Perceptions and preferences for urban trees across multiple socio-economic contexts in the Eastern Cape, South Africa
- Gwedla, Nanamhla, Shackleton, Charlie M
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177419 , vital:42820 , https://doi.org/10.1016/j.landurbplan.2019.05.001
- Description: Urban trees are vital components of urban ecosystems, and thus important for environmental quality, urban sustainability, and quality of life in cities. Regrettably, urban trees are sometimes unequally distributed both between and within towns, a pattern largely associated with differences in the social environment of cities and historical patterns of development, and the dearth in strategic management plans and systematic monitoring of the existing urban forest. Most management plans focus on ecological and arboricultural aspects at the expense of the social, and studies examining perceptions in relation urban forests are largely from developed countries. Accordingly, we conducted a study to examine the perceptions and preferences regarding urban trees of 1200 residents from 10 urban areas across multiple socio-economic contexts in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177419 , vital:42820 , https://doi.org/10.1016/j.landurbplan.2019.05.001
- Description: Urban trees are vital components of urban ecosystems, and thus important for environmental quality, urban sustainability, and quality of life in cities. Regrettably, urban trees are sometimes unequally distributed both between and within towns, a pattern largely associated with differences in the social environment of cities and historical patterns of development, and the dearth in strategic management plans and systematic monitoring of the existing urban forest. Most management plans focus on ecological and arboricultural aspects at the expense of the social, and studies examining perceptions in relation urban forests are largely from developed countries. Accordingly, we conducted a study to examine the perceptions and preferences regarding urban trees of 1200 residents from 10 urban areas across multiple socio-economic contexts in South Africa.
- Full Text:
- Date Issued: 2019
Pereskiophaga brasiliensis, a natural enemy of the invasive alien cactus Pereskia aculeata, is not suitably host specific for biological control in South Africa
- Paterson, Iain D, Muskett, Phillipa A, Mdodana, LL, Vitorino, M D
- Authors: Paterson, Iain D , Muskett, Phillipa A , Mdodana, LL , Vitorino, M D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417498 , vital:71458 , xlink:href="https://doi.org/10.1080/09583157.2019.1581132"
- Description: The stem-mining weevil, Pereskiophaga brasiliensis, was a candidate biological control agent for the invasive cactus Pereskia aculeata in South Africa. In host specificity trials, it developed on two indigenous test plant species under choice and no-choice conditions. Pereskiophaga brasiliensis is therefore not suitably host specific for release in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Paterson, Iain D , Muskett, Phillipa A , Mdodana, LL , Vitorino, M D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417498 , vital:71458 , xlink:href="https://doi.org/10.1080/09583157.2019.1581132"
- Description: The stem-mining weevil, Pereskiophaga brasiliensis, was a candidate biological control agent for the invasive cactus Pereskia aculeata in South Africa. In host specificity trials, it developed on two indigenous test plant species under choice and no-choice conditions. Pereskiophaga brasiliensis is therefore not suitably host specific for release in South Africa.
- Full Text:
- Date Issued: 2019
Perspectives in coastal human ecology (CHE) for marine conservation
- Authors: Aswani, Shankar
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125576 , vital:35797 , https://doi.10.1016/j.biocon.2019.05.047
- Description: Coastal human ecology (CHE) is a mixture of different theoretical and thematic approaches straddling between the humanities and social and natural sciences which studies human and coastal/marine interactions at the local-scale and through intense fieldwork. Topics of interest include human coastal adaptations past and present; the historical ecology of fisheries and future implications; local forms of marine governance and economic systems; local food security and livelihoods, and indigenous/local ecological knowledge systems among many research themes. In this paper, I explore different strands of CHE in the study of tribal, artisanal, and small-scale industrial fisheries from the mid-90s onward that can contribute to the foundational knowledge necessary for designing and implementing successful coastal fisheries management and conservation programs. Marine conservation has often failed due to a lack of understanding of the fine grained marine human-environmental interactions at the local scale. In this context, I also examine developing and future research directions in CHE, and discuss their potential contribution for filling the gap in existing approaches to actionable scholarship in marine conservation. The strength of many CHE approaches lies in their potential for bridging humanism and natural science, and thus CHE approaches are well equipped to address many of the challenges faced by marine conservation practitioners today.
- Full Text:
- Date Issued: 2019
- Authors: Aswani, Shankar
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125576 , vital:35797 , https://doi.10.1016/j.biocon.2019.05.047
- Description: Coastal human ecology (CHE) is a mixture of different theoretical and thematic approaches straddling between the humanities and social and natural sciences which studies human and coastal/marine interactions at the local-scale and through intense fieldwork. Topics of interest include human coastal adaptations past and present; the historical ecology of fisheries and future implications; local forms of marine governance and economic systems; local food security and livelihoods, and indigenous/local ecological knowledge systems among many research themes. In this paper, I explore different strands of CHE in the study of tribal, artisanal, and small-scale industrial fisheries from the mid-90s onward that can contribute to the foundational knowledge necessary for designing and implementing successful coastal fisheries management and conservation programs. Marine conservation has often failed due to a lack of understanding of the fine grained marine human-environmental interactions at the local scale. In this context, I also examine developing and future research directions in CHE, and discuss their potential contribution for filling the gap in existing approaches to actionable scholarship in marine conservation. The strength of many CHE approaches lies in their potential for bridging humanism and natural science, and thus CHE approaches are well equipped to address many of the challenges faced by marine conservation practitioners today.
- Full Text:
- Date Issued: 2019
Photo-physicochemical properties and in vitro photodynamic therapy activity of morpholine-substituted Zinc (II)-Phthalocyanines π-π stacked on biotinylated graphene quantum dots
- Nene, Lindokuhle, Managa, Muthumuni, Nyokong, Tebello
- Authors: Nene, Lindokuhle , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186993 , vital:44554 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.03.002"
- Description: Two morpholine-substituted Zn(II) phthalocyanines, complex 4 and the cationic 5, were synthesized and conjugated to graphene quantum dots (GQDs) and biotinylated GQDs (GQDs-biotin) by non-covalent π-π interactions. The GQDs-biotin are prepared as potential nanoparticle-based Pc delivery vector combined with a receptor-mediated transport system using biotin. The photo-physicochemical properties of the Pc complexes and their corresponding conjugates were studied. Upon conjugation, the fluorescence quantum yields decrease for 4 and 5, however, the triplet quantum yields were increased for the conjugates. All samples demonstrated singlet oxygen generation. For conjugated complexes, the singlet quantum yields decreased due to the screening effect in some cases. An increase in the photodynamic therapy activities upon quaternization was observed for the conjugates, with the cell viability decreasing from 66.2% to 51.2% after treatment for 4-GQDs and 5-GQDs, respectively. A relatively better performance was also observed for the cationic complex in combination with the biotin functionalized GQDs, 5-GQDs-biotin, where the cell viability was 34.9% after treatment. Moreover, the cellular uptake of 5-GQDs-biotin over 24 h was relatively higher compared to Pc complex alone and other PcsGQDs conjugates.
- Full Text:
- Date Issued: 2019
- Authors: Nene, Lindokuhle , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186993 , vital:44554 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.03.002"
- Description: Two morpholine-substituted Zn(II) phthalocyanines, complex 4 and the cationic 5, were synthesized and conjugated to graphene quantum dots (GQDs) and biotinylated GQDs (GQDs-biotin) by non-covalent π-π interactions. The GQDs-biotin are prepared as potential nanoparticle-based Pc delivery vector combined with a receptor-mediated transport system using biotin. The photo-physicochemical properties of the Pc complexes and their corresponding conjugates were studied. Upon conjugation, the fluorescence quantum yields decrease for 4 and 5, however, the triplet quantum yields were increased for the conjugates. All samples demonstrated singlet oxygen generation. For conjugated complexes, the singlet quantum yields decreased due to the screening effect in some cases. An increase in the photodynamic therapy activities upon quaternization was observed for the conjugates, with the cell viability decreasing from 66.2% to 51.2% after treatment for 4-GQDs and 5-GQDs, respectively. A relatively better performance was also observed for the cationic complex in combination with the biotin functionalized GQDs, 5-GQDs-biotin, where the cell viability was 34.9% after treatment. Moreover, the cellular uptake of 5-GQDs-biotin over 24 h was relatively higher compared to Pc complex alone and other PcsGQDs conjugates.
- Full Text:
- Date Issued: 2019
Photophysical and enhanced nonlinear optical response in asymmetric benzothiazole substituted phthalocyanine covalently linked to semiconductor quantum dots
- Nwaji, Njemuwa, Dingiswayo, Somila, Mack, John, Nyokong, Tebello
- Authors: Nwaji, Njemuwa , Dingiswayo, Somila , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187851 , vital:44703 , xlink:href="https://doi.org/10.1016/j.saa.2018.06.098"
- Description: The synthesis of asymmetric benzothiazole substituted phthalocyanines (complexes 3 to 5) and their covalent attachment to glutathione (GSH) functionalized quantum dots (QDs) are reported in this work. Additionally, their photophysical and nonlinear optical properties were investigated. A decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield was observed when the complexes were covalently linked to glutathione (GSH) functionalized cadmium telluride (CdTe) quantum dots. Reverse saturable absorption was found to be predominantly dominated by excited state absorption. The observed limiting threshold values range from 0.29–0.75 J/cm2.
- Full Text:
- Date Issued: 2019
- Authors: Nwaji, Njemuwa , Dingiswayo, Somila , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187851 , vital:44703 , xlink:href="https://doi.org/10.1016/j.saa.2018.06.098"
- Description: The synthesis of asymmetric benzothiazole substituted phthalocyanines (complexes 3 to 5) and their covalent attachment to glutathione (GSH) functionalized quantum dots (QDs) are reported in this work. Additionally, their photophysical and nonlinear optical properties were investigated. A decrease in the fluorescence quantum yield with corresponding increase in the triplet quantum yield was observed when the complexes were covalently linked to glutathione (GSH) functionalized cadmium telluride (CdTe) quantum dots. Reverse saturable absorption was found to be predominantly dominated by excited state absorption. The observed limiting threshold values range from 0.29–0.75 J/cm2.
- Full Text:
- Date Issued: 2019
Photophysical and nonlinear optical characteristics of pyridyl substituted phthalocyanine-detonation nanodiamond conjugated systems in solution
- Matshitse, Refilwe, Khene, Samson M, Nyokong, Tebello
- Authors: Matshitse, Refilwe , Khene, Samson M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187079 , vital:44563 , xlink:href="https://doi.org/10.1016/j.diamond.2019.03.013"
- Description: In this study photophysical, nonlinear absorption and optical limiting properties of detonation nanodiamonds (DNDs)-phthalocyanine nanoconjugate systems containing: 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyaninato (H2TPPc), 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyanato zinc(II) (ZnTPPc) and 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyanato silicon(IV) hydroxide (Si(OH)2TPPc), were investigated in dimethylsulfoxide solution. Pcs were non-covalently linked to nanondiamonds (also covalently linked for Si(OH)2TPPc) and investigated using 532 nm laser excitation at 10 ns pulses for their optical limiting properties. Complexes that have higher triplet state absorption also possessed enhanced nonlinear optical behaviour following reverse saturable absorption mechanism. Superior optical performance is observed when the Pcs had a central metal with axial ligands conjugated to DNDs in solution. Nanoconjugate of DNDs-Si(OH)2TPPc and respective Pc in solution gave the highest imaginary third-order susceptibility (Im[X(3)]) and hyperpolarizability (γ) at 2.91 × 10−8 and 3.17 × 10−8 esu and 3.88 × 10−28 and 4.22 × 10−28 esu, respectively, with Ilim value of 0.47 and 0.39 J·cm−2.
- Full Text:
- Date Issued: 2019
- Authors: Matshitse, Refilwe , Khene, Samson M , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187079 , vital:44563 , xlink:href="https://doi.org/10.1016/j.diamond.2019.03.013"
- Description: In this study photophysical, nonlinear absorption and optical limiting properties of detonation nanodiamonds (DNDs)-phthalocyanine nanoconjugate systems containing: 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyaninato (H2TPPc), 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyanato zinc(II) (ZnTPPc) and 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyanato silicon(IV) hydroxide (Si(OH)2TPPc), were investigated in dimethylsulfoxide solution. Pcs were non-covalently linked to nanondiamonds (also covalently linked for Si(OH)2TPPc) and investigated using 532 nm laser excitation at 10 ns pulses for their optical limiting properties. Complexes that have higher triplet state absorption also possessed enhanced nonlinear optical behaviour following reverse saturable absorption mechanism. Superior optical performance is observed when the Pcs had a central metal with axial ligands conjugated to DNDs in solution. Nanoconjugate of DNDs-Si(OH)2TPPc and respective Pc in solution gave the highest imaginary third-order susceptibility (Im[X(3)]) and hyperpolarizability (γ) at 2.91 × 10−8 and 3.17 × 10−8 esu and 3.88 × 10−28 and 4.22 × 10−28 esu, respectively, with Ilim value of 0.47 and 0.39 J·cm−2.
- Full Text:
- Date Issued: 2019
Photophysical properties and photodynamic therapy activities of detonated nanodiamonds-BODIPY-phthalocyanines nanoassemblies
- Matshitse, Refilwe, Ngoy, Bokolombe P, Managa, Muthumuni, Mack, John, Nyokong, Tebello
- Authors: Matshitse, Refilwe , Ngoy, Bokolombe P , Managa, Muthumuni , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186981 , vital:44553 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.03.007"
- Description: This work reports on the synthesis of nanoassemblies of supramolecular hybrids containing detonated nanodiamonds (DNDs) covalently linked to halogenated BODIPY (DNDs-BODIPY) by an amide bond, followed by π–π stacking of 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]-phthalocyanine (ZnTPPcQ) on the DNDs-BODIPY conjugate, to form nanoassembly represented as ZnTPPcQ-DNDs-BODIPY. ZnTPPcQ-DNDs-BODIPY has a higher singlet oxygen quantum yield of 0.50 in water. Therefore, the construction of a three component photodynamic therapy agent (ZnTPPcQ-DNDs-BODIPY) as a single photosentisiser improved singlet quantum yields of the Pc. Zeta potential studies of ZnTPPcQ-DNDs-BODIPY under various temperatures, concentrations and pH conditions, showed the conjugate is more stable at pHs 2, 4 and 7 and at high concentrations (50 μg/mL) and temperatures (80 °C). ZnTPPcQ-DNDs-BODIPY showed high photodynamic therapy (PDT) activity with a low MCF-7 cell viability of 21 ± 5% when compared to 31 ± 2%, 30 ± 2% and 28 ± 2% cell viability at the highest tested concentration of 50 μg/mL for DNDs, ZnTPPcQ-DND and DNDs-BODIPY, respectively.
- Full Text:
- Date Issued: 2019
- Authors: Matshitse, Refilwe , Ngoy, Bokolombe P , Managa, Muthumuni , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186981 , vital:44553 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.03.007"
- Description: This work reports on the synthesis of nanoassemblies of supramolecular hybrids containing detonated nanodiamonds (DNDs) covalently linked to halogenated BODIPY (DNDs-BODIPY) by an amide bond, followed by π–π stacking of 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]-phthalocyanine (ZnTPPcQ) on the DNDs-BODIPY conjugate, to form nanoassembly represented as ZnTPPcQ-DNDs-BODIPY. ZnTPPcQ-DNDs-BODIPY has a higher singlet oxygen quantum yield of 0.50 in water. Therefore, the construction of a three component photodynamic therapy agent (ZnTPPcQ-DNDs-BODIPY) as a single photosentisiser improved singlet quantum yields of the Pc. Zeta potential studies of ZnTPPcQ-DNDs-BODIPY under various temperatures, concentrations and pH conditions, showed the conjugate is more stable at pHs 2, 4 and 7 and at high concentrations (50 μg/mL) and temperatures (80 °C). ZnTPPcQ-DNDs-BODIPY showed high photodynamic therapy (PDT) activity with a low MCF-7 cell viability of 21 ± 5% when compared to 31 ± 2%, 30 ± 2% and 28 ± 2% cell viability at the highest tested concentration of 50 μg/mL for DNDs, ZnTPPcQ-DND and DNDs-BODIPY, respectively.
- Full Text:
- Date Issued: 2019
Photophysical properties and photodynamic therapy activity of a meso-tetra (4-carboxyphenyl) porphyrin tetramethyl ester–graphene quantum dot conjugate
- Managa, Muthumuni, Ngoy, Bokolombe P, Nyokong, Tebello
- Authors: Managa, Muthumuni , Ngoy, Bokolombe P , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187533 , vital:44669 , xlink:href="https://doi.org/10.1039/C8NJ06175K"
- Description: Novel meso-tetra(4-carboxyphenyl)porphyrin tetramethyl ester metal derivatives were synthesised and characterized. These derivatives were interacted with graphene quantum dots (GDQs). Spectroscopic evidence that was obtained showed that the resultant conjugates were stable due to the strong π–π stacking interaction between the GQDs and the porphyrins. The fluorescence and singlet oxygen generating behaviour of the porphyrins and the nanoconjugates were investigated following incorporation. The dark toxicity and photodynamic therapy activities of the porphyrins and the nanoconjugates were successfully studied using MCF-7 breast cancer cells. Cell viability for the dark toxicity was more than 90% for all complexes. The PDT activities at the highest concentration of 120 μg ml−1 showed a decrease in cell viability down to 15.2% for the GaClTMPP–GQDs.
- Full Text:
- Date Issued: 2019
- Authors: Managa, Muthumuni , Ngoy, Bokolombe P , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187533 , vital:44669 , xlink:href="https://doi.org/10.1039/C8NJ06175K"
- Description: Novel meso-tetra(4-carboxyphenyl)porphyrin tetramethyl ester metal derivatives were synthesised and characterized. These derivatives were interacted with graphene quantum dots (GDQs). Spectroscopic evidence that was obtained showed that the resultant conjugates were stable due to the strong π–π stacking interaction between the GQDs and the porphyrins. The fluorescence and singlet oxygen generating behaviour of the porphyrins and the nanoconjugates were investigated following incorporation. The dark toxicity and photodynamic therapy activities of the porphyrins and the nanoconjugates were successfully studied using MCF-7 breast cancer cells. Cell viability for the dark toxicity was more than 90% for all complexes. The PDT activities at the highest concentration of 120 μg ml−1 showed a decrease in cell viability down to 15.2% for the GaClTMPP–GQDs.
- Full Text:
- Date Issued: 2019
Photophysicochemical and photodynamic therapy properties of metallophthalocyanines linked to gold speckled silica nanoparticles
- Dube, Edith, Oluwole, David O, Niemuwa, Nwaji, Prinsloo, Earl, Nyokong, Tebello
- Authors: Dube, Edith , Oluwole, David O , Niemuwa, Nwaji , Prinsloo, Earl , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187472 , vital:44657 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.01.019"
- Description: This work reports on the linkage of 2(3),9(10),16(17),23(24) tetrakis [(benzo[d]thiazol-2-yl phenoxy) phthalocyaninato] zinc(II) (1) and indium(III) chloride (2) to gold speckled silica (GSS) nanoparticles via gold to sulphur (Au-S) and gold to nitrogen (Au-N) self-assembly to form the conjugates: 1-GSS and 2-GSS. The formed conjugates were characterized using microscopic and spectroscopic techniques, and the photophysicochemical properties and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) were studied. The conjugates afforded decrease in fluorescence quantum yields with corresponding increase in triplet and singlet oxygen quantum yields when compared to phthalocyanines alone. Singlet oxygen is cytotoxic to cancer cells hence it is important for PDT. The in vitro dark toxicity of complex 2 and 2-GSS against MCF–7 cells showed ≥93% viable cells within concentration ranges of 10–160 μg/mL. 2–GSS showed enhanced PDT activity with less than 50% viable cells at 80 μg/mL as compared to 2 and GSS alone which showed > 60% viable cells within 10–160 μg/mL. The observed improvements in the PDT activity of 2-GSS could be attributed to the high singlet oxygen generation of 2-GSS compared to 2 alone in addition to the phototoxicity of GSS.
- Full Text:
- Date Issued: 2019
- Authors: Dube, Edith , Oluwole, David O , Niemuwa, Nwaji , Prinsloo, Earl , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187472 , vital:44657 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.01.019"
- Description: This work reports on the linkage of 2(3),9(10),16(17),23(24) tetrakis [(benzo[d]thiazol-2-yl phenoxy) phthalocyaninato] zinc(II) (1) and indium(III) chloride (2) to gold speckled silica (GSS) nanoparticles via gold to sulphur (Au-S) and gold to nitrogen (Au-N) self-assembly to form the conjugates: 1-GSS and 2-GSS. The formed conjugates were characterized using microscopic and spectroscopic techniques, and the photophysicochemical properties and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) were studied. The conjugates afforded decrease in fluorescence quantum yields with corresponding increase in triplet and singlet oxygen quantum yields when compared to phthalocyanines alone. Singlet oxygen is cytotoxic to cancer cells hence it is important for PDT. The in vitro dark toxicity of complex 2 and 2-GSS against MCF–7 cells showed ≥93% viable cells within concentration ranges of 10–160 μg/mL. 2–GSS showed enhanced PDT activity with less than 50% viable cells at 80 μg/mL as compared to 2 and GSS alone which showed > 60% viable cells within 10–160 μg/mL. The observed improvements in the PDT activity of 2-GSS could be attributed to the high singlet oxygen generation of 2-GSS compared to 2 alone in addition to the phototoxicity of GSS.
- Full Text:
- Date Issued: 2019
Physicochemical and antimicrobial photodynamic chemotherapy (against E. coli) by indium phthalocyanines in the presence of silver–iron bimetallic nanoparticles
- Magadla, Aviwe, Oluwole, David O, Managa, Muthumuni, Nyokong, Tebello
- Authors: Magadla, Aviwe , Oluwole, David O , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187091 , vital:44564 , xlink:href="https://doi.org/10.1016/j.poly.2019.01.032"
- Description: In this work, Schiff base indium phthalocyanines: In–Cl tetrakis N,N-dimethyl-4-(methylimino) phthalocyanine (complex 1b) and In–Cl tetrakis phenoxy N,N-dimethyl-4-(methylimino) phthalocyanine (complex 2b) are synthesized from tetra amino and tetra phenoxy amino phthalocyanines, respectively. These complexes were further quartenised with 1,3-propanesultone to form zwitterionic complexes 1 and 2, respectively. Silver–iron dimers (Ag–Fe3O4) and silver-iron core shell (Ag@Fe3O4) nanoparticles (NPs) were linked to the synthesised complexes. The photophysical and photochemical behaviour of the complexes and their conjugates with NPs were investigated in dimethyl sulfoxide. Complexes 2 and 2b and their conjugates were then used for photodynamic antimicrobial chemotherapy on Escherichia coli. The zwitter ionic photosensitiser 2 and its conjugates showed better efficiency for photodynamic antimicrobial chemotherapy compared to their neutral counterparts.
- Full Text:
- Date Issued: 2019
- Authors: Magadla, Aviwe , Oluwole, David O , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187091 , vital:44564 , xlink:href="https://doi.org/10.1016/j.poly.2019.01.032"
- Description: In this work, Schiff base indium phthalocyanines: In–Cl tetrakis N,N-dimethyl-4-(methylimino) phthalocyanine (complex 1b) and In–Cl tetrakis phenoxy N,N-dimethyl-4-(methylimino) phthalocyanine (complex 2b) are synthesized from tetra amino and tetra phenoxy amino phthalocyanines, respectively. These complexes were further quartenised with 1,3-propanesultone to form zwitterionic complexes 1 and 2, respectively. Silver–iron dimers (Ag–Fe3O4) and silver-iron core shell (Ag@Fe3O4) nanoparticles (NPs) were linked to the synthesised complexes. The photophysical and photochemical behaviour of the complexes and their conjugates with NPs were investigated in dimethyl sulfoxide. Complexes 2 and 2b and their conjugates were then used for photodynamic antimicrobial chemotherapy on Escherichia coli. The zwitter ionic photosensitiser 2 and its conjugates showed better efficiency for photodynamic antimicrobial chemotherapy compared to their neutral counterparts.
- Full Text:
- Date Issued: 2019
Physicochemical and photodynamic antimicrobial chemotherapy activity of morpholine-substituted phthalocyanines: Effect of point of substitution and central metal
- Sindelo, Azole, Kobayashi, Nagao, Kimura, Mutsumi, Nyokong, Tebello
- Authors: Sindelo, Azole , Kobayashi, Nagao , Kimura, Mutsumi , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187438 , vital:44652 , xlink:href="https://doi.org/10.1016/j.jphotochem.2019.01.025"
- Description: In this study, novel metal-free, zinc and indium 1(4),8(11),15(18),22(25)-tetramorpholine (1a, 2a, 3a respectively) and 2(3), 9(10), 16(17),23(24)-tetramorpholine (1b, 2b, 3b respectively) phthalocyanines were synthesized and complexes 2 and 3 were quaternized. The photophysical and photochemical properties were investigated in dimethylsulfoxide. The non-peripherally substituted phthalocyanines generated higher singlet oxygen than the peripherally substituted phthalocyanines. Photodynamic antimicrobial chemotherapy activities towards inactivation of Escherichia coli, Staphylococcus aureus and Candida albican were evaluated, where all the quaternized Pcs showed total elimination of the micro-organism with log reductions greater than 9. Though the neutral Pcs had log reductions less than 2, for C. albican the percentage reduction was 68.5% for 2b showing the antifungal properties of the morpholine group.
- Full Text:
- Date Issued: 2019
- Authors: Sindelo, Azole , Kobayashi, Nagao , Kimura, Mutsumi , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187438 , vital:44652 , xlink:href="https://doi.org/10.1016/j.jphotochem.2019.01.025"
- Description: In this study, novel metal-free, zinc and indium 1(4),8(11),15(18),22(25)-tetramorpholine (1a, 2a, 3a respectively) and 2(3), 9(10), 16(17),23(24)-tetramorpholine (1b, 2b, 3b respectively) phthalocyanines were synthesized and complexes 2 and 3 were quaternized. The photophysical and photochemical properties were investigated in dimethylsulfoxide. The non-peripherally substituted phthalocyanines generated higher singlet oxygen than the peripherally substituted phthalocyanines. Photodynamic antimicrobial chemotherapy activities towards inactivation of Escherichia coli, Staphylococcus aureus and Candida albican were evaluated, where all the quaternized Pcs showed total elimination of the micro-organism with log reductions greater than 9. Though the neutral Pcs had log reductions less than 2, for C. albican the percentage reduction was 68.5% for 2b showing the antifungal properties of the morpholine group.
- Full Text:
- Date Issued: 2019
Phytochemical, anti-inflammatory and anti-trypanosomal properties of Anthocleista vogelii Planch (Loganiaceae) stem bark
- Eze, Fabian I, Siwe-Noundou, Xavier, Osadebe, Patience, Krause, Rui W M
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Osadebe, Patience , Krause, Rui W M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194059 , vital:45419 , xlink:href="https://doi.org/10.1016/j.jep.2019.111851"
- Description: Ethnopharmacological relevance: Anthocleista vogelii Planch (Loganiaceae) is used in African Traditional Medicine for the treatment of pain and inflammatory disorders as well as sleeping sickness. Aim of the study: To determine the in vivo anti-inflammatory and in vitro anti-trypanosomal activities of the extracts of A. vogelii stem bark and identify the phytochemical classes of the fractions responsible for the activities. Materials and methods: The in vivo anti-inflammatory activity of the extracts was evaluated using the egg albumin-induced rat paw oedema model while the in vitro anti-trypanosomal activity was assessed on Trypanosoma brucei brucei. The in vitro cytotoxicity was assessed on HeLa (human cervix adenocarcinoma) cell line. Results: The methanolic extract of A. vogelii stem bark, with 11.2% yield, gave LD50 > 5000 mg/kg. The n-hexane fraction of the extract contains steroids, terpenes and fatty acids and yielded non-cytotoxic terpenoidal column fraction with anti-trypanosomal IC50 of 3.0 μg/mL. The ethylacetate fraction at 100 mg/kg dose significantly (p less than 0.05) provoked 37.8, 62.5 and 69.7% inhibition of oedema induced by egg-albumin at the second, fourth and sixth hours respectively. Conclusion: The study demonstrated that the anti-inflammatory and anti-trypanosomal activities of A. vogelii are probably due to non-cytotoxic terpenoids and validated the traditional use of A. vogelii in the treatment of inflammation and sleeping sickness.
- Full Text:
- Date Issued: 2019
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Osadebe, Patience , Krause, Rui W M
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194059 , vital:45419 , xlink:href="https://doi.org/10.1016/j.jep.2019.111851"
- Description: Ethnopharmacological relevance: Anthocleista vogelii Planch (Loganiaceae) is used in African Traditional Medicine for the treatment of pain and inflammatory disorders as well as sleeping sickness. Aim of the study: To determine the in vivo anti-inflammatory and in vitro anti-trypanosomal activities of the extracts of A. vogelii stem bark and identify the phytochemical classes of the fractions responsible for the activities. Materials and methods: The in vivo anti-inflammatory activity of the extracts was evaluated using the egg albumin-induced rat paw oedema model while the in vitro anti-trypanosomal activity was assessed on Trypanosoma brucei brucei. The in vitro cytotoxicity was assessed on HeLa (human cervix adenocarcinoma) cell line. Results: The methanolic extract of A. vogelii stem bark, with 11.2% yield, gave LD50 > 5000 mg/kg. The n-hexane fraction of the extract contains steroids, terpenes and fatty acids and yielded non-cytotoxic terpenoidal column fraction with anti-trypanosomal IC50 of 3.0 μg/mL. The ethylacetate fraction at 100 mg/kg dose significantly (p less than 0.05) provoked 37.8, 62.5 and 69.7% inhibition of oedema induced by egg-albumin at the second, fourth and sixth hours respectively. Conclusion: The study demonstrated that the anti-inflammatory and anti-trypanosomal activities of A. vogelii are probably due to non-cytotoxic terpenoids and validated the traditional use of A. vogelii in the treatment of inflammation and sleeping sickness.
- Full Text:
- Date Issued: 2019
Pigs vs people: the use of pigs as analogues for humans in forensic entomology and taphonomy research
- Matuszewski, Szymon, Hall, Martin J R, Moreau, Gaétan, Schoenly, Kenneth G, Tarone, Aaron M, Villet, Martin H
- Authors: Matuszewski, Szymon , Hall, Martin J R , Moreau, Gaétan , Schoenly, Kenneth G , Tarone, Aaron M , Villet, Martin H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140557 , vital:37898 , DOI: 10.1007/s00414-019-02074-5
- Description: Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.
- Full Text:
- Date Issued: 2019
- Authors: Matuszewski, Szymon , Hall, Martin J R , Moreau, Gaétan , Schoenly, Kenneth G , Tarone, Aaron M , Villet, Martin H
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140557 , vital:37898 , DOI: 10.1007/s00414-019-02074-5
- Description: Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.
- Full Text:
- Date Issued: 2019
Plaxenone A and B: Cytotoxic halogenated monoterpenes from the South African red seaweed Plocamium maxillosum
- Knott, Michael G, de la Mare, Jo-Anne, Edkins, Adrienne L, Zhang, Angel, Stillman, Martin J, Bolton, John J, Antunes, Edith M, Beukes, Denzil R
- Authors: Knott, Michael G , de la Mare, Jo-Anne , Edkins, Adrienne L , Zhang, Angel , Stillman, Martin J , Bolton, John J , Antunes, Edith M , Beukes, Denzil R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164446 , vital:41119 , https://doi.org/10.1016/j.phytol.2018.12.009
- Description: The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.
- Full Text:
- Date Issued: 2019
- Authors: Knott, Michael G , de la Mare, Jo-Anne , Edkins, Adrienne L , Zhang, Angel , Stillman, Martin J , Bolton, John J , Antunes, Edith M , Beukes, Denzil R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164446 , vital:41119 , https://doi.org/10.1016/j.phytol.2018.12.009
- Description: The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.
- Full Text:
- Date Issued: 2019
Preparation of NIR absorbing axial substituted tin (iv) porphyrins and their photocytotoxic properties
- Babu, Balaji, Amuhaya, Edith K, Oluwole, David O, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
- Date Issued: 2019
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
- Date Issued: 2019
Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa
- Adjei, Anane Yaw, Apalata, Teke, Vasaikar, Sandeep, Okuthe, Grace Emily, Songca, Sandile
- Authors: Adjei, Anane Yaw , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2019
- Subjects: Acinetobacter baumannii , Carbapenemase-encoding genes , Multidrug-resistance , ISAba1 , intI1
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/2409 , vital:41457 , https://doi.org/10.1016/j.bjid.2019.09.004
- Description: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagarTM Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.
- Full Text:
- Date Issued: 2019
- Authors: Adjei, Anane Yaw , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2019
- Subjects: Acinetobacter baumannii , Carbapenemase-encoding genes , Multidrug-resistance , ISAba1 , intI1
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/2409 , vital:41457 , https://doi.org/10.1016/j.bjid.2019.09.004
- Description: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagarTM Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.
- Full Text:
- Date Issued: 2019
Prime time geographies: dancehall performance, visual communication and the philosophy of ‘Boundarylessness'
- Authors: Stanley Niaah, Sonjah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145930 , vital:38479 , https://0-doi.org.wam.seals.ac.za/10.1080/00086495.2019.1565218
- Description: What is Dancehall, and how does it employ visual technologies? Dancehall is not just a musical genre. It is Jamaica’s premier popular street theatre, a celebration of the entire spectrum of life from birth to death, expressed at events that combine dance and music, where consenting adults leave their troubles behind just for a moment to revel in the deep and old rhythmic structures that transport them into scape beyond the urban, beyond the inner city, into spaces of fulfilment.
- Full Text:
- Date Issued: 2019
- Authors: Stanley Niaah, Sonjah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145930 , vital:38479 , https://0-doi.org.wam.seals.ac.za/10.1080/00086495.2019.1565218
- Description: What is Dancehall, and how does it employ visual technologies? Dancehall is not just a musical genre. It is Jamaica’s premier popular street theatre, a celebration of the entire spectrum of life from birth to death, expressed at events that combine dance and music, where consenting adults leave their troubles behind just for a moment to revel in the deep and old rhythmic structures that transport them into scape beyond the urban, beyond the inner city, into spaces of fulfilment.
- Full Text:
- Date Issued: 2019
Privately protected areas provide key opportunities for the regional persistence of large- and medium-sized mammals
- Clements, Hayley S, Kerley, Graham I, Cumming, Graeme S, de Vos, Alta, Cook, Carly N
- Authors: Clements, Hayley S , Kerley, Graham I , Cumming, Graeme S , de Vos, Alta , Cook, Carly N
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416383 , vital:71344 , xlink:href="https://doi.org/10.1111/1365-2664.13300"
- Description: Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., low -land habitats on fertile soils, coastal zones), land is often privately owned and state-owned PAs tend to be under-represented. Despite the potentially disproportionate contribution that privately protected areas (PPAs) could make to representing biodiversity and supporting its persistence across regional PA estates, this contribution is poorly understood.
- Full Text:
- Date Issued: 2019
- Authors: Clements, Hayley S , Kerley, Graham I , Cumming, Graeme S , de Vos, Alta , Cook, Carly N
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416383 , vital:71344 , xlink:href="https://doi.org/10.1111/1365-2664.13300"
- Description: Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., low -land habitats on fertile soils, coastal zones), land is often privately owned and state-owned PAs tend to be under-represented. Despite the potentially disproportionate contribution that privately protected areas (PPAs) could make to representing biodiversity and supporting its persistence across regional PA estates, this contribution is poorly understood.
- Full Text:
- Date Issued: 2019
Purification and biochemical characterisation of a putative sodium channel agonist secreted from the South African Knobbly sea anemone Bunodosoma capense
- van Losenoord, Wynand, Krause, Jason, Parker-Nance, Shirley, Krause, Rui W M, Stoychey, Stoyan, Frost, Carminita L
- Authors: van Losenoord, Wynand , Krause, Jason , Parker-Nance, Shirley , Krause, Rui W M , Stoychey, Stoyan , Frost, Carminita L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194082 , vital:45421 , xlink:href="https://doi.org/10.1016/j.toxicon.2019.06.222"
- Description: Voltage gated ion channels have become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to anti-inflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel toxins. A putative novel sodium channel agonist (molecular mass of 4619.7 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii bio-assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel agonist/inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated the presence of multiple disulfide bonds in a tight β-defensin cystine conformation. An IC50 value of 26 nM was determined for total channel inhibition on MCF-7 cells. The unique putative sodium channel agonist initiating with a cystine bond indicates a divergent evolution to those previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
- Authors: van Losenoord, Wynand , Krause, Jason , Parker-Nance, Shirley , Krause, Rui W M , Stoychey, Stoyan , Frost, Carminita L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194082 , vital:45421 , xlink:href="https://doi.org/10.1016/j.toxicon.2019.06.222"
- Description: Voltage gated ion channels have become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to anti-inflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel toxins. A putative novel sodium channel agonist (molecular mass of 4619.7 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii bio-assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel agonist/inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated the presence of multiple disulfide bonds in a tight β-defensin cystine conformation. An IC50 value of 26 nM was determined for total channel inhibition on MCF-7 cells. The unique putative sodium channel agonist initiating with a cystine bond indicates a divergent evolution to those previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
Pushing against ‘China-Africa’ slowly, and with small stories:
- Authors: Simbao, Ruth K
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146778 , vital:38556 , http://www.somethingweafricansgot.com/about-1
- Description: the new focus on african arts and critical thought.
- Full Text:
- Date Issued: 2019
- Authors: Simbao, Ruth K
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146778 , vital:38556 , http://www.somethingweafricansgot.com/about-1
- Description: the new focus on african arts and critical thought.
- Full Text:
- Date Issued: 2019