Framed photograph of Dr. Brigalia Bam and former South African President Thabo Mbeki
- Date: 2022 , 2022-10-06
- Subjects: Bam, Brigalia
- Language: English
- Type: photograph , realia
- Identifier: http://hdl.handle.net/10948/56985 , vital:57210
- Description: Framed photograph of Dr. Brigalia Bam and former South African President Thabo Mbeki. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-06
- Subjects: Bam, Brigalia
- Language: English
- Type: photograph , realia
- Identifier: http://hdl.handle.net/10948/56985 , vital:57210
- Description: Framed photograph of Dr. Brigalia Bam and former South African President Thabo Mbeki. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Fuelwood in South Africa Revisited: Widespread Use in a Policy Vacuum
- Shackleton, Charlie M, Sinasson, Gisele, Adeyemi, Opeyemi, Martins, Vusumzi
- Authors: Shackleton, Charlie M , Sinasson, Gisele , Adeyemi, Opeyemi , Martins, Vusumzi
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402275 , vital:69837 , xlink:href="https://doi.org/10.3390/su141711018"
- Description: South Africa has experienced massive urbanisation and socioeconomic development over the past two decades. Concomitantly, the national energy policy focuses on the provision of modern fuels, notably electricity, for domestic use. Given this policy environment and socioeconomic development, we examine pertinent literature and policies from South Africa on fuelwood use, value, and sustainability to understand how it might have changed in tandem with the national shifts in urbanisation and socioeconomic development over the last 20 years. Recent literature shows that fuelwood is still used to some extent by 96% of rural households and 69% of low-income urban ones. We also estimate that the use of fuelwood by rural households alone is valued at approximately ZAR 10.5 billion (approx. USD 700 million) annually, with the probability of an equally high value to low-income urban households. However, despite the extensive use and high value, our analysis of cognate national policies related to energy, forestry, environment, and social development, show that fuelwood and its use is hardly considered, indicating a policy vacuum. This policy vacuum means that there is no strategic or apposite support or interventions in any localised areas where fuelwood demand might exceed supply, thereby undermining the livelihoods and energy security of affected citizens, most notably the poor.
- Full Text:
- Date Issued: 2022
- Authors: Shackleton, Charlie M , Sinasson, Gisele , Adeyemi, Opeyemi , Martins, Vusumzi
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402275 , vital:69837 , xlink:href="https://doi.org/10.3390/su141711018"
- Description: South Africa has experienced massive urbanisation and socioeconomic development over the past two decades. Concomitantly, the national energy policy focuses on the provision of modern fuels, notably electricity, for domestic use. Given this policy environment and socioeconomic development, we examine pertinent literature and policies from South Africa on fuelwood use, value, and sustainability to understand how it might have changed in tandem with the national shifts in urbanisation and socioeconomic development over the last 20 years. Recent literature shows that fuelwood is still used to some extent by 96% of rural households and 69% of low-income urban ones. We also estimate that the use of fuelwood by rural households alone is valued at approximately ZAR 10.5 billion (approx. USD 700 million) annually, with the probability of an equally high value to low-income urban households. However, despite the extensive use and high value, our analysis of cognate national policies related to energy, forestry, environment, and social development, show that fuelwood and its use is hardly considered, indicating a policy vacuum. This policy vacuum means that there is no strategic or apposite support or interventions in any localised areas where fuelwood demand might exceed supply, thereby undermining the livelihoods and energy security of affected citizens, most notably the poor.
- Full Text:
- Date Issued: 2022
Ga III triarylcorroles with push–pull substitutions
- Niu, Yingjie, Wang, Lin, Guo, Yingxin, Zhu, Weihua, Soy, Rodah C, Babu, Balaji, Mack, John, Nyokong, Tebello, Xu, Haijun, Liang, Xu
- Authors: Niu, Yingjie , Wang, Lin , Guo, Yingxin , Zhu, Weihua , Soy, Rodah C , Babu, Balaji , Mack, John , Nyokong, Tebello , Xu, Haijun , Liang, Xu
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300079 , vital:57890 , xlink:href="https://doi.org/10.1039/D2DT01262F"
- Description: Two A2B type H3corroles and two GaIIItriarylcorroles with carbazole substitutions at 10-positions were synthesized and characterized. An analysis of structure–property relationships of the corroles has been carried out by investigating the optical spectroscopy of the dyes to trends predicted in DFT and TD-DFT calculations. Interestingly, the photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties of the GaIIItriarylcorroles were determined against the MCF-7 breast cancer line, and Staphyloccocus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The cationic G-2Q species exhibited the most favorable properties with an IC50 value of 7.8 μM against MCF-7 cells, and Log reduction values of 7.78 and 3.26 against planktonic S. aureus and E. coli at 0.5 and 10 μM, respectively.
- Full Text:
- Date Issued: 2022
- Authors: Niu, Yingjie , Wang, Lin , Guo, Yingxin , Zhu, Weihua , Soy, Rodah C , Babu, Balaji , Mack, John , Nyokong, Tebello , Xu, Haijun , Liang, Xu
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300079 , vital:57890 , xlink:href="https://doi.org/10.1039/D2DT01262F"
- Description: Two A2B type H3corroles and two GaIIItriarylcorroles with carbazole substitutions at 10-positions were synthesized and characterized. An analysis of structure–property relationships of the corroles has been carried out by investigating the optical spectroscopy of the dyes to trends predicted in DFT and TD-DFT calculations. Interestingly, the photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties of the GaIIItriarylcorroles were determined against the MCF-7 breast cancer line, and Staphyloccocus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The cationic G-2Q species exhibited the most favorable properties with an IC50 value of 7.8 μM against MCF-7 cells, and Log reduction values of 7.78 and 3.26 against planktonic S. aureus and E. coli at 0.5 and 10 μM, respectively.
- Full Text:
- Date Issued: 2022
Hand painted portrait of Dr. Brigalia Bam, with a blue and yellow background
- Date: 2022 , 2022-09-23
- Subjects: Bam, Brigalia , Bam, Brigalia -- Portraits
- Language: English
- Type: Portraits , realia
- Identifier: http://hdl.handle.net/10948/56575 , vital:56865
- Description: Hand painted portrait of Dr. Brigalia Bam, with a blue and yellow background. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-09-23
- Subjects: Bam, Brigalia , Bam, Brigalia -- Portraits
- Language: English
- Type: Portraits , realia
- Identifier: http://hdl.handle.net/10948/56575 , vital:56865
- Description: Hand painted portrait of Dr. Brigalia Bam, with a blue and yellow background. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Hand-lettered praise citation with blue and yellow painted background
- Date: 2022 , 2022-10-11
- Subjects: Bam, Brigalia
- Language: English
- Type: painting , realia
- Identifier: http://hdl.handle.net/10948/57115 , vital:57323
- Description: Hand-lettered praise citation with blue and yellow painted background, in a wooden frame and cream mount board. This was a gift to Dr. Brigalia Bam from the Christiam Women's Movement. , Dr. Brigalia Bam was honored as heroic daughter of Africa, with deep respect and sisterly appreciation of her outstanding achievement for God, for Women and for Africa. Dr. Brigalia Bam was also honored for her enthusiastic and dynamic contribution to society, youth, human rights, Christian Unity, justice and reconciliation. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-11
- Subjects: Bam, Brigalia
- Language: English
- Type: painting , realia
- Identifier: http://hdl.handle.net/10948/57115 , vital:57323
- Description: Hand-lettered praise citation with blue and yellow painted background, in a wooden frame and cream mount board. This was a gift to Dr. Brigalia Bam from the Christiam Women's Movement. , Dr. Brigalia Bam was honored as heroic daughter of Africa, with deep respect and sisterly appreciation of her outstanding achievement for God, for Women and for Africa. Dr. Brigalia Bam was also honored for her enthusiastic and dynamic contribution to society, youth, human rights, Christian Unity, justice and reconciliation. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
How many people globally actually use non-timber forest products?
- Shackleton, Charlie M, de Vos, Alta
- Authors: Shackleton, Charlie M , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403200 , vital:69933 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Non-timber forest products (NTFPs) are widely used wild, biological products harvested from rural and urban landscapes for household subsistence, income and culture, thereby contributing to human wellbeing. Estimates of the numbers of people making use of, or being dependent on, NTFPs vary widely, and global estimates to date have excluded urban populations and also NTFP users in the Global North. Additionally, most global or continental estimates are two or more decades old, and hence do not account for significant worldwide changes in societies, cultures, economies and landscapes since the estimates were made. Here we collate more recent empirical studies reporting the number of NTFP users at fine scales that we extrapolate up for three broad regions, viz. rural areas of the Global South, urban areas of the Global South, and the Global North, as the basis for estimating the number of NTFP users globally. We calculate the lower and upper bounds, as well a median estimate. We find the lowest and median approximations to be 3.5 billion and 5.76 billion users globally, respectively, based on conservative approaches. This is more than double and triple, respectively, the oft cited and dated figure of 1.6 billion. Moreover, we find that only half of the global NTFP users are located in rural regions of the Global South, and that the other half are in urban areas and the Global North, showing that NTFPs are of importance across socio-economic and geographic regions, not just in remote and underdeveloped villages of the Global South. With such large numbers of users around the world, it is imperative that the supply, management, conservation and safeguarding of the values of NTFPs take a more central place in sectoral and development policies.
- Full Text:
- Date Issued: 2022
- Authors: Shackleton, Charlie M , de Vos, Alta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/403200 , vital:69933 , xlink:href="https://doi.org/10.1016/j.forpol.2021.102659"
- Description: Non-timber forest products (NTFPs) are widely used wild, biological products harvested from rural and urban landscapes for household subsistence, income and culture, thereby contributing to human wellbeing. Estimates of the numbers of people making use of, or being dependent on, NTFPs vary widely, and global estimates to date have excluded urban populations and also NTFP users in the Global North. Additionally, most global or continental estimates are two or more decades old, and hence do not account for significant worldwide changes in societies, cultures, economies and landscapes since the estimates were made. Here we collate more recent empirical studies reporting the number of NTFP users at fine scales that we extrapolate up for three broad regions, viz. rural areas of the Global South, urban areas of the Global South, and the Global North, as the basis for estimating the number of NTFP users globally. We calculate the lower and upper bounds, as well a median estimate. We find the lowest and median approximations to be 3.5 billion and 5.76 billion users globally, respectively, based on conservative approaches. This is more than double and triple, respectively, the oft cited and dated figure of 1.6 billion. Moreover, we find that only half of the global NTFP users are located in rural regions of the Global South, and that the other half are in urban areas and the Global North, showing that NTFPs are of importance across socio-economic and geographic regions, not just in remote and underdeveloped villages of the Global South. With such large numbers of users around the world, it is imperative that the supply, management, conservation and safeguarding of the values of NTFPs take a more central place in sectoral and development policies.
- Full Text:
- Date Issued: 2022
Impedimetric aptasensor for HER2 biomarker using graphene quantum dots, polypyrrole and cobalt phthalocyanine modified electrodes
- Centane, Sixolile, Nyokong, Tebello
- Authors: Centane, Sixolile , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230960 , vital:49836 , xlink:href="https://doi.org/10.1016/j.sbsr.2021.100467"
- Description: A method is presented for the electrochemical detection of the breast cancer biomarker human epidermal growth factor receptor 2 (HER2). A glassy carbon electrode was modified using two techniques known as sequential adsorption and electro-polymerization, and the results are compared. The highly conductive polypyrrole (PPy) is used, in the presence of sulfur/nitrogen doped graphene quantum dots (SNGQDs) and a known cobalt phthalocyanine (CoPc). The different nanomaterials were used as an immobilization platform for the HER2 specific HB5 aptamer via amide linkage. The nanomaterials were arranged in various ways on the glassy carbon electrode, to investigate the effect of the electrode interface on the operational characteristics of a biosensor. The immobilized aptamer selectively recognizes HER2 on the electrode interface, and this leads to an increased charge transfer resistance (Rct) of the electrode when using ferricyanide as the electrochemical probe. The developed immunosensors showed high sensitivity with the best detection limit of 0.00141 ng/mL. The results showed that the method is simple and sensitive enough for the determination of HER2 in serum samples with good reproducibility and accuracy.
- Full Text:
- Date Issued: 2022
- Authors: Centane, Sixolile , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230960 , vital:49836 , xlink:href="https://doi.org/10.1016/j.sbsr.2021.100467"
- Description: A method is presented for the electrochemical detection of the breast cancer biomarker human epidermal growth factor receptor 2 (HER2). A glassy carbon electrode was modified using two techniques known as sequential adsorption and electro-polymerization, and the results are compared. The highly conductive polypyrrole (PPy) is used, in the presence of sulfur/nitrogen doped graphene quantum dots (SNGQDs) and a known cobalt phthalocyanine (CoPc). The different nanomaterials were used as an immobilization platform for the HER2 specific HB5 aptamer via amide linkage. The nanomaterials were arranged in various ways on the glassy carbon electrode, to investigate the effect of the electrode interface on the operational characteristics of a biosensor. The immobilized aptamer selectively recognizes HER2 on the electrode interface, and this leads to an increased charge transfer resistance (Rct) of the electrode when using ferricyanide as the electrochemical probe. The developed immunosensors showed high sensitivity with the best detection limit of 0.00141 ng/mL. The results showed that the method is simple and sensitive enough for the determination of HER2 in serum samples with good reproducibility and accuracy.
- Full Text:
- Date Issued: 2022
In Silico analysis of Spermidine, Spermine and Putrescine interaction with selected heat shock proteins from Plasmodium falciparum 3D7 towards malaria drug development
- Authors: Godlo, Sesethu
- Date: 2022
- Subjects: Heat shock proteins , Malaria vaccine , Plasmodium falciparum
- Language: English
- Type: Master'stheses , text
- Identifier: http://hdl.handle.net/10353/27709 , vital:69395
- Description: Malaria is a mosquito-borne disease that affects around half of the world's population. It is one of the most common parasite infections that endangers human life. One of the most serious issues in malaria therapy is the emergence and spread of antimalarial drug-resistant Plasmodium parasites. This is due to the Plasmodium parasite's constant evolution and development of new methods of surviving medication toxicity. Studies of antimalarial drug development have been focused on polyamine biosynthesis by targeting precursors such as ornithine decarboxylase, adenosylmethionine decarboxylase, and spermidine synthase and protein-protein interactions between Plasmodium falciparum chaperones spotting out Hsp90, Hsp70, and Hsp40 as potential targets with little attention being paid to the interaction between polyamines and molecular chaperones. Therefore, this study seeks to identify interactions between polyamines and molecular chaperones present in the malarial parasite Plasmodium falciparum 3D7. The identification of these interactions might lead to the design of effective drugs to treat and eliminate malaria. Using computational analysis, this study aims to find interactions between polyamines and molecular chaperones found in the malarial parasite Plasmodium falciparum 3D7. The sequences of the selected heat proteins retrieved, and the 3D structures predicted and validated. These structures were docked with polyamines retrieved from PubChem and MD simulations on the docked interactions were performed. Docking revealed common amino acid residues with hydrogen bonds and salt bridges between all receptors and ligands, with glutamine and aspartic acid standing out. MD simulations revealed that when HSP20 and HSP40 transport the ligands, they pop up or are released too quickly. However, HSP60, HSP70, and HSP90 provide optimism since the ligands remain attached to the proteins for a specific amount of time. To further understand and confirm these interactions wet laboratory studies may be carried out in future. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
- Authors: Godlo, Sesethu
- Date: 2022
- Subjects: Heat shock proteins , Malaria vaccine , Plasmodium falciparum
- Language: English
- Type: Master'stheses , text
- Identifier: http://hdl.handle.net/10353/27709 , vital:69395
- Description: Malaria is a mosquito-borne disease that affects around half of the world's population. It is one of the most common parasite infections that endangers human life. One of the most serious issues in malaria therapy is the emergence and spread of antimalarial drug-resistant Plasmodium parasites. This is due to the Plasmodium parasite's constant evolution and development of new methods of surviving medication toxicity. Studies of antimalarial drug development have been focused on polyamine biosynthesis by targeting precursors such as ornithine decarboxylase, adenosylmethionine decarboxylase, and spermidine synthase and protein-protein interactions between Plasmodium falciparum chaperones spotting out Hsp90, Hsp70, and Hsp40 as potential targets with little attention being paid to the interaction between polyamines and molecular chaperones. Therefore, this study seeks to identify interactions between polyamines and molecular chaperones present in the malarial parasite Plasmodium falciparum 3D7. The identification of these interactions might lead to the design of effective drugs to treat and eliminate malaria. Using computational analysis, this study aims to find interactions between polyamines and molecular chaperones found in the malarial parasite Plasmodium falciparum 3D7. The sequences of the selected heat proteins retrieved, and the 3D structures predicted and validated. These structures were docked with polyamines retrieved from PubChem and MD simulations on the docked interactions were performed. Docking revealed common amino acid residues with hydrogen bonds and salt bridges between all receptors and ligands, with glutamine and aspartic acid standing out. MD simulations revealed that when HSP20 and HSP40 transport the ligands, they pop up or are released too quickly. However, HSP60, HSP70, and HSP90 provide optimism since the ligands remain attached to the proteins for a specific amount of time. To further understand and confirm these interactions wet laboratory studies may be carried out in future. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
In vitro photoinactivation of S. aureus and photocatalytic degradation of tetracycline by novel phthalocyanine-graphene quantum dots nano-assemblies
- Openda, Yolande Ikala, Mgidlana, Sithi, Nyokong, Tebello
- Authors: Openda, Yolande Ikala , Mgidlana, Sithi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229895 , vital:49721 , xlink:href="https://doi.org/10.1016/j.jlumin.2022.118863"
- Description: A novel asymmetrical zinc (II) phthalocyanine (Pc) 4 bearing three dimethoxy groups and one carboxyl group was linked to glutathione capped graphene quantum dots (GQDs) by the reaction of carboxylic acid substituent on Pc 4 with the amino group on the GQDs. On the other side, the symmetrical Pc analog 3 was linked to the same nanoparticles through π-π interactions. The as-formed nano-photosensitizers were fully characterized by spectroscopic methods and their photophysicochemical properties were investigated as well. Photodynamic antimicrobial chemotherapy was performed on the planktonic cells of S. aureus strain. And the results show that these nano assemblies were able to completely inhibit the metabolic activity of the resistant bacteria strain S. aureus with a 10.26 log reduction in the viable count. Again, asymmetrical Pc showed higher photocatalytic activity compared to the symmetrical complex with higher kobs and fast initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model. The target conjugates showed all the advantages of two different groups existing on a single entity.
- Full Text:
- Date Issued: 2022
- Authors: Openda, Yolande Ikala , Mgidlana, Sithi , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229895 , vital:49721 , xlink:href="https://doi.org/10.1016/j.jlumin.2022.118863"
- Description: A novel asymmetrical zinc (II) phthalocyanine (Pc) 4 bearing three dimethoxy groups and one carboxyl group was linked to glutathione capped graphene quantum dots (GQDs) by the reaction of carboxylic acid substituent on Pc 4 with the amino group on the GQDs. On the other side, the symmetrical Pc analog 3 was linked to the same nanoparticles through π-π interactions. The as-formed nano-photosensitizers were fully characterized by spectroscopic methods and their photophysicochemical properties were investigated as well. Photodynamic antimicrobial chemotherapy was performed on the planktonic cells of S. aureus strain. And the results show that these nano assemblies were able to completely inhibit the metabolic activity of the resistant bacteria strain S. aureus with a 10.26 log reduction in the viable count. Again, asymmetrical Pc showed higher photocatalytic activity compared to the symmetrical complex with higher kobs and fast initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model. The target conjugates showed all the advantages of two different groups existing on a single entity.
- Full Text:
- Date Issued: 2022
Indifference and Epistemic Injustice: Phenomenological Reflections
- Roos,R
- Authors: Roos,R
- Date: 2022
- Subjects: Epistemic logic , Virtue epistemology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27150 , vital:66324
- Description: The proposed research seeks to address salient questions concerning the relation of indifference and epistemic injustice. This involves questions dealing with the necessary and sufficient conditions for indifference; how it arises through our conditions of lived experience and how it extends to the production, maintenance and engagement with knowledge. In short, to what extent does indifference play a role in epistemic injustice? Conversely, to what extent does epistemic injustice relate to indifference? The proposed research will explore major concepts of the relation between indifference and epistemic injustice. The research will settle on a phenomenological approach. Its claim is that major contemporary concepts of indifference and injustice can be critically informed by a phenomenological analysis of these concepts. Thus, it will attempt to analyse the relation of indifference and injustice from within the context of our lived conditions of experience. Ultimately, this research will try to locate the similarities between the experience of indifference and the act of epistemic injustice. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
- Authors: Roos,R
- Date: 2022
- Subjects: Epistemic logic , Virtue epistemology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27150 , vital:66324
- Description: The proposed research seeks to address salient questions concerning the relation of indifference and epistemic injustice. This involves questions dealing with the necessary and sufficient conditions for indifference; how it arises through our conditions of lived experience and how it extends to the production, maintenance and engagement with knowledge. In short, to what extent does indifference play a role in epistemic injustice? Conversely, to what extent does epistemic injustice relate to indifference? The proposed research will explore major concepts of the relation between indifference and epistemic injustice. The research will settle on a phenomenological approach. Its claim is that major contemporary concepts of indifference and injustice can be critically informed by a phenomenological analysis of these concepts. Thus, it will attempt to analyse the relation of indifference and injustice from within the context of our lived conditions of experience. Ultimately, this research will try to locate the similarities between the experience of indifference and the act of epistemic injustice. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2022
- Full Text:
- Date Issued: 2022
Indium phthalocyanines
- Pinar, Sen, Mack, John, Nyokong, Tebello
- Authors: Pinar, Sen , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229998 , vital:49731 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.131850"
- Description: In this study, the photodynamic antimicrobial activities of a series of new tetra-substituted indium phthalocyanine (InPc) complexes are assessed. An aldehyde substituted complex (2) was initially prepared, which was converted through a condensatioreaction to an imine-pyrrolidine substituted complex (3), which in turn was quaternized to form a tetracationic species (4). Favorable photophysicochemical properties were obtained by incorporating a heavy In(III) ion into the central cavity. Aggregation studies revealed that 2–4 remain non-aggregated in DMSO at concentration below 25 µM. The photodeactivation of S.aureus and E.coli was studied. Log reduction values > 9.0 were obtained for cationic InPc 4 after 30 min of incubation and exposure to light for 75 min.
- Full Text:
- Date Issued: 2022
- Authors: Pinar, Sen , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229998 , vital:49731 , xlink:href="https://doi.org/10.1016/j.molstruc.2021.131850"
- Description: In this study, the photodynamic antimicrobial activities of a series of new tetra-substituted indium phthalocyanine (InPc) complexes are assessed. An aldehyde substituted complex (2) was initially prepared, which was converted through a condensatioreaction to an imine-pyrrolidine substituted complex (3), which in turn was quaternized to form a tetracationic species (4). Favorable photophysicochemical properties were obtained by incorporating a heavy In(III) ion into the central cavity. Aggregation studies revealed that 2–4 remain non-aggregated in DMSO at concentration below 25 µM. The photodeactivation of S.aureus and E.coli was studied. Log reduction values > 9.0 were obtained for cationic InPc 4 after 30 min of incubation and exposure to light for 75 min.
- Full Text:
- Date Issued: 2022
Integrated photocatalyst adsorbents based on porphyrin anchored to activated carbon granules for water treatment
- Oyim, James, Amuhaya, Edith, Matshitse, Refilwe, Mack, John, Nyokong, Tebello
- Authors: Oyim, James , Amuhaya, Edith , Matshitse, Refilwe , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300101 , vital:57893 , xlink:href="https://doi.org/10.1016/j.cartre.2022.100191"
- Description: Integration of adsorption and photocatalysis processes can lead to several benefits in water treatment. Integrating well-known adsorbents with photocatalysts ensures that all the interesting components are preserved and helps to overcome the serious downsides of each material and technique when operated independently. In this work, we introduce a new concept of combining both absorption and photodegradation mechanisms using organic photocatalytic adsorbents for water purification. This was achieved by formulating photosensitizing hybrids based on a newly synthesized chloroindium (III) 5,10,15,20-tetrakis(4-acetamidophenyl) porphyrin (InTAAP) compound, anchored on oxygen functionalized coconut shell-based activated carbon granules supports. The fashioned integrated photocatalyst adsorbent hybrid (InTAAP(ACO)) was then studied for their adsorption and photodegradation efficiency using methylene blue dye, where InTAAP(ACO) showed excellent photocatalytic activity compared to ACO and unfunctionalized activated carbon granules (AC), with appreciably high and adsorption properties as AC and ACO.
- Full Text:
- Date Issued: 2022
- Authors: Oyim, James , Amuhaya, Edith , Matshitse, Refilwe , Mack, John , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300101 , vital:57893 , xlink:href="https://doi.org/10.1016/j.cartre.2022.100191"
- Description: Integration of adsorption and photocatalysis processes can lead to several benefits in water treatment. Integrating well-known adsorbents with photocatalysts ensures that all the interesting components are preserved and helps to overcome the serious downsides of each material and technique when operated independently. In this work, we introduce a new concept of combining both absorption and photodegradation mechanisms using organic photocatalytic adsorbents for water purification. This was achieved by formulating photosensitizing hybrids based on a newly synthesized chloroindium (III) 5,10,15,20-tetrakis(4-acetamidophenyl) porphyrin (InTAAP) compound, anchored on oxygen functionalized coconut shell-based activated carbon granules supports. The fashioned integrated photocatalyst adsorbent hybrid (InTAAP(ACO)) was then studied for their adsorption and photodegradation efficiency using methylene blue dye, where InTAAP(ACO) showed excellent photocatalytic activity compared to ACO and unfunctionalized activated carbon granules (AC), with appreciably high and adsorption properties as AC and ACO.
- Full Text:
- Date Issued: 2022
Interaction between an entomopathogenic fungus and entomopathogenic nematodes for increased mortality of Thaumatotibia leucotreta (Lepidoptera: Tortricidae)
- Prinsloo, Sandra, Hill, Martin P, Moore, Sean D, Malan, Antoinette P, Coombes, Candice
- Authors: Prinsloo, Sandra , Hill, Martin P , Moore, Sean D , Malan, Antoinette P , Coombes, Candice
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417738 , vital:71482 , xlink:href="https://doi.org/10.1080/09583157.2022.2099528"
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a major phytosanitary pest of citrus in South Africa. Although several management tools exist, control options registered for use against the soil-dwelling life stages are limited. Both entomopathogenic nematodes (EPNs) and entomopathogenic fungi have been investigated previously, but they have not been studied in combination against T. leucotreta. Thus, this study investigated the interaction of an indigenous entomopathogenic fungus, Metarhizium pinghaense (previously anisopliae) FCM Ar 23 B3 with three indigenous EPNs: Steinernema yirgalemense 157-C, S. jeffreyense J194 and Heterorhabditis noenieputensis 158-C for increased late instar T. leucotreta larval mortality. Before interaction experiments, lethal concentration (LC) values for each of these microbial agents were determined through dose–response bioassays. Heterorhabditis noenieputensis recorded the highest LC50 amongst the nematodes (7.11 IJs/50 µl). Using the pre-determined LC70 value of M. pinghaense and the LC50 values for each of the nematode species, interaction experiments were conducted. Combinations of the nematodes either applied simultaneously with the fungus or at 24, 48, 72 or 96 h post-fungal application showed predominantly additive interactions. Synergy between the simultaneous application of S. yirgalemense and M. pinghaense was found, whilst the interaction between H. noenieputensis and M. pinghaense applied simultaneously and S. jeffreyense applied 24 h post-fungal application, recorded antagonistic interactions. The use of these agents in combination may therefore have the potential to increase control of T. leucotreta soil-dwelling life stages in citrus orchards across South Africa and should be further investigated.
- Full Text:
- Date Issued: 2022
- Authors: Prinsloo, Sandra , Hill, Martin P , Moore, Sean D , Malan, Antoinette P , Coombes, Candice
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417738 , vital:71482 , xlink:href="https://doi.org/10.1080/09583157.2022.2099528"
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a major phytosanitary pest of citrus in South Africa. Although several management tools exist, control options registered for use against the soil-dwelling life stages are limited. Both entomopathogenic nematodes (EPNs) and entomopathogenic fungi have been investigated previously, but they have not been studied in combination against T. leucotreta. Thus, this study investigated the interaction of an indigenous entomopathogenic fungus, Metarhizium pinghaense (previously anisopliae) FCM Ar 23 B3 with three indigenous EPNs: Steinernema yirgalemense 157-C, S. jeffreyense J194 and Heterorhabditis noenieputensis 158-C for increased late instar T. leucotreta larval mortality. Before interaction experiments, lethal concentration (LC) values for each of these microbial agents were determined through dose–response bioassays. Heterorhabditis noenieputensis recorded the highest LC50 amongst the nematodes (7.11 IJs/50 µl). Using the pre-determined LC70 value of M. pinghaense and the LC50 values for each of the nematode species, interaction experiments were conducted. Combinations of the nematodes either applied simultaneously with the fungus or at 24, 48, 72 or 96 h post-fungal application showed predominantly additive interactions. Synergy between the simultaneous application of S. yirgalemense and M. pinghaense was found, whilst the interaction between H. noenieputensis and M. pinghaense applied simultaneously and S. jeffreyense applied 24 h post-fungal application, recorded antagonistic interactions. The use of these agents in combination may therefore have the potential to increase control of T. leucotreta soil-dwelling life stages in citrus orchards across South Africa and should be further investigated.
- Full Text:
- Date Issued: 2022
International Centre for parliamentary Studies (ICPS) Award for Peace and Human Rights
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Bam, Brigalia -- Awards
- Language: English
- Type: award , realia
- Identifier: http://hdl.handle.net/10948/56813 , vital:57191
- Description: Dr. Brigalia Bam received the International Centre for parliamentary Studies (ICPS) Award for Peace and Human Rights. , The International Centre for Parliamentary Studies exists to promote effective policy making and good governance through better interaction between Parliaments, Governments and other stakeholders in society. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Bam, Brigalia -- Awards
- Language: English
- Type: award , realia
- Identifier: http://hdl.handle.net/10948/56813 , vital:57191
- Description: Dr. Brigalia Bam received the International Centre for parliamentary Studies (ICPS) Award for Peace and Human Rights. , The International Centre for Parliamentary Studies exists to promote effective policy making and good governance through better interaction between Parliaments, Governments and other stakeholders in society. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Invasive alien aquatic plant species management drives aquatic ecosystem community recovery: An exploration using stable isotope analysis
- Motitsoe, Samuel N, Hill, Jaclyn M, Coetzee, Julie A, Hill, Martin P
- Authors: Motitsoe, Samuel N , Hill, Jaclyn M , Coetzee, Julie A , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423527 , vital:72069 , xlink:href="https://doi.org/10.1016/j.biocontrol.2022.104995"
- Description: The socio-economic and ecological impacts of invasive alien aquatic plant (IAAP) species have been well studied globally. However less is known about ecosystem recovery following the management of IAAP species. This study employed a before-after study design to investigate ecological recovery following the management of Salvinia molesta D.S. Mitchell, at four field sites in South Africa. We hypothesized that the presence of S. molesta would have a negative impact on the ecosystem food web structure, and that following S. molesta control, the systems would show positive ecosystem recovery. Aquatic macroinvertebrate and macrophyte samples collected before and after mechanical or biological control of S. molesta, were analysed for δ13C and δ15N stable isotopes. Salvinia molesta infestations negatively impacted the food web structure, indicated by reduced food chain length, trophic diversity and basal resources. This represented an altered aquatic food web structure, that in some cases, led to the collapse of the aquatic community. In contrast, after either mechanical or biological control, there were increases in food chain length, trophic diversity and abundance of energy resources accessed by consumers, indicating improved food web structure. Although the study showed positive ecosystem recovery following control, we noted that each control method followed a different recovery trajectory. We conclude that S. molesta invasions reduce aquatic biodiversity and alter ecosystem trophic dynamics and related ecosystem processes, necessitating control.
- Full Text:
- Date Issued: 2022
- Authors: Motitsoe, Samuel N , Hill, Jaclyn M , Coetzee, Julie A , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423527 , vital:72069 , xlink:href="https://doi.org/10.1016/j.biocontrol.2022.104995"
- Description: The socio-economic and ecological impacts of invasive alien aquatic plant (IAAP) species have been well studied globally. However less is known about ecosystem recovery following the management of IAAP species. This study employed a before-after study design to investigate ecological recovery following the management of Salvinia molesta D.S. Mitchell, at four field sites in South Africa. We hypothesized that the presence of S. molesta would have a negative impact on the ecosystem food web structure, and that following S. molesta control, the systems would show positive ecosystem recovery. Aquatic macroinvertebrate and macrophyte samples collected before and after mechanical or biological control of S. molesta, were analysed for δ13C and δ15N stable isotopes. Salvinia molesta infestations negatively impacted the food web structure, indicated by reduced food chain length, trophic diversity and basal resources. This represented an altered aquatic food web structure, that in some cases, led to the collapse of the aquatic community. In contrast, after either mechanical or biological control, there were increases in food chain length, trophic diversity and abundance of energy resources accessed by consumers, indicating improved food web structure. Although the study showed positive ecosystem recovery following control, we noted that each control method followed a different recovery trajectory. We conclude that S. molesta invasions reduce aquatic biodiversity and alter ecosystem trophic dynamics and related ecosystem processes, necessitating control.
- Full Text:
- Date Issued: 2022
Is education blithely producing unemployed graduates?: A reflection based on a review of environmental skills initiatives 2016-2021
- Authors: Rosenberg, Eureta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370619 , vital:66360 , xlink:href="http://dx.doi.org/10.17159/2520-9868/i89a08"
- Description: A statement from the president of the Black Business Council (BBC) that "our education system continues to produce the unemployed graduates" (NewZRoomAfrika, 2021) because "the courses they are doing are not required by industry" reflects the perennial perception that South Africa's education system is a cause of unemployment. In this paper, I explore aspects of this perception through a meta-review of environmental skills-related studies conducted over the past five years. Data used in these studies include graduation trends based on higher education, employer surveys, analyses of skills needs in the workplace compared to courses offered, and case examples of internships and teacher development. Using an ecological-systems model, I relate the findings, in a layered critical realist analysis, to the socio-cultural milieu in South Africa. I challenge the conception of relevant graduate education evident in the BBC's statement.
- Full Text:
- Date Issued: 2022
- Authors: Rosenberg, Eureta
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370619 , vital:66360 , xlink:href="http://dx.doi.org/10.17159/2520-9868/i89a08"
- Description: A statement from the president of the Black Business Council (BBC) that "our education system continues to produce the unemployed graduates" (NewZRoomAfrika, 2021) because "the courses they are doing are not required by industry" reflects the perennial perception that South Africa's education system is a cause of unemployment. In this paper, I explore aspects of this perception through a meta-review of environmental skills-related studies conducted over the past five years. Data used in these studies include graduation trends based on higher education, employer surveys, analyses of skills needs in the workplace compared to courses offered, and case examples of internships and teacher development. Using an ecological-systems model, I relate the findings, in a layered critical realist analysis, to the socio-cultural milieu in South Africa. I challenge the conception of relevant graduate education evident in the BBC's statement.
- Full Text:
- Date Issued: 2022
Is green space associated with reduced crime? A national-scale study from the Global South
- Venter, Zander S, Shackleton, Charlie M, Faull, Andrew, Lancaster, Lizette, Breetzke, Gregory, Edelstein, Ian
- Authors: Venter, Zander S , Shackleton, Charlie M , Faull, Andrew , Lancaster, Lizette , Breetzke, Gregory , Edelstein, Ian
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402340 , vital:69843 , xlink:href="https://doi.org/10.1016/j.scitotenv.2022.154005"
- Description: Assumptions about the link between green space and crime mitigation are informed by literature that overwhelmingly originates in the Global North. Little is known about the association between green spaces and crime in the Global South. We utilized 10 years of precinct-level crime statistics (n = 1152) over South Africa, a global crime hotspot, to test the hypothesis that green space is associated with reduced crime rates. We found that, after controlling for a number of socio-demographic confounders (unemployment, income, age, education, land use and population density), for every 1% increase in total green space there is a 1.2% (0.7 to 1.7%; 95% confidence interval) decrease in violent crime, and 1.3% (0.8 to 1.8%) decrease in property crime, with no effect on sexual crimes. However, the direction of the association changed for property crimes when exploring the effect of green space characteristics including tree cover and park accessibility. Property crimes increase by 0.4% (0.1 to 0.7%) with a percentage increase in tree cover, and by 0.9% (0.5 to 1.3%) with every kilometer increase in proximity to a public park. Further research, including experimental studies, is needed to better isolate causal mechanisms behind crime-green space associations, especially considering that green space may map to race and income inequality and that there may be more crime reporting in affluent areas. Nevertheless, our results provide a complementary contribution to the evidence from the Global North, highlighting the need for more nuanced definitions of green space and its characteristics when considering links to crime. When viewed in light of the broader suite of ecosystem services provided by green space, our results support urban greening as a major strategy towards achieving just and sustainable cities and towns.
- Full Text:
- Date Issued: 2022
- Authors: Venter, Zander S , Shackleton, Charlie M , Faull, Andrew , Lancaster, Lizette , Breetzke, Gregory , Edelstein, Ian
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402340 , vital:69843 , xlink:href="https://doi.org/10.1016/j.scitotenv.2022.154005"
- Description: Assumptions about the link between green space and crime mitigation are informed by literature that overwhelmingly originates in the Global North. Little is known about the association between green spaces and crime in the Global South. We utilized 10 years of precinct-level crime statistics (n = 1152) over South Africa, a global crime hotspot, to test the hypothesis that green space is associated with reduced crime rates. We found that, after controlling for a number of socio-demographic confounders (unemployment, income, age, education, land use and population density), for every 1% increase in total green space there is a 1.2% (0.7 to 1.7%; 95% confidence interval) decrease in violent crime, and 1.3% (0.8 to 1.8%) decrease in property crime, with no effect on sexual crimes. However, the direction of the association changed for property crimes when exploring the effect of green space characteristics including tree cover and park accessibility. Property crimes increase by 0.4% (0.1 to 0.7%) with a percentage increase in tree cover, and by 0.9% (0.5 to 1.3%) with every kilometer increase in proximity to a public park. Further research, including experimental studies, is needed to better isolate causal mechanisms behind crime-green space associations, especially considering that green space may map to race and income inequality and that there may be more crime reporting in affluent areas. Nevertheless, our results provide a complementary contribution to the evidence from the Global North, highlighting the need for more nuanced definitions of green space and its characteristics when considering links to crime. When viewed in light of the broader suite of ecosystem services provided by green space, our results support urban greening as a major strategy towards achieving just and sustainable cities and towns.
- Full Text:
- Date Issued: 2022
Is the instrumental approach a ‘silver bullet’for addressing non-compliance in recreational fisheries: A South African case study
- Bova, Christopher S, Stephens, Jed, Aswani, Shankar, Potts, Warren M
- Authors: Bova, Christopher S , Stephens, Jed , Aswani, Shankar , Potts, Warren M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391359 , vital:68644 , xlink:href="https://doi.org/10.1016/j.fishres.2022.106439"
- Description: Non-compliance with recreational fishery regulations is considered to be one of the biggest threats to the sustainability of fisheries. Dedicated non-compliance studies are seldom carried out at the national level which makes it difficult to discern the behavioural compliance norms within a population. The instrumental approach for compliance is the traditional paradigm in recreational fisheries. It postulates that increased enforcement activities and the corresponding punishment will improve compliance behaviour, although there is little empirical evidence for such a supposition within the recreational fisheries context. Using face-to-face encounter surveys employing the ballot box method for reducing social desirability bias (SDB), South African marine shore-based fishery (MSBF) participants were questioned on their compliance behaviour with a set of regulations pertaining to the fishery. Overall non-compliance levels were very high (52%), and non-compliance levels with individual regulations varied based on provincial locality. Perceptions and observations of enforcement activity had no significant impact on compliance behaviour. Participants that had previously been caught by law enforcement violating the regulations were still more likely to violate the regulations than participants that had not faced enforcement action. Results indicate that calls for increased enforcement as a means of improving compliance behaviour are questionable in the South African MSBF, and further emphasise the need to develop alternative approaches, such as those pertaining to normative theory, within recreational fisheries.
- Full Text:
- Date Issued: 2022
- Authors: Bova, Christopher S , Stephens, Jed , Aswani, Shankar , Potts, Warren M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391359 , vital:68644 , xlink:href="https://doi.org/10.1016/j.fishres.2022.106439"
- Description: Non-compliance with recreational fishery regulations is considered to be one of the biggest threats to the sustainability of fisheries. Dedicated non-compliance studies are seldom carried out at the national level which makes it difficult to discern the behavioural compliance norms within a population. The instrumental approach for compliance is the traditional paradigm in recreational fisheries. It postulates that increased enforcement activities and the corresponding punishment will improve compliance behaviour, although there is little empirical evidence for such a supposition within the recreational fisheries context. Using face-to-face encounter surveys employing the ballot box method for reducing social desirability bias (SDB), South African marine shore-based fishery (MSBF) participants were questioned on their compliance behaviour with a set of regulations pertaining to the fishery. Overall non-compliance levels were very high (52%), and non-compliance levels with individual regulations varied based on provincial locality. Perceptions and observations of enforcement activity had no significant impact on compliance behaviour. Participants that had previously been caught by law enforcement violating the regulations were still more likely to violate the regulations than participants that had not faced enforcement action. Results indicate that calls for increased enforcement as a means of improving compliance behaviour are questionable in the South African MSBF, and further emphasise the need to develop alternative approaches, such as those pertaining to normative theory, within recreational fisheries.
- Full Text:
- Date Issued: 2022
It's a numbers game: inundative biological control of water hyacinth (Pontederia crassipes), using Megamelus scutellaris (Hemiptera: Delphacidae) yields success at a high elevation, hypertrophic reservoir in South Africa
- Coetzee, Julie A, Miller, Benjamin E, Kinsler, David, Sebola, Keneilwe, Hill, Martin P
- Authors: Coetzee, Julie A , Miller, Benjamin E , Kinsler, David , Sebola, Keneilwe , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417749 , vital:71483 , xlink:href="https://doi.org/10.1080/09583157.2022.2109594"
- Description: Classical biological control of water hyacinth in South Africa has been constrained by cool winter temperatures that limit population growth of the biological control agents, and highly eutrophic waters which enhance plant growth. However, inundative releases of the control agent, Megamelus scutellaris (Hemiptera: Delphacidae), at the Hartbeespoort Dam, South Africa, suggest that water hyacinth can be managed successfully using biological control as a standalone intervention for the first time in the absence of herbicide operations, despite eutrophication and a temperate climate. Sentinel-2 satellite images were used to measure the reduction in water hyacinth cover from over 37% to less than 6% over two consecutive years since M. scutellaris was first released on the dam in 2018, while site surveys confirmed a corresponding increase in M. scutellaris population density from fewer than 500 insects/m2 in October 2019, to more than 6000 insects/m2 by March 2020. Inundative release strategies are recommended for the control of water hyacinth in South Africa at key stages of its invasion, particularly after winter, and flooding events.
- Full Text:
- Date Issued: 2022
- Authors: Coetzee, Julie A , Miller, Benjamin E , Kinsler, David , Sebola, Keneilwe , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417749 , vital:71483 , xlink:href="https://doi.org/10.1080/09583157.2022.2109594"
- Description: Classical biological control of water hyacinth in South Africa has been constrained by cool winter temperatures that limit population growth of the biological control agents, and highly eutrophic waters which enhance plant growth. However, inundative releases of the control agent, Megamelus scutellaris (Hemiptera: Delphacidae), at the Hartbeespoort Dam, South Africa, suggest that water hyacinth can be managed successfully using biological control as a standalone intervention for the first time in the absence of herbicide operations, despite eutrophication and a temperate climate. Sentinel-2 satellite images were used to measure the reduction in water hyacinth cover from over 37% to less than 6% over two consecutive years since M. scutellaris was first released on the dam in 2018, while site surveys confirmed a corresponding increase in M. scutellaris population density from fewer than 500 insects/m2 in October 2019, to more than 6000 insects/m2 by March 2020. Inundative release strategies are recommended for the control of water hyacinth in South Africa at key stages of its invasion, particularly after winter, and flooding events.
- Full Text:
- Date Issued: 2022
Kinetic energy radio
- Date: 2022 , 2022-09-20
- Subjects: Bam, Brigalia , Radio
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56423 , vital:56648
- Description: South African Broadcasting Corporation (SABC) kinetic energy radio, given to the first Board of the Democratic Dispensation of South Africa. It is a symbol of transformation and access to information and some form of entertainment to the rest of South Africa. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-09-20
- Subjects: Bam, Brigalia , Radio
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56423 , vital:56648
- Description: South African Broadcasting Corporation (SABC) kinetic energy radio, given to the first Board of the Democratic Dispensation of South Africa. It is a symbol of transformation and access to information and some form of entertainment to the rest of South Africa. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022