Graphene quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as fluorescence “turn-on” nanosensors
- Achadu, Ojodomo J, Britton, Jonathan, Nyokong, Tebello
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
Interaction of graphene quantum dots with 4-acetamido-2, 2, 6, 6-tetramethylpiperidine-oxyl free radicals
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
The interaction between graphene quantum dots grafted with polyethyleneimine and Au@ Ag nanoparticles
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
Fluorescence behavior of nanoconjugates of graphene quantum dots and zinc phthalocyanines
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
Distribution and use of cash income from basket and mat crafting: Implications for rural livelihoods in the Eastern Cape, South Africa
- Adam, Y O, Shackleton, Charlie M
- Authors: Adam, Y O , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180434 , vital:43388 , xlink:href="https://doi.org/10.1080/14728028.2016.1186576"
- Description: The objective of this paper was to investigate the extent to which baskets and mats local trade contributes to rural livelihoods of the crafters’ household and community downstream income. Primary data were collected through structured interviews with 83 crafters from Noqhekwana village in Port St. Johns municipality using snowball sampling in May, 2015. The survey was supplemented by secondary data and direct observations. The findings show that crafting contributed 35% of crafter’s household total income. The received income is spent on expenses in the household and downstream actors depending on the crafter’s priorities. Lack of organization between crafters, access to sufficient raw material, and low prices were identified as major challenges involved in the production and trade of the products.
- Full Text:
- Date Issued: 2016
- Authors: Adam, Y O , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180434 , vital:43388 , xlink:href="https://doi.org/10.1080/14728028.2016.1186576"
- Description: The objective of this paper was to investigate the extent to which baskets and mats local trade contributes to rural livelihoods of the crafters’ household and community downstream income. Primary data were collected through structured interviews with 83 crafters from Noqhekwana village in Port St. Johns municipality using snowball sampling in May, 2015. The survey was supplemented by secondary data and direct observations. The findings show that crafting contributed 35% of crafter’s household total income. The received income is spent on expenses in the household and downstream actors depending on the crafter’s priorities. Lack of organization between crafters, access to sufficient raw material, and low prices were identified as major challenges involved in the production and trade of the products.
- Full Text:
- Date Issued: 2016
Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells
- Adegoke, Oluwasesan, Mashazi, Philani N, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
- Date Issued: 2016
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
- Date Issued: 2016
A feminist perspective on autonomism and commoning, with reference to Zimbabwe
- Alexander, Tarryn, Helliker, Kirk D
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
SEAmester – South Africa’s first class afloat
- Ansorge, Isabelle J, Brundrit, Geoff, Brundrit, Jean, Dorrington, Rosemary A, Fawcett, Sarah, Gammon, David, Henry, Tahlia, Hermes, Juliet, Hölscher, Beate, d’Hotman, Jethan, Meiklejohn, Ian, Morris, Tammy, Pinto, Izidine, Du Plessis, Marcel, Roman, Raymond, Saunders, Clinton, Shabangu, Fannie W, De Vos, Marc, Walker, David R, Louw, Gavin
- Authors: Ansorge, Isabelle J , Brundrit, Geoff , Brundrit, Jean , Dorrington, Rosemary A , Fawcett, Sarah , Gammon, David , Henry, Tahlia , Hermes, Juliet , Hölscher, Beate , d’Hotman, Jethan , Meiklejohn, Ian , Morris, Tammy , Pinto, Izidine , Du Plessis, Marcel , Roman, Raymond , Saunders, Clinton , Shabangu, Fannie W , De Vos, Marc , Walker, David R , Louw, Gavin
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65539 , vital:28808 , https://doi.org/10.17159/sajs.2016/a0171
- Description: publisher version , From Introduction: Marine science is a highly competitive environment. The need to improve the cohort of South African postgraduates, who would be recognised both nationally and internationally for their scientific excellence, is crucial. It is possible to attract students early on in their careers to this discipline via cutting-edge science, technology and unique field experiences. Through the engagement of students with real-life experiences such as SEAmester, universities supporting marine science postgraduate degree programmes can attract a sustainable throughput of numerically proficient students. By achieving a more quantitative and experienced input into our postgraduate degree programmes, we will, as a scientific community, greatly improve our long-term capabilities to accurately measure, model and predict the impacts of current climate change scenarios. The short-term goal is to attract and establish a cohort of proficient marine and atmospheric science graduates who will contribute to filling the capacity needs of South African marine science as a whole. The SEAmester programme, by involving researchers from across all the relevant disciplines and tertiary institutions, provides an opportunity to build a network of collaborative teaching within the marine field. In doing so, these researchers will foster and strengthen new and current collaborations between historically white and black universities (Figure 1). The long-term objective of SEAmester is to build critical mass within the marine sciences to ensure sustained growth of human capacity in marine science in South Africa – aligning closely with the current DST Research and Development strategies and the Operation Phakisa Oceans Economy initiative.
- Full Text:
- Date Issued: 2016
- Authors: Ansorge, Isabelle J , Brundrit, Geoff , Brundrit, Jean , Dorrington, Rosemary A , Fawcett, Sarah , Gammon, David , Henry, Tahlia , Hermes, Juliet , Hölscher, Beate , d’Hotman, Jethan , Meiklejohn, Ian , Morris, Tammy , Pinto, Izidine , Du Plessis, Marcel , Roman, Raymond , Saunders, Clinton , Shabangu, Fannie W , De Vos, Marc , Walker, David R , Louw, Gavin
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65539 , vital:28808 , https://doi.org/10.17159/sajs.2016/a0171
- Description: publisher version , From Introduction: Marine science is a highly competitive environment. The need to improve the cohort of South African postgraduates, who would be recognised both nationally and internationally for their scientific excellence, is crucial. It is possible to attract students early on in their careers to this discipline via cutting-edge science, technology and unique field experiences. Through the engagement of students with real-life experiences such as SEAmester, universities supporting marine science postgraduate degree programmes can attract a sustainable throughput of numerically proficient students. By achieving a more quantitative and experienced input into our postgraduate degree programmes, we will, as a scientific community, greatly improve our long-term capabilities to accurately measure, model and predict the impacts of current climate change scenarios. The short-term goal is to attract and establish a cohort of proficient marine and atmospheric science graduates who will contribute to filling the capacity needs of South African marine science as a whole. The SEAmester programme, by involving researchers from across all the relevant disciplines and tertiary institutions, provides an opportunity to build a network of collaborative teaching within the marine field. In doing so, these researchers will foster and strengthen new and current collaborations between historically white and black universities (Figure 1). The long-term objective of SEAmester is to build critical mass within the marine sciences to ensure sustained growth of human capacity in marine science in South Africa – aligning closely with the current DST Research and Development strategies and the Operation Phakisa Oceans Economy initiative.
- Full Text:
- Date Issued: 2016
The complex immunological and inflammatory network of adipose tissue in obesity
- Apostolopoulos, Vasso, De Courten, Maximilian P J, Stojanovska, Lily, Blatch, Gregory L, Tangalakis, Kathy, De Courten, Barbora
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
Audit, investigation, search, seizure and access to information
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131245 , vital:36541 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 5 of the Tax Administration Act, which supplements the various fiscal statutes, empowers SARS to call for information on taxpayers, conduct audits, investigations and in certain instances to search premises and seize goods and records. For this purpose, taxpayers are required to keep proper books and records (see § 8.2 and § 4). The purpose of a tax audit is to verify the accuracy and timing of an assessment, but more specifically to ensure accuracy and full disclosure in terms of the law. In the event that an audit reveals non-compliance, criminal and/or civil charges may be initiated by SARS (see § 8.5).
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131245 , vital:36541 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 5 of the Tax Administration Act, which supplements the various fiscal statutes, empowers SARS to call for information on taxpayers, conduct audits, investigations and in certain instances to search premises and seize goods and records. For this purpose, taxpayers are required to keep proper books and records (see § 8.2 and § 4). The purpose of a tax audit is to verify the accuracy and timing of an assessment, but more specifically to ensure accuracy and full disclosure in terms of the law. In the event that an audit reveals non-compliance, criminal and/or civil charges may be initiated by SARS (see § 8.5).
- Full Text: false
- Date Issued: 2016
Miscellaneous provisions
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131276 , vital:36548 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Miscellaneous provisions pertaining to tax administration are explained in this chapter.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131276 , vital:36548 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Miscellaneous provisions pertaining to tax administration are explained in this chapter.
- Full Text: false
- Date Issued: 2016
Dispute resolution
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131084 , vital:36522 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 9 of the Tax Administration Act 2011, deals with the objection and appeals processes of the tax Acts administered by SARS in terms of s 4 of the SARS Act, 1997. A taxpayer who is aggrieved by an assessment or a decision in which he has an interest, has the right to object against the assessment or decision.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131084 , vital:36522 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 9 of the Tax Administration Act 2011, deals with the objection and appeals processes of the tax Acts administered by SARS in terms of s 4 of the SARS Act, 1997. A taxpayer who is aggrieved by an assessment or a decision in which he has an interest, has the right to object against the assessment or decision.
- Full Text: false
- Date Issued: 2016
Registration, returns, assessments and records
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131060 , vital:36520 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: This chapter covers the administrative provisions dealing with the requirements for certain persons to register with SARS, the submission of tax returns, the raising of assessments and the maintenance of records.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131060 , vital:36520 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: This chapter covers the administrative provisions dealing with the requirements for certain persons to register with SARS, the submission of tax returns, the raising of assessments and the maintenance of records.
- Full Text: false
- Date Issued: 2016
Advance rulings
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131195 , vital:36535 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 7 of the Tax Administration Act, namely ss 75–90, deals with the formal system and process of the advance tax ruling system. It therefore follows that SARS may now issue advance rulings in respect of all tax types and tax Acts administered by the Commissioner. Procedures and guidelines, in the form of ‘binding general rulings’, for implementation and operation of the ‘advance ruling’ system may be issued by the Commissioner to give effect to the advance tax ruling system.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131195 , vital:36535 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Chapter 7 of the Tax Administration Act, namely ss 75–90, deals with the formal system and process of the advance tax ruling system. It therefore follows that SARS may now issue advance rulings in respect of all tax types and tax Acts administered by the Commissioner. Procedures and guidelines, in the form of ‘binding general rulings’, for implementation and operation of the ‘advance ruling’ system may be issued by the Commissioner to give effect to the advance tax ruling system.
- Full Text: false
- Date Issued: 2016
Administrative penalties
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131225 , vital:36539 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Provisions dealing with the levying of interest and penalties are contained in the Tax Administration Act and specific provisions also exist in the various tax Acts. Most of the specific penalty provisions in the various tax Acts have been replaced by the general provisions contained in the Tax Administration Act.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131225 , vital:36539 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: Provisions dealing with the levying of interest and penalties are contained in the Tax Administration Act and specific provisions also exist in the various tax Acts. Most of the specific penalty provisions in the various tax Acts have been replaced by the general provisions contained in the Tax Administration Act.
- Full Text: false
- Date Issued: 2016
Payment of taxes, refunds and SARS’ collection powers
- Arendse, Jacqueline A, Clegg, David, Williams, Robert C
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131264 , vital:36547 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: The Tax Administration Act and the various tax Acts administered by the Commissioner contain specific provisions dealing with the payment and recovery of tax, which are explained in this chapter.
- Full Text: false
- Date Issued: 2016
- Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/131264 , vital:36547 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
- Description: The Tax Administration Act and the various tax Acts administered by the Commissioner contain specific provisions dealing with the payment and recovery of tax, which are explained in this chapter.
- Full Text: false
- Date Issued: 2016
Recommendations for the future of recreational fisheries to prepare the social‐ecological system to cope with change
- Arlinghaus, Robert, Cooke, Steven J, Sutton, S G, Danylchuk, A J, Potts, Warren M, Freire, K D M, Alós, J, Da Silva, E T, Cowx, Ian G, Van Anrooy, R
- Authors: Arlinghaus, Robert , Cooke, Steven J , Sutton, S G , Danylchuk, A J , Potts, Warren M , Freire, K D M , Alós, J , Da Silva, E T , Cowx, Ian G , Van Anrooy, R
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125810 , vital:35819 , https://doi.10.1111/fme.12191
- Description: This paper presents conclusions and recommendations that emerged from the 7th World Recreational Fishing Conference (WRFC) held in Campinas, Brazil in September 2014. Based on the recognition of the immense social and economic importance of recreational fisheries coupled with weaknesses in robust information about these fisheries in many areas of the world, particularly in many economies in transition, it is recommended to increase effort to build effective governance arrangements and improve monitoring and assessment frameworks in data-poor situations. Moreover, there is a need to increase interdisciplinary studies that will foster a systematic understanding of recreational fisheries as complex adaptive social-ecological systems. To promote sustainable recreational fisheries on a global scale, it is recommended the detailed suggestions for governance and management outlined in the United Nations Food and Agricultural Organization Technical Guidelines for Responsible Fisheries: Recreational Fisheries are followed.
- Full Text:
- Date Issued: 2016
- Authors: Arlinghaus, Robert , Cooke, Steven J , Sutton, S G , Danylchuk, A J , Potts, Warren M , Freire, K D M , Alós, J , Da Silva, E T , Cowx, Ian G , Van Anrooy, R
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125810 , vital:35819 , https://doi.10.1111/fme.12191
- Description: This paper presents conclusions and recommendations that emerged from the 7th World Recreational Fishing Conference (WRFC) held in Campinas, Brazil in September 2014. Based on the recognition of the immense social and economic importance of recreational fisheries coupled with weaknesses in robust information about these fisheries in many areas of the world, particularly in many economies in transition, it is recommended to increase effort to build effective governance arrangements and improve monitoring and assessment frameworks in data-poor situations. Moreover, there is a need to increase interdisciplinary studies that will foster a systematic understanding of recreational fisheries as complex adaptive social-ecological systems. To promote sustainable recreational fisheries on a global scale, it is recommended the detailed suggestions for governance and management outlined in the United Nations Food and Agricultural Organization Technical Guidelines for Responsible Fisheries: Recreational Fisheries are followed.
- Full Text:
- Date Issued: 2016
Geospatial technologies and indigenous Knowledge Systems:
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
- Date Issued: 2016
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
- Date Issued: 2016
A Review of Arterial Stiffness and HIV Infection in Adult Africans
- Awotedu, Kofoworola Olajire, Iputo, Jehu
- Authors: Awotedu, Kofoworola Olajire , Iputo, Jehu
- Date: 09-06-2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3484 , vital:43615 , https://www.hilarispublisher.com/open-access/a-review-of-arterial-stiffness-and-hiv-infection-in-adult-africans-2167-1095-1000221.pdf
- Description: Aim: To review the impact of the human immunodeficiency virus and antiretroviral therapy on the vasculature. Objectives: This review seeks to identify the burden which the human immunodeficiency virus and antiretroviral therapy have on the vasculature. Method: Medline/PubMed and Google scholar were searched. There were over 100 publications reviewed. Some people who worked in similar fields were also contacted. The present review summarized current understanding of Human immunodeficiency virus, antiretroviral therapy and effect on the vasculature such as arterial stiffness. Atherosclerosis, endothelial dysfunction, the strengths and weaknesses of current testing strategies, and their potential applications in clinical research and patient care. The association of inflammatory biomarkers, blood pressure and ageing with arterial stiffness were also reviewed. Conclusion: Available literature shows that HIV and antiretroviral agents have a great impact on the vasculature and its progression.
- Full Text:
- Date Issued: 09-06-2016
- Authors: Awotedu, Kofoworola Olajire , Iputo, Jehu
- Date: 09-06-2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3484 , vital:43615 , https://www.hilarispublisher.com/open-access/a-review-of-arterial-stiffness-and-hiv-infection-in-adult-africans-2167-1095-1000221.pdf
- Description: Aim: To review the impact of the human immunodeficiency virus and antiretroviral therapy on the vasculature. Objectives: This review seeks to identify the burden which the human immunodeficiency virus and antiretroviral therapy have on the vasculature. Method: Medline/PubMed and Google scholar were searched. There were over 100 publications reviewed. Some people who worked in similar fields were also contacted. The present review summarized current understanding of Human immunodeficiency virus, antiretroviral therapy and effect on the vasculature such as arterial stiffness. Atherosclerosis, endothelial dysfunction, the strengths and weaknesses of current testing strategies, and their potential applications in clinical research and patient care. The association of inflammatory biomarkers, blood pressure and ageing with arterial stiffness were also reviewed. Conclusion: Available literature shows that HIV and antiretroviral agents have a great impact on the vasculature and its progression.
- Full Text:
- Date Issued: 09-06-2016
SASO and Black Consciousness, and the shift to congress politics
- Authors: Badat, Saleem
- Date: 2016
- Language: English
- Type: book chapter , text
- Identifier: http://hdl.handle.net/10962/59755 , vital:27645 , http://witspress.co.za/catalogue/students-must-rise/
- Description: Students Must Rise 98 Chapter 8 SASO and Black Consciousness, and the shift to congress politics I n 1960, demonstrators protesting against pass laws were killed and injured by police at Sharpeville. Soon afterwards, the apartheid government declared a state of emergency. Over 11 000 political activists were detained, and repressive new laws, police raids, arrests, bannings, and torture were used to crush political opposition to apartheid. The African National Congress (ANC) and Pan Africanist Congress (PAC) were banned, and many leaders of the ANC and PAC were arrested and imprisoned , and hundreds fled into exile. For many white South Africans, the rest of the 1960s were a time of economic boom, political calm, prosperity, and rising living standards. Some blacks took the opportunity to accumulate wealth, power, and privilege through the Bantustans that the apartheid government established as part of its separate development programme. For most blacks, it was a period of great economic exploitation, extensive political and social control, fear, and demoralisation. It was difficult to see how there could be any political challenge to white minority rule. Anti-apartheid organisations faced immediate repression. They also had to overcome black people’s fear and demoralisation, which stood in the way of mobilising opposition against apartheid. The emergence of the South African Students’ Organisation and Black Consciousness Despite many problems, the South African Students’ Organisation (SASO) was formed as an exclusively black university and college student organisation in 1968. It escaped immediate state repression, and developed a following among students at the Saleem Badat SASO and Black Consciousness, and the shift to congress politics 99 universities reserved for blacks. Thereafter, the ideology of Black Consciousness (BC) was developed and other BC organisations were formed, resulting in the BC movement. SASO saw its challenge as the ‘assertion, manifestation and development of a sense of awareness politically, socially and economically among the black community’.1 It emphasised black ‘group cohesion and solidarity’ as ‘important facets of Black Consciousness’, the need for ‘the totality of involvement of the oppressed people’, and for BC ‘to be spread to reach all sections of the black community’.2 SASO began community development, literacy, education, media, culture, and sports projects, which aimed to help black communities to determine and realise their own needs. They were seen as a means to win the trust of people and to educate and mobilise them.3 Projects instilled the idea of self-reliance, seen as important for achieving freedom, in members and communities. SASO created a favourable political climate for various organisations to emerge.
- Full Text: false
- Date Issued: 2016
- Authors: Badat, Saleem
- Date: 2016
- Language: English
- Type: book chapter , text
- Identifier: http://hdl.handle.net/10962/59755 , vital:27645 , http://witspress.co.za/catalogue/students-must-rise/
- Description: Students Must Rise 98 Chapter 8 SASO and Black Consciousness, and the shift to congress politics I n 1960, demonstrators protesting against pass laws were killed and injured by police at Sharpeville. Soon afterwards, the apartheid government declared a state of emergency. Over 11 000 political activists were detained, and repressive new laws, police raids, arrests, bannings, and torture were used to crush political opposition to apartheid. The African National Congress (ANC) and Pan Africanist Congress (PAC) were banned, and many leaders of the ANC and PAC were arrested and imprisoned , and hundreds fled into exile. For many white South Africans, the rest of the 1960s were a time of economic boom, political calm, prosperity, and rising living standards. Some blacks took the opportunity to accumulate wealth, power, and privilege through the Bantustans that the apartheid government established as part of its separate development programme. For most blacks, it was a period of great economic exploitation, extensive political and social control, fear, and demoralisation. It was difficult to see how there could be any political challenge to white minority rule. Anti-apartheid organisations faced immediate repression. They also had to overcome black people’s fear and demoralisation, which stood in the way of mobilising opposition against apartheid. The emergence of the South African Students’ Organisation and Black Consciousness Despite many problems, the South African Students’ Organisation (SASO) was formed as an exclusively black university and college student organisation in 1968. It escaped immediate state repression, and developed a following among students at the Saleem Badat SASO and Black Consciousness, and the shift to congress politics 99 universities reserved for blacks. Thereafter, the ideology of Black Consciousness (BC) was developed and other BC organisations were formed, resulting in the BC movement. SASO saw its challenge as the ‘assertion, manifestation and development of a sense of awareness politically, socially and economically among the black community’.1 It emphasised black ‘group cohesion and solidarity’ as ‘important facets of Black Consciousness’, the need for ‘the totality of involvement of the oppressed people’, and for BC ‘to be spread to reach all sections of the black community’.2 SASO began community development, literacy, education, media, culture, and sports projects, which aimed to help black communities to determine and realise their own needs. They were seen as a means to win the trust of people and to educate and mobilise them.3 Projects instilled the idea of self-reliance, seen as important for achieving freedom, in members and communities. SASO created a favourable political climate for various organisations to emerge.
- Full Text: false
- Date Issued: 2016