125X"
- Description: Cobalt phthalocyanine (CoPc), cobalt tetracarboxy phthalocyanine (CoTCPc) and cobalt octacarboxy phthalocyanine (CoOCPc), adsorbed onto glassy carbon electrodes, have been used for the electrocatalytic detection of nitrite, L-cysteine and melatonin. The modified electrodes electrocatalytically detected nitrite around 800 mV vs.Ag|AgCl, a value less positive compared to that of an unmodified glassy carbon electrode (at 950 mV vs.Ag|AgCl) and also gave detection limits in the 10-7 M range for nitrite detection. L-cysteine was detected by the modified electrodes at potentials between 0.50 to 0.65 V vs.Ag|AgCl, with L-cysteine detection limits also in the 10-7 M range. The detection limits for melatonin ranged from 10-7 to 10-6 M. CoPc-modified electrodes displayed good separation of interferents (tryptophan and ascorbic acid) in the presence of melatonin. Analyses of commercial melatonin tablets using modified electrodes gave excellent agreement with manufacturer's value for all modified electrodes of this work.
- Full Text:
- Date Issued: 2009
- Authors: Matemadombo, Fungisai , Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263408 , vital:53625 , xlink:href="https://doi.org/10.1142/S108842460900125X"
- Description: Cobalt phthalocyanine (CoPc), cobalt tetracarboxy phthalocyanine (CoTCPc) and cobalt octacarboxy phthalocyanine (CoOCPc), adsorbed onto glassy carbon electrodes, have been used for the electrocatalytic detection of nitrite, L-cysteine and melatonin. The modified electrodes electrocatalytically detected nitrite around 800 mV vs.Ag|AgCl, a value less positive compared to that of an unmodified glassy carbon electrode (at 950 mV vs.Ag|AgCl) and also gave detection limits in the 10-7 M range for nitrite detection. L-cysteine was detected by the modified electrodes at potentials between 0.50 to 0.65 V vs.Ag|AgCl, with L-cysteine detection limits also in the 10-7 M range. The detection limits for melatonin ranged from 10-7 to 10-6 M. CoPc-modified electrodes displayed good separation of interferents (tryptophan and ascorbic acid) in the presence of melatonin. Analyses of commercial melatonin tablets using modified electrodes gave excellent agreement with manufacturer's value for all modified electrodes of this work.
- Full Text:
- Date Issued: 2009
Electrostatic self-assembly of quaternized 2,(3)-tetra (oxo-pyridine) phthalocyaninato chloroindium (III) with a series of tetrasulfonated phthalocyanines
- George, Reama C, Durmus, Mahmut, Egharevba, Gabriel O, Nyokong, Tebello
- Authors: George, Reama C , Durmus, Mahmut , Egharevba, Gabriel O , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263330 , vital:53618 , xlink:href="https://doi.org/10.1016/j.poly.2009.07.035"
- Description: The self-assembly of oppositely charged phthalocyanines, fabricated using quaternized 2,(3)-tetra(oxo-pyridine) phthalocyaninato chloroindium (III) (QInPyPc) as the positively charge molecule and a series of tetrasulfonate phthalocyanine (MTSPc), M = 2H, Mn, Fe, Co and Ni as negatively charged molecules are reported. The self-assembly results in the formation of heteroaggregates. The metallated sulfonated phthalocyanines form nanorod and nanoleaf shaped structures as evidenced by transmission electron microscopy (TEM). The UV–Vis spectra showed blue shifted Q bands, suggesting that these structures were in a face-to-face arrangement. The Raman spectra of the heteroaggregates showed shifting compared to the spectra of the precursors.
- Full Text:
- Date Issued: 2009
- Authors: George, Reama C , Durmus, Mahmut , Egharevba, Gabriel O , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263330 , vital:53618 , xlink:href="https://doi.org/10.1016/j.poly.2009.07.035"
- Description: The self-assembly of oppositely charged phthalocyanines, fabricated using quaternized 2,(3)-tetra(oxo-pyridine) phthalocyaninato chloroindium (III) (QInPyPc) as the positively charge molecule and a series of tetrasulfonate phthalocyanine (MTSPc), M = 2H, Mn, Fe, Co and Ni as negatively charged molecules are reported. The self-assembly results in the formation of heteroaggregates. The metallated sulfonated phthalocyanines form nanorod and nanoleaf shaped structures as evidenced by transmission electron microscopy (TEM). The UV–Vis spectra showed blue shifted Q bands, suggesting that these structures were in a face-to-face arrangement. The Raman spectra of the heteroaggregates showed shifting compared to the spectra of the precursors.
- Full Text:
- Date Issued: 2009
eServices provisioning in a community development context through a JADE MAS platform
- Thinyane, Mamello, Terzoli, Alfredo, Clayton, Peter G
- Authors: Thinyane, Mamello , Terzoli, Alfredo , Clayton, Peter G
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430836 , vital:72720 , 10.1109/ICTD.2009.5426697
- Description: A growing proliferation of ICT4D interventions has necessitated the ex-ploration of innovative solutions for the provisioning of eServices in ru-ral, marginalized communities. The challenges currently faced in these interventions include: situating the developed applications within the cultural and ethnographic context of the target communities, integrating greater levels of granularity and flexibility within the applications for in-creased context sensitivity, handling the intermittence and instability of supporting infrastructural services. These are the challenges that we address in the context of ICT4D intervention undertaken in a rural community in the Eastern Cape province of South Africa. We explore the design and implementation of a Multi-Agent System (MAS) for this community as a platform for provisioning of context-sensitive eServ-ices, and highlight some observations with regards to the applicability and adequacy of the solution.
- Full Text:
- Date Issued: 2009
- Authors: Thinyane, Mamello , Terzoli, Alfredo , Clayton, Peter G
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430836 , vital:72720 , 10.1109/ICTD.2009.5426697
- Description: A growing proliferation of ICT4D interventions has necessitated the ex-ploration of innovative solutions for the provisioning of eServices in ru-ral, marginalized communities. The challenges currently faced in these interventions include: situating the developed applications within the cultural and ethnographic context of the target communities, integrating greater levels of granularity and flexibility within the applications for in-creased context sensitivity, handling the intermittence and instability of supporting infrastructural services. These are the challenges that we address in the context of ICT4D intervention undertaken in a rural community in the Eastern Cape province of South Africa. We explore the design and implementation of a Multi-Agent System (MAS) for this community as a platform for provisioning of context-sensitive eServ-ices, and highlight some observations with regards to the applicability and adequacy of the solution.
- Full Text:
- Date Issued: 2009
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
Evaluating text preprocessing to improve compression on maillogs
- Otten, Fred, Irwin, Barry V W, Thinyane, Hannah
- Authors: Otten, Fred , Irwin, Barry V W , Thinyane, Hannah
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430138 , vital:72668 , https://doi.org/10.1145/1632149.1632157
- Description: Maillogs contain important information about mail which has been sent or received. This information can be used for statistical purposes, to help prevent viruses or to help prevent SPAM. In order to satisfy regula-tions and follow good security practices, maillogs need to be monitored and archived. Since there is a large quantity of data, some form of data reduction is necessary. Data compression programs such as gzip and bzip2 are commonly used to reduce the quantity of data. Text preprocessing can be used to aid the compression of English text files. This paper evaluates whether text preprocessing, particularly word replacement, can be used to improve the compression of maillogs. It presents an algorithm for constructing a dictionary for word replacement and provides the results of experiments conducted using the ppmd, gzip, bzip2 and 7zip programs. These tests show that text prepro-cessing improves data compression on maillogs. Improvements of up to 56 percent in compression time and up to 32 percent in compression ratio are achieved. It also shows that a dictionary may be generated and used on other maillogs to yield reductions within half a percent of the results achieved for the maillog used to generate the dictionary.
- Full Text:
- Date Issued: 2009
- Authors: Otten, Fred , Irwin, Barry V W , Thinyane, Hannah
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430138 , vital:72668 , https://doi.org/10.1145/1632149.1632157
- Description: Maillogs contain important information about mail which has been sent or received. This information can be used for statistical purposes, to help prevent viruses or to help prevent SPAM. In order to satisfy regula-tions and follow good security practices, maillogs need to be monitored and archived. Since there is a large quantity of data, some form of data reduction is necessary. Data compression programs such as gzip and bzip2 are commonly used to reduce the quantity of data. Text preprocessing can be used to aid the compression of English text files. This paper evaluates whether text preprocessing, particularly word replacement, can be used to improve the compression of maillogs. It presents an algorithm for constructing a dictionary for word replacement and provides the results of experiments conducted using the ppmd, gzip, bzip2 and 7zip programs. These tests show that text prepro-cessing improves data compression on maillogs. Improvements of up to 56 percent in compression time and up to 32 percent in compression ratio are achieved. It also shows that a dictionary may be generated and used on other maillogs to yield reductions within half a percent of the results achieved for the maillog used to generate the dictionary.
- Full Text:
- Date Issued: 2009
Evaluating the IRI topside model for the South African region: An overview of the modelling techniques
- Sibanda, Patrick, McKinnell, Lee-Anne
- Authors: Sibanda, Patrick , McKinnell, Lee-Anne
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6810 , http://hdl.handle.net/10962/d1004303
- Description: The representation of the topside ionosphere (the region above the F2 peak) is critical because of the limited experimental data available. Over the years, a wide range of models have been developed in an effort to represent the behaviour and the shape of the electron density (Ne) profile of the topside ionosphere. Various studies have been centred around calculating the vertical scale height (VSH) and have included (a) obtaining VSH from Global Positioning System (GPS) derived total electron content (TEC), (b) calculating the VSH from ground-based ionosonde measurements, (c) using topside sounder vertical Ne profiles to obtain the VSH. One or a combination of the topside profilers (Chapman function, exponential function, sech-squared (Epstein) function, and/or parabolic function) is then used to reconstruct the topside Ne profile. The different approaches and the modelling techniques are discussed with a view to identifying the most adequate approach to apply to the South African region’s topside modelling efforts. The IRI-2001 topside model is evaluated based on how well it reproduces measured topside profiles over the South African region. This study is a first step in the process of developing a South African topside ionosphere model.
- Full Text:
- Date Issued: 2009
- Authors: Sibanda, Patrick , McKinnell, Lee-Anne
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6810 , http://hdl.handle.net/10962/d1004303
- Description: The representation of the topside ionosphere (the region above the F2 peak) is critical because of the limited experimental data available. Over the years, a wide range of models have been developed in an effort to represent the behaviour and the shape of the electron density (Ne) profile of the topside ionosphere. Various studies have been centred around calculating the vertical scale height (VSH) and have included (a) obtaining VSH from Global Positioning System (GPS) derived total electron content (TEC), (b) calculating the VSH from ground-based ionosonde measurements, (c) using topside sounder vertical Ne profiles to obtain the VSH. One or a combination of the topside profilers (Chapman function, exponential function, sech-squared (Epstein) function, and/or parabolic function) is then used to reconstruct the topside Ne profile. The different approaches and the modelling techniques are discussed with a view to identifying the most adequate approach to apply to the South African region’s topside modelling efforts. The IRI-2001 topside model is evaluated based on how well it reproduces measured topside profiles over the South African region. This study is a first step in the process of developing a South African topside ionosphere model.
- Full Text:
- Date Issued: 2009
Exploratory mathematics talk in a second language: a sociolinguistic perspective:
- Graven, Mellony, Robertson, Sally-Ann
- Authors: Graven, Mellony , Robertson, Sally-Ann
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69907 , vital:29594 , https://doi.org/10.1007/s11858-018-0952-2
- Description: This paper illuminates challenges confronting teachers and students at the literacy/numeracy interface in contexts where students have not developed sufficient English language proficiency to be learning mathematics through English but, due to socio-politically and economically driven perceptions are being taught in English. We analyse transcript data of classroom talk in a South African grade 4 mathematics lesson on fractions. Together with interview data, the lesson data highlight some of the consequences students’ diminished access to their home language appear to have on their access to mathematical meaning-making.
- Full Text:
- Date Issued: 2009
- Authors: Graven, Mellony , Robertson, Sally-Ann
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69907 , vital:29594 , https://doi.org/10.1007/s11858-018-0952-2
- Description: This paper illuminates challenges confronting teachers and students at the literacy/numeracy interface in contexts where students have not developed sufficient English language proficiency to be learning mathematics through English but, due to socio-politically and economically driven perceptions are being taught in English. We analyse transcript data of classroom talk in a South African grade 4 mathematics lesson on fractions. Together with interview data, the lesson data highlight some of the consequences students’ diminished access to their home language appear to have on their access to mathematical meaning-making.
- Full Text:
- Date Issued: 2009
Exploring job search and the causes of endogenous unemployment: evidence from Duncan Village, South Africa
- Authors: Duff, Patrick Alexander
- Date: 2009
- Subjects: Unemployment , Unemployment -- Social aspects -- South Africa -- East London -- Duncan Village , Job hunting -- South Africa -- East London -- Duncan Village , Labor market -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:1026
- Description: Despite high rates of unemployment in South Africa, there is little consensus about its origins and solutions to the problem. Job search (how and when people search for work)is one aspect of the unemployment problem. Job search is shown to be a complex process strongly linked to the endogenous structure of the labour market. The flaws in traditional methods (theoretical and measurement) highlight this. Using data from a tailor-made survey in Duncan Village (a peri-urban area in Buffalo City, South Africa) the research examines factors that influence the effectiveness of job search. The results show that mode of search (how people look for work) is used as a signal by employers. Degrees of success are stratified amongst searchers using either ‘word of mouth’, place-to-place or formal modes of search. The thesis provides a method-test to reveal a complex body of evidence that has yet to be fully explored by practitioners in this field.
- Full Text:
- Date Issued: 2009
- Authors: Duff, Patrick Alexander
- Date: 2009
- Subjects: Unemployment , Unemployment -- Social aspects -- South Africa -- East London -- Duncan Village , Job hunting -- South Africa -- East London -- Duncan Village , Labor market -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:1026
- Description: Despite high rates of unemployment in South Africa, there is little consensus about its origins and solutions to the problem. Job search (how and when people search for work)is one aspect of the unemployment problem. Job search is shown to be a complex process strongly linked to the endogenous structure of the labour market. The flaws in traditional methods (theoretical and measurement) highlight this. Using data from a tailor-made survey in Duncan Village (a peri-urban area in Buffalo City, South Africa) the research examines factors that influence the effectiveness of job search. The results show that mode of search (how people look for work) is used as a signal by employers. Degrees of success are stratified amongst searchers using either ‘word of mouth’, place-to-place or formal modes of search. The thesis provides a method-test to reveal a complex body of evidence that has yet to be fully explored by practitioners in this field.
- Full Text:
- Date Issued: 2009
Exploring Learner Participation in Waste-Management Activities in a Rural Botswana Primary School
- Authors: Silo, Nthalivi
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386509 , vital:68148 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122820"
- Description: In Botswana, participation in environmental learning activities has been perceived as a central component of environmental education in formal education. Driven by the need to implement the objective of making the participatory approach part of the infusion of environmental education in the school curriculum as prescribed by the infusion policy, Botswana schools have come up with initiatives to involve learners in environmental education activities that seem to have ‘a direct, perceived benefit to the learners’ (NEESAP, 2007:9). Within this approach it is expected that learners should participate in these activities. However, Ketlhoilwe (2007) revealed that there has been a normalisation of environmental education into existing school culture through equating waste-management activities with environmental education. This generally entails cleaning activities by learners to maintain ‘clean schools’, which is directly associated with environmental education. Drawing from detailed case study data in one rural primary school with Standard 6 learners, I used Cultural Historical Activity Theory to investigate and explain how learners participate in these waste-management activities. Findings from this study revealed that attempts by teachers to meet the policy imperative through prescription of rules, and ascribing roles to learners in waste-management activities, create tensions. This gave rise to an elusive object of learner participation, as the purpose for their participation in these activities is not clear.
- Full Text:
- Date Issued: 2009
- Authors: Silo, Nthalivi
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386509 , vital:68148 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122820"
- Description: In Botswana, participation in environmental learning activities has been perceived as a central component of environmental education in formal education. Driven by the need to implement the objective of making the participatory approach part of the infusion of environmental education in the school curriculum as prescribed by the infusion policy, Botswana schools have come up with initiatives to involve learners in environmental education activities that seem to have ‘a direct, perceived benefit to the learners’ (NEESAP, 2007:9). Within this approach it is expected that learners should participate in these activities. However, Ketlhoilwe (2007) revealed that there has been a normalisation of environmental education into existing school culture through equating waste-management activities with environmental education. This generally entails cleaning activities by learners to maintain ‘clean schools’, which is directly associated with environmental education. Drawing from detailed case study data in one rural primary school with Standard 6 learners, I used Cultural Historical Activity Theory to investigate and explain how learners participate in these waste-management activities. Findings from this study revealed that attempts by teachers to meet the policy imperative through prescription of rules, and ascribing roles to learners in waste-management activities, create tensions. This gave rise to an elusive object of learner participation, as the purpose for their participation in these activities is not clear.
- Full Text:
- Date Issued: 2009