South Africa in the Antarctic Circumnavigation Expedition: a multi-institutional and interdisciplinary scientific project
- Halo, Issufo, Dorrington, Rosemary A, Bornman, Thomas G, De Villiers, Stephanie, Fawcett, Sarah
- Authors: Halo, Issufo , Dorrington, Rosemary A , Bornman, Thomas G , De Villiers, Stephanie , Fawcett, Sarah
- Date: 2016
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/65428 , vital:28790 , https://doi.org/10.17159/sajs.2016/a0173
- Description: publisher version , The polar regions are more critically affected by climate change than any other region on our planet.1,2 On the Antarctic continent and in its surrounding oceans, the effects of climate change are likely to be dramatic,3 and include largescale catastrophic ice melt, loss of habitat and biodiversity, and global sea level rise. The ‘Southern Ocean’ refers to the region where Atlantic, Indian and Pacific Ocean waters come together to encircle Antarctica. These waters connect the different ocean basins by linking the shallow and deep limbs of the global ocean current system (‘overturning circulation’) and play a critical role in storing and distributing heat and carbon dioxide (CO2 ). The Southern Ocean thus regulates not only the climate of the Antarctic, but of the entire earth system.1,4 By extension, the capacity of the global ocean to ameliorate earth’s changing climate is strongly controlled by the Southern Ocean. Marine phytoplankton (microscopic plants inhabiting the sunlit upper ocean) convert CO2 (an inorganic form of carbon) dissolved in surface waters into organic carbon through photosynthesis. This organic carbon fuels upper trophic levels such as fish, mammals and birds, and a portion sinks into the deep ocean where it remains stored for hundreds to thousands of years. This mechanism, which lowers the atmospheric concentration of CO2 , is termed the ‘biological pump’.5 The efficiency of the global ocean’s biological pump is currently limited by the Southern Ocean, where the macronutrients (nitrate and phosphate) required for photosynthesis are never fully consumed in surface waters. In theory, increased consumption of these nutrients could drive higher organic carbon removal to the deep ocean, enhancing the oceanic uptake of atmospheric CO2 . Indeed, more complete consumption of Southern Ocean nutrients is a leading hypothesis for the decrease in atmospheric CO2 that characterised the ice ages.6 Despite the global importance of the Southern Ocean, knowledge of the controls on and interactions among the physical, chemical and biological processes operating in Antarctic ecosystems is limited, largely because of a scarcity of in-situ observational data, compounded by the challenge of integrating siloed scientific fields. Given predictions that diverse aspects of Southern Ocean physics and carbon biogeochemistry are likely to change in the coming decades, a transdisciplinary approach to studying Antarctic systems is critical.
- Full Text:
- Date Issued: 2016
- Authors: Halo, Issufo , Dorrington, Rosemary A , Bornman, Thomas G , De Villiers, Stephanie , Fawcett, Sarah
- Date: 2016
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/65428 , vital:28790 , https://doi.org/10.17159/sajs.2016/a0173
- Description: publisher version , The polar regions are more critically affected by climate change than any other region on our planet.1,2 On the Antarctic continent and in its surrounding oceans, the effects of climate change are likely to be dramatic,3 and include largescale catastrophic ice melt, loss of habitat and biodiversity, and global sea level rise. The ‘Southern Ocean’ refers to the region where Atlantic, Indian and Pacific Ocean waters come together to encircle Antarctica. These waters connect the different ocean basins by linking the shallow and deep limbs of the global ocean current system (‘overturning circulation’) and play a critical role in storing and distributing heat and carbon dioxide (CO2 ). The Southern Ocean thus regulates not only the climate of the Antarctic, but of the entire earth system.1,4 By extension, the capacity of the global ocean to ameliorate earth’s changing climate is strongly controlled by the Southern Ocean. Marine phytoplankton (microscopic plants inhabiting the sunlit upper ocean) convert CO2 (an inorganic form of carbon) dissolved in surface waters into organic carbon through photosynthesis. This organic carbon fuels upper trophic levels such as fish, mammals and birds, and a portion sinks into the deep ocean where it remains stored for hundreds to thousands of years. This mechanism, which lowers the atmospheric concentration of CO2 , is termed the ‘biological pump’.5 The efficiency of the global ocean’s biological pump is currently limited by the Southern Ocean, where the macronutrients (nitrate and phosphate) required for photosynthesis are never fully consumed in surface waters. In theory, increased consumption of these nutrients could drive higher organic carbon removal to the deep ocean, enhancing the oceanic uptake of atmospheric CO2 . Indeed, more complete consumption of Southern Ocean nutrients is a leading hypothesis for the decrease in atmospheric CO2 that characterised the ice ages.6 Despite the global importance of the Southern Ocean, knowledge of the controls on and interactions among the physical, chemical and biological processes operating in Antarctic ecosystems is limited, largely because of a scarcity of in-situ observational data, compounded by the challenge of integrating siloed scientific fields. Given predictions that diverse aspects of Southern Ocean physics and carbon biogeochemistry are likely to change in the coming decades, a transdisciplinary approach to studying Antarctic systems is critical.
- Full Text:
- Date Issued: 2016
Spectroscopic investigations and theoretical calculations of DABCO induced xanthene bridged self-assembled zinc (II) porphyrin dimer
- Xu, Li, Huang, Tingting, Liang, Xu, Mack, John, Harris, Jessica, Nyokong, Tebello, Li, Minzhi, Zhu, Weihua
- Authors: Xu, Li , Huang, Tingting , Liang, Xu , Mack, John , Harris, Jessica , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240732 , vital:50866 , xlink:href="https://doi.org/10.1142/S1088424616500231"
- Description: An in-depth study of the electronic structure of a 1,4-diazabicyclo[2.2.2]octane (DABCO) induced molecular self-assembled xanthene-bridged and amide-bonded porphyrin dimer is reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are used to identify trends in the optical spectroscopic properties. B3LYP geometry optimization predicts the formation of an almost perfectly eclipsed structure with respect to the two porphyrin rings with the analogous pyrrole nitrogens separated by 7.7–8.1 Å. The observed distinctive derivative-shaped band morphology of the pseudo-Faraday-A11 terms in the MCD spectra has been used to identify the main electronic Q and B-bands and to validate the TD-DFT calculations. The absence of a discernible splitting of the redox steps or a quenching of the fluorescence demonstrates that there is no significant exciton coupling between the two porphyrin rings.
- Full Text:
- Date Issued: 2016
- Authors: Xu, Li , Huang, Tingting , Liang, Xu , Mack, John , Harris, Jessica , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240732 , vital:50866 , xlink:href="https://doi.org/10.1142/S1088424616500231"
- Description: An in-depth study of the electronic structure of a 1,4-diazabicyclo[2.2.2]octane (DABCO) induced molecular self-assembled xanthene-bridged and amide-bonded porphyrin dimer is reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are used to identify trends in the optical spectroscopic properties. B3LYP geometry optimization predicts the formation of an almost perfectly eclipsed structure with respect to the two porphyrin rings with the analogous pyrrole nitrogens separated by 7.7–8.1 Å. The observed distinctive derivative-shaped band morphology of the pseudo-Faraday-A11 terms in the MCD spectra has been used to identify the main electronic Q and B-bands and to validate the TD-DFT calculations. The absence of a discernible splitting of the redox steps or a quenching of the fluorescence demonstrates that there is no significant exciton coupling between the two porphyrin rings.
- Full Text:
- Date Issued: 2016
Sport consumption patterns in the Eastern Cape: cricket spectators as sporting univores or omnivores
- Brock, Kelcey, Fraser, Gavin C G, Botha, Ferdi
- Authors: Brock, Kelcey , Fraser, Gavin C G , Botha, Ferdi
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69362 , vital:29508 , https://doi.org/10.4102/jef.v9i3.64
- Description: Since its inception, consumption behaviour theory has developed to account for the important social aspects that underpin or at least to some extent explain consumer behaviour. Empirical studies on consumption behaviour of cultural activities, entertainment and sport have used Bourdieu’s (1984) omnivore/univore theory to investigate consumption of leisure activities. The aim of this study is to investigate whether South African cricket spectators are sporting omnivores or univores. The study was conducted among cricket spectators in the Eastern Cape at four limited overs cricket matches in the 2012/2013 cricket season. The results indicate that consumption behaviour of sport predominantly differs on the grounds of education and race. This suggests that there are aspects of social connotations underpinning sports consumption behaviour within South Africa.
- Full Text:
- Date Issued: 2016
Sport consumption patterns in the Eastern Cape: cricket spectators as sporting univores or omnivores
- Authors: Brock, Kelcey , Fraser, Gavin C G , Botha, Ferdi
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69362 , vital:29508 , https://doi.org/10.4102/jef.v9i3.64
- Description: Since its inception, consumption behaviour theory has developed to account for the important social aspects that underpin or at least to some extent explain consumer behaviour. Empirical studies on consumption behaviour of cultural activities, entertainment and sport have used Bourdieu’s (1984) omnivore/univore theory to investigate consumption of leisure activities. The aim of this study is to investigate whether South African cricket spectators are sporting omnivores or univores. The study was conducted among cricket spectators in the Eastern Cape at four limited overs cricket matches in the 2012/2013 cricket season. The results indicate that consumption behaviour of sport predominantly differs on the grounds of education and race. This suggests that there are aspects of social connotations underpinning sports consumption behaviour within South Africa.
- Full Text:
- Date Issued: 2016
Spotlight on the Art of Darkness: The Kin Artstudio
- Authors: Tshilumba Mukendi, J S
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146434 , vital:38525 , https://artafricamagazine.org/magazine-archive/?v=e4dd286dc7d7
- Description: Issue December 2016. What Really Matters.
- Full Text:
- Date Issued: 2016
- Authors: Tshilumba Mukendi, J S
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146434 , vital:38525 , https://artafricamagazine.org/magazine-archive/?v=e4dd286dc7d7
- Description: Issue December 2016. What Really Matters.
- Full Text:
- Date Issued: 2016
Structure based docking and molecular dynamic studies of plasmodial cysteine proteases against a South African natural compound and its analogs:
- Musyoka, Thommas M, Kanzi, Aquillah M, Lobb, Kevin A, Tastan Bishop, Özlem
- Authors: Musyoka, Thommas M , Kanzi, Aquillah M , Lobb, Kevin A , Tastan Bishop, Özlem
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148027 , vital:38703 , DOI: 10.1038/srep23690
- Description: Identification of potential drug targets as well as development of novel antimalarial chemotherapies with unique mode of actions due to drug resistance by Plasmodium parasites are inevitable. Falcipains (falcipain-2 and falcipain-3) of Plasmodium falciparum, which catalyse the haemoglobin degradation process, are validated drug targets. Previous attempts to develop peptide based drugs against these enzymes have been futile due to the poor pharmacological profiles and susceptibility to degradation by host enzymes. This study aimed to identify potential non-peptide inhibitors against falcipains and their homologs from other Plasmodium species.
- Full Text:
- Date Issued: 2016
- Authors: Musyoka, Thommas M , Kanzi, Aquillah M , Lobb, Kevin A , Tastan Bishop, Özlem
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148027 , vital:38703 , DOI: 10.1038/srep23690
- Description: Identification of potential drug targets as well as development of novel antimalarial chemotherapies with unique mode of actions due to drug resistance by Plasmodium parasites are inevitable. Falcipains (falcipain-2 and falcipain-3) of Plasmodium falciparum, which catalyse the haemoglobin degradation process, are validated drug targets. Previous attempts to develop peptide based drugs against these enzymes have been futile due to the poor pharmacological profiles and susceptibility to degradation by host enzymes. This study aimed to identify potential non-peptide inhibitors against falcipains and their homologs from other Plasmodium species.
- Full Text:
- Date Issued: 2016
Subcellular localisation of Theiler's murine encephalomyelitis virus (TMEV) capsid subunit VP1 vis-á-vis host protein Hsp90:
- Ross, Caroline J, Upfold, Nicole, Luke, Garry A, Tastan Bishop, Özlem, Knox, Caroline M
- Authors: Ross, Caroline J , Upfold, Nicole , Luke, Garry A , Tastan Bishop, Özlem , Knox, Caroline M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148016 , vital:38702 , DOI: 10.1016/j.virusres.2016.06.003
- Description: The VP1 subunit of the picornavirus capsid is the major antigenic determinant and mediates host cell attachment and virus entry. To investigate the localisation of Theiler's murine encephalomyelitis virus (TMEV) VP1 during infection, a bioinformatics approach was used to predict a surface-exposed, linear epitope region of the protein for subsequent expression and purification. This region, comprising the N-terminal 112 amino acids of the protein, was then used for rabbit immunisation, and the resultant polyclonal antibodies were able to recognise full length VP1 in infected cell lysates by Western blot. Following optimisation, the antibodies were used to investigate the localisation of VP1 in relation to Hsp90 in infected cells by indirect immunofluorescence and confocal microscopy.
- Full Text:
- Date Issued: 2016
- Authors: Ross, Caroline J , Upfold, Nicole , Luke, Garry A , Tastan Bishop, Özlem , Knox, Caroline M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148016 , vital:38702 , DOI: 10.1016/j.virusres.2016.06.003
- Description: The VP1 subunit of the picornavirus capsid is the major antigenic determinant and mediates host cell attachment and virus entry. To investigate the localisation of Theiler's murine encephalomyelitis virus (TMEV) VP1 during infection, a bioinformatics approach was used to predict a surface-exposed, linear epitope region of the protein for subsequent expression and purification. This region, comprising the N-terminal 112 amino acids of the protein, was then used for rabbit immunisation, and the resultant polyclonal antibodies were able to recognise full length VP1 in infected cell lysates by Western blot. Following optimisation, the antibodies were used to investigate the localisation of VP1 in relation to Hsp90 in infected cells by indirect immunofluorescence and confocal microscopy.
- Full Text:
- Date Issued: 2016
Supplementary Material Synthesis and biological evaluation of (E)-cinnamic acid,(E)-2-styrylthiazole and (E)-2-[2-(naphthalen-1-yl) vinyl] thiazole derivatives
- Olawode, Emmanuel O, Tandlich, Roman, Prinsloo, Earl, Isaacs, Michelle, Hoppe, Heinrich, Seldon, Ronnett, Warner, Digby F, Steenkamp, Vanessa, Kaye, Perry T
- Authors: Olawode, Emmanuel O , Tandlich, Roman , Prinsloo, Earl , Isaacs, Michelle , Hoppe, Heinrich , Seldon, Ronnett , Warner, Digby F , Steenkamp, Vanessa , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431778 , vital:72803 , xlink:href=" https://www.arkat-usa.org/get-file/59868/"
- Description: The screening was conducted using multi-well plates which are suited for HeLa cells in the log phase of growth with final cell density > 10 cells/cm. Each experiment normally includes a blank control, containing medium without the cells.28,45 Non-contaminated HeLa cells (6.57 x 105 cells per well) in media were allowed to grow in the incubator under an atmosphere of 5% CO2 at 37 0C for 24 h. To each well was dispensed 200 µL of HeLa culture, containing 6.57 x 105 cells under LabEAir laminar flow hood (Vivid Air, South Africa); 20 µL of resazurin dye (Sigma TOX-8) and test compound (50 µL) were added, which were then incubated in the presence of 5% CO2 at 37 0C for 24 hours in a shaker, to enhance the distribution of the dye. The absorbance of each well was measured with Bio-tek Power Wave X fluorometer (Beijing, China), and increases in fluorescence was monitored at a wavelength of 590 nm, using an excitation wavelength of 560 nm.
- Full Text:
- Date Issued: 2016
- Authors: Olawode, Emmanuel O , Tandlich, Roman , Prinsloo, Earl , Isaacs, Michelle , Hoppe, Heinrich , Seldon, Ronnett , Warner, Digby F , Steenkamp, Vanessa , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431778 , vital:72803 , xlink:href=" https://www.arkat-usa.org/get-file/59868/"
- Description: The screening was conducted using multi-well plates which are suited for HeLa cells in the log phase of growth with final cell density > 10 cells/cm. Each experiment normally includes a blank control, containing medium without the cells.28,45 Non-contaminated HeLa cells (6.57 x 105 cells per well) in media were allowed to grow in the incubator under an atmosphere of 5% CO2 at 37 0C for 24 h. To each well was dispensed 200 µL of HeLa culture, containing 6.57 x 105 cells under LabEAir laminar flow hood (Vivid Air, South Africa); 20 µL of resazurin dye (Sigma TOX-8) and test compound (50 µL) were added, which were then incubated in the presence of 5% CO2 at 37 0C for 24 hours in a shaker, to enhance the distribution of the dye. The absorbance of each well was measured with Bio-tek Power Wave X fluorometer (Beijing, China), and increases in fluorescence was monitored at a wavelength of 590 nm, using an excitation wavelength of 560 nm.
- Full Text:
- Date Issued: 2016
Synthesis and dark toxicity of 5-(4-carboxyphenyl)-10, 15, 20-tris (phenyl)-porphyrinato chlorido gallium (III) when conjugated to δ-aminolevulinic acid
- Managa, Muthumuni, Mkhize, Scebi, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Managa, Muthumuni , Mkhize, Scebi , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240014 , vital:50789 , xlink:href="https://doi.org/10.1080/00958972.2016.1223292"
- Description: 5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (ΦΔ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.
- Full Text:
- Date Issued: 2016
- Authors: Managa, Muthumuni , Mkhize, Scebi , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240014 , vital:50789 , xlink:href="https://doi.org/10.1080/00958972.2016.1223292"
- Description: 5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (ΦΔ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.
- Full Text:
- Date Issued: 2016
Synthesis and optical limiting properties of new lanthanide bis-and tris-phthalocyanines
- Sekhosana, Kutloana Edward, Manyeruke, Meloddy Hlatini, Nyokong, Tebello
- Authors: Sekhosana, Kutloana Edward , Manyeruke, Meloddy Hlatini , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240063 , vital:50795 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.05.068"
- Description: This manuscript reports on syntheses of new multi-decker phthalocyanines, namely: bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} cerium(III) (2), tris-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} dicerium(III) (4) and bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} gadolinium(III) (5). Complex 4 which is a tris phthalocyanine showed better nonlinear optical behavior in solution than 2 which is a bis phthalocyanine, both containing the same central metal, Ce. All the three molecules possess good optical limiting properties judged by the limiting threshold values which ranged from 0.04 to 0.09 J cm−2 with complex 5 embedded in thin films, showing the lowest value of 0.04 J cm−2. Furthermore, nonlinear optical processes responsible for reverse saturable absorption data are investigated.
- Full Text:
- Date Issued: 2016
- Authors: Sekhosana, Kutloana Edward , Manyeruke, Meloddy Hlatini , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240063 , vital:50795 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.05.068"
- Description: This manuscript reports on syntheses of new multi-decker phthalocyanines, namely: bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} cerium(III) (2), tris-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} dicerium(III) (4) and bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} gadolinium(III) (5). Complex 4 which is a tris phthalocyanine showed better nonlinear optical behavior in solution than 2 which is a bis phthalocyanine, both containing the same central metal, Ce. All the three molecules possess good optical limiting properties judged by the limiting threshold values which ranged from 0.04 to 0.09 J cm−2 with complex 5 embedded in thin films, showing the lowest value of 0.04 J cm−2. Furthermore, nonlinear optical processes responsible for reverse saturable absorption data are investigated.
- Full Text:
- Date Issued: 2016
Synthesis and photophysicochemical properties of BODIPY dye functionalized gold nanorods for use in antimicrobial photodynamic therapy
- Kubheka, Gugu, Uddin, Imran, Amuhaya, Edith, Mack, John, Nyokong, Tebello
- Authors: Kubheka, Gugu , Uddin, Imran , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239897 , vital:50778 , xlink:href="https://doi.org/10.1142/S108842461650070X"
- Description: A series of boron dipyrromethene (BODIPY) dyes with properties that are ideal for a good photosensitizer have been prepared. Functionalization with bromine atoms and attachment to gold nanoparticles through a meso-aniline group results in high singlet oxygen quantum yields and low fluorescent quantum yields. Molecular modelling was used to analyze trends in the MO energies of various brominated aniline BODIPY dyes.
- Full Text:
- Date Issued: 2016
- Authors: Kubheka, Gugu , Uddin, Imran , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239897 , vital:50778 , xlink:href="https://doi.org/10.1142/S108842461650070X"
- Description: A series of boron dipyrromethene (BODIPY) dyes with properties that are ideal for a good photosensitizer have been prepared. Functionalization with bromine atoms and attachment to gold nanoparticles through a meso-aniline group results in high singlet oxygen quantum yields and low fluorescent quantum yields. Molecular modelling was used to analyze trends in the MO energies of various brominated aniline BODIPY dyes.
- Full Text:
- Date Issued: 2016
Synthesis and physicochemical properties of zinc and indium phthalocyanines conjugated to quantum dots, gold and magnetic nanoparticles
- Osifeko, Olawale, Nyokong, Tebello
- Authors: Osifeko, Olawale , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188639 , vital:44771 , xlink:href="https://doi.org/10.1016/j.dyepig.2016.04.015"
- Description: This work reports on the conjugation of semiconductors quantum dots (QDs), gold (AuNPs) or Fe3O4 magnetic (MNPs) nanoparticles to 4-(4,6-diaminopyrimidin-2-ylthio) substituted indium or zinc phthalocyanines (Pcs). The QDs and MNPs were linked to the Pcs via an amide bond and by chemisorption unto AuNP surface. There is a general decrease in fluorescence quantum yields of the Pcs in the presence of all the nanoparticles. There is an increase triplet quantum yields for Pcs in the presence of AuNPs and QDs, but not in the presence of MNPs. AuNPs conjugates irrespective of the central atoms have the highest singlet oxygen quantum yield and are more photo-stable than all the other conjugates. MPcs are less photostable in the presence of MNPs.
- Full Text:
- Date Issued: 2016
- Authors: Osifeko, Olawale , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188639 , vital:44771 , xlink:href="https://doi.org/10.1016/j.dyepig.2016.04.015"
- Description: This work reports on the conjugation of semiconductors quantum dots (QDs), gold (AuNPs) or Fe3O4 magnetic (MNPs) nanoparticles to 4-(4,6-diaminopyrimidin-2-ylthio) substituted indium or zinc phthalocyanines (Pcs). The QDs and MNPs were linked to the Pcs via an amide bond and by chemisorption unto AuNP surface. There is a general decrease in fluorescence quantum yields of the Pcs in the presence of all the nanoparticles. There is an increase triplet quantum yields for Pcs in the presence of AuNPs and QDs, but not in the presence of MNPs. AuNPs conjugates irrespective of the central atoms have the highest singlet oxygen quantum yield and are more photo-stable than all the other conjugates. MPcs are less photostable in the presence of MNPs.
- Full Text:
- Date Issued: 2016
Synthesis and singlet oxygen production by a phthalocyanine when embedded in asymmetric polymer membranes
- Mafukidze, Donovan M, Mashazi, Philani N, Nyokong, Tebello
- Authors: Mafukidze, Donovan M , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188563 , vital:44765 , xlink:href="https://doi.org/10.1016/j.polymer.2016.10.032"
- Description: 2(3), 9(10), 16(17), 23(24)-Tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (ClInTAPPc, 3) was first conjugated to two different polymers: polystyrene (PS) and polyacrylonitrile (PAN) to form 3-PS and 3-PAN. The conjugates were cast into the corresponding polymers to form membranes represented as 3-PS-membrane and 3-PAN-membrane, respectively. The prepared membranes were characterized using various techniques including scanning electron microscopy and solid state UV/Vis spectroscopy. Singlet oxygen quantum yields were higher for the 3-PS-membrane at 0.51 compared to 3-PAN-membrane at 0.35. The larger singlet oxygen also applies to 3-PS (0.63) compared to 3-PAN (0.38) when in solution.
- Full Text:
- Date Issued: 2016
- Authors: Mafukidze, Donovan M , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188563 , vital:44765 , xlink:href="https://doi.org/10.1016/j.polymer.2016.10.032"
- Description: 2(3), 9(10), 16(17), 23(24)-Tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (ClInTAPPc, 3) was first conjugated to two different polymers: polystyrene (PS) and polyacrylonitrile (PAN) to form 3-PS and 3-PAN. The conjugates were cast into the corresponding polymers to form membranes represented as 3-PS-membrane and 3-PAN-membrane, respectively. The prepared membranes were characterized using various techniques including scanning electron microscopy and solid state UV/Vis spectroscopy. Singlet oxygen quantum yields were higher for the 3-PS-membrane at 0.51 compared to 3-PAN-membrane at 0.35. The larger singlet oxygen also applies to 3-PS (0.63) compared to 3-PAN (0.38) when in solution.
- Full Text:
- Date Issued: 2016
Synthesis, characterization and electrochemistry of rhodium (iii) complexes of meso-substituted [14] tribenzotriphyrin (2.1. 1)
- Xue, Zhaoli, Wang, Yemei, Mack, John, Mkhize, Scebi, Nyokong, Tebello, Fang, Yuanyuan, Ou, Zhongping, Kadish, Karl M
- Authors: Xue, Zhaoli , Wang, Yemei , Mack, John , Mkhize, Scebi , Nyokong, Tebello , Fang, Yuanyuan , Ou, Zhongping , Kadish, Karl M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241043 , vital:50899 , xlink:href="https://doi.org/10.1039/C6RA03028A"
- Description: A thermal reaction using a series of [14]tribenzotriphyrins(2.1.1) (TriPs, 1a–d) with Rh2(C8H12)Cl2 provides RhIII–TriP complexes (2a–d) in 40−52% yields. The complexes were characterized by mass spectrometry, UV-visible absorption and 1H NMR spectroscopy. Single crystal X-ray analysis reveals that 2b adopts a dome-shaped conformation. The rhodium(III) ion is coordinated by the three pyrrole nitrogen atoms, two chloride ions and the nitrogen atom of an acetonitrile (CH3CN) solvent molecule. The optical spectra can be assigned using Michl's perimeter model. The L and B bands of the 2a–d complexes lie at ca. 600 and 500 nm, respectively, and are markedly red shifted relative to those of 1a–d. A reversible one-electron oxidation and two reversible one-electron reductions are observed in the cyclic voltammograms of 2a–d in CH2Cl2. The redox potentials are consistent with the optical data and the relatively narrow HOMO–LUMO gaps that are predicted in DFT calculations. TD-DFT calculations have been used to assign a third intense spectral band at 375 nm to a higher energy π → π* transition of the [14]tribenzotriphyrin(2.1.1) π-system.
- Full Text:
- Date Issued: 2016
- Authors: Xue, Zhaoli , Wang, Yemei , Mack, John , Mkhize, Scebi , Nyokong, Tebello , Fang, Yuanyuan , Ou, Zhongping , Kadish, Karl M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241043 , vital:50899 , xlink:href="https://doi.org/10.1039/C6RA03028A"
- Description: A thermal reaction using a series of [14]tribenzotriphyrins(2.1.1) (TriPs, 1a–d) with Rh2(C8H12)Cl2 provides RhIII–TriP complexes (2a–d) in 40−52% yields. The complexes were characterized by mass spectrometry, UV-visible absorption and 1H NMR spectroscopy. Single crystal X-ray analysis reveals that 2b adopts a dome-shaped conformation. The rhodium(III) ion is coordinated by the three pyrrole nitrogen atoms, two chloride ions and the nitrogen atom of an acetonitrile (CH3CN) solvent molecule. The optical spectra can be assigned using Michl's perimeter model. The L and B bands of the 2a–d complexes lie at ca. 600 and 500 nm, respectively, and are markedly red shifted relative to those of 1a–d. A reversible one-electron oxidation and two reversible one-electron reductions are observed in the cyclic voltammograms of 2a–d in CH2Cl2. The redox potentials are consistent with the optical data and the relatively narrow HOMO–LUMO gaps that are predicted in DFT calculations. TD-DFT calculations have been used to assign a third intense spectral band at 375 nm to a higher energy π → π* transition of the [14]tribenzotriphyrin(2.1.1) π-system.
- Full Text:
- Date Issued: 2016
Synthesis, Characterization, and Electronic Structures of Porphyrins Fused with Polycyclic Aromatic Ring Systems
- Okujima, Tetsuo, Mack, John, Nakamura, Jun, Kubheka, Gugu, Nyokong, Tebello, Zhu, Hua, Komobuchi, Naoki, Ono, Noboru, Yamada, Hiroko, Uno, Hidemitsu, Kobayashi, Nagao
- Authors: Okujima, Tetsuo , Mack, John , Nakamura, Jun , Kubheka, Gugu , Nyokong, Tebello , Zhu, Hua , Komobuchi, Naoki , Ono, Noboru , Yamada, Hiroko , Uno, Hidemitsu , Kobayashi, Nagao
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240360 , vital:50827 , xlink:href="https://doi.org/10.1002/chem.201602213"
- Description: A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels–Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.
- Full Text:
- Date Issued: 2016
- Authors: Okujima, Tetsuo , Mack, John , Nakamura, Jun , Kubheka, Gugu , Nyokong, Tebello , Zhu, Hua , Komobuchi, Naoki , Ono, Noboru , Yamada, Hiroko , Uno, Hidemitsu , Kobayashi, Nagao
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240360 , vital:50827 , xlink:href="https://doi.org/10.1002/chem.201602213"
- Description: A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels–Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.
- Full Text:
- Date Issued: 2016
Teacher code switching consistency and precision in a multilingual mathematics classroom:
- Chikiwa, Clemence, Schäfer, Marc
- Authors: Chikiwa, Clemence , Schäfer, Marc
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141087 , vital:37943 , https://doi.org/10.1080/18117295.2016.1228823
- Description: This paper reports on a study that investigated teacher code switching consistency and precision in multilingual secondary school mathematics classrooms in South Africa. Data was obtained through interviewing and observing five lessons of each of three mathematics teachers purposively selected from three township schools in the Eastern Cape Province. Elements of Gumperz and Mercer’s work on lesson categories and Dowling’s Domains of Mathematical Practice were used to analyse data. Results showed that code switching frequency in general was inconsistent across different lessons for the same teacher.
- Full Text:
- Date Issued: 2016
- Authors: Chikiwa, Clemence , Schäfer, Marc
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141087 , vital:37943 , https://doi.org/10.1080/18117295.2016.1228823
- Description: This paper reports on a study that investigated teacher code switching consistency and precision in multilingual secondary school mathematics classrooms in South Africa. Data was obtained through interviewing and observing five lessons of each of three mathematics teachers purposively selected from three township schools in the Eastern Cape Province. Elements of Gumperz and Mercer’s work on lesson categories and Dowling’s Domains of Mathematical Practice were used to analyse data. Results showed that code switching frequency in general was inconsistent across different lessons for the same teacher.
- Full Text:
- Date Issued: 2016
Teaching and Learning of ‘Water for Agriculture’in Primary Schools in Lesotho, South Africa and Zimbabwe
- Pesanayi, Tichaona V, Mashozhera, Farasten, Khitsane, Lintle
- Authors: Pesanayi, Tichaona V , Mashozhera, Farasten , Khitsane, Lintle
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387289 , vital:68222 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152741"
- Description: Teaching youths about the subject of water for agriculture is vital in southern Africa where climate adaptation is imperative. Fresh water is a critical natural resource experiencing dangerous scarcity globally, with climate change and variability being key drivers. Agriculture consumes most of the allocated water in most of the southern African countries, so this sector needs particular water harvesting and conservation education. The Food and Agriculture Organisation (FAO) reported that 93% of cultivated land in southern Africa was rain-fed at the beginning of the 21st century. Drought hinders effective agricultural practices in poor-rainfall areas and is a common feature in most southern African countries. Increasingly frequent drought events affect Lesotho, South Africa and Zimbabwe chronically due to climate variability and change. These three countries have school curricula that carry agricultural and sustainability learning to varying extents. Agriculture is taught as a science subject, and tends to be inclined towards normative technicist approaches at the expense of traditional and innovative sustainability practices. This omission in curriculum development and teaching may miss the opportunity to learn from lessons offered by these traditional and innovative systems that have demonstrated resilience to climate variability and change. This paper explores the opportunities and enablers of sustainability learning and relevance in the primary school agriculture curricula of these three countries. The paper argues for inclusion of sustainable agricultural water learning as an act of educational quality and relevance that reflects 21st century socio-ecological, agro-climate and socioeconomic challenges in southern Africa.
- Full Text:
- Date Issued: 2016
- Authors: Pesanayi, Tichaona V , Mashozhera, Farasten , Khitsane, Lintle
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387289 , vital:68222 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152741"
- Description: Teaching youths about the subject of water for agriculture is vital in southern Africa where climate adaptation is imperative. Fresh water is a critical natural resource experiencing dangerous scarcity globally, with climate change and variability being key drivers. Agriculture consumes most of the allocated water in most of the southern African countries, so this sector needs particular water harvesting and conservation education. The Food and Agriculture Organisation (FAO) reported that 93% of cultivated land in southern Africa was rain-fed at the beginning of the 21st century. Drought hinders effective agricultural practices in poor-rainfall areas and is a common feature in most southern African countries. Increasingly frequent drought events affect Lesotho, South Africa and Zimbabwe chronically due to climate variability and change. These three countries have school curricula that carry agricultural and sustainability learning to varying extents. Agriculture is taught as a science subject, and tends to be inclined towards normative technicist approaches at the expense of traditional and innovative sustainability practices. This omission in curriculum development and teaching may miss the opportunity to learn from lessons offered by these traditional and innovative systems that have demonstrated resilience to climate variability and change. This paper explores the opportunities and enablers of sustainability learning and relevance in the primary school agriculture curricula of these three countries. The paper argues for inclusion of sustainable agricultural water learning as an act of educational quality and relevance that reflects 21st century socio-ecological, agro-climate and socioeconomic challenges in southern Africa.
- Full Text:
- Date Issued: 2016
Technauriture as an Educational Tool in South Africa: translating to read across Africa
- Authors: Kaschula, Russell H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174865 , vital:42516 , https://njas.fi/njas/article/view/109
- Description: This article seeks to situate the importance of orality in southern African communities within the paradigm of Technauriture, that being the intersection of technology, auriture and literature and how it relates to imparting educational messages within South Africa in particular. The process of orality as allowed for through, for example oral histories, music, poetry and story-telling, and how it interacts with the recording process facilitated through modern technology, as well as the return of the oral material via technology in educational and archival circles is further explored in this article. The question which this article seeks to understand is how technology can contribute in the educational milieu.
- Full Text:
- Date Issued: 2016
- Authors: Kaschula, Russell H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174865 , vital:42516 , https://njas.fi/njas/article/view/109
- Description: This article seeks to situate the importance of orality in southern African communities within the paradigm of Technauriture, that being the intersection of technology, auriture and literature and how it relates to imparting educational messages within South Africa in particular. The process of orality as allowed for through, for example oral histories, music, poetry and story-telling, and how it interacts with the recording process facilitated through modern technology, as well as the return of the oral material via technology in educational and archival circles is further explored in this article. The question which this article seeks to understand is how technology can contribute in the educational milieu.
- Full Text:
- Date Issued: 2016
TeleWeaver: an architectural overview of a customised application server for rurality
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Gumbo, Sibukelo
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Gumbo, Sibukelo
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430624 , vital:72704 , 10.1109/ISTAFRICA.2016.7530616
- Description: The Siyakhula Living Lab in the rural Eastern Cape province of South Africa has been in existence for over a decade now. In this time, sever-al software artefacts have been developed by students and partners with the aim of providing contextually-relevant services to the rural community. However, reliance on different platforms and paradigms has meant that the deployment of such services would be difficult to implement and maintain reliably in actual practice. What is required is a single software platform that can act as a docking station for multiple applications, as well as a routing substrate for applications living inside and outside the platform. A candidate platform to enable this is currently being integrated under the codename Teleweaver and is built from a free, open source J2EE application server and integrates with other software components. This paper provides an architectural overview of the platform and demonstrates how it provides a sustainable context for application development going forward.
- Full Text:
- Date Issued: 2016
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Gumbo, Sibukelo
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430624 , vital:72704 , 10.1109/ISTAFRICA.2016.7530616
- Description: The Siyakhula Living Lab in the rural Eastern Cape province of South Africa has been in existence for over a decade now. In this time, sever-al software artefacts have been developed by students and partners with the aim of providing contextually-relevant services to the rural community. However, reliance on different platforms and paradigms has meant that the deployment of such services would be difficult to implement and maintain reliably in actual practice. What is required is a single software platform that can act as a docking station for multiple applications, as well as a routing substrate for applications living inside and outside the platform. A candidate platform to enable this is currently being integrated under the codename Teleweaver and is built from a free, open source J2EE application server and integrates with other software components. This paper provides an architectural overview of the platform and demonstrates how it provides a sustainable context for application development going forward.
- Full Text:
- Date Issued: 2016
Temperature-dependent performance and potential distribution of Pareuchaetes insulata, a biological control agent of Chromolaena odorata in South Africa
- Uyi, Osariyekemwen O, Zachariades, Costas, Hill, Martin P, McConnachie, Andrew J
- Authors: Uyi, Osariyekemwen O , Zachariades, Costas , Hill, Martin P , McConnachie, Andrew J
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418067 , vital:71505 , xlink:href="https://doi.org/10.1007/s10526-016-9760-1"
- Description: Despite the release of about 1.9 million individuals of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) in KwaZulu-Natal for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae) in South Africa, the moth probably only established at one of the 30 release sites and its population level is generally low in the field. To determine whether climate incompatibility in South Africa is responsible for the poor performance of P. insulata, the effects of temperature on life-history traits were investigated under several constant temperatures. Although a degree-day model estimated between 3.9 and 10.0 generations of the moth per year in the weed’s invaded range, survival and fecundity declined while development time was prolonged at constant temperatures below 25 °C, indicating that both direct and indirect negative impacts of low winter temperatures, such as increased mortality, slow development and reduced fecundity as well as exposure to natural enemies, may partly explain the poor performance of P. insulata in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Uyi, Osariyekemwen O , Zachariades, Costas , Hill, Martin P , McConnachie, Andrew J
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418067 , vital:71505 , xlink:href="https://doi.org/10.1007/s10526-016-9760-1"
- Description: Despite the release of about 1.9 million individuals of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) in KwaZulu-Natal for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae) in South Africa, the moth probably only established at one of the 30 release sites and its population level is generally low in the field. To determine whether climate incompatibility in South Africa is responsible for the poor performance of P. insulata, the effects of temperature on life-history traits were investigated under several constant temperatures. Although a degree-day model estimated between 3.9 and 10.0 generations of the moth per year in the weed’s invaded range, survival and fecundity declined while development time was prolonged at constant temperatures below 25 °C, indicating that both direct and indirect negative impacts of low winter temperatures, such as increased mortality, slow development and reduced fecundity as well as exposure to natural enemies, may partly explain the poor performance of P. insulata in South Africa.
- Full Text:
- Date Issued: 2016
The Bero Volcanic Complex: extension of the Paraná-Etendeka Igneous Province into SW Angola
- Marsh, Julian S, Swart, Roger S
- Authors: Marsh, Julian S , Swart, Roger S
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60763 , vital:27827 , https://www.sciencedirect.com/science/article/pii/S0377027316304176
- Description: An extension of the Etendeka-Paraná Igneous Province into SW Angola occurs as minor basalt lavas, intrusive gabbro sheets, minor mafic dykes and thick sheets and lava flows (with minor pyroclastics) of quartz latite composition This suite crops out along the eastern margin of the Cretaceous Namibe Basin in SW Angola. The quartz latites from one locality have been referred to informally as the Giraul volcanics but the name ‘Giraul’ has previously been used for Cretaceous conglomerates. We propose the name Bero Volcanic Complex for this suite of intrusive and extrusive rocks on the basis that the full compositional range of this diverse suite crops out along the Rio Bero. Major and trace element compositions and Sr-, Nd-, and Pb-isotopic compositions indicate that the basalts and gabbros are equivalent to the high-Ti Khumib/Urubici and Pitanga types from the Etendeka and Paraná. The basalts underlie the quartz latites which are cut by mafic dykes some of which are compositionally equivalent to the Paranapanema lavas in the Paraná. Five different geochemical types of high-Ti quartz latite are recognised amongst the silicic volcanics, 3 of which have very close geochemical affinities to the Ventura, Sarusas, and Khoraseb types of the northern Etendeka. Their relative stratigraphic position in the Bero volcanic sequence is the same as in the Etendeka sequence and extend significantly the area over which these types were erupted. The two remaining types, Chinguau and High-Nb are not known from either the Etendeka or the Paraná provinces.
- Full Text:
- Date Issued: 2016
- Authors: Marsh, Julian S , Swart, Roger S
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60763 , vital:27827 , https://www.sciencedirect.com/science/article/pii/S0377027316304176
- Description: An extension of the Etendeka-Paraná Igneous Province into SW Angola occurs as minor basalt lavas, intrusive gabbro sheets, minor mafic dykes and thick sheets and lava flows (with minor pyroclastics) of quartz latite composition This suite crops out along the eastern margin of the Cretaceous Namibe Basin in SW Angola. The quartz latites from one locality have been referred to informally as the Giraul volcanics but the name ‘Giraul’ has previously been used for Cretaceous conglomerates. We propose the name Bero Volcanic Complex for this suite of intrusive and extrusive rocks on the basis that the full compositional range of this diverse suite crops out along the Rio Bero. Major and trace element compositions and Sr-, Nd-, and Pb-isotopic compositions indicate that the basalts and gabbros are equivalent to the high-Ti Khumib/Urubici and Pitanga types from the Etendeka and Paraná. The basalts underlie the quartz latites which are cut by mafic dykes some of which are compositionally equivalent to the Paranapanema lavas in the Paraná. Five different geochemical types of high-Ti quartz latite are recognised amongst the silicic volcanics, 3 of which have very close geochemical affinities to the Ventura, Sarusas, and Khoraseb types of the northern Etendeka. Their relative stratigraphic position in the Bero volcanic sequence is the same as in the Etendeka sequence and extend significantly the area over which these types were erupted. The two remaining types, Chinguau and High-Nb are not known from either the Etendeka or the Paraná provinces.
- Full Text:
- Date Issued: 2016