Stock returns and Friday the 13th effect in five African countries
- Authors: Botha, Ferdi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396127 , vital:69152 , xlink:href="https://www.ajol.info/index.php/aref/article/view/91060"
- Description: This study is concerned with Friday the 13th and daily stock market returns in five African countries. Using the MSCI Global Equity Indices during various periods, the evidence overwhelmingly suggests that there is no Friday the 13th effect.
- Full Text:
- Authors: Botha, Ferdi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396127 , vital:69152 , xlink:href="https://www.ajol.info/index.php/aref/article/view/91060"
- Description: This study is concerned with Friday the 13th and daily stock market returns in five African countries. Using the MSCI Global Equity Indices during various periods, the evidence overwhelmingly suggests that there is no Friday the 13th effect.
- Full Text:
Stratigraphy and age of Karoo basalts of Lesotho and implications for correlations within the Karoo igneous province
- Marsh, Julian S, Hooper, P R, Rehacek, J, Duncan, R A, Duncan, Andrew R
- Authors: Marsh, Julian S , Hooper, P R , Rehacek, J , Duncan, R A , Duncan, Andrew R
- Date: 2013
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/149507 , vital:38859 , https://doi.org/10.1029/GM100p0247
- Description: Remnants of the erupted and intrusive products of the Karoo igneous province, one of the classic Mesozoic continental flood basalt provinces, are found throughout southern Africa. Such large continental igneous events are frequently ascribed to the rise of deep-seated mantle plumes and, in some instances, are thought to be related to continental breakup.
- Full Text: false
- Authors: Marsh, Julian S , Hooper, P R , Rehacek, J , Duncan, R A , Duncan, Andrew R
- Date: 2013
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/149507 , vital:38859 , https://doi.org/10.1029/GM100p0247
- Description: Remnants of the erupted and intrusive products of the Karoo igneous province, one of the classic Mesozoic continental flood basalt provinces, are found throughout southern Africa. Such large continental igneous events are frequently ascribed to the rise of deep-seated mantle plumes and, in some instances, are thought to be related to continental breakup.
- Full Text: false
Study South Africa
- International Education Association of South Africa (IEASA), Jooste, Nico
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2013
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64878 , vital:28623
- Description: [Editor's Letter]: Study South Africa has been the global mouthpiece of the International Education Association of South Africa (IEASA) and South African Higher Education since the publication of its first edition in 1999. It grew from a publication that served as a guide to South African Higher Education to a comprehensive source of information for the international academic community and others interested in South Africa’s tertiary education sector. This annual publication requires knowledgeable contributors as well as skilful editorial and other technical support. For the past number of years the editorial team was ably supported by Loveness Kaunda from the University of Cape Town (UCT). She provided the publication with her time, energy and knowledge. However, as she retired from her UCT position, she will no longer be available to consult with on a regular basis. This edition of Study South Africa is dedicated to her as a token of gratitude for all her time and passion. Another source of knowledge and inspiration is Patrick Fish - a higher education specialist who does research on topics relevant to the South African Higher Education landscape and provides us with up-to-date information. His writing skills turn the first number of pages of this publication into a real source of information. The knowledge about South African universities will be incomplete without the contributions of the universities themselves. A common trend this year is the focus on excellence of teaching and research as well as the relevance of South African Higher Education to local students functioning in an ever globalising world. It is also evident that most of the South African universities are aware of the need to be globally competitive, not only to attract the best international students, but also to be able to compete in a very competitive global knowledge driven environment. Study South Africa is again proudly presented by IEASA. This edition, focussing on Internationalisation of Higher Education, with a specific focus on South Africa in a changing world, again illustrates the interconnectedness of global higher education. It is envisaged that future editions will explore and document the collaboration between IEASA and similar organisations that is promoting the Internationalisation of Higher Education as well as global trends in international higher education affecting internationalisation of higher education in emerging countries. , 13th Edition
- Full Text:
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2013
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64878 , vital:28623
- Description: [Editor's Letter]: Study South Africa has been the global mouthpiece of the International Education Association of South Africa (IEASA) and South African Higher Education since the publication of its first edition in 1999. It grew from a publication that served as a guide to South African Higher Education to a comprehensive source of information for the international academic community and others interested in South Africa’s tertiary education sector. This annual publication requires knowledgeable contributors as well as skilful editorial and other technical support. For the past number of years the editorial team was ably supported by Loveness Kaunda from the University of Cape Town (UCT). She provided the publication with her time, energy and knowledge. However, as she retired from her UCT position, she will no longer be available to consult with on a regular basis. This edition of Study South Africa is dedicated to her as a token of gratitude for all her time and passion. Another source of knowledge and inspiration is Patrick Fish - a higher education specialist who does research on topics relevant to the South African Higher Education landscape and provides us with up-to-date information. His writing skills turn the first number of pages of this publication into a real source of information. The knowledge about South African universities will be incomplete without the contributions of the universities themselves. A common trend this year is the focus on excellence of teaching and research as well as the relevance of South African Higher Education to local students functioning in an ever globalising world. It is also evident that most of the South African universities are aware of the need to be globally competitive, not only to attract the best international students, but also to be able to compete in a very competitive global knowledge driven environment. Study South Africa is again proudly presented by IEASA. This edition, focussing on Internationalisation of Higher Education, with a specific focus on South Africa in a changing world, again illustrates the interconnectedness of global higher education. It is envisaged that future editions will explore and document the collaboration between IEASA and similar organisations that is promoting the Internationalisation of Higher Education as well as global trends in international higher education affecting internationalisation of higher education in emerging countries. , 13th Edition
- Full Text:
Subterranean control of an arboreal pest: EPNs and EPFs for FCM
- Moore, Sean, Coombes, Candice, Manrakhan, Aruna, Kirkman, Wayne, Hill, Martin P, Ehlers, Ralf-Udo, Daneel, John-Henry, De Waal, Jeanne, Dames, Joanna F, Malan, Antoinettre
- Authors: Moore, Sean , Coombes, Candice , Manrakhan, Aruna , Kirkman, Wayne , Hill, Martin P , Ehlers, Ralf-Udo , Daneel, John-Henry , De Waal, Jeanne , Dames, Joanna F , Malan, Antoinettre
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425450 , vital:72241 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257699"
- Description: Control measures against the false codling moth (FCM), Thaumatotibia leucotreta, have traditionally ignored the soil-borne pupal stage. Recent trials with entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPFs) have targeted this life-stage. Application of Heterorhabditis bacteriophora to a citrus orchard floor, reduced T. leucotreta infestation of fruit by up to 81%. Conservation of H. zealandica through non-usage of a nematicide also resulted in dramatically lower fruit infestation. Dose-response and exposure time-response bioassays identified the three most promising fungal isolates against pupating T. leucotreta. Orchard trials showed persistence of these fungi in orchard soil for at least six months.
- Full Text:
- Authors: Moore, Sean , Coombes, Candice , Manrakhan, Aruna , Kirkman, Wayne , Hill, Martin P , Ehlers, Ralf-Udo , Daneel, John-Henry , De Waal, Jeanne , Dames, Joanna F , Malan, Antoinettre
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425450 , vital:72241 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257699"
- Description: Control measures against the false codling moth (FCM), Thaumatotibia leucotreta, have traditionally ignored the soil-borne pupal stage. Recent trials with entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPFs) have targeted this life-stage. Application of Heterorhabditis bacteriophora to a citrus orchard floor, reduced T. leucotreta infestation of fruit by up to 81%. Conservation of H. zealandica through non-usage of a nematicide also resulted in dramatically lower fruit infestation. Dose-response and exposure time-response bioassays identified the three most promising fungal isolates against pupating T. leucotreta. Orchard trials showed persistence of these fungi in orchard soil for at least six months.
- Full Text:
Surface patterning using scanning electrochemical microscopy to locally trigger a “click” chemistry reaction
- Quinton, Damien, Maringa, Audacity, Griveau, Sophie, Nyokong, Tebello, Bedioui, Fethi
- Authors: Quinton, Damien , Maringa, Audacity , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241805 , vital:50971 , xlink:href="https://doi.org/10.1016/j.elecom.2013.03.021"
- Description: We report on the surface micropatterning of conductive surfaces via the electrochemical triggering of a click reaction, the copper(I) catalyzed azide–alkyne cycloaddition reaction (CuAAC) by SECM via a two-step approach: (i) functionalization on the entire surface with azido-aryl groups by using the diazonium approach followed by (ii) the covalent linkage of alkyne-bearing ferrocene by CuAAC within a local area by SECM. More precisely, the click reaction was triggered by Cu(I) catalyst generation for 30 min at the SECM tip positioned ≈ 10 μm above the azido-aryl modified surface. The dimension of the spot obtained under these conditions was ≈ 75 μm. The electrochemical imaging by SECM of the ultra thin area locally clicked with ferrocene moieties was made thanks to the electrocatalytic properties of the ferrocene modified surface towards ferrocyanide electrooxidation. This local clicking procedure opens the gate to further controlled functionalization of restricted small substrates.
- Full Text:
- Authors: Quinton, Damien , Maringa, Audacity , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241805 , vital:50971 , xlink:href="https://doi.org/10.1016/j.elecom.2013.03.021"
- Description: We report on the surface micropatterning of conductive surfaces via the electrochemical triggering of a click reaction, the copper(I) catalyzed azide–alkyne cycloaddition reaction (CuAAC) by SECM via a two-step approach: (i) functionalization on the entire surface with azido-aryl groups by using the diazonium approach followed by (ii) the covalent linkage of alkyne-bearing ferrocene by CuAAC within a local area by SECM. More precisely, the click reaction was triggered by Cu(I) catalyst generation for 30 min at the SECM tip positioned ≈ 10 μm above the azido-aryl modified surface. The dimension of the spot obtained under these conditions was ≈ 75 μm. The electrochemical imaging by SECM of the ultra thin area locally clicked with ferrocene moieties was made thanks to the electrocatalytic properties of the ferrocene modified surface towards ferrocyanide electrooxidation. This local clicking procedure opens the gate to further controlled functionalization of restricted small substrates.
- Full Text:
Synthesis and magnetic properties of a superparamagnetic nanocomposite pectin-magnetite nanocomposite
- Namanga, Jude, Foba, Josepha, Ndinteh, Derek T, Yufanyi, Divine M, Krause, Rui W M
- Authors: Namanga, Jude , Foba, Josepha , Ndinteh, Derek T , Yufanyi, Divine M , Krause, Rui W M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125075 , vital:35726 , https://doi.org/10.1155/2013/137275
- Description: Magnetic nanocomposites composed of superparamagnetic magnetite nanoparticles in a pectin matrix were synthesized by anin situ coprecipitation method. The pectin matrix acted as a stabilizer and size control host for the magnetite nanoparticles(MNPs) ensuring particle size homogeneity. The effects of the different reactant ratios and nanocomposite drying conditions onthe magnetic properties were investigated. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transforminfrared (FT-IR) spectroscopy, and superconducting quantum interference device magnetometer (SQUID). Superparamagneticmagnetite nanoparticles with mean diameters of 9 and 13 nm were obtained, and the freeze-dried nanocomposites had a saturationmagnetization of 54 and 53 emu/g, respectivel
- Full Text:
- Authors: Namanga, Jude , Foba, Josepha , Ndinteh, Derek T , Yufanyi, Divine M , Krause, Rui W M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125075 , vital:35726 , https://doi.org/10.1155/2013/137275
- Description: Magnetic nanocomposites composed of superparamagnetic magnetite nanoparticles in a pectin matrix were synthesized by anin situ coprecipitation method. The pectin matrix acted as a stabilizer and size control host for the magnetite nanoparticles(MNPs) ensuring particle size homogeneity. The effects of the different reactant ratios and nanocomposite drying conditions onthe magnetic properties were investigated. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transforminfrared (FT-IR) spectroscopy, and superconducting quantum interference device magnetometer (SQUID). Superparamagneticmagnetite nanoparticles with mean diameters of 9 and 13 nm were obtained, and the freeze-dried nanocomposites had a saturationmagnetization of 54 and 53 emu/g, respectivel
- Full Text:
Synthesis and nonlinear optical examination of 3 (4), 15 (16)-Bis-(4-tert-butyl-phenoxy)-10, 22-diaminohemiporphyrazinato chloroindium
- Britton, Jonathan, Antunes, Edith M, Nyokong, Tebello
- Authors: Britton, Jonathan , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241739 , vital:50965 , xlink:href="https://doi.org/10.1016/j.molstruc.2013.05.001"
- Description: 3(4),15(16)-Bis-(4-tert-butyl-phenoxy)-10,22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1,3,5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
- Full Text:
- Authors: Britton, Jonathan , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241739 , vital:50965 , xlink:href="https://doi.org/10.1016/j.molstruc.2013.05.001"
- Description: 3(4),15(16)-Bis-(4-tert-butyl-phenoxy)-10,22-diaminohemiporphyrazinato chloroindium hemiporphyrazine was synthesized from 1,3,5-triaminobenzene and 4-tert-butyl-phenoxyisoindoline. The structure of the complex was confirmed using mass, nuclear magnetic resonance and infrared spectroscopies. The nonlinear parameters of the compound was also analyzed in dimethylformamide and found to be significantly greater than previously analyzed phthalocyanines.
- Full Text:
Synthesis and photophysicochemical properties of zinc phthalocyanine derivatized with benzothiazole or carbazole photosensitizers
- Khoza, Phindile, Antunes, Edith M, Nyokong, Tebello
- Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241728 , vital:50964 , xlink:href="https://doi.org/10.1016/j.poly.2013.05.046"
- Description: The synthesis of new zinc phthalocyanine complexes containing 3-(2-benzothiazol-2-yloxy) (complex 3) and 3-(carbazol-2-yloxy) (complex 4) substituents at the non-peripheral positions are reported. The new compounds were characterized by elemental analysis, FT-IR, 1H NMR, mass spectrometry and UV–Vis spectroscopy. The effects of carbazole and benzothiazole substitutents on the photophysical and photochemical parameters of ZnPc are reported. These new phthalocyanines are non-aggregated in common solvents and show improved photophysicochemical properties. The 3-(2-benzothiazol-2-yloxy) substituted complex showed the longest triplet lifetime ever reported for a zinc phthalocyanine (1.7 ms).
- Full Text:
- Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241728 , vital:50964 , xlink:href="https://doi.org/10.1016/j.poly.2013.05.046"
- Description: The synthesis of new zinc phthalocyanine complexes containing 3-(2-benzothiazol-2-yloxy) (complex 3) and 3-(carbazol-2-yloxy) (complex 4) substituents at the non-peripheral positions are reported. The new compounds were characterized by elemental analysis, FT-IR, 1H NMR, mass spectrometry and UV–Vis spectroscopy. The effects of carbazole and benzothiazole substitutents on the photophysical and photochemical parameters of ZnPc are reported. These new phthalocyanines are non-aggregated in common solvents and show improved photophysicochemical properties. The 3-(2-benzothiazol-2-yloxy) substituted complex showed the longest triplet lifetime ever reported for a zinc phthalocyanine (1.7 ms).
- Full Text:
Synthesis and photophysicochemical studies of a water soluble conjugate between folic acid and zinc tetraaminophthalocyanine
- Khoza, Phindile, Antunes, Edith M, Chen, Ji-Yao, Nyokong, Tebello
- Authors: Khoza, Phindile , Antunes, Edith M , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242142 , vital:51005 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.06.048"
- Description: This work reports on the synthesis of zinc tetraaminophthalocyanine (ZnTAPc) functionalized with folic acid (FA), forming ZnTAPcFA. The conjugate between FA and ZnTAPc was soluble in water whereas ZnTAPc alone is not. The structure of ZnTAPcFA conjugate was elucidated by 1H NMR, MALDI-TOF mass and FTIR spectra. Photophysical and photochemical studies of ZnTAPcFA were conducted in DMSO. The increase in fluorescence quantum yield of the conjugate was accompanied by a decrease in the triplet and singlet oxygen quantum yields. The changes in triplet quantum and singlet oxygen quantum yields were marginal when ZnTAPc was simply mixed with FA without a chemical bond.
- Full Text:
- Authors: Khoza, Phindile , Antunes, Edith M , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242142 , vital:51005 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.06.048"
- Description: This work reports on the synthesis of zinc tetraaminophthalocyanine (ZnTAPc) functionalized with folic acid (FA), forming ZnTAPcFA. The conjugate between FA and ZnTAPc was soluble in water whereas ZnTAPc alone is not. The structure of ZnTAPcFA conjugate was elucidated by 1H NMR, MALDI-TOF mass and FTIR spectra. Photophysical and photochemical studies of ZnTAPcFA were conducted in DMSO. The increase in fluorescence quantum yield of the conjugate was accompanied by a decrease in the triplet and singlet oxygen quantum yields. The changes in triplet quantum and singlet oxygen quantum yields were marginal when ZnTAPc was simply mixed with FA without a chemical bond.
- Full Text:
Synthesis and physicochemical behaviour of aluminium bis and tris (diammine platinum) octacarboxyphthalocyanine
- Malinga, Nduduzo, Antunes, Edith M, Nyokong, Tebello
- Authors: Malinga, Nduduzo , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241970 , vital:50988 , xlink:href="https://doi.org/10.1016/j.poly.2013.02.073"
- Description: Hydroxy aluminium octacarboxy phthalocyanine (Al(OH)OCPc) was conjugated with a diammine platinum complex to give conjugates containing two or three platinum complexes (represented as: Al(OH)OCPc(Pt)2 and Al(OH)OCPc(Pt)3). It was found that the complexes were soluble in water at a pH > 8.2. Both conjugates were found to have two fluorescence lifetimes. The triplet and singlet oxygen quantum yields increased for the conjugates compared to Al(OH)OCPc alone.
- Full Text:
- Authors: Malinga, Nduduzo , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241970 , vital:50988 , xlink:href="https://doi.org/10.1016/j.poly.2013.02.073"
- Description: Hydroxy aluminium octacarboxy phthalocyanine (Al(OH)OCPc) was conjugated with a diammine platinum complex to give conjugates containing two or three platinum complexes (represented as: Al(OH)OCPc(Pt)2 and Al(OH)OCPc(Pt)3). It was found that the complexes were soluble in water at a pH > 8.2. Both conjugates were found to have two fluorescence lifetimes. The triplet and singlet oxygen quantum yields increased for the conjugates compared to Al(OH)OCPc alone.
- Full Text:
TeleWeaver: an innovative telecommunication platform for marginalized communities in Africa
- Dalvit, Lorenzo, Gumbo, Sibukelo, Ntshinga, Lindikaya, Terzoli, Alfredo, Hansen, Susan
- Authors: Dalvit, Lorenzo , Gumbo, Sibukelo , Ntshinga, Lindikaya , Terzoli, Alfredo , Hansen, Susan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431317 , vital:72763 , https://www.academic-bookshop.com/ourshop/prod_2659103-ECEG-2013-13th-European-Conference-on-eGovernment-Como-Italy-PRINT-version.html
- Description: Information and Communication Technologies for Development (ICT4D) is becoming an increasingly important and multi‐faceted area of research and software development. Particularly through provision via mobile devices, e‐services can potentially reach and improve the lives of millions of people living in marginalised areas. The efforts of many governments in sub‐Saharan Africa are frustrated by poor tele-communication infrastructure, lack of skills and unsustainable models of intervention. In this paper we describe the holistic solution offered by the TeleWeaver platform. The novel approach to the development of the software, the strong sense of social responsibility of the developers and the collaborative spirit that shaped the ecosystem of which Tele-Weaver is part, warrants the adoption of an innovative approach to its marketing and implementation. On the one hand, the project needs to provide returns on investment and generate profit for the key stake-holders (ie government at the local and national level, academia, indus-try and socio‐-entrepreneurs in the target community). On the other, it must benefit all members of the marginalised communities it is intended to serve as well as the global community of software developers. Tele-Weaver was developed in close collaboration with the community of Dwesa, a rural area on the Wild Cost of the Transkei regions in eastern South Africa.
- Full Text:
- Authors: Dalvit, Lorenzo , Gumbo, Sibukelo , Ntshinga, Lindikaya , Terzoli, Alfredo , Hansen, Susan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431317 , vital:72763 , https://www.academic-bookshop.com/ourshop/prod_2659103-ECEG-2013-13th-European-Conference-on-eGovernment-Como-Italy-PRINT-version.html
- Description: Information and Communication Technologies for Development (ICT4D) is becoming an increasingly important and multi‐faceted area of research and software development. Particularly through provision via mobile devices, e‐services can potentially reach and improve the lives of millions of people living in marginalised areas. The efforts of many governments in sub‐Saharan Africa are frustrated by poor tele-communication infrastructure, lack of skills and unsustainable models of intervention. In this paper we describe the holistic solution offered by the TeleWeaver platform. The novel approach to the development of the software, the strong sense of social responsibility of the developers and the collaborative spirit that shaped the ecosystem of which Tele-Weaver is part, warrants the adoption of an innovative approach to its marketing and implementation. On the one hand, the project needs to provide returns on investment and generate profit for the key stake-holders (ie government at the local and national level, academia, indus-try and socio‐-entrepreneurs in the target community). On the other, it must benefit all members of the marginalised communities it is intended to serve as well as the global community of software developers. Tele-Weaver was developed in close collaboration with the community of Dwesa, a rural area on the Wild Cost of the Transkei regions in eastern South Africa.
- Full Text:
The AES64 Connection Management and Control Protocol
- Foss, Richard, Gurdan, Robby, Klinkradt, Bradley, Chigwamba, Nyasha
- Authors: Foss, Richard , Gurdan, Robby , Klinkradt, Bradley , Chigwamba, Nyasha
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426933 , vital:72402 , https://www.aes.org/e-lib/browse.cfm?elib=16705
- Description: AES64, which is an IP-based peer-to-peer network control protocol, integrates the connection management and control capabilities across digital audio networks. This enables the streaming of all types of media content among devices from different manufactures because it provides a common approach for device control. This paper describes this protocol. Each parameter of a device can be addressed with a 7-level hierarchical structure that reflects the functional layout of the device. The protocol has been implemented in many different types of networks.
- Full Text:
- Authors: Foss, Richard , Gurdan, Robby , Klinkradt, Bradley , Chigwamba, Nyasha
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426933 , vital:72402 , https://www.aes.org/e-lib/browse.cfm?elib=16705
- Description: AES64, which is an IP-based peer-to-peer network control protocol, integrates the connection management and control capabilities across digital audio networks. This enables the streaming of all types of media content among devices from different manufactures because it provides a common approach for device control. This paper describes this protocol. Each parameter of a device can be addressed with a 7-level hierarchical structure that reflects the functional layout of the device. The protocol has been implemented in many different types of networks.
- Full Text:
The African coelacanth genome provides insights into tetrapod evolution:
- Amemiya, Chris T, Alföldi, Jessica, Lee, Alison P, Fan, Shaohua, Philippe, Herve´, MacCallum, Iain, Braasch, Ingo, Manousaki, Tereza, Schneider, Igor, Rohner, Nicolas, Organ, Chris, Chalopin, Domitille, Smith, Jeramiah J, Robinson, Mark, Dorrington, Rosemary A, Gerdol, Marco, Aken, Bronwen, Biscotti, Maria Assunta, Barucca, Marco, Baurain, Denis, Berlin, Aaron, Blatch, Gregory L, Buonocore, Francesco, Burmester, Thorsten, Campbell, Michael S, Canapa, Adriana, Cannon, John P, Christoffels, Alan, De Moro, Gianluca, Edkins, Adrienne L, Fan, Lin, Fausto, Anna Maria, Feiner, Nathalie, Forconi, Mariko, Gamieldien, Junaid, Gnerre, Sante, Gnirke, Andreas, Goldstone, Jared V, Haerty, Wilfried, Hahn, Mark E, Hesse, Uljana, Hoffmann, Steve, Johnson, Jeremy, Karchner, Sibel I, Kuraku, Shigehiro, Lara, Marcia, Levin, Joshua Z, Litman, Gary W, Mauceli, Evan, Miyake, Tsutomu, Mueller, M Gail, Nelson, David R, Nitsche, Anne, Olmo, Ettore, Ota, Tatsuya, Pallavicini, Alberto, Panji, Sumir, Picone, Barbara, Ponting, Chris P, Prohaska, Sonja J, Przybylski, Dariusz, Ratan Saha, Nil, Ravi, Vydianathan, Ribeiro, Filipe J, Sauka-Spengler, Tatjana, Scapigliati, Giuseppe, Searle, Stephen M J, Sharpe, Ted, Simakov, Oleg, Stadler, Peter F, Stegeman, John J, Sumiyama, Kenta, Tabbaa, Diana, Tafer, Hakim, Turner-Maier, Jason, van Heusden, Peter, White, Simon, Williams, Louise, Yandell, Mark, Brinkmann, Henner, Volff, Jean-Nicolas, Tabin, Clifford J, Shubin, Neil, Schartl, Manfred, Jaffe, David B, Postlethwait, John H, Venkatesh, Byrappa, Di Palma, Frederica, Lander, Eric S, Meyer, Axel, Lindblad-Toh, Kerstin
- Authors: Amemiya, Chris T , Alföldi, Jessica , Lee, Alison P , Fan, Shaohua , Philippe, Herve´ , MacCallum, Iain , Braasch, Ingo , Manousaki, Tereza , Schneider, Igor , Rohner, Nicolas , Organ, Chris , Chalopin, Domitille , Smith, Jeramiah J , Robinson, Mark , Dorrington, Rosemary A , Gerdol, Marco , Aken, Bronwen , Biscotti, Maria Assunta , Barucca, Marco , Baurain, Denis , Berlin, Aaron , Blatch, Gregory L , Buonocore, Francesco , Burmester, Thorsten , Campbell, Michael S , Canapa, Adriana , Cannon, John P , Christoffels, Alan , De Moro, Gianluca , Edkins, Adrienne L , Fan, Lin , Fausto, Anna Maria , Feiner, Nathalie , Forconi, Mariko , Gamieldien, Junaid , Gnerre, Sante , Gnirke, Andreas , Goldstone, Jared V , Haerty, Wilfried , Hahn, Mark E , Hesse, Uljana , Hoffmann, Steve , Johnson, Jeremy , Karchner, Sibel I , Kuraku, Shigehiro , Lara, Marcia , Levin, Joshua Z , Litman, Gary W , Mauceli, Evan , Miyake, Tsutomu , Mueller, M Gail , Nelson, David R , Nitsche, Anne , Olmo, Ettore , Ota, Tatsuya , Pallavicini, Alberto , Panji, Sumir , Picone, Barbara , Ponting, Chris P , Prohaska, Sonja J , Przybylski, Dariusz , Ratan Saha, Nil , Ravi, Vydianathan , Ribeiro, Filipe J , Sauka-Spengler, Tatjana , Scapigliati, Giuseppe , Searle, Stephen M J , Sharpe, Ted , Simakov, Oleg , Stadler, Peter F , Stegeman, John J , Sumiyama, Kenta , Tabbaa, Diana , Tafer, Hakim , Turner-Maier, Jason , van Heusden, Peter , White, Simon , Williams, Louise , Yandell, Mark , Brinkmann, Henner , Volff, Jean-Nicolas , Tabin, Clifford J , Shubin, Neil , Schartl, Manfred , Jaffe, David B , Postlethwait, John H , Venkatesh, Byrappa , Di Palma, Frederica , Lander, Eric S , Meyer, Axel , Lindblad-Toh, Kerstin
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165030 , vital:41202 , DOI: 10.1038/nature12027
- Description: The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.
- Full Text:
- Authors: Amemiya, Chris T , Alföldi, Jessica , Lee, Alison P , Fan, Shaohua , Philippe, Herve´ , MacCallum, Iain , Braasch, Ingo , Manousaki, Tereza , Schneider, Igor , Rohner, Nicolas , Organ, Chris , Chalopin, Domitille , Smith, Jeramiah J , Robinson, Mark , Dorrington, Rosemary A , Gerdol, Marco , Aken, Bronwen , Biscotti, Maria Assunta , Barucca, Marco , Baurain, Denis , Berlin, Aaron , Blatch, Gregory L , Buonocore, Francesco , Burmester, Thorsten , Campbell, Michael S , Canapa, Adriana , Cannon, John P , Christoffels, Alan , De Moro, Gianluca , Edkins, Adrienne L , Fan, Lin , Fausto, Anna Maria , Feiner, Nathalie , Forconi, Mariko , Gamieldien, Junaid , Gnerre, Sante , Gnirke, Andreas , Goldstone, Jared V , Haerty, Wilfried , Hahn, Mark E , Hesse, Uljana , Hoffmann, Steve , Johnson, Jeremy , Karchner, Sibel I , Kuraku, Shigehiro , Lara, Marcia , Levin, Joshua Z , Litman, Gary W , Mauceli, Evan , Miyake, Tsutomu , Mueller, M Gail , Nelson, David R , Nitsche, Anne , Olmo, Ettore , Ota, Tatsuya , Pallavicini, Alberto , Panji, Sumir , Picone, Barbara , Ponting, Chris P , Prohaska, Sonja J , Przybylski, Dariusz , Ratan Saha, Nil , Ravi, Vydianathan , Ribeiro, Filipe J , Sauka-Spengler, Tatjana , Scapigliati, Giuseppe , Searle, Stephen M J , Sharpe, Ted , Simakov, Oleg , Stadler, Peter F , Stegeman, John J , Sumiyama, Kenta , Tabbaa, Diana , Tafer, Hakim , Turner-Maier, Jason , van Heusden, Peter , White, Simon , Williams, Louise , Yandell, Mark , Brinkmann, Henner , Volff, Jean-Nicolas , Tabin, Clifford J , Shubin, Neil , Schartl, Manfred , Jaffe, David B , Postlethwait, John H , Venkatesh, Byrappa , Di Palma, Frederica , Lander, Eric S , Meyer, Axel , Lindblad-Toh, Kerstin
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165030 , vital:41202 , DOI: 10.1038/nature12027
- Description: The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.
- Full Text:
The amaXhosa ukuthwala marriage custom in fact and fiction: a contemporary critique
- Kaschula, Russell H, Huisamen, Tim, Mostert, Andre, Nosilela, Bulelwa
- Authors: Kaschula, Russell H , Huisamen, Tim , Mostert, Andre , Nosilela, Bulelwa
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68344 , vital:29241 , https://doi.org/10.1080/02572117.2013.871454
- Description: publisher version , Ukuthwala is traditionally a marriage custom within the amaXhosa culture in South Africa which permits a ‘legal abduction’ of a bride-to-be. Similar customs of ‘bridal abduction’ exist, most notably in Kyrgyzstan, where it is known as ala kachuu. Research into these customs necessitates a more innovative approach to explore the impact of this social phenomenon. In this article the authors mobilise a fictional narrative to offer a backdrop for a comparative assessment of the impact of bridal ‘legal abduction’ and assess its contemporary status and role within a multicultural society which celebrates the rights of the individual while recognising the value and importance of maintaining cultural identity and traditions. Cultural dissonance has always been characteristic of modern and post-modern societies as they strive for a workable shared ethos. However, when customs such as ‘legal abduction’ (Mtuze, 1993:50) continue under the veil of cultural rights, the wider social sensibilities and perspectives can be at odds with the maintenance of such activities where these activities contradict the rights of the individual as enshrined for example in what can be seen as a liberal South African Constitution.
- Full Text: false
- Authors: Kaschula, Russell H , Huisamen, Tim , Mostert, Andre , Nosilela, Bulelwa
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68344 , vital:29241 , https://doi.org/10.1080/02572117.2013.871454
- Description: publisher version , Ukuthwala is traditionally a marriage custom within the amaXhosa culture in South Africa which permits a ‘legal abduction’ of a bride-to-be. Similar customs of ‘bridal abduction’ exist, most notably in Kyrgyzstan, where it is known as ala kachuu. Research into these customs necessitates a more innovative approach to explore the impact of this social phenomenon. In this article the authors mobilise a fictional narrative to offer a backdrop for a comparative assessment of the impact of bridal ‘legal abduction’ and assess its contemporary status and role within a multicultural society which celebrates the rights of the individual while recognising the value and importance of maintaining cultural identity and traditions. Cultural dissonance has always been characteristic of modern and post-modern societies as they strive for a workable shared ethos. However, when customs such as ‘legal abduction’ (Mtuze, 1993:50) continue under the veil of cultural rights, the wider social sensibilities and perspectives can be at odds with the maintenance of such activities where these activities contradict the rights of the individual as enshrined for example in what can be seen as a liberal South African Constitution.
- Full Text: false
The art of change: perspectives on transformation in South Africa
- Makhubu, Nomusa, Simbao, Ruth K
- Authors: Makhubu, Nomusa , Simbao, Ruth K
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147642 , vital:38657 , https://0-doi.org.wam.seals.ac.za/10.1080/09528822.2013.798180
- Description: There have been almost two decades of democracy in South Africa, yet rising anger and violent discontent lay bare continuing inequity. It is timely to ask the question: can South Africans really be frank about how meaningful the transformation from oppressive political and economic structures has been? Does the inclination towards neo-liberalism and capitalism in South Africa’s post-Apartheid democracy allow real change? Where economic inequality and spatial divisions still persist and, indeed, are actively reproduced by current market forces, can South Africans really create inclusive and integrative spaces? The Art of Change: Perspectives on Transformation in South Africa confronts some of these issues, reopening debates and encouraging reflection on cultural dynamics in South Africa during the past two decades.
- Full Text:
- Authors: Makhubu, Nomusa , Simbao, Ruth K
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147642 , vital:38657 , https://0-doi.org.wam.seals.ac.za/10.1080/09528822.2013.798180
- Description: There have been almost two decades of democracy in South Africa, yet rising anger and violent discontent lay bare continuing inequity. It is timely to ask the question: can South Africans really be frank about how meaningful the transformation from oppressive political and economic structures has been? Does the inclination towards neo-liberalism and capitalism in South Africa’s post-Apartheid democracy allow real change? Where economic inequality and spatial divisions still persist and, indeed, are actively reproduced by current market forces, can South Africans really create inclusive and integrative spaces? The Art of Change: Perspectives on Transformation in South Africa confronts some of these issues, reopening debates and encouraging reflection on cultural dynamics in South Africa during the past two decades.
- Full Text:
The challenges of alleviating poverty through ecological restoration: Insights from South Africa's “working for water” program
- McConnachie, Matthew M, Cowling, Richard M, Shackleton, Charlie M, Knight, Andrew T
- Authors: McConnachie, Matthew M , Cowling, Richard M , Shackleton, Charlie M , Knight, Andrew T
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181003 , vital:43680 , xlink:href="https://doi.org/10.1111/rec.12038"
- Description: Public works programs have been posited as win–win solutions for achieving societal goals for ecological restoration and poverty alleviation. However, little is documented regarding the challenges of implementing such projects. A commonly cited example is South Africa's invasive alien plant control program “Working for Water” (WfW), which aims to create employment via restoring landscapes invaded with alien plants. Recent studies have raised questions over the effectiveness of this program in achieving both its restoration and poverty alleviation goals. This is the first study that we are aware of that synthesizes the knowledge of managers on both the poverty alleviation and environmental outcomes of a public works project. Herein, we sought to understand the challenges and constraints faced by 23 WfW managers in fulfilling the program's environmental and poverty alleviation objectives. We found that the challenges most frequently cited by managers related to the capacity and competence of managers and teams, followed by challenges relating to planning and coordination, specifically the challenges of being flexible and adaptive when constrained by operating procedures. In addition, the current focus on maximizing short-term employment was perceived by some as limiting the efficiency and long-term effectiveness of the WfW program in achieving its environmental and social goals. We suggest that improving the conditions and duration of employment could improve the effectiveness of invasive alien plant control and ecological outcomes. We also suggest that WfW measure the impacts of their interventions through an adaptive management approach so that it can learn and adapt to the challenges it faces.
- Full Text:
- Authors: McConnachie, Matthew M , Cowling, Richard M , Shackleton, Charlie M , Knight, Andrew T
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181003 , vital:43680 , xlink:href="https://doi.org/10.1111/rec.12038"
- Description: Public works programs have been posited as win–win solutions for achieving societal goals for ecological restoration and poverty alleviation. However, little is documented regarding the challenges of implementing such projects. A commonly cited example is South Africa's invasive alien plant control program “Working for Water” (WfW), which aims to create employment via restoring landscapes invaded with alien plants. Recent studies have raised questions over the effectiveness of this program in achieving both its restoration and poverty alleviation goals. This is the first study that we are aware of that synthesizes the knowledge of managers on both the poverty alleviation and environmental outcomes of a public works project. Herein, we sought to understand the challenges and constraints faced by 23 WfW managers in fulfilling the program's environmental and poverty alleviation objectives. We found that the challenges most frequently cited by managers related to the capacity and competence of managers and teams, followed by challenges relating to planning and coordination, specifically the challenges of being flexible and adaptive when constrained by operating procedures. In addition, the current focus on maximizing short-term employment was perceived by some as limiting the efficiency and long-term effectiveness of the WfW program in achieving its environmental and social goals. We suggest that improving the conditions and duration of employment could improve the effectiveness of invasive alien plant control and ecological outcomes. We also suggest that WfW measure the impacts of their interventions through an adaptive management approach so that it can learn and adapt to the challenges it faces.
- Full Text:
The Dangers of Student-Centered Learning-A Caution about Blind Spots in the Scholarship of Teaching and Learning
- Authors: McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187362 , vital:44624 , xlink:href="https://doi.org/10.20429/ijsotl.2013.070206"
- Description: Student-centered learning is an increasingly popular approach that shifts the focus from the teacher to the student. The approach argues that we need to have a clear understanding of who our students are and what their needs are in order for us to provide quality education. This paper applauds the focus on the student but raises two concerns about absences in this approach. Firstly, student-centered approaches rarely consider the actual knowledge being taught and learnt. There is little consideration of how the disciplinary knowledge is constructed and what norms and values underpin such constructions. Secondly, student-centered approaches are often undertaken within the dominant autonomous discourse where student success or failure is seen to result from characteristics inherent in the student. She is understood as an individual rather than as a member of a larger social group and there is equally little acknowledgement of the socially constructed nature of universities and the practices within them.
- Full Text:
- Authors: McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187362 , vital:44624 , xlink:href="https://doi.org/10.20429/ijsotl.2013.070206"
- Description: Student-centered learning is an increasingly popular approach that shifts the focus from the teacher to the student. The approach argues that we need to have a clear understanding of who our students are and what their needs are in order for us to provide quality education. This paper applauds the focus on the student but raises two concerns about absences in this approach. Firstly, student-centered approaches rarely consider the actual knowledge being taught and learnt. There is little consideration of how the disciplinary knowledge is constructed and what norms and values underpin such constructions. Secondly, student-centered approaches are often undertaken within the dominant autonomous discourse where student success or failure is seen to result from characteristics inherent in the student. She is understood as an individual rather than as a member of a larger social group and there is equally little acknowledgement of the socially constructed nature of universities and the practices within them.
- Full Text:
The development and assessment of sustained release nevirapine tablets
- Authors: Mwila, Chiluba
- Date: 2013
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54667 , vital:26598
- Description: The use of antiretroviral (ARV) agents in the management of HIV/AIDS has significantly improved the lifestyle and wellbeing of patients. Despite the success that has been achieved with the use of ARV therapy, the occurrence of adverse effects and unpredictable bioavailability associated with most of these drugs remains a major concern. Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is used in combination with other ARV compounds for the treatment of HIV-1 infections. It is also used for the prevention of mother to child transmission of the HIV-1 virus. NVP is a Biopharmaceutics Classification System (BCS) Class II compound. Although NVP exhibits good oral absorption, it induces self-metabolism leading to low and sometimes unpredictable bioavailability. NVP is commercially available as an immediate release and extended release dosage form, viz., Viramune® XR. Formulation of a generic sustained release (SR) dosage form for once daily dosing would result in delivery of constant amount of the drug to the circulation, reduce dose related adverse effects, improve patient compliance to medication and reduce the costs of therapy. A simple RP-HPLC method was developed and optimised using a central composite design approach. The method was validated using ICH guidelines and was found to be linear, precise, specific and accurate for the analysis of NVP both in bulk and dosage forms. Direct compression was used as the method of tablet manufacture. Different polymers were assessed for suitability as rate retarding polymers and included Methocel® K4M, Carbopol® 71G NF and Eudragit® RSPO. Powder blends were assessed for flow properties using the angle of repose, bulk and tapped density, Carr’s Compressibility index and Hausner’s ratio. The traditional approach of changing the amount of polymers and diluents systematically to achieve a desired NVP release profile was used for the development of a preliminary formulation. Response surface methodology was used for the optimisation of the formulation using a Box-Behnken quadratic design. Physical characteristics of the tablets such as thickness, weight, hardness, tensile strength and friability were assessed and the tablets passed Pharmacopoeial testing. NVP assay and content uniformity were assessed using a validated RP-HPLC method. Initially, USP Apparatus 2 was used to study NVP release over a 24 hour period and subsequently dissolution studies were performed using USP Apparatus 3 as it can be used to simulate GIT conditions. The dissolution profiles generated were used to determine the agitation rate for USP Apparatus 3 that would be equivalent to an agitation rate of 50 rpm when using USP Apparatus 2. The effect of the mesh screen pore size, buffer molarity strength and concentration of surfactant on NVP release were also investigated in order to select discriminatory dissolution test conditions for the test formulation. Dissolution profiles were compared to those of the commercially available Viramune® XR using the FDA recommended difference (f1) and similarity (f2) factors. The calculated values for f1 and f2 revealed that the dissolution profile for the optimised formulation that was identified was statistically similar to Viramune® XR. In vitro release data were fitted to different kinetic models to study the release kinetics of NVP. The overall mechanism of NVP release was best described using the Korsmeyer-Peppas diffusion exponent value, n. NVP release was found to be anomalous, implying that the release was influenced by a combination of diffusion, swelling and polymer chain relaxation. The Hixson-Crowell model revealed that there was constant change in surface area of the dosage form suggesting that erosion and swelling were significant factors affecting NVP release from the hydrophilic matrix technology. The release kinetics data were also used to design the optimised formulation. Tablets manufactured using the optimised formulation were subjected to water uptake and erosion studies and the results revealed that swelling and erosion occur simultaneously. The effects of pH and molarity on the swelling and erosion of the tablets were also investigated. The data suggest that increase in pH resulted in a slight increase in swelling while an increase in molarity did not have a significant effect on swelling. The change in pH did not have a significant effect on erosion while an increase in molarity strength resulted in a decrease in matrix erosion. The effect of HPMC grade on swelling, erosion and NVP release revealed that the grade of HPMC used had a significant effect on NVP release, with the release rate decreasing, swelling increasing and erosion decreasing as the viscosity of the HPMC grade increased. The effect of the particle size of MCC on NVP release was also studied by manufacturing tablets containing different grades of MCC and these studies revealed that particle size did not appear to have a significant effect on NVP release. Similarly the use of different types of lactose did not appear to have a significant impact on NVP release. In conclusion a sustained release NVP tablet formulation that has the potential for further development and optimisation has been developed, assessed and manufactured successfully and has been shown to exhibit similar dissolution behaviour to Viramune® XR, a commercially available NVP extended release product.
- Full Text:
- Authors: Mwila, Chiluba
- Date: 2013
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54667 , vital:26598
- Description: The use of antiretroviral (ARV) agents in the management of HIV/AIDS has significantly improved the lifestyle and wellbeing of patients. Despite the success that has been achieved with the use of ARV therapy, the occurrence of adverse effects and unpredictable bioavailability associated with most of these drugs remains a major concern. Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is used in combination with other ARV compounds for the treatment of HIV-1 infections. It is also used for the prevention of mother to child transmission of the HIV-1 virus. NVP is a Biopharmaceutics Classification System (BCS) Class II compound. Although NVP exhibits good oral absorption, it induces self-metabolism leading to low and sometimes unpredictable bioavailability. NVP is commercially available as an immediate release and extended release dosage form, viz., Viramune® XR. Formulation of a generic sustained release (SR) dosage form for once daily dosing would result in delivery of constant amount of the drug to the circulation, reduce dose related adverse effects, improve patient compliance to medication and reduce the costs of therapy. A simple RP-HPLC method was developed and optimised using a central composite design approach. The method was validated using ICH guidelines and was found to be linear, precise, specific and accurate for the analysis of NVP both in bulk and dosage forms. Direct compression was used as the method of tablet manufacture. Different polymers were assessed for suitability as rate retarding polymers and included Methocel® K4M, Carbopol® 71G NF and Eudragit® RSPO. Powder blends were assessed for flow properties using the angle of repose, bulk and tapped density, Carr’s Compressibility index and Hausner’s ratio. The traditional approach of changing the amount of polymers and diluents systematically to achieve a desired NVP release profile was used for the development of a preliminary formulation. Response surface methodology was used for the optimisation of the formulation using a Box-Behnken quadratic design. Physical characteristics of the tablets such as thickness, weight, hardness, tensile strength and friability were assessed and the tablets passed Pharmacopoeial testing. NVP assay and content uniformity were assessed using a validated RP-HPLC method. Initially, USP Apparatus 2 was used to study NVP release over a 24 hour period and subsequently dissolution studies were performed using USP Apparatus 3 as it can be used to simulate GIT conditions. The dissolution profiles generated were used to determine the agitation rate for USP Apparatus 3 that would be equivalent to an agitation rate of 50 rpm when using USP Apparatus 2. The effect of the mesh screen pore size, buffer molarity strength and concentration of surfactant on NVP release were also investigated in order to select discriminatory dissolution test conditions for the test formulation. Dissolution profiles were compared to those of the commercially available Viramune® XR using the FDA recommended difference (f1) and similarity (f2) factors. The calculated values for f1 and f2 revealed that the dissolution profile for the optimised formulation that was identified was statistically similar to Viramune® XR. In vitro release data were fitted to different kinetic models to study the release kinetics of NVP. The overall mechanism of NVP release was best described using the Korsmeyer-Peppas diffusion exponent value, n. NVP release was found to be anomalous, implying that the release was influenced by a combination of diffusion, swelling and polymer chain relaxation. The Hixson-Crowell model revealed that there was constant change in surface area of the dosage form suggesting that erosion and swelling were significant factors affecting NVP release from the hydrophilic matrix technology. The release kinetics data were also used to design the optimised formulation. Tablets manufactured using the optimised formulation were subjected to water uptake and erosion studies and the results revealed that swelling and erosion occur simultaneously. The effects of pH and molarity on the swelling and erosion of the tablets were also investigated. The data suggest that increase in pH resulted in a slight increase in swelling while an increase in molarity did not have a significant effect on swelling. The change in pH did not have a significant effect on erosion while an increase in molarity strength resulted in a decrease in matrix erosion. The effect of HPMC grade on swelling, erosion and NVP release revealed that the grade of HPMC used had a significant effect on NVP release, with the release rate decreasing, swelling increasing and erosion decreasing as the viscosity of the HPMC grade increased. The effect of the particle size of MCC on NVP release was also studied by manufacturing tablets containing different grades of MCC and these studies revealed that particle size did not appear to have a significant effect on NVP release. Similarly the use of different types of lactose did not appear to have a significant impact on NVP release. In conclusion a sustained release NVP tablet formulation that has the potential for further development and optimisation has been developed, assessed and manufactured successfully and has been shown to exhibit similar dissolution behaviour to Viramune® XR, a commercially available NVP extended release product.
- Full Text:
The development of an arousal and anxiety control mental skills training programme for the Rhodes University archery club
- Authors: Chiweshe, Malvern Tatenda
- Date: 2013
- Subjects: Anxiety , Arousal , Mental skills , Training , Sports -- Psychological aspects -- Research -- South Africa , Archers -- Training of -- Research -- South Africa , Archers -- Psychological aspects -- Research -- South Africa , Psychology, Applied
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2917 , http://hdl.handle.net/10962/d1002082
- Description: Research on the development of Mental Skills Training (MST) programmes in sport psychology has largely increased as sport has become more competitive. MST programmes have been seen to improve the performance of athletes. This particular research study focuses on the development of an anxiety and arousal control MST programme designed specifically for, and tailored exclusively to, the needs of four archers from the Rhodes Archery Club in Grahamstown, Eastern Cape, South Africa. The development of the programme was guided by the Organisational Development Process model as the research methodology design. Data from two quantitative measures (CSAI-2 and Sport Grid-R), a focus group, and an individual interview were integrated with currently existing mental skills literature and theory to devise this particular MST programme. The results of the assessment phase showed that individual archers have different experiences in how anxiety and arousal affect their performances. The results also showed that archers have different zones in which they feel their performance is good. These zones depend on their subjective interpretations of anxiety and arousal. The results also showed that other factors that include personality differences, level of experience and level of expertise also influence how anxiety and arousal affect performance. The archers had previous exposure to MST programmes although they had not received systematic training in mental skills training. The programme was developed in the form of MST workshops that would run over a three week period. As part of the programme the archers would be given a mental skills manual to aid in the mental skills training. It is recommended in future that more research in MST programmes be done as a way of improving the performance of athletes in South Africa
- Full Text:
- Authors: Chiweshe, Malvern Tatenda
- Date: 2013
- Subjects: Anxiety , Arousal , Mental skills , Training , Sports -- Psychological aspects -- Research -- South Africa , Archers -- Training of -- Research -- South Africa , Archers -- Psychological aspects -- Research -- South Africa , Psychology, Applied
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2917 , http://hdl.handle.net/10962/d1002082
- Description: Research on the development of Mental Skills Training (MST) programmes in sport psychology has largely increased as sport has become more competitive. MST programmes have been seen to improve the performance of athletes. This particular research study focuses on the development of an anxiety and arousal control MST programme designed specifically for, and tailored exclusively to, the needs of four archers from the Rhodes Archery Club in Grahamstown, Eastern Cape, South Africa. The development of the programme was guided by the Organisational Development Process model as the research methodology design. Data from two quantitative measures (CSAI-2 and Sport Grid-R), a focus group, and an individual interview were integrated with currently existing mental skills literature and theory to devise this particular MST programme. The results of the assessment phase showed that individual archers have different experiences in how anxiety and arousal affect their performances. The results also showed that archers have different zones in which they feel their performance is good. These zones depend on their subjective interpretations of anxiety and arousal. The results also showed that other factors that include personality differences, level of experience and level of expertise also influence how anxiety and arousal affect performance. The archers had previous exposure to MST programmes although they had not received systematic training in mental skills training. The programme was developed in the form of MST workshops that would run over a three week period. As part of the programme the archers would be given a mental skills manual to aid in the mental skills training. It is recommended in future that more research in MST programmes be done as a way of improving the performance of athletes in South Africa
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The development of catalytic oxovanadium (IV)-containing microspheres for the oxidation of various organosulfur compounds
- Ogunlaja, Adeniyi S, Khene, Samson M, Antunes, Edith M, Nyokong, Tebello, Torto, Nelson, Tshentu, Zenixole R
- Authors: Ogunlaja, Adeniyi S , Khene, Samson M , Antunes, Edith M , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241783 , vital:50969 , xlink:href="https://doi.org/10.1016/j.apcata.2013.05.004"
- Description: The development of poly[allylSB-co-EGDMA] beads containing a tetradentate ligand was achieved via suspension polymerization. The catalyst poly[allylSB-co-EGDMA]-VO was synthesized by reacting VIVOSO4 with poly[allylSB-co-EGDMA]. XPS and EPR were used to confirm the presence of vanadium (V4+) on the beads. The synthesized catalyst (poly[allylSB-co-EGDMA]-VO) was found to have a BET surface area of 22 m2 g−1 and porosity of 135 Å, with the atomic force microscopy (AFM) showing more insight on the porous nature of the beads. Oxidation of thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was carried out using tert-butyl hydroperoxide (t-BuOOH) as oxidant. An overall conversion of 60%, 82%, 98% and 87% was achieved for thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6 dimethyldibenzothiophene (4,6-DMDBT) respectively at higher (t-BuOOH) to substrate ratio and at a temperature of 40 °C. The efficient oxidation of the various organosulfur compounds presents potential for the possible application of this catalyst in oxidative desulfurization (ODS) of crude oil.
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- Authors: Ogunlaja, Adeniyi S , Khene, Samson M , Antunes, Edith M , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241783 , vital:50969 , xlink:href="https://doi.org/10.1016/j.apcata.2013.05.004"
- Description: The development of poly[allylSB-co-EGDMA] beads containing a tetradentate ligand was achieved via suspension polymerization. The catalyst poly[allylSB-co-EGDMA]-VO was synthesized by reacting VIVOSO4 with poly[allylSB-co-EGDMA]. XPS and EPR were used to confirm the presence of vanadium (V4+) on the beads. The synthesized catalyst (poly[allylSB-co-EGDMA]-VO) was found to have a BET surface area of 22 m2 g−1 and porosity of 135 Å, with the atomic force microscopy (AFM) showing more insight on the porous nature of the beads. Oxidation of thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was carried out using tert-butyl hydroperoxide (t-BuOOH) as oxidant. An overall conversion of 60%, 82%, 98% and 87% was achieved for thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6 dimethyldibenzothiophene (4,6-DMDBT) respectively at higher (t-BuOOH) to substrate ratio and at a temperature of 40 °C. The efficient oxidation of the various organosulfur compounds presents potential for the possible application of this catalyst in oxidative desulfurization (ODS) of crude oil.
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