Zimbabwe's Land Reform: myths and realities
- Authors: Helliker, Kirk D
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144710 , vital:38372 , DOI: 10.1080/02589001.2011.581502
- Description: Zimbabwe’s land reform is the first book on contemporary Zimbabwe that offers an empirically-rich and detailed account of redistributed farms that arose from ‘fasttrack’ land reform 10 years ago. In order to fully appreciate the significance of this book, it is necessary to outline briefly recent intellectual debates on Zimbabwe. Two main positions exist on Zimbabwean politics and society. The first position argues that the radical restructuring of agrarian relations (including undermining white agricultural capital and breaking up large commercial farms into smaller units) is a progressive tendency that has opened up opportunities for black small-scale farmers. Simultaneously, this position often underplays the existence of state restructuring of an authoritarian kind. The second position argues that land redistribution has dramatically undercut agricultural production thereby severely compromising food security for all Zimbabweans. It brings to the fore violent state action in instigating land occupations and in thwarting political opposition to ‘fast-track’.
- Full Text:
- Date Issued: 2011
- Authors: Helliker, Kirk D
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144710 , vital:38372 , DOI: 10.1080/02589001.2011.581502
- Description: Zimbabwe’s land reform is the first book on contemporary Zimbabwe that offers an empirically-rich and detailed account of redistributed farms that arose from ‘fasttrack’ land reform 10 years ago. In order to fully appreciate the significance of this book, it is necessary to outline briefly recent intellectual debates on Zimbabwe. Two main positions exist on Zimbabwean politics and society. The first position argues that the radical restructuring of agrarian relations (including undermining white agricultural capital and breaking up large commercial farms into smaller units) is a progressive tendency that has opened up opportunities for black small-scale farmers. Simultaneously, this position often underplays the existence of state restructuring of an authoritarian kind. The second position argues that land redistribution has dramatically undercut agricultural production thereby severely compromising food security for all Zimbabweans. It brings to the fore violent state action in instigating land occupations and in thwarting political opposition to ‘fast-track’.
- Full Text:
- Date Issued: 2011
When breast is not best: young women and breast reduction surgery
- Lamb, Tessa, Vincent, Louise
- Authors: Lamb, Tessa , Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141832 , vital:38008 , DOI: 10.1080/10130950.2011.610978
- Description: Most cosmetic surgery patients in South Africa are younger than 21, and in this focus we examine narrative accounts from young South African women who have chosen to undergo cosmetic breast reduction surgery. Feminist debates on cosmetic surgery have focused on the question of whether to regard women who modify their bodies in this way as active agents engaged in liberatory ‘body projects’, or whether such projects are evidence of their subjection to oppressive stereotypes and beauty norms. The latter perspective is challenged here by the participants’ characterisation of breast reduction surgery as profoundly ‘freeing’. The article deals in particular with the conscious choice of participants to knowingly risk not being able to breastfeed children in future in order to achieve a body type which conforms to their understanding of youthful beauty and sexuality.
- Full Text:
- Date Issued: 2011
- Authors: Lamb, Tessa , Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141832 , vital:38008 , DOI: 10.1080/10130950.2011.610978
- Description: Most cosmetic surgery patients in South Africa are younger than 21, and in this focus we examine narrative accounts from young South African women who have chosen to undergo cosmetic breast reduction surgery. Feminist debates on cosmetic surgery have focused on the question of whether to regard women who modify their bodies in this way as active agents engaged in liberatory ‘body projects’, or whether such projects are evidence of their subjection to oppressive stereotypes and beauty norms. The latter perspective is challenged here by the participants’ characterisation of breast reduction surgery as profoundly ‘freeing’. The article deals in particular with the conscious choice of participants to knowingly risk not being able to breastfeed children in future in order to achieve a body type which conforms to their understanding of youthful beauty and sexuality.
- Full Text:
- Date Issued: 2011
Water-soluble quaternized mercaptopyridine-substituted zinc-phthalocyanines
- Durmuş, Mahmut, Yaman, Hanif, Göl, Cem, Ahsen, Vefa, Nyokong, Tebello
- Authors: Durmuş, Mahmut , Yaman, Hanif , Göl, Cem , Ahsen, Vefa , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247133 , vital:51549 , xlink:href="https://doi.org/10.1016/j.dyepig.2011.02.007"
- Description: The synthesis and characterization of the new zinc phthalocyanine derivatives, tetra- (non-peripheral, 5) and octa-(peripheral, 6) substituted with 2-mercaptopyridine and their respective quaternized derivatives (8 and 9) are reported. Photochemical and photophysical properties of the new complexes are compared with those of the previously reported peripherally tetra-substituted complexes 7 and 10. The quaternized compounds exhibit excellent solubility in water, making them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. Spectroscopic, aggregation, photophysical and photochemical properties of these complexes are also investigated and compared. Photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yield) properties of these phthalocyanine photosensitizers are very important for the assessment of these complexes as PDT agents. In this study, the effects of the position of the substituents and quaternization of the substituents on the photophysical and photochemical parameters of the zinc phthalocyanines are also reported. This study also showed that the water-soluble quaternized zinc phthalocyanines strongly bind to blood plasma proteins such as bovine serum albumin (BSA).
- Full Text:
- Date Issued: 2011
- Authors: Durmuş, Mahmut , Yaman, Hanif , Göl, Cem , Ahsen, Vefa , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247133 , vital:51549 , xlink:href="https://doi.org/10.1016/j.dyepig.2011.02.007"
- Description: The synthesis and characterization of the new zinc phthalocyanine derivatives, tetra- (non-peripheral, 5) and octa-(peripheral, 6) substituted with 2-mercaptopyridine and their respective quaternized derivatives (8 and 9) are reported. Photochemical and photophysical properties of the new complexes are compared with those of the previously reported peripherally tetra-substituted complexes 7 and 10. The quaternized compounds exhibit excellent solubility in water, making them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. Spectroscopic, aggregation, photophysical and photochemical properties of these complexes are also investigated and compared. Photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yield) properties of these phthalocyanine photosensitizers are very important for the assessment of these complexes as PDT agents. In this study, the effects of the position of the substituents and quaternization of the substituents on the photophysical and photochemical parameters of the zinc phthalocyanines are also reported. This study also showed that the water-soluble quaternized zinc phthalocyanines strongly bind to blood plasma proteins such as bovine serum albumin (BSA).
- Full Text:
- Date Issued: 2011
Water chemistry and effect of evapotranspiration on chemical sedimentation on the Mkuze River floodplain, South Africa:
- Humphries, M S, Kindness, A, Ellery, William F N, Hughes, J C
- Authors: Humphries, M S , Kindness, A , Ellery, William F N , Hughes, J C
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144376 , vital:38340 , https://doi.org/10.1016/j.jaridenv.2011.01.013
- Description: The Mkuze Wetland System, forming part of the iSimangaliso World Heritage Site, is South Africa’s largest freshwater wetland area and is known to act as a sink for naturally occurring solutes within the landscape. The chemistry of groundwater and porewater samples, collected from two transects on the Mkuze River floodplain, was investigated to identify processes involved in the control of solute concentrations. Results show that solutes in the groundwater become increasingly concentrated under the influence of evapotranspiration, resulting in the saturation, precipitation, and accumulation of less soluble compounds.
- Full Text:
- Date Issued: 2011
- Authors: Humphries, M S , Kindness, A , Ellery, William F N , Hughes, J C
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144376 , vital:38340 , https://doi.org/10.1016/j.jaridenv.2011.01.013
- Description: The Mkuze Wetland System, forming part of the iSimangaliso World Heritage Site, is South Africa’s largest freshwater wetland area and is known to act as a sink for naturally occurring solutes within the landscape. The chemistry of groundwater and porewater samples, collected from two transects on the Mkuze River floodplain, was investigated to identify processes involved in the control of solute concentrations. Results show that solutes in the groundwater become increasingly concentrated under the influence of evapotranspiration, resulting in the saturation, precipitation, and accumulation of less soluble compounds.
- Full Text:
- Date Issued: 2011
Voltammetry and electrochemical impedance spectroscopy of gold electrodes modified with CdTe quantum dots and their conjugates with nickel tetraamino phthalocyanine
- Khene, Samson, Moeno, Sharon, Nyokong, Tebello
- Authors: Khene, Samson , Moeno, Sharon , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247187 , vital:51554 , xlink:href="https://doi.org/10.1016/j.poly.2011.06.002"
- Description: This work reports on the synthesis of conjugates of cadmium telluride quantum dots (CdTe-QDs) caped with thioglycolic acid and peripherally substituted nickel tetraamino phthalocyanine (NiTAPc) complex. The conjugates are characterized using cyclic (CV) and differential pulse (DPV) voltammetries, electrochemical impedance spectroscopy, X-ray powder diffraction, infrared spectroscopy, Raman spectroscopy, atomic force microscopy and time correlated single photon counting. CV and DPV show that NiTAPc stabilizes the CdTe QDs against oxidation to metallic products.
- Full Text:
- Date Issued: 2011
- Authors: Khene, Samson , Moeno, Sharon , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247187 , vital:51554 , xlink:href="https://doi.org/10.1016/j.poly.2011.06.002"
- Description: This work reports on the synthesis of conjugates of cadmium telluride quantum dots (CdTe-QDs) caped with thioglycolic acid and peripherally substituted nickel tetraamino phthalocyanine (NiTAPc) complex. The conjugates are characterized using cyclic (CV) and differential pulse (DPV) voltammetries, electrochemical impedance spectroscopy, X-ray powder diffraction, infrared spectroscopy, Raman spectroscopy, atomic force microscopy and time correlated single photon counting. CV and DPV show that NiTAPc stabilizes the CdTe QDs against oxidation to metallic products.
- Full Text:
- Date Issued: 2011
Violence, postcolonial fiction, and the limits of sympathy:
- Authors: Marais, Mike
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143993 , vital:38301 , DOI: 10.1353/sdn.2011.0034
- Description: In this article, I consider the implications for fiction of Slavo Zizek’s argument that the violence of individual subjects is informed by ‘symbolic violence’ (1-2), that is, the distortions concomitant on languages’s constitutive, rather than merely referential, relation to the world.
- Full Text:
- Date Issued: 2011
- Authors: Marais, Mike
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143993 , vital:38301 , DOI: 10.1353/sdn.2011.0034
- Description: In this article, I consider the implications for fiction of Slavo Zizek’s argument that the violence of individual subjects is informed by ‘symbolic violence’ (1-2), that is, the distortions concomitant on languages’s constitutive, rather than merely referential, relation to the world.
- Full Text:
- Date Issued: 2011
Use and users of municipal commonage around three small towns in the Eastern Cape, South Africa
- Davenport, Nicholas A, Shackleton, Charlie M, Gambiza, James
- Authors: Davenport, Nicholas A , Shackleton, Charlie M , Gambiza, James
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181116 , vital:43700 , xlink:href="https://doi.org/10.1016/j.jenvman.2010.11.003"
- Description: Municipal commonages surround many small towns throughout South Africa, and are an integral component of the national land reform programme. But little is known about their extent, use or value, and most appear to have limited or no management or investment. This paper reports on a survey of randomly selected households in three small towns in the Eastern Cape to ascertain the extent and purpose of use of municipal commonages. Between 27% and 70% of urban households used commonage depending on site. Key resources used were fuelwood, medicinal plants, and grazing of livestock. Typically, commonage using households were poorer and less educated than other urban residents, although the profile of users is unique for each town. Given the extensive use of commonage resources, and their contribution to the livelihoods of the poor, local municipalities need to develop and implement sound management strategies that account for all users of commonages, rather than the oft encountered focus on livestock owners and production.
- Full Text:
- Date Issued: 2011
- Authors: Davenport, Nicholas A , Shackleton, Charlie M , Gambiza, James
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181116 , vital:43700 , xlink:href="https://doi.org/10.1016/j.jenvman.2010.11.003"
- Description: Municipal commonages surround many small towns throughout South Africa, and are an integral component of the national land reform programme. But little is known about their extent, use or value, and most appear to have limited or no management or investment. This paper reports on a survey of randomly selected households in three small towns in the Eastern Cape to ascertain the extent and purpose of use of municipal commonages. Between 27% and 70% of urban households used commonage depending on site. Key resources used were fuelwood, medicinal plants, and grazing of livestock. Typically, commonage using households were poorer and less educated than other urban residents, although the profile of users is unique for each town. Given the extensive use of commonage resources, and their contribution to the livelihoods of the poor, local municipalities need to develop and implement sound management strategies that account for all users of commonages, rather than the oft encountered focus on livestock owners and production.
- Full Text:
- Date Issued: 2011
Theiler’s murine encephalomyelitis virus infection induces a redistribution of heat shock proteins 70 and 90 in BHK-21 cells, and is inhibited by novobiocin and geldanamycin:
- Mutsvunguma, Lorraine Z, Moetlhoa, Boitumelo, Edkins, Adrienne L, Luke, Garry A, Blatch, Gregory L, Knox, Caroline M
- Authors: Mutsvunguma, Lorraine Z , Moetlhoa, Boitumelo , Edkins, Adrienne L , Luke, Garry A , Blatch, Gregory L , Knox, Caroline M
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165085 , vital:41207 , DOI: 10.1007/s12192-011-0262-x
- Description: Theiler’s murine encephalomyelitis virus (TMEV) is a positive-sense RNA virus belonging to the Cardiovirus genus in the family Picornaviridae. In addition to other host cellular factors and pathways, picornaviruses utilise heat shock proteins (Hsps) to facilitate their propagation in cells. This study investigated the localisation of Hsps 70 and 90 in TMEV-infected BHK-21 cells by indirect immunofluorescence and confocal microscopy. The effect of Hsp90 inhibitors novobiocin (Nov) and geldanamycin (GA) on the development of cytopathic effect (CPE) induced by infection was also examined. Hsp90 staining was uniformly distributed in the cytoplasm of uninfected cells but was found concentrated in the perinuclear region during late infection where it overlapped with the signal for non-structural protein 2C within the viral replication complex.
- Full Text:
- Date Issued: 2011
- Authors: Mutsvunguma, Lorraine Z , Moetlhoa, Boitumelo , Edkins, Adrienne L , Luke, Garry A , Blatch, Gregory L , Knox, Caroline M
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165085 , vital:41207 , DOI: 10.1007/s12192-011-0262-x
- Description: Theiler’s murine encephalomyelitis virus (TMEV) is a positive-sense RNA virus belonging to the Cardiovirus genus in the family Picornaviridae. In addition to other host cellular factors and pathways, picornaviruses utilise heat shock proteins (Hsps) to facilitate their propagation in cells. This study investigated the localisation of Hsps 70 and 90 in TMEV-infected BHK-21 cells by indirect immunofluorescence and confocal microscopy. The effect of Hsp90 inhibitors novobiocin (Nov) and geldanamycin (GA) on the development of cytopathic effect (CPE) induced by infection was also examined. Hsp90 staining was uniformly distributed in the cytoplasm of uninfected cells but was found concentrated in the perinuclear region during late infection where it overlapped with the signal for non-structural protein 2C within the viral replication complex.
- Full Text:
- Date Issued: 2011
The ‘refeudalisation’ or the ‘return of the repressed’ of the public sphere?:
- Authors: Garman, Anthea
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159857 , vital:40350 , DOI: 10.1080/02560054.2011.621293
- Description: The prevalent depiction of the heyday of the public sphere and its fall from grace under present-day, publicity-ridden, highly commercialised media, with their individualised address of entertainment, is an inadequate conception of today's complex public spheres. The 18th-century bourgeois public sphere had a number of features – often repressed in practice and in theory – which were bound to have their outcomes and a/effects in the public spaces, practices and vehicles we experience today.
- Full Text:
- Date Issued: 2011
- Authors: Garman, Anthea
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159857 , vital:40350 , DOI: 10.1080/02560054.2011.621293
- Description: The prevalent depiction of the heyday of the public sphere and its fall from grace under present-day, publicity-ridden, highly commercialised media, with their individualised address of entertainment, is an inadequate conception of today's complex public spheres. The 18th-century bourgeois public sphere had a number of features – often repressed in practice and in theory – which were bound to have their outcomes and a/effects in the public spaces, practices and vehicles we experience today.
- Full Text:
- Date Issued: 2011
The use of experimental design in the development of an HPLC–ECD method for the analysis of captopril
- Khamanga, Sandile M, Walker, Roderick B
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184056 , vital:44163 , xlink:href="https://doi.org/10.1016/j.talanta.2010.11.025"
- Description: An accurate, sensitive and specific high performance liquid chromatography–electrochemical detection (HPLC–ECD) method that was developed and validated for captopril (CPT) is presented. Separation was achieved using a Phenomenex® Luna 5 μm (C18) column and a mobile phase comprised of phosphate buffer (adjusted to pH 3.0): acetonitrile in a ratio of 70:30 (v/v). Detection was accomplished using a full scan multi channel ESA Coulometric detector in the “oxidative-screen” mode with the upstream electrode (E1) set at +600 mV and the downstream (analytical) electrode (E2) set at +950 mV, while the potential of the guard cell was maintained at +1050 mV. The detector gain was set at 300. Experimental design using central composite design (CCD) was used to facilitate method development. Mobile phase pH, molarity and concentration of acetonitrile (ACN) were considered the critical factors to be studied to establish the retention time of CPT and cyclizine (CYC) that was used as the internal standard. Twenty experiments including centre points were undertaken and a quadratic model was derived for the retention time for CPT using the experimental data. The method was validated for linearity, accuracy, precision, limits of quantitation and detection, as per the ICH guidelines. The system was found to produce sharp and well-resolved peaks for CPT and CYC with retention times of 3.08 and 7.56 min, respectively. Linear regression analysis for the calibration curve showed a good linear relationship with a regression coefficient of 0.978 in the concentration range of 2–70 μg/mL. The linear regression equation was y = 0.0131x + 0.0275. The limits of detection (LOQ) and quantitation (LOD) were found to be 2.27 and 0.6 μg/mL, respectively. The method was used to analyze CPT in tablets. The wide range for linearity, accuracy, sensitivity, short retention time and composition of the mobile phase indicated that this method is better for the quantification of CPT than the pharmacopoeial methods.
- Full Text:
- Date Issued: 2011
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184056 , vital:44163 , xlink:href="https://doi.org/10.1016/j.talanta.2010.11.025"
- Description: An accurate, sensitive and specific high performance liquid chromatography–electrochemical detection (HPLC–ECD) method that was developed and validated for captopril (CPT) is presented. Separation was achieved using a Phenomenex® Luna 5 μm (C18) column and a mobile phase comprised of phosphate buffer (adjusted to pH 3.0): acetonitrile in a ratio of 70:30 (v/v). Detection was accomplished using a full scan multi channel ESA Coulometric detector in the “oxidative-screen” mode with the upstream electrode (E1) set at +600 mV and the downstream (analytical) electrode (E2) set at +950 mV, while the potential of the guard cell was maintained at +1050 mV. The detector gain was set at 300. Experimental design using central composite design (CCD) was used to facilitate method development. Mobile phase pH, molarity and concentration of acetonitrile (ACN) were considered the critical factors to be studied to establish the retention time of CPT and cyclizine (CYC) that was used as the internal standard. Twenty experiments including centre points were undertaken and a quadratic model was derived for the retention time for CPT using the experimental data. The method was validated for linearity, accuracy, precision, limits of quantitation and detection, as per the ICH guidelines. The system was found to produce sharp and well-resolved peaks for CPT and CYC with retention times of 3.08 and 7.56 min, respectively. Linear regression analysis for the calibration curve showed a good linear relationship with a regression coefficient of 0.978 in the concentration range of 2–70 μg/mL. The linear regression equation was y = 0.0131x + 0.0275. The limits of detection (LOQ) and quantitation (LOD) were found to be 2.27 and 0.6 μg/mL, respectively. The method was used to analyze CPT in tablets. The wide range for linearity, accuracy, sensitivity, short retention time and composition of the mobile phase indicated that this method is better for the quantification of CPT than the pharmacopoeial methods.
- Full Text:
- Date Issued: 2011
The synthesis and photophysical properties of peripherally and non-peripherally substituted ball-type Mg (II) and Zn (II) phthalocyanines
- Canlica, Mevlude, Nyokong, Tebello
- Authors: Canlica, Mevlude , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248417 , vital:51684 , xlink:href="https://doi.org/10.1039/C0DT00920B"
- Description: Newly synthesized ball-type Zn(II) and Mg(II) phthalocyanines containing four 1,1′-binaphthol substituents at peripheral and non-peripheral positions are presented. The structures of the synthesized compounds were characterized by using elemental analysis, UV-vis, FT-IR, 1H-NMR and mass spectroscopies. The ΦF values were 0.33, 0.08, 0.20 and 0.08 for 6–9, respectively. The ΦT values were 0.56, 0.85, 0.64 and 0.88 for 6–9, respectively. All the complexes showed reasonably large triplet lifetimes with τT values of 710 (6), 170 (7), 1490 (8) and 380 μs (9) in DMSO. These complexes offer potential as photosensitizers in photodynamic therapy.
- Full Text:
- Date Issued: 2011
- Authors: Canlica, Mevlude , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248417 , vital:51684 , xlink:href="https://doi.org/10.1039/C0DT00920B"
- Description: Newly synthesized ball-type Zn(II) and Mg(II) phthalocyanines containing four 1,1′-binaphthol substituents at peripheral and non-peripheral positions are presented. The structures of the synthesized compounds were characterized by using elemental analysis, UV-vis, FT-IR, 1H-NMR and mass spectroscopies. The ΦF values were 0.33, 0.08, 0.20 and 0.08 for 6–9, respectively. The ΦT values were 0.56, 0.85, 0.64 and 0.88 for 6–9, respectively. All the complexes showed reasonably large triplet lifetimes with τT values of 710 (6), 170 (7), 1490 (8) and 380 μs (9) in DMSO. These complexes offer potential as photosensitizers in photodynamic therapy.
- Full Text:
- Date Issued: 2011
The synthesis and fluorescence behaviour of new unsymmetrically mono-functionalized carboxy Ge, Ti and Sn phthalocynines
- Masilela, Nkosiphile, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246977 , vital:51534 , xlink:href="https://doi.org/10.1016/j.dyepig.2011.03.026"
- Description: This work reports on the synthesis and fluorescence behaviour of novel unsymmetrically substituted monocarboxy germanium ((OH)2GeMCPc, 3), titanium (OTiMCPc 4) and tin ((ac)2SnMCPc, 5) phthalocyanines. The fluorescence quantum yields ranged from 0.09 to 0.14. The fluorescence lifetimes were found to be higher for the complex with higher fluorescence quantum yield value. Higher fluorescence quantum yields and lifetimes were obtained for the (ac)2SnMCPc complex (5), followed by OTiMCPc complex (4), and the lowest fluorescence quantum yield and lifetime were observed for (OH)2GeMCPc (3).
- Full Text:
- Date Issued: 2011
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246977 , vital:51534 , xlink:href="https://doi.org/10.1016/j.dyepig.2011.03.026"
- Description: This work reports on the synthesis and fluorescence behaviour of novel unsymmetrically substituted monocarboxy germanium ((OH)2GeMCPc, 3), titanium (OTiMCPc 4) and tin ((ac)2SnMCPc, 5) phthalocyanines. The fluorescence quantum yields ranged from 0.09 to 0.14. The fluorescence lifetimes were found to be higher for the complex with higher fluorescence quantum yield value. Higher fluorescence quantum yields and lifetimes were obtained for the (ac)2SnMCPc complex (5), followed by OTiMCPc complex (4), and the lowest fluorescence quantum yield and lifetime were observed for (OH)2GeMCPc (3).
- Full Text:
- Date Issued: 2011
The role of eutrophication in the biological control of water hyacinth, Eichhornia crassipes, in South Africa
- Coetzee, Julie A, Hill, Martin P
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
- Authors: Coetzee, Julie A , Hill, Martin P
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69263 , vital:29474 , https://doi.org/10.1007/s10526-011-9426-y
- Description: South Africa has some of the most eutrophic aquatic systems in the world, as a result of the adoption of an unnecessarily high 1 mg l-1 phosphorus (P) standard for all water treatment works in the 1970 s. The floating aquatic macrophyte, water hyacinth (Eichhornia crassipes (Mart.) Solms (Pontederiaceae), has taken advantage of these nutrient rich systems, becoming highly invasive and damaging. Despite the implementation of a biological control programme in South Africa, water hyacinth remains the worst aquatic weed. A meta-analysis of published and unpublished laboratory studies that investigated the combined effect of P and nitrogen (N) water nutrient concentration and control agent herbivory showed that water nutrient status was more important than herbivory in water hyacinth growth. Analysis of long-term field data collected monthly from 14 sites around South Africa between 2004 and 2005 supported these findings. Therefore, the first step in any water hyacinth control programme should be to reduce the nutrient status of the water body.
- Full Text:
- Date Issued: 2011
The problems of proving actual or apparent bias: an analysis of contemporary developments in South Africa
- Okpaluba, Chuks, Juma, Laurence
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127498 , vital:36017 , https://doi.org/10.17159/1727-3781/2011/v14i7a2616
- Description: This article takes a critical look at the divergent approaches of courts in constructing the meaning of actual and apparent bias in adjudicative contexts. It argues that while proving actual bias on the part of an adjudicator may not always be easy and parties often revert to apprehended bias, an allegation of bias in any adjudication process is a matter that courts take very seriously. This notwithstanding, the courts have failed to consistently demarcate the necessary elements and threshold of proof that complainants must overcome to secure a successful challenge of decisions based on adjudicative impartiality. Upon critical evaluation of the decisions on the subject so far rendered, this article suggests that the pattern which has seemingly emerged is that which weighs the allegations of bias against the presumption of impartiality and the requirements of the double reasonableness test.
- Full Text:
- Date Issued: 2011
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127498 , vital:36017 , https://doi.org/10.17159/1727-3781/2011/v14i7a2616
- Description: This article takes a critical look at the divergent approaches of courts in constructing the meaning of actual and apparent bias in adjudicative contexts. It argues that while proving actual bias on the part of an adjudicator may not always be easy and parties often revert to apprehended bias, an allegation of bias in any adjudication process is a matter that courts take very seriously. This notwithstanding, the courts have failed to consistently demarcate the necessary elements and threshold of proof that complainants must overcome to secure a successful challenge of decisions based on adjudicative impartiality. Upon critical evaluation of the decisions on the subject so far rendered, this article suggests that the pattern which has seemingly emerged is that which weighs the allegations of bias against the presumption of impartiality and the requirements of the double reasonableness test.
- Full Text:
- Date Issued: 2011
The PINIT domain of PIAS3: structure-function analysis of its interaction with STAT3
- Mautsa, Nicodemus, Prinsloo, Earl, Tastan Bishop, Özlem, Blatch, Gregory L
- Authors: Mautsa, Nicodemus , Prinsloo, Earl , Tastan Bishop, Özlem , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148082 , vital:38708 , DOI: 10.1002/jmr.1111
- Description: The protein inhibitor of activated signal transducer and activator of transcription 3 (PIAS3) regulates the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) which regulates transcription of genes involved in cell growth, proliferation and apoptosis. The conserved proline, isoleucine, asparagine, isoleucine, threonine (PINIT) domain of PIAS3 is thought to promote STAT3–PIAS3 interaction.
- Full Text:
- Date Issued: 2011
- Authors: Mautsa, Nicodemus , Prinsloo, Earl , Tastan Bishop, Özlem , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148082 , vital:38708 , DOI: 10.1002/jmr.1111
- Description: The protein inhibitor of activated signal transducer and activator of transcription 3 (PIAS3) regulates the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) which regulates transcription of genes involved in cell growth, proliferation and apoptosis. The conserved proline, isoleucine, asparagine, isoleucine, threonine (PINIT) domain of PIAS3 is thought to promote STAT3–PIAS3 interaction.
- Full Text:
- Date Issued: 2011
The origin and development of the Nyl River floodplain wetland, Limpopo Province, South Africa: trunk–tributary river interactions in a dryland setting
- McCarthy, T S, Tooth, Stephen, Jacobs, Zenobia, Rowberry, Matthew D, Thompson, Mark, Brandt, Dion, Hancox, P John, Marren, Philip M, Woodborne, Stephan, Ellery, William F N
- Authors: McCarthy, T S , Tooth, Stephen , Jacobs, Zenobia , Rowberry, Matthew D , Thompson, Mark , Brandt, Dion , Hancox, P John , Marren, Philip M , Woodborne, Stephan , Ellery, William F N
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144321 , vital:38331 , DOI: 10.1080/03736245.2011.619324
- Description: The Nyl River floodplain wetland, one of South Africa's largest floodplain wetlands and a Ramsar site of international conservation importance, is located in an area of long-term and still active valley sediment accumulation. Creation of accommodation space for sedimentation has previously been attributed to tectonic controls, but new investigations reveal that a more likely cause is progradation of coarse-grained tributary fans across the narrow river valley downstream of the main area of floodplain wetland. Obstruction of trunk river flow and sediment transfer by these tributary fans has led to backponding and upstream gradient reduction and to accumulation of valley fills up to ∼35 m thick. Chronological control for the timing and rate of sediment accumulation is limited, but we hypothesise that a semi-arid to arid climate, characterised by asynchronous trunk–tributary activity that results in marked discontinuities in downstream water and sediment transfer, is likely to have been a key control. These interpretations are supported by other studies of dryland rivers globally and the findings add to our growing understanding of the controls on the origin and development of southern African wetlands, particularly by demonstrating how the combination of a particular physiography and a dryland climate can impart some distinctive geomorphological characteristics.
- Full Text:
- Date Issued: 2011
- Authors: McCarthy, T S , Tooth, Stephen , Jacobs, Zenobia , Rowberry, Matthew D , Thompson, Mark , Brandt, Dion , Hancox, P John , Marren, Philip M , Woodborne, Stephan , Ellery, William F N
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144321 , vital:38331 , DOI: 10.1080/03736245.2011.619324
- Description: The Nyl River floodplain wetland, one of South Africa's largest floodplain wetlands and a Ramsar site of international conservation importance, is located in an area of long-term and still active valley sediment accumulation. Creation of accommodation space for sedimentation has previously been attributed to tectonic controls, but new investigations reveal that a more likely cause is progradation of coarse-grained tributary fans across the narrow river valley downstream of the main area of floodplain wetland. Obstruction of trunk river flow and sediment transfer by these tributary fans has led to backponding and upstream gradient reduction and to accumulation of valley fills up to ∼35 m thick. Chronological control for the timing and rate of sediment accumulation is limited, but we hypothesise that a semi-arid to arid climate, characterised by asynchronous trunk–tributary activity that results in marked discontinuities in downstream water and sediment transfer, is likely to have been a key control. These interpretations are supported by other studies of dryland rivers globally and the findings add to our growing understanding of the controls on the origin and development of southern African wetlands, particularly by demonstrating how the combination of a particular physiography and a dryland climate can impart some distinctive geomorphological characteristics.
- Full Text:
- Date Issued: 2011
The next decade of environmental science in South Africa: a horizon scan
- Shackleton, Charlie M, Scholes, Robert J, Vogel, Coleen, Wynberg, Rachel, Abrahamse, Tanya, Shackleton, Sheona E, Ellery, William F N, Gambiza, James
- Authors: Shackleton, Charlie M , Scholes, Robert J , Vogel, Coleen , Wynberg, Rachel , Abrahamse, Tanya , Shackleton, Sheona E , Ellery, William F N , Gambiza, James
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157124 , vital:40088 , https://doi.org/10.1080/03736245.2011.563064
- Description: Environmental systems are in constant flux, with feedbacks and non-linearities catalysed by natural trends and shocks as well as human actions. This poses challenges for sustainable management to promote human well-being. It requires environmental understanding and application that can accommodate such fluxes and pressures, as well as knowledge production systems and institutions that produce graduates with appropriate skills. In this article we consider these challenges in the South African context. Firstly, we summarise six significant environmental realisations from the last decade of environmental science internationally and question what they mean for the teaching of environmental science and research into environmental systems in South Africa in the near future. We then consider these lessons within the context of a horizon scan of near-term pressing environmental issues in South Africa. These include wateruse efficiency, poverty, food security, inequities in land and resource access, urbanisation, agrochemicals and water quality, promoting human well-being and economic adaptability in the face of climate change, and imbuing stronger environmental elements and stewardship into the integrated development planning processes and outcomes. Lastly, we consider the knowledge areas and skills that environmental graduates will require to be able to confront these problems in South Africa and simultaneously contribute to international debates and understandings around the complexity of environmental systems and how to manage them.
- Full Text:
- Date Issued: 2011
- Authors: Shackleton, Charlie M , Scholes, Robert J , Vogel, Coleen , Wynberg, Rachel , Abrahamse, Tanya , Shackleton, Sheona E , Ellery, William F N , Gambiza, James
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157124 , vital:40088 , https://doi.org/10.1080/03736245.2011.563064
- Description: Environmental systems are in constant flux, with feedbacks and non-linearities catalysed by natural trends and shocks as well as human actions. This poses challenges for sustainable management to promote human well-being. It requires environmental understanding and application that can accommodate such fluxes and pressures, as well as knowledge production systems and institutions that produce graduates with appropriate skills. In this article we consider these challenges in the South African context. Firstly, we summarise six significant environmental realisations from the last decade of environmental science internationally and question what they mean for the teaching of environmental science and research into environmental systems in South Africa in the near future. We then consider these lessons within the context of a horizon scan of near-term pressing environmental issues in South Africa. These include wateruse efficiency, poverty, food security, inequities in land and resource access, urbanisation, agrochemicals and water quality, promoting human well-being and economic adaptability in the face of climate change, and imbuing stronger environmental elements and stewardship into the integrated development planning processes and outcomes. Lastly, we consider the knowledge areas and skills that environmental graduates will require to be able to confront these problems in South Africa and simultaneously contribute to international debates and understandings around the complexity of environmental systems and how to manage them.
- Full Text:
- Date Issued: 2011
The nature of geometry instruction and observed learning-outcomes opportunities in Nigerian and South African high schools:
- Atebe, Humphrey U, Schäfer, Marc
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140919 , vital:37929 , DOI: 10.1080/10288457.2011.10740712
- Description: The purpose of this qualitative case study involving six secondary school teachers was to obtain insight into how geometry is taught in selected Nigerian and South African high schools. It also aimed, by making use of the van Hiele model of geometry instruction, to elucidate what possible learning opportunities observed instructional methods could offer learners in the subject. The sample comprised three mathematics teachers from Nigeria and three mathematics teachers from South Africa, all of whom were selected using purposive sampling techniques. Instructional activities in six geometry classrooms were recorded on videotape. The van Hiele learning phases provided the framework for data analysis. The findings of this study indicate that observed teaching methods in geometry classrooms in the participating schools offer learners scant opportunity to learn geometry.
- Full Text:
- Date Issued: 2013
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140919 , vital:37929 , DOI: 10.1080/10288457.2011.10740712
- Description: The purpose of this qualitative case study involving six secondary school teachers was to obtain insight into how geometry is taught in selected Nigerian and South African high schools. It also aimed, by making use of the van Hiele model of geometry instruction, to elucidate what possible learning opportunities observed instructional methods could offer learners in the subject. The sample comprised three mathematics teachers from Nigeria and three mathematics teachers from South Africa, all of whom were selected using purposive sampling techniques. Instructional activities in six geometry classrooms were recorded on videotape. The van Hiele learning phases provided the framework for data analysis. The findings of this study indicate that observed teaching methods in geometry classrooms in the participating schools offer learners scant opportunity to learn geometry.
- Full Text:
- Date Issued: 2013
The nature and quality of the mathematical connections teachers make:
- Mhlolo, Michael K, Schäfer, Marc, Venkat, Hamsa
- Authors: Mhlolo, Michael K , Schäfer, Marc , Venkat, Hamsa
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140893 , vital:37927 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC120887
- Description: Current reforms in mathematics education emphasise the need for pedagogy because it offers learners opportunities to develop their proficiency with complex high-level cognitive processes. One has always associated the ability to make mathematical connections, together with the teacher's role in teaching them, with deep mathematical understanding. This article examines the nature and quality of the mathematical connections that the teachers' representations of those connections enabled or constrained. The researchers made video recordings of four Grade 11 teachers as they taught a series of five lessons on algebra-related topics. The results showed that the teachers' representations of mathematical connections were either faulty or superficial in most cases. It compromised the learners' opportunities for making meaningful mathematical connections. The researchers concluded by suggesting that helping teachers to build their representation repertoires could increase the effectiveness of their instructional practices.
- Full Text:
- Date Issued: 2012
- Authors: Mhlolo, Michael K , Schäfer, Marc , Venkat, Hamsa
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140893 , vital:37927 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC120887
- Description: Current reforms in mathematics education emphasise the need for pedagogy because it offers learners opportunities to develop their proficiency with complex high-level cognitive processes. One has always associated the ability to make mathematical connections, together with the teacher's role in teaching them, with deep mathematical understanding. This article examines the nature and quality of the mathematical connections that the teachers' representations of those connections enabled or constrained. The researchers made video recordings of four Grade 11 teachers as they taught a series of five lessons on algebra-related topics. The results showed that the teachers' representations of mathematical connections were either faulty or superficial in most cases. It compromised the learners' opportunities for making meaningful mathematical connections. The researchers concluded by suggesting that helping teachers to build their representation repertoires could increase the effectiveness of their instructional practices.
- Full Text:
- Date Issued: 2012
The laws of Lerotholi: role and status of codified rules of custom in the kingdom of Lesotho
- Authors: Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/128810 , vital:36162 , https://heinonline.org/HOL/P?h=hein.journals/pacinlwr23ampi=94
- Description: The status of customary law in African societies is diminished by factors, most of which are generated by the machinery of the modern state. But its mantle, kept alive by neo-traditional scholarship and a commitment to multiculturalism in the post-independence era, has nevertheless sustained an active discussion on its relevance to the future of law and the general administration of justice in African states.2
- Full Text:
- Date Issued: 2011
- Authors: Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/128810 , vital:36162 , https://heinonline.org/HOL/P?h=hein.journals/pacinlwr23ampi=94
- Description: The status of customary law in African societies is diminished by factors, most of which are generated by the machinery of the modern state. But its mantle, kept alive by neo-traditional scholarship and a commitment to multiculturalism in the post-independence era, has nevertheless sustained an active discussion on its relevance to the future of law and the general administration of justice in African states.2
- Full Text:
- Date Issued: 2011