The contribution of wild palms to the livelihoods and diversification of rural households in southern Mozambique
- King, Angelina R, Shackleton, Charlie M
- Authors: King, Angelina R , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399846 , vital:69563 , xlink:href="https://doi.org/10.1016/j.forpol.2022.102793"
- Description: In most low-income countries, rural households combine a range of economic activities to generate income, achieve food and nutritional security and fulfill other livelihood objectives, including: small-scale farming, fishing, hunting, livestock and timber production, and non-timber forest products gathering, as well as off-farm activities such as wage labour and informal trading. This work examines the role of diversification, including palm products income, on rural livelihoods in the Zitundo area, southern Mozambique. Seven livelihood strategies were identified, with every strategy combining cash income from several sources. Most households adopt a wage-based strategy to some degree, although this strategy shows low potential for reducing poverty in the area. Households adopting a palm-based strategy show between 23% and 60% lower poverty incidence than those adopting alternatives strategies. Yet, a palm-based livelihood strategy was adopted by only 11% of households. Traders of palm products earn approximately double the annual income and per capita income than non-traders. Village of residency and some household socio-economic and demographic characteristics correlate with a households' choice of livelihood strategy and palm income dependency. The adherence of many households to a less remunerative wage strategy indicates other factors also influence the choice of livelihood strategies. The study shows that future development plans and policy interventions to mitigate poverty in the area should go beyond the usual agricultural sector and recognize the role of non-timber forest products, especially palm products, for people's livelihoods and poverty alleviation.
- Full Text:
- Date Issued: 2022
- Authors: King, Angelina R , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/399846 , vital:69563 , xlink:href="https://doi.org/10.1016/j.forpol.2022.102793"
- Description: In most low-income countries, rural households combine a range of economic activities to generate income, achieve food and nutritional security and fulfill other livelihood objectives, including: small-scale farming, fishing, hunting, livestock and timber production, and non-timber forest products gathering, as well as off-farm activities such as wage labour and informal trading. This work examines the role of diversification, including palm products income, on rural livelihoods in the Zitundo area, southern Mozambique. Seven livelihood strategies were identified, with every strategy combining cash income from several sources. Most households adopt a wage-based strategy to some degree, although this strategy shows low potential for reducing poverty in the area. Households adopting a palm-based strategy show between 23% and 60% lower poverty incidence than those adopting alternatives strategies. Yet, a palm-based livelihood strategy was adopted by only 11% of households. Traders of palm products earn approximately double the annual income and per capita income than non-traders. Village of residency and some household socio-economic and demographic characteristics correlate with a households' choice of livelihood strategy and palm income dependency. The adherence of many households to a less remunerative wage strategy indicates other factors also influence the choice of livelihood strategies. The study shows that future development plans and policy interventions to mitigate poverty in the area should go beyond the usual agricultural sector and recognize the role of non-timber forest products, especially palm products, for people's livelihoods and poverty alleviation.
- Full Text:
- Date Issued: 2022
The effect of charge on Zn tetra morpholine porphyrin conjugated to folic acid-nitrogen doped graphene quantum dots for photodynamic therapy studies
- Magaela, N Bridged, Matshitse, Refilwe, Nyokong, Tebello
- Authors: Magaela, N Bridged , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295840 , vital:57383 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102898"
- Description: Zinc tetra morpholine porphyrin (complex 2), and its quaternized derivative (complex 3) were synthesized and conjugated to folic acid decorated nitrogen doped graphene quantum dots (FA-NGQDs) through π−π stacking to study their photodynamic therapy (PDT) efficacy. Photophysiochemical properties of complexes 2, 3, and their conjugates (2-FA-NGQDs, 3-FA-NGQDs) were studied. It was found that complex 3 had higher ϕΔ of 0.56 compared to complex 2 with ϕΔ of 0.24, and respective composites: 3-FA-NGQDs had higher ϕΔ compared to 2-FA-NGQDs. The PDT studies were conducted for nanoparticles (FA-NGQDs), complexes (2, 3), and respective composites (2-FA-NGQDs, and 3-FA-NGQDs) using MCF-7 breast cancer cell. Dark toxicity of all compounds was above 90% which is negligible. At a highest concentration of 40 µg/mL, 3-FA-NGQDs gave the lowest cell viability of 28% compared to all other conjugates and porphyrins alone.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, N Bridged , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295840 , vital:57383 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.102898"
- Description: Zinc tetra morpholine porphyrin (complex 2), and its quaternized derivative (complex 3) were synthesized and conjugated to folic acid decorated nitrogen doped graphene quantum dots (FA-NGQDs) through π−π stacking to study their photodynamic therapy (PDT) efficacy. Photophysiochemical properties of complexes 2, 3, and their conjugates (2-FA-NGQDs, 3-FA-NGQDs) were studied. It was found that complex 3 had higher ϕΔ of 0.56 compared to complex 2 with ϕΔ of 0.24, and respective composites: 3-FA-NGQDs had higher ϕΔ compared to 2-FA-NGQDs. The PDT studies were conducted for nanoparticles (FA-NGQDs), complexes (2, 3), and respective composites (2-FA-NGQDs, and 3-FA-NGQDs) using MCF-7 breast cancer cell. Dark toxicity of all compounds was above 90% which is negligible. At a highest concentration of 40 µg/mL, 3-FA-NGQDs gave the lowest cell viability of 28% compared to all other conjugates and porphyrins alone.
- Full Text:
- Date Issued: 2022
The genetic architecture of the corpus callosum and its subregions
- Campbell, Megan M, Dalvie, Shareefa, Shadrin, Alexey, Van der Meer, Dennis, Andreassen, Ola, Stein, Dan J, Rokicki, Jaroslav
- Authors: Campbell, Megan M , Dalvie, Shareefa , Shadrin, Alexey , Van der Meer, Dennis , Andreassen, Ola , Stein, Dan J , Rokicki, Jaroslav
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302542 , vital:58206 , xlink:href="https://doi.org/10.1016/j.euroneuro.2022.07.263"
- Description: Background: Regional surface area and thickness of the cerebral cortex and volume of subcortical structures are highly heritable brain morphological features with complex genetic architectures, involving many common genetic variants with small effect sizes. However, the genetic architecture of the corpus callosum (CC) and its subregions remains largely unclear. We aim to determine the heritability and genetic architecture of CC volume and each subregion and the extent to which this overlaps with that of psychiatric disorders. Methods: Genetic and T1-weighted MRI data of 40,894 individuals from the UK-biobank was used to construct a multivariate GWAS. Here, we utilized a multivariate approach (Multivariate Omnibus Statistical Test, MOSTest) to assess the distributive effects of common variants across the five subregions of the CC (posterior, mid posterior, central, mid anterior and anterior) obtained by running the automatic subcortical segmentation algorithm in FreeSurfer 5.3. Gene-set enrichment analyses were performed using MAGMA. Linkage disequilibrium score regression was used to determine the SNP-based heritability of the CC and will be used to assess the genetic correlation between each subregion and a variety of psychiatric disorders. Results: Following MOSTest, 70 independent loci show pooled effects across the 5 subregions of the CC (p more than 5×10-8). Using LDSC, we found evidence to suggest that CC volume is heritable (h2SNP= 0.38, SE=0.03). Significant variants showed enrichment in pathways related to regulation of the nervous system and cell development, neurogenesis, and regulation of neuron differentiation. Gene-set analysis revealed 156 significant genes (p is less than 2.6x10-6). Many of the significant SNPs have been previously associated with white matter hyperintensity volume as well as a range of psychiatric disorders. Discussion: Here we provide the first preliminary evidence to suggest that volume of the CC is heritable. Gene set enrichment analyses identified pathways related to neuron development and neurogenesis, suggesting that CC alteration may have an independent developmental origin. Further investigation into the shared genetic architecture of CC subregions and psychiatric disorders may provide novel insight into disease manifestation.
- Full Text:
- Date Issued: 2022
- Authors: Campbell, Megan M , Dalvie, Shareefa , Shadrin, Alexey , Van der Meer, Dennis , Andreassen, Ola , Stein, Dan J , Rokicki, Jaroslav
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302542 , vital:58206 , xlink:href="https://doi.org/10.1016/j.euroneuro.2022.07.263"
- Description: Background: Regional surface area and thickness of the cerebral cortex and volume of subcortical structures are highly heritable brain morphological features with complex genetic architectures, involving many common genetic variants with small effect sizes. However, the genetic architecture of the corpus callosum (CC) and its subregions remains largely unclear. We aim to determine the heritability and genetic architecture of CC volume and each subregion and the extent to which this overlaps with that of psychiatric disorders. Methods: Genetic and T1-weighted MRI data of 40,894 individuals from the UK-biobank was used to construct a multivariate GWAS. Here, we utilized a multivariate approach (Multivariate Omnibus Statistical Test, MOSTest) to assess the distributive effects of common variants across the five subregions of the CC (posterior, mid posterior, central, mid anterior and anterior) obtained by running the automatic subcortical segmentation algorithm in FreeSurfer 5.3. Gene-set enrichment analyses were performed using MAGMA. Linkage disequilibrium score regression was used to determine the SNP-based heritability of the CC and will be used to assess the genetic correlation between each subregion and a variety of psychiatric disorders. Results: Following MOSTest, 70 independent loci show pooled effects across the 5 subregions of the CC (p more than 5×10-8). Using LDSC, we found evidence to suggest that CC volume is heritable (h2SNP= 0.38, SE=0.03). Significant variants showed enrichment in pathways related to regulation of the nervous system and cell development, neurogenesis, and regulation of neuron differentiation. Gene-set analysis revealed 156 significant genes (p is less than 2.6x10-6). Many of the significant SNPs have been previously associated with white matter hyperintensity volume as well as a range of psychiatric disorders. Discussion: Here we provide the first preliminary evidence to suggest that volume of the CC is heritable. Gene set enrichment analyses identified pathways related to neuron development and neurogenesis, suggesting that CC alteration may have an independent developmental origin. Further investigation into the shared genetic architecture of CC subregions and psychiatric disorders may provide novel insight into disease manifestation.
- Full Text:
- Date Issued: 2022
The implications of ortho-, meta-and para-directors on the in-vitro photodynamic antimicrobial chemotherapy activity of cationic pyridyl-dihydrothiazole phthalocyanines
- Magadla, Aviwe, Openda, Yolande Ikala, Nyokong, Tebello
- Authors: Magadla, Aviwe , Openda, Yolande Ikala , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295875 , vital:57386 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.103029"
- Description: Cationic Zn phthalocyanine complexes were derived by alkylation reaction of tetra-(pyridinyloxy) phthalocyanines (Pcs) at the ortho, meta, and para positions to form Zn (II) tetrakis 3-(4-(2-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (2), Zn (II) tetrakis 3-(4-(3-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (4) and Zn (II) tetrakis 3-(4-(4-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (6). The photophysicochemical behaviors of the Pc complexes were assessed. The meta and para-substituted complexes gave high singlet oxygen quantum yields. The cationic Pcs demonstrated good planktonic antibacterial activity against Staphylococcus aureus and Escherichia coli with the high log reduction values of 9.29 and 8.55, respectively. The cationic complexes also showed a significant decrease in the viability of in vitro biofilms after photo-antimicrobial chemotherapy at 100 µM for both Staphylococcus aureus and Escherichia coli biofilms.
- Full Text:
- Date Issued: 2022
- Authors: Magadla, Aviwe , Openda, Yolande Ikala , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295875 , vital:57386 , xlink:href="https://doi.org/10.1016/j.pdpdt.2022.103029"
- Description: Cationic Zn phthalocyanine complexes were derived by alkylation reaction of tetra-(pyridinyloxy) phthalocyanines (Pcs) at the ortho, meta, and para positions to form Zn (II) tetrakis 3-(4-(2-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (2), Zn (II) tetrakis 3-(4-(3-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (4) and Zn (II) tetrakis 3-(4-(4-pyridin-1-ium-1-yl) butyl)-2-mercapto-4,5-dihydrothiazol-3-ium phthalocyanine (6). The photophysicochemical behaviors of the Pc complexes were assessed. The meta and para-substituted complexes gave high singlet oxygen quantum yields. The cationic Pcs demonstrated good planktonic antibacterial activity against Staphylococcus aureus and Escherichia coli with the high log reduction values of 9.29 and 8.55, respectively. The cationic complexes also showed a significant decrease in the viability of in vitro biofilms after photo-antimicrobial chemotherapy at 100 µM for both Staphylococcus aureus and Escherichia coli biofilms.
- Full Text:
- Date Issued: 2022
The in vitro photo-sonodynamic combinatorial therapy activity of cationic and zwitterionic phthalocyanines on MCF-7 and HeLa cancer cell lines
- Nene, Lindokuhle Cindy, Buthelezi, Khanyisile, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
- Full Text:
- Date Issued: 2022
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
- Full Text:
- Date Issued: 2022
The photocatalytic properties of zinc phthalocyanines supported on hematite nanofibers for use against methyl orange and Staphylococcus aureus
- Mapukata, Sivuyisiwe, Britton, Jonathan, Nwahara, Nnamdi, Nyokong, Tebello
- Authors: Mapukata, Sivuyisiwe , Britton, Jonathan , Nwahara, Nnamdi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230184 , vital:49751 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113637"
- Description: Heterogeneous photocatalysis is a promising approach for environmental remediation from contaminants including microorganisms and organic pollutants. In this work, hematite nanofibers are fabricated and modified with a novel monosubstituted Pc (4) as well as an asymmetrical tetrasubstituted Pc (5) with the aim of creating hybrid photocatalysts. The photocatalytic activities of the unmodified and phthalocyanine modified hematite nanofibers were compared based on their efficiencies in the photoinactivation of S. aureus and photooxidation of methyl orange. For both applications, the hybrid nanofibers were found to be more efficient photocatalysts than the unmodified hematite nanofibers. Comparison of the modified nanofibers (4-Fe2O3 and 5-Fe2O3) showed that they have comparable antibacterial activity while the 5-Fe2O3 nanofibers are the best for the photooxidation of methyl orange. The singlet oxygen generation efficiency, high activity, versatility, regenerability and thus reusability of the fabricated hybrid nanofibers makes them ideal candidates for real life water treatment studies.
- Full Text:
- Date Issued: 2022
- Authors: Mapukata, Sivuyisiwe , Britton, Jonathan , Nwahara, Nnamdi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230184 , vital:49751 , xlink:href="https://doi.org/10.1016/j.jphotochem.2021.113637"
- Description: Heterogeneous photocatalysis is a promising approach for environmental remediation from contaminants including microorganisms and organic pollutants. In this work, hematite nanofibers are fabricated and modified with a novel monosubstituted Pc (4) as well as an asymmetrical tetrasubstituted Pc (5) with the aim of creating hybrid photocatalysts. The photocatalytic activities of the unmodified and phthalocyanine modified hematite nanofibers were compared based on their efficiencies in the photoinactivation of S. aureus and photooxidation of methyl orange. For both applications, the hybrid nanofibers were found to be more efficient photocatalysts than the unmodified hematite nanofibers. Comparison of the modified nanofibers (4-Fe2O3 and 5-Fe2O3) showed that they have comparable antibacterial activity while the 5-Fe2O3 nanofibers are the best for the photooxidation of methyl orange. The singlet oxygen generation efficiency, high activity, versatility, regenerability and thus reusability of the fabricated hybrid nanofibers makes them ideal candidates for real life water treatment studies.
- Full Text:
- Date Issued: 2022
The prevalence, composition and distribution of forageable plant species in different urban spaces in two medium-sized towns in South Africa
- Garekae, Hesekia, Shackleton, Charlie M, Tsheboeng, Gaolathe
- Authors: Garekae, Hesekia , Shackleton, Charlie M , Tsheboeng, Gaolathe
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401300 , vital:69724 , xlink:href="https://doi.org/10.1016/j.gecco.2021.e01972"
- Description: Globally, the importance of urban vegetation in the quality and maintenance of life in urban areas is increasingly recognized. As the basis of urban green infrastructure, urban vegetation provides a diversity of ecosystem services, including provisioning services. However, there is limited understanding of the potential of urban vegetation as a supply of forageable resources within urban landscapes. This study examined the prevalence and distribution of forageable plant species across different spaces in the towns of Potchefstroom and Thabazimbi, South Africa. A multi-stage sampling technique was employed for selecting study sites, with a total of 136 plots sampled. In total, 88 plant species (foraged and forageable) were encountered across the sample plots, with almost three-quarters (70%) being indigenous to South Africa. Most of the species had multiple uses, with medicine, food and firewood being the most common uses, in order of frequency. Species cover and richness significantly differed across the urban spaces, being markedly higher in protected areas as compared to other spaces. Moreover, five plant communities were identified, resembling various species uses. Overall, the findings show that the fragmented urban spaces are endowed with a diversity of forageable plant species, with many valuable to particular sectors of urban society, such as foragers. Moreover, the notable number of forageable plant species encountered across the different spaces demonstrates the potential of urban green infrastructure as a supply of provisioning and cultural ecosystem services. This provides the basis for the selection of a diversity of species in urban greening programs for enhancing liveability and overall well-being in urban areas.
- Full Text:
- Date Issued: 2022
- Authors: Garekae, Hesekia , Shackleton, Charlie M , Tsheboeng, Gaolathe
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401300 , vital:69724 , xlink:href="https://doi.org/10.1016/j.gecco.2021.e01972"
- Description: Globally, the importance of urban vegetation in the quality and maintenance of life in urban areas is increasingly recognized. As the basis of urban green infrastructure, urban vegetation provides a diversity of ecosystem services, including provisioning services. However, there is limited understanding of the potential of urban vegetation as a supply of forageable resources within urban landscapes. This study examined the prevalence and distribution of forageable plant species across different spaces in the towns of Potchefstroom and Thabazimbi, South Africa. A multi-stage sampling technique was employed for selecting study sites, with a total of 136 plots sampled. In total, 88 plant species (foraged and forageable) were encountered across the sample plots, with almost three-quarters (70%) being indigenous to South Africa. Most of the species had multiple uses, with medicine, food and firewood being the most common uses, in order of frequency. Species cover and richness significantly differed across the urban spaces, being markedly higher in protected areas as compared to other spaces. Moreover, five plant communities were identified, resembling various species uses. Overall, the findings show that the fragmented urban spaces are endowed with a diversity of forageable plant species, with many valuable to particular sectors of urban society, such as foragers. Moreover, the notable number of forageable plant species encountered across the different spaces demonstrates the potential of urban green infrastructure as a supply of provisioning and cultural ecosystem services. This provides the basis for the selection of a diversity of species in urban greening programs for enhancing liveability and overall well-being in urban areas.
- Full Text:
- Date Issued: 2022
The synergistic effects of coupling Au nanoparticles with an alkynyl Co (II) phthalocyanine on the detection of prostate specific antigen
- Nxele, Siphesihle Robin, Nkhahle, Reitumetse, Nyokong, Tebello
- Authors: Nxele, Siphesihle Robin , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230232 , vital:49756 , xlink:href="https://doi.org/10.1016/j.talanta.2021.122948"
- Description: Prostate specific antigen (PSA) aptasensors are fabricated using a novel asymmetrically substituted Co phthalocyanine (CoPc), gold nanoparticles (AuNPs) and PSA-specific antigen. The fabricated aptasensors are: GCE-AuNPs-Aptamer, GCE@CoPc-Aptamer and GCE-AuNPs@CoPc-Aptamer (GCE = glassy carbon electrode). The fabricated sensors are characterized at each modification step to monitor the changes occurring at the sensor surface. Concentration studies were carried out using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to determine detection limits. All the fabricated aptasensors were found to be highly specific and selective but the GCE-AuNPs@CoPc-Aptamer nanoconjugate performed the best. The aptasensors were also tested in spiked serum samples and detection limits, as well as % recoveries were determined. The results obtained showed that the GCE-AuNPs@CoPc-Aptamer has the potential to be used for clinical studies as the results agree with those obtained for detection of PSA in buffer.
- Full Text:
- Date Issued: 2022
- Authors: Nxele, Siphesihle Robin , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230232 , vital:49756 , xlink:href="https://doi.org/10.1016/j.talanta.2021.122948"
- Description: Prostate specific antigen (PSA) aptasensors are fabricated using a novel asymmetrically substituted Co phthalocyanine (CoPc), gold nanoparticles (AuNPs) and PSA-specific antigen. The fabricated aptasensors are: GCE-AuNPs-Aptamer, GCE@CoPc-Aptamer and GCE-AuNPs@CoPc-Aptamer (GCE = glassy carbon electrode). The fabricated sensors are characterized at each modification step to monitor the changes occurring at the sensor surface. Concentration studies were carried out using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to determine detection limits. All the fabricated aptasensors were found to be highly specific and selective but the GCE-AuNPs@CoPc-Aptamer nanoconjugate performed the best. The aptasensors were also tested in spiked serum samples and detection limits, as well as % recoveries were determined. The results obtained showed that the GCE-AuNPs@CoPc-Aptamer has the potential to be used for clinical studies as the results agree with those obtained for detection of PSA in buffer.
- Full Text:
- Date Issued: 2022
Time-dependent characterization of graphene quantum dots and graphitic carbon nitride quantum dots synthesized by hydrothermal methods
- Nxele, Siphesihle Robin, Nyokong, Tebello
- Authors: Nxele, Siphesihle Robin , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230917 , vital:49831 , xlink:href="https://doi.org/10.1016/j.diamond.2021.108751"
- Description: We report on the facile synthesis of graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) by the bottom-up hydrothermal synthetic process. The time is varied to study its effects on the structural, hydrodynamic and optical properties of these nanostructures. The techniques used to characterize these nanostructures were transmission electron microscopy, X-ray diffractometry, dynamic light scattering, and zetametry (zeta potential), and by energy dispersive X-ray, UV/vis, fluorescence, Fourier transform infrared, Raman and X-ray photoelectron spectroscopies. For gCNQDs and NGQDs, Raman spectroscopy showed an increase in disorder with synthesis time, indicating introduction of more triazine groups for the former and increase in doping with the N atoms for the latter, hence higher temperatures are recommended. For GQDs, Raman spectra showed an increase in the spatial order of the π-conjugated structure with synthesis time. Considering all the techniques employed in this work, the synthesis times of 6h and 8 h are recommended for GQDs and NGQDs.
- Full Text:
- Date Issued: 2022
- Authors: Nxele, Siphesihle Robin , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230917 , vital:49831 , xlink:href="https://doi.org/10.1016/j.diamond.2021.108751"
- Description: We report on the facile synthesis of graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) by the bottom-up hydrothermal synthetic process. The time is varied to study its effects on the structural, hydrodynamic and optical properties of these nanostructures. The techniques used to characterize these nanostructures were transmission electron microscopy, X-ray diffractometry, dynamic light scattering, and zetametry (zeta potential), and by energy dispersive X-ray, UV/vis, fluorescence, Fourier transform infrared, Raman and X-ray photoelectron spectroscopies. For gCNQDs and NGQDs, Raman spectroscopy showed an increase in disorder with synthesis time, indicating introduction of more triazine groups for the former and increase in doping with the N atoms for the latter, hence higher temperatures are recommended. For GQDs, Raman spectra showed an increase in the spatial order of the π-conjugated structure with synthesis time. Considering all the techniques employed in this work, the synthesis times of 6h and 8 h are recommended for GQDs and NGQDs.
- Full Text:
- Date Issued: 2022
Towards SDG 15.3: The biome context as the appropriate degradation monitoring dimension
- Xoxo, Sinetemba, Mantel, Sukhmani K, de Vos, Alta, Mahlaba, Bawinile, le Maître, David, Tanner, Jane L
- Authors: Xoxo, Sinetemba , Mantel, Sukhmani K , de Vos, Alta , Mahlaba, Bawinile , le Maître, David , Tanner, Jane L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415961 , vital:71304 , xlink:href="https://doi.org/10.1016/j.envsci.2022.07.008"
- Description: Accurate and reliable estimation of terrestrial ecosystem degradation is critical to meeting the challenge of reversing land degradation. Remote sensing data (especially land productivity dynamics) is commonly used to estimate land degradation, and this study uses the TRENDS.EARTH toolbox for the period covering 2000–2018, demonstrating the benefit of tracking the degradation process (SDG 15.3.1) at a biophysical unit. Contributing to the country’s SDG 15.3.1 monitoring, anthropogenic degradation was estimated based on RESTREND land productivity, biome-specific land cover trends, and soil organic carbon (SOC) stocks. Underlying degradation was evaluated by reclassifying a 28-year national land cover change dataset to match the UNCCD land cover legend. Analysis results indicate that land productivity changes (especially in stable grasslands, afforested, and cropland areas) mainly influenced the degradation status of the biome (19.9% degraded and 25.6% improvement). Global datasets also suggest that land cover and SOC had a minimal contribution (more than 2%) to anthropogenic degradation dynamics in the biome between 2000 and 2018. The GIS analysis showed that long-term, the major contributors to the biome’s underlying 9% anthropogenic degradation were woody proliferation into the Grassland Biome, urban expansion, and wetland drainage.
- Full Text:
- Date Issued: 2022
- Authors: Xoxo, Sinetemba , Mantel, Sukhmani K , de Vos, Alta , Mahlaba, Bawinile , le Maître, David , Tanner, Jane L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/415961 , vital:71304 , xlink:href="https://doi.org/10.1016/j.envsci.2022.07.008"
- Description: Accurate and reliable estimation of terrestrial ecosystem degradation is critical to meeting the challenge of reversing land degradation. Remote sensing data (especially land productivity dynamics) is commonly used to estimate land degradation, and this study uses the TRENDS.EARTH toolbox for the period covering 2000–2018, demonstrating the benefit of tracking the degradation process (SDG 15.3.1) at a biophysical unit. Contributing to the country’s SDG 15.3.1 monitoring, anthropogenic degradation was estimated based on RESTREND land productivity, biome-specific land cover trends, and soil organic carbon (SOC) stocks. Underlying degradation was evaluated by reclassifying a 28-year national land cover change dataset to match the UNCCD land cover legend. Analysis results indicate that land productivity changes (especially in stable grasslands, afforested, and cropland areas) mainly influenced the degradation status of the biome (19.9% degraded and 25.6% improvement). Global datasets also suggest that land cover and SOC had a minimal contribution (more than 2%) to anthropogenic degradation dynamics in the biome between 2000 and 2018. The GIS analysis showed that long-term, the major contributors to the biome’s underlying 9% anthropogenic degradation were woody proliferation into the Grassland Biome, urban expansion, and wetland drainage.
- Full Text:
- Date Issued: 2022
Trees stocks in domestic gardens and willingness to participate in tree planting initiatives in low-cost housing areas of the Eastern Cape, South Africa
- Gwedla, Nanamhla, Shackleton, Charlie M, Olvitt, Lausanne L
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M , Olvitt, Lausanne L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372825 , vital:66626 , xlink:href="https://doi.org/10.1016/j.ufug.2022.127484"
- Description: Increasing human populations and rapid urbanization in sub-Saharan Africa have prompted the development and maintenance of urban green infrastructure, including urban trees for sustainability, human wellbeing, liveability and climate resilience. However, there are still insufficient amounts and large inequities in the distribution of trees between and within towns and cities of the Global North and South. In South Africa, urban green space planning and planting are encoded in several policies at national level. However, these policies are rarely translated into specific guides, standards or actions, and consequently disparities in urban trees and green space distribution persist. This study assessed the prevalence of urban trees in domestic gardens in low-cost housing areas (LCHAs) of eight small to medium-sized towns in the Eastern Cape province of South Africa and examined residents’ perceptions in this regard. This was done via surveys with 800 households in old and recently developed LCHAs. The results revealed that most households (52 %) had at least one tree in their yard, with more households in the older neighbourhoods (60 %) reporting having trees than in the newer ones (44 %). Most of the trees (66 %) had been deliberately planted as opposed to natural regeneration. Experience of formal urban tree planting programs was low, but 75 % of residents expressed willingness to participate in the future, preferably in tree planting and maintenance. Urban green spaces and trees cannot be an afterthought in the development of sustainable human settlements, and municipal plans should reflect tangible commitments in this regard. Meeting goals for greener LCHAs requires the involvement of local residents, and for municipal authorities to be receptive to the wishes of residents and willingness to green their residential areas.
- Full Text:
- Date Issued: 2022
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M , Olvitt, Lausanne L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372825 , vital:66626 , xlink:href="https://doi.org/10.1016/j.ufug.2022.127484"
- Description: Increasing human populations and rapid urbanization in sub-Saharan Africa have prompted the development and maintenance of urban green infrastructure, including urban trees for sustainability, human wellbeing, liveability and climate resilience. However, there are still insufficient amounts and large inequities in the distribution of trees between and within towns and cities of the Global North and South. In South Africa, urban green space planning and planting are encoded in several policies at national level. However, these policies are rarely translated into specific guides, standards or actions, and consequently disparities in urban trees and green space distribution persist. This study assessed the prevalence of urban trees in domestic gardens in low-cost housing areas (LCHAs) of eight small to medium-sized towns in the Eastern Cape province of South Africa and examined residents’ perceptions in this regard. This was done via surveys with 800 households in old and recently developed LCHAs. The results revealed that most households (52 %) had at least one tree in their yard, with more households in the older neighbourhoods (60 %) reporting having trees than in the newer ones (44 %). Most of the trees (66 %) had been deliberately planted as opposed to natural regeneration. Experience of formal urban tree planting programs was low, but 75 % of residents expressed willingness to participate in the future, preferably in tree planting and maintenance. Urban green spaces and trees cannot be an afterthought in the development of sustainable human settlements, and municipal plans should reflect tangible commitments in this regard. Meeting goals for greener LCHAs requires the involvement of local residents, and for municipal authorities to be receptive to the wishes of residents and willingness to green their residential areas.
- Full Text:
- Date Issued: 2022
Ultrasensitive detection of prostate-specific antigen using glucose-encapsulated nanoliposomes anti-PSA polyclonal antibody as detection nanobioprobes
- Mwanza, Daniel, Mfamela, Nololo, Adeniyi, Omotayo, Nyokong, Tebello, Mashazi, Philani N
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
- Authors: Mwanza, Daniel , Mfamela, Nololo , Adeniyi, Omotayo , Nyokong, Tebello , Mashazi, Philani N
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300268 , vital:57911 , xlink:href="https://doi.org/10.1016/j.talanta.2022.123483"
- Description: In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL−1, 64 fg mL−1 and 10 fg mL−1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4–10 ng mL−1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.
- Full Text:
- Date Issued: 2022
Validity of categories related to gender identity in ICD-11 and DSM-5 among transgender individuals who seek gender-affirming medical procedures
- Robles, Rebeca, Keeley, Jared W, Vega-Ramírez, H, Cruz-Islas, Jeremy, Rodríguez-Pérez, Victor, Sharan, Pratap, Purnima, Shivani, Rao, Ravindra, Rodrigues-Lobato, María I, Soll, Bianca, Askevis-Leherpeux, Françoise, Roelandt, Jean-Luc, Campbell, Megan M, Grobler, Gerhard, Stein, Dan H, Khoury, Brigitte, El Khoury, Joseph, Fresán, Ana, Medina-Mora, María, Reed, Geoffrey M
- Authors: Robles, Rebeca , Keeley, Jared W , Vega-Ramírez, H , Cruz-Islas, Jeremy , Rodríguez-Pérez, Victor , Sharan, Pratap , Purnima, Shivani , Rao, Ravindra , Rodrigues-Lobato, María I , Soll, Bianca , Askevis-Leherpeux, Françoise , Roelandt, Jean-Luc , Campbell, Megan M , Grobler, Gerhard , Stein, Dan H , Khoury, Brigitte , El Khoury, Joseph , Fresán, Ana , Medina-Mora, María , Reed, Geoffrey M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302589 , vital:58210 , xlink:href="https://doi.org/10.1016/j.ijchp.2021.100281"
- Description: Background/Objective: The most recent versions of the two main mental disorders classifications—the World Health Organization's ICD-11 and the American Psychiatric Association's DSM–5—differ substantially in their diagnostic categories related to transgender identity. ICD-11 gender incongruence (GI), in contrast to DSM-5 gender dysphoria (GD), is explicitly not a mental disorder; neither distress nor dysfunction is a required feature. The objective was compared ICD-11 and DSM-5 diagnostic requirements in terms of their sensitivity, specificity, discriminability and ability to predict the use of gender-affirming medical procedures. Method: A total of 649 of transgender adults in six countries completed a retrospective structured interview. Results: Using ROC analysis, sensitivity of the diagnostic requirements was equivalent for both systems, but ICD-11 showed greater specificity than DSM-5. Regression analyses indicated that history of hormones and/or surgery was predicted by variables that are an intrinsic aspect of GI/GD more than by distress and dysfunction. IRT analyses showed that the ICD-11 diagnostic formulation was more parsimonious and contained more information about caseness than the DSM-5 model. Conclusions: This study supports the ICD-11 position that GI/GD is not a mental disorder; additional diagnostic requirements of distress and/or dysfunction in DSM-5 reduce the predictive power of the diagnostic model.
- Full Text:
- Date Issued: 2022
- Authors: Robles, Rebeca , Keeley, Jared W , Vega-Ramírez, H , Cruz-Islas, Jeremy , Rodríguez-Pérez, Victor , Sharan, Pratap , Purnima, Shivani , Rao, Ravindra , Rodrigues-Lobato, María I , Soll, Bianca , Askevis-Leherpeux, Françoise , Roelandt, Jean-Luc , Campbell, Megan M , Grobler, Gerhard , Stein, Dan H , Khoury, Brigitte , El Khoury, Joseph , Fresán, Ana , Medina-Mora, María , Reed, Geoffrey M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302589 , vital:58210 , xlink:href="https://doi.org/10.1016/j.ijchp.2021.100281"
- Description: Background/Objective: The most recent versions of the two main mental disorders classifications—the World Health Organization's ICD-11 and the American Psychiatric Association's DSM–5—differ substantially in their diagnostic categories related to transgender identity. ICD-11 gender incongruence (GI), in contrast to DSM-5 gender dysphoria (GD), is explicitly not a mental disorder; neither distress nor dysfunction is a required feature. The objective was compared ICD-11 and DSM-5 diagnostic requirements in terms of their sensitivity, specificity, discriminability and ability to predict the use of gender-affirming medical procedures. Method: A total of 649 of transgender adults in six countries completed a retrospective structured interview. Results: Using ROC analysis, sensitivity of the diagnostic requirements was equivalent for both systems, but ICD-11 showed greater specificity than DSM-5. Regression analyses indicated that history of hormones and/or surgery was predicted by variables that are an intrinsic aspect of GI/GD more than by distress and dysfunction. IRT analyses showed that the ICD-11 diagnostic formulation was more parsimonious and contained more information about caseness than the DSM-5 model. Conclusions: This study supports the ICD-11 position that GI/GD is not a mental disorder; additional diagnostic requirements of distress and/or dysfunction in DSM-5 reduce the predictive power of the diagnostic model.
- Full Text:
- Date Issued: 2022
The significance of mentorship in supporting the career advancement of women in the public sector
- Authors: Mcilongo, M , Strydom, K
- Date: 2021-06-11
- Subjects: Career development Career advancement ; Career ladder ; Career management ; Career planning ; Development, Career ; Development, Professional ; Employee development ; Organizational career development ; Professional development Computer File , Mentoring Mentorship Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6434 , vital:45498 , https://doi.org/10.1016/j.heliyon.2021.e07321
- Description: Historically, patriarchy has manifested itself in the workplace and influenced career opportunities afforded to women in the public sector. The slow progress in the transformation of organisations indicates there is a need for a structural developmental approach for women's career advancement. Mentoring has been recognised as a valuable development strategy and an affirmative action tool that can be used to support and promote women and groups that have been viewed as previously disadvantaged. The aim of the study was to highlight the significance of mentorship as a career advancement mechanism for women in the South African public sector. The study identified dimensions of mentorship (female mentors, career support, mentoring policy and leadership development) and tested the proposed hypotheses to determine whether a statistically significant relationship existed between mentorship and career advancement. A quantitative approach was followed to collect data from a sample of 200 women employed in the public sector in the different provinces of South Africa. Statistical methods used to conduct the data analysis included descriptive statistics and inferential statistics. The results indicate that women employees in the public sector view mentorship as an important factor for development; however, the gender of the mentor does not necessarily influence career advancement. Mechanisms to support mentoring have not been established in the public sector, highlighting the urgency for managers in the public sector to ensure that mentorship policies are put in place.
- Full Text:
- Date Issued: 2021-06-11
- Authors: Mcilongo, M , Strydom, K
- Date: 2021-06-11
- Subjects: Career development Career advancement ; Career ladder ; Career management ; Career planning ; Development, Career ; Development, Professional ; Employee development ; Organizational career development ; Professional development Computer File , Mentoring Mentorship Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6434 , vital:45498 , https://doi.org/10.1016/j.heliyon.2021.e07321
- Description: Historically, patriarchy has manifested itself in the workplace and influenced career opportunities afforded to women in the public sector. The slow progress in the transformation of organisations indicates there is a need for a structural developmental approach for women's career advancement. Mentoring has been recognised as a valuable development strategy and an affirmative action tool that can be used to support and promote women and groups that have been viewed as previously disadvantaged. The aim of the study was to highlight the significance of mentorship as a career advancement mechanism for women in the South African public sector. The study identified dimensions of mentorship (female mentors, career support, mentoring policy and leadership development) and tested the proposed hypotheses to determine whether a statistically significant relationship existed between mentorship and career advancement. A quantitative approach was followed to collect data from a sample of 200 women employed in the public sector in the different provinces of South Africa. Statistical methods used to conduct the data analysis included descriptive statistics and inferential statistics. The results indicate that women employees in the public sector view mentorship as an important factor for development; however, the gender of the mentor does not necessarily influence career advancement. Mechanisms to support mentoring have not been established in the public sector, highlighting the urgency for managers in the public sector to ensure that mentorship policies are put in place.
- Full Text:
- Date Issued: 2021-06-11
The significance of mentorship in supporting the career advancement of women in the public sector
- Mcilongo, M, Strydom, K (https://orcid.org/ 0000-0001-8141-7673)
- Authors: Mcilongo, M , Strydom, K (https://orcid.org/ 0000-0001-8141-7673)
- Date: 2021-06-11
- Subjects: Career development Career advancement ; Career ladder ; Career management ; Career planning ; Development, Career ; Development, Professional ; Employee development ; Organizational career development ; Professional development Computer File , Mentoring Mentorship Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6423 , vital:45497 , https://doi.org/10.1016/j.heliyon.2021.e07321
- Description: Historically, patriarchy has manifested itself in the workplace and influenced career opportunities afforded to women in the public sector. The slow progress in the transformation of organisations indicates there is a need for a structural developmental approach for women's career advancement. Mentoring has been recognised as a valuable development strategy and an affirmative action tool that can be used to support and promote women and groups that have been viewed as previously disadvantaged. The aim of the study was to highlight the significance of mentorship as a career advancement mechanism for women in the South African public sector. The study identified dimensions of mentorship (female mentors, career support, mentoring policy and leadership development) and tested the proposed hypotheses to determine whether a statistically significant relationship existed between mentorship and career advancement. A quantitative approach was followed to collect data from a sample of 200 women employed in the public sector in the different provinces of South Africa. Statistical methods used to conduct the data analysis included descriptive statistics and inferential statistics. The results indicate that women employees in the public sector view mentorship as an important factor for development; however, the gender of the mentor does not necessarily influence career advancement. Mechanisms to support mentoring have not been established in the public sector, highlighting the urgency for managers in the public sector to ensure that mentorship policies are put in place.
- Full Text:
- Date Issued: 2021-06-11
- Authors: Mcilongo, M , Strydom, K (https://orcid.org/ 0000-0001-8141-7673)
- Date: 2021-06-11
- Subjects: Career development Career advancement ; Career ladder ; Career management ; Career planning ; Development, Career ; Development, Professional ; Employee development ; Organizational career development ; Professional development Computer File , Mentoring Mentorship Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6423 , vital:45497 , https://doi.org/10.1016/j.heliyon.2021.e07321
- Description: Historically, patriarchy has manifested itself in the workplace and influenced career opportunities afforded to women in the public sector. The slow progress in the transformation of organisations indicates there is a need for a structural developmental approach for women's career advancement. Mentoring has been recognised as a valuable development strategy and an affirmative action tool that can be used to support and promote women and groups that have been viewed as previously disadvantaged. The aim of the study was to highlight the significance of mentorship as a career advancement mechanism for women in the South African public sector. The study identified dimensions of mentorship (female mentors, career support, mentoring policy and leadership development) and tested the proposed hypotheses to determine whether a statistically significant relationship existed between mentorship and career advancement. A quantitative approach was followed to collect data from a sample of 200 women employed in the public sector in the different provinces of South Africa. Statistical methods used to conduct the data analysis included descriptive statistics and inferential statistics. The results indicate that women employees in the public sector view mentorship as an important factor for development; however, the gender of the mentor does not necessarily influence career advancement. Mechanisms to support mentoring have not been established in the public sector, highlighting the urgency for managers in the public sector to ensure that mentorship policies are put in place.
- Full Text:
- Date Issued: 2021-06-11
5-Fu inclusion complex capped gold nanoparticles for breast cancer therapy
- Lakkakula, Jaya R, Krause, Rui W M, Divakaran, Deepika, Barage, Sagar, Srivastava, Rohit
- Authors: Lakkakula, Jaya R , Krause, Rui W M , Divakaran, Deepika , Barage, Sagar , Srivastava, Rohit
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191713 , vital:45150 , xlink:href="https://doi.org/10.1016/j.molliq.2021.117262"
- Description: We have attempted to prolong the circulation time and increase the solubility of 5-Fluorouracil by complexing it with cyclodextrin and then further conjugating onto the gold nanoparticle to form 5Fu ICAu. The 1H NMR and molecular docking studies suggested that 5-Fu was included within the 2HP-β-CD cavity and H-5 proton probably serves as the binding site for stabilization of the inclusion complex. The 5Fu-ICAu showed higher cell inhibition rate when studied on MDA-MB-231 and MCF-7 breast cancer cell lines due to the enhanced permeability and retention (EPR) effect by allowing the selective accumulation of nanoparticles at tumor site. This unique system can serve as a novel nanocarrier for delivery of hydrophobic drugs.
- Full Text:
- Date Issued: 2021
- Authors: Lakkakula, Jaya R , Krause, Rui W M , Divakaran, Deepika , Barage, Sagar , Srivastava, Rohit
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191713 , vital:45150 , xlink:href="https://doi.org/10.1016/j.molliq.2021.117262"
- Description: We have attempted to prolong the circulation time and increase the solubility of 5-Fluorouracil by complexing it with cyclodextrin and then further conjugating onto the gold nanoparticle to form 5Fu ICAu. The 1H NMR and molecular docking studies suggested that 5-Fu was included within the 2HP-β-CD cavity and H-5 proton probably serves as the binding site for stabilization of the inclusion complex. The 5Fu-ICAu showed higher cell inhibition rate when studied on MDA-MB-231 and MCF-7 breast cancer cell lines due to the enhanced permeability and retention (EPR) effect by allowing the selective accumulation of nanoparticles at tumor site. This unique system can serve as a novel nanocarrier for delivery of hydrophobic drugs.
- Full Text:
- Date Issued: 2021
Addressing the red flags in cochineal identification: The use of molecular techniques to identify cochineal insects that are used as biological control agents for invasive alien cacti
- van Steenderen, Clarke J M, Paterson, Iain D, Edwards, Shelley, Day, Michael D
- Authors: van Steenderen, Clarke J M , Paterson, Iain D , Edwards, Shelley , Day, Michael D
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423282 , vital:72044 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104426"
- Description: Invasive Cactaceae cause considerable damage to ecosystem function and agricultural practices around the world. The most successful biological control agents used to combat this group of weeds belong to the genus Dactylopius (Hemiptera: Dactylopiidae), commonly known as ‘cochineal’. Effective control relies on selecting the correct species, or in some cases, the most effective intraspecific lineage, of cochineal for the target cactus species. Many of the Dactylopius species are so morphologically similar, and in the case of intraspecific lineages, identical, that numerous misidentifications have been made in the past. These errors have resulted in failed attempts at the biological control of some cactus species. This study aimed to generate a multi-locus genetic database to enable the accurate identification of dactylopiids. Genetic characterization was achieved through the nucleotide sequencing of three gene regions (12S rRNA, 18S rRNA, and COI) and two inter-simple sequence repeats (ISSR). Nucleotide sequences were very effective for species-level and D. tomentosus lineage-level identification, but could not distinguish between the two lineages within D. opuntiae commonly used for biological control of various Opuntia spp. Fragment analysis through the use of ISSRs successfully addressed this issue. This is the first time that a method has been developed that can distinguish between these two D. opuntiae lineages. Using the methods developed in this study, biological control practitioners can ensure that the most effective agent species and lineages are used for each cactus target weed, thus maximizing the level of control.
- Full Text:
- Date Issued: 2021
- Authors: van Steenderen, Clarke J M , Paterson, Iain D , Edwards, Shelley , Day, Michael D
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423282 , vital:72044 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104426"
- Description: Invasive Cactaceae cause considerable damage to ecosystem function and agricultural practices around the world. The most successful biological control agents used to combat this group of weeds belong to the genus Dactylopius (Hemiptera: Dactylopiidae), commonly known as ‘cochineal’. Effective control relies on selecting the correct species, or in some cases, the most effective intraspecific lineage, of cochineal for the target cactus species. Many of the Dactylopius species are so morphologically similar, and in the case of intraspecific lineages, identical, that numerous misidentifications have been made in the past. These errors have resulted in failed attempts at the biological control of some cactus species. This study aimed to generate a multi-locus genetic database to enable the accurate identification of dactylopiids. Genetic characterization was achieved through the nucleotide sequencing of three gene regions (12S rRNA, 18S rRNA, and COI) and two inter-simple sequence repeats (ISSR). Nucleotide sequences were very effective for species-level and D. tomentosus lineage-level identification, but could not distinguish between the two lineages within D. opuntiae commonly used for biological control of various Opuntia spp. Fragment analysis through the use of ISSRs successfully addressed this issue. This is the first time that a method has been developed that can distinguish between these two D. opuntiae lineages. Using the methods developed in this study, biological control practitioners can ensure that the most effective agent species and lineages are used for each cactus target weed, thus maximizing the level of control.
- Full Text:
- Date Issued: 2021
Allosteric pockets and dynamic residue network hubs of falcipain 2 in mutations including those linked to artemisinin resistance
- Okeke, Chiamaka J, Musyoka, Thommas M, Sheik Amamuddy, Olivier, Barozi, Victor, Tastan Bishop, Özlem
- Authors: Okeke, Chiamaka J , Musyoka, Thommas M , Sheik Amamuddy, Olivier , Barozi, Victor , Tastan Bishop, Özlem
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/476585 , vital:77939 , xlink:href="https://doi.org/10.1016/j.csbj.2021.10.011"
- Description: Continually emerging resistant strains of malarial parasites to current drugs present challenges. Understanding the underlying resistance mechanisms, especially those linked to allostery is, thus, highly crucial for drug design. This forms the main concern of the paper through a case study of falcipain 2 (FP-2) and its mutations, some of which are linked to artemisinin (ART) drug resistance. Here, we applied a variety of in silico approaches and tools that we developed recently, together with existing computational tools. This included novel essential dynamics and dynamic residue network (DRN) analysis algorithms. We identified six pockets demonstrating dynamic differences in the presence of some mutations. We observed striking allosteric effects in two mutant proteins. In the presence of M245I, a cryptic pocket was detected via a unique mechanism in which Pocket 2 fused with Pocket 6. In the presence of the A353T mutation, which is located at Pocket 2, the pocket became the most rigid among all protein systems analyzed. Pocket 6 was also highly stable in all cases, except in the presence of M245I mutation. The effect of ART linked mutations was more subtle, and the changes were at residue level. Importantly, we identified an allosteric communication path formed by four unique averaged BC hubs going from the mutated residue to the catalytic site and passing through the interface of three identified pockets. Collectively, we established and demonstrated that we have robust tools and a pipeline that can be applicable to the analysis of mutations.
- Full Text:
- Date Issued: 2021
- Authors: Okeke, Chiamaka J , Musyoka, Thommas M , Sheik Amamuddy, Olivier , Barozi, Victor , Tastan Bishop, Özlem
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/476585 , vital:77939 , xlink:href="https://doi.org/10.1016/j.csbj.2021.10.011"
- Description: Continually emerging resistant strains of malarial parasites to current drugs present challenges. Understanding the underlying resistance mechanisms, especially those linked to allostery is, thus, highly crucial for drug design. This forms the main concern of the paper through a case study of falcipain 2 (FP-2) and its mutations, some of which are linked to artemisinin (ART) drug resistance. Here, we applied a variety of in silico approaches and tools that we developed recently, together with existing computational tools. This included novel essential dynamics and dynamic residue network (DRN) analysis algorithms. We identified six pockets demonstrating dynamic differences in the presence of some mutations. We observed striking allosteric effects in two mutant proteins. In the presence of M245I, a cryptic pocket was detected via a unique mechanism in which Pocket 2 fused with Pocket 6. In the presence of the A353T mutation, which is located at Pocket 2, the pocket became the most rigid among all protein systems analyzed. Pocket 6 was also highly stable in all cases, except in the presence of M245I mutation. The effect of ART linked mutations was more subtle, and the changes were at residue level. Importantly, we identified an allosteric communication path formed by four unique averaged BC hubs going from the mutated residue to the catalytic site and passing through the interface of three identified pockets. Collectively, we established and demonstrated that we have robust tools and a pipeline that can be applicable to the analysis of mutations.
- Full Text:
- Date Issued: 2021
Aluminum corrosion retardation properties of acetamidophenoxy phthalocyanines: Effect of central metal
- Nnaji, Nnaemeka, Sen, Pinar, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Sen, Pinar , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185433 , vital:44386 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130806"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for metal free (2), ClGa (3) and Co (4) tetrakis (4-acetamidophenoxy) phthalocyanine. Electrochemical techniques were used in the study and complemented with Fourier transform infrared, scanning electron microscopy and X-ray diffraction measurements. Potentiodynamic polarization technique gave inhibition efficiency values as 93.3% (2), 69.7% (3) and 87.7% (4) at 28°C at highest inhibitor concentration (10 µM) in the following order 2 > 4 > 3. These compounds exhibited good corrosion inhibition performance as mixed-type corrosion inhibitors. All applied techniques gave results which corroborated.
- Full Text:
- Date Issued: 2021
- Authors: Nnaji, Nnaemeka , Sen, Pinar , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185433 , vital:44386 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.130806"
- Description: Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for metal free (2), ClGa (3) and Co (4) tetrakis (4-acetamidophenoxy) phthalocyanine. Electrochemical techniques were used in the study and complemented with Fourier transform infrared, scanning electron microscopy and X-ray diffraction measurements. Potentiodynamic polarization technique gave inhibition efficiency values as 93.3% (2), 69.7% (3) and 87.7% (4) at 28°C at highest inhibitor concentration (10 µM) in the following order 2 > 4 > 3. These compounds exhibited good corrosion inhibition performance as mixed-type corrosion inhibitors. All applied techniques gave results which corroborated.
- Full Text:
- Date Issued: 2021
Amphiphilic axially modified cationic indium-porphyrins linked to hydrophilic magnetic nanoparticles for photodynamic antimicrobial chemotherapy against gram-negative strain; Escherichia coli
- Makolla, Collen L, Mgidlana, Sithi, Nyokong, Tebello
- Authors: Makolla, Collen L , Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185024 , vital:44317 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109262"
- Description: In this study, we report on the synthesis, characterization, and application of indium porphyrins linked to silver core-shell magnetic nanoparticles for in vitro photodynamic antimicrobial chemotherapy (PACT) against gram-negative strain, E. coli. This work compares the photophysicochemical and PACT activities of InCl 5-p-carboxyphenyl-10-15-20-(tris-4-methylpyridinium)-triiodide porphyrin (1), InCl 5-p-carboxyphenyl-10-15-20-(tris-4-hexylpyridinium)-triiodide porphyrin (2), In (para-aminophenyl) 5,10,15,20-tetrakis(4-methylpyridinium)-tetraiodide porphyrin (3), and In (para-aminophenyl) 5,10,15,20-tetrakis(4-hexylpyridinium)-tetraiodide porphyrin (4). The comparisons were based on the structure and number of charges. Hydrophilic and hydrophobic characters of the amphiphilic porphyrins were studied by comparing the effect of the different alkyl halides (iodomethane and iodohexane) quaternizing agents. The porphyrin complexes were further linked to magnetic nanoparticles to facilitate antimicrobial synergy and recovery of the complexes after use. High Log reduction values ranging from 7.19 to 9.58 were obtained for the quaternized complexes.
- Full Text:
- Date Issued: 2021
- Authors: Makolla, Collen L , Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185024 , vital:44317 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109262"
- Description: In this study, we report on the synthesis, characterization, and application of indium porphyrins linked to silver core-shell magnetic nanoparticles for in vitro photodynamic antimicrobial chemotherapy (PACT) against gram-negative strain, E. coli. This work compares the photophysicochemical and PACT activities of InCl 5-p-carboxyphenyl-10-15-20-(tris-4-methylpyridinium)-triiodide porphyrin (1), InCl 5-p-carboxyphenyl-10-15-20-(tris-4-hexylpyridinium)-triiodide porphyrin (2), In (para-aminophenyl) 5,10,15,20-tetrakis(4-methylpyridinium)-tetraiodide porphyrin (3), and In (para-aminophenyl) 5,10,15,20-tetrakis(4-hexylpyridinium)-tetraiodide porphyrin (4). The comparisons were based on the structure and number of charges. Hydrophilic and hydrophobic characters of the amphiphilic porphyrins were studied by comparing the effect of the different alkyl halides (iodomethane and iodohexane) quaternizing agents. The porphyrin complexes were further linked to magnetic nanoparticles to facilitate antimicrobial synergy and recovery of the complexes after use. High Log reduction values ranging from 7.19 to 9.58 were obtained for the quaternized complexes.
- Full Text:
- Date Issued: 2021