Physicochemical and antimicrobial photodynamic chemotherapy of unsymmetrical indium phthalocyanines alone or in the presence of magnetic nanoparticles
- Authors: Osifeko, Olawale L , Uddin, Imran , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189121 , vital:44818 , xlink:href="https://doi.org/10.1039/C5NJ01922B"
- Description: An AB3 type photosensitiser, consisting of 4-pyridylsulfanyl units (denoted as B3) and one aminophenoxy (denoted as A) group (complex 3) was synthesized. Complex 3 was then quaternized to form complex 4. The aminophenoxy substituent of complex 3 was used for the formation of the amide linkage with the carboxylic functionalised magnetic nanoparticles. Complexes 3 and 4 and their conjugates with magnetic nanoparticles were then used for photodynamic antimicrobial chemotherapy on E. coli. The cationic photosensitiser 4 showed a high efficiency for photodynamic antimicrobial chemotherapy at a very low concentration compared to its conjugate on E. coli.
- Full Text:
- Date Issued: 2016
Registration, returns, assessments and records
- 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
Reviewing strategies in/for ESD policy engagement: Agency reclaimed
- Authors: Lotz-Sisitka, Heila
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182483 , vital:43834 , xlink:href="https://doi.org/10.1080/00958964.2015.1113915"
- Description: In this response article, I draw on critical realist perspectives to engage with the argument put forward in Bengtsson's study, which sees agency as an ontological necessity for Education for Sustainable Development (ESD) policy engagement. Bengtsson supports a notion of the logic of contingent action over the logic of power as dominance, suggesting possibilities for agency and resistance. Although I do not in principle disagree with the agentive possibilities embedded in this aspect of the Bengtsson argument, it is the scope of the conceptualization thereof that I consider in this response. I start with considering the limitations of a Westphalian analysis of policy appropriations and agency for ESD, and argue that the Westphalian frame for policy analysis may be inadequate for capturing the significance of non-state actors and wider generative mechanisms such as informal normative structures, and private, economic power in the global political economy. Drawing on Fraser's (2008) concept of the transnational public sphere, I explore other potential possibilities for agency-centered appropriations or negations of, and/or resistance to ESD policy discourses, potentially expanding the agency-centered perspective referred to in Bengtsson's analysis and critique of policy making for ESD, or, at the very least, by offering a wider view of possibility for what he refers to as the ‘ineradicable moment of conflict, or antagonism.’ In particular, I broaden the notion of the transnational public sphere to be inclusive of Dussel's (1998) three concerns of transformation, namely; poverty and wealth inequality, environmental degradation, and narrow rationalities involving ongoing colonization of people, territories and resources. In doing this, I concur with Fraser, who suggests that the concept of the public sphere may well be “so thoroughly Westphalian in its deep conceptual structure as to be unsalvageable as a critical tool for theorizing the present” and suggest that public sphere thinking and associated conceptions of agency require expansion, which I offer from postcolonial and decolonization literature, critical realism, ontological experiences, and reflection on Environmental Education (EE) /ESD policy in the southern African region. Ultimately, I propose need for a more radical framework for EE/ ESD policy research that reaches beyond analyses of appropriations of policy within the Wesphalian state framework, and that moves beyond critiquing or seeking out resistance moments associated with the assumptions of trickle down effects from UN level policy, or analysis that is centered on the EE versus ESD debate. Such a framework requires a revitalized notion of agency involving commitment to collective, relational (including the socio-materially relational) and transgressive forms of agency for deep societal transformations all round. Overall, it seems that environmental education policy and praxis research conceptualized within a decolonizing transnational sphere frame appears to still be an open and as yet under-explored terrain.
- Full Text:
- Date Issued: 2016
Schools performing against the odds
- Authors: Niacker, Inbanathan , Grant, Carolyn , Pillay, Sivanandani
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281126 , vital:55694 , xlink:href="https://doi.org/10.15700/saje.v36n4a1321"
- Description: There are many schools in developing countries which, despite the challenges they face, defy the odds and continue to perform at exceptionally high levels. We cast our gaze on one of these resilient schools in South Africa, and sought to learn about the leadership practices prevalent in this school and the enablements and constraints to the school leadership practice. Underpinned by a critical realist lens, and drawing on social realist theory, this case study of one school generated data through interviews, observation, document analysis and transect walks. The school principal, one head of department and two teachers, were selected as participants. The findings indicate that the school embraced an expansive form of teacher leadership comprising leadership within and beyond the classroom. Further, the structural, cultural and agential climate was receptive to the expansive leadership. We conclude that the professional capital of teachers, together with teachers serving as social actors rather than remaining primary agents, are key resources to change and transformation in an emerging economy.
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- Date Issued: 2016
Screening of entomopathogenic fungi against citrus mealybug, Plannococcus citri (Hemiptera: Pseudococcidae)
- Authors: Chartier Fitzgerald, Veronique , Hill, Martin P , Moore, Sean D , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407059 , vital:70333 , xlink:href="https://hdl.handle.net/10520/EJC195093"
- Description: Planococcus citri (citrus mealybug) is a common and damaging citrus crop pest which has proven difficult to control using conventional methods, such as chemical pesticides and insect growth regulators, particularly late in the citrus growing season. The virulence of two entomopathogenic fungal species was studied in laboratory bioassays against the crawlers and adults of P. citri. Isolates of Metarhizium anisopliae and Beauveria bassiana, collected from citrus orchards in the Eastern Cape Province in South Africa, were verified using and molecular techniques. Mealybug bioassays were performed in 24-well plates. Beauveria bassiana (GAR 17 B3) and M. anisopliae (FCM AR 23 B3) isolates both resulted in 67.5 % mortality of mealybug crawlers and B. bassiana (GB AR 23 13 3) resulted in 64 % crawler mortality with concentrations of 1 x 107 conidia/ml. These three isolates were further tested in multipledose bioassays to determine the median lethal concentration (LC50), which were 5.29 x 105conidia/ml for the M. anisopliae isolate (FCM AR 23 B3), 4.25 x 106 conidia/ml for B. bassiana (GAR 17 B3), and 6.65 x 107 conidia/ml B. bassiana (GB AR 23 13 3) for crawlers, respectively. The results of this study suggested that two isolates (M. anisopliae FCM AR 23 B3 and B. bassiana GAR 17 B3) showed potential for further development as biological control agents against citrus mealybug. Further research would be required to determine their ability to perform under field conditions.
- Full Text:
- Date Issued: 2016
Sentential negation in South African Sign Language: A case study
- Authors: De Barros, Courtney , Siebörger, Ian
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385377 , vital:68013 , xlink:href=" https://hdl.handle.net/10520/EJC-4acb542a9"
- Description: As with other sign languages, South African Sign Language (SASL) expresses negation using both manual and non-manual features. In this case study, naturalistic data provided by two native signers of SASL are analysed to show the syntactic relationship between these two sets of features. Using a Principles and Parameters approach and Government and Binding Theory, we investigate the syntactic scope of negation in our SASL data. We observe that side-to-side headshake, as a non-manual feature, appears to be the chief clausal negator in SASL, with a clause-final manual negative particle, NOT, playing a secondary role. We describe the negative headshake as a featural affix which is base-generated in the head of NegP and triggers V-to- Neg raising. The negative particle NOT appears to be base-generated in the Specifier of NegP. Suggestions for further syntactic research on SASL are provided.
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- Date Issued: 2016
Spectroscopic investigations and theoretical calculations of DABCO induced xanthene bridged self-assembled zinc (II) porphyrin dimer
- Authors: Xu, Li , Huang, Tingting , Liang, Xu , Mack, John , Harris, Jessica , Nyokong, Tebello , Li, Minzhi , Zhu, Weihua
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240732 , vital:50866 , xlink:href="https://doi.org/10.1142/S1088424616500231"
- Description: An in-depth study of the electronic structure of a 1,4-diazabicyclo[2.2.2]octane (DABCO) induced molecular self-assembled xanthene-bridged and amide-bonded porphyrin dimer is reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations are used to identify trends in the optical spectroscopic properties. B3LYP geometry optimization predicts the formation of an almost perfectly eclipsed structure with respect to the two porphyrin rings with the analogous pyrrole nitrogens separated by 7.7–8.1 Å. The observed distinctive derivative-shaped band morphology of the pseudo-Faraday-A11 terms in the MCD spectra has been used to identify the main electronic Q and B-bands and to validate the TD-DFT calculations. The absence of a discernible splitting of the redox steps or a quenching of the fluorescence demonstrates that there is no significant exciton coupling between the two porphyrin rings.
- Full Text:
- Date Issued: 2016
Synthesis and dark toxicity of 5-(4-carboxyphenyl)-10, 15, 20-tris (phenyl)-porphyrinato chlorido gallium (III) when conjugated to δ-aminolevulinic acid
- Authors: Managa, Muthumuni , Mkhize, Scebi , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240014 , vital:50789 , xlink:href="https://doi.org/10.1080/00958972.2016.1223292"
- Description: 5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (ΦΔ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.
- Full Text:
- Date Issued: 2016
Synthesis and optical limiting properties of new lanthanide bis-and tris-phthalocyanines
- Authors: Sekhosana, Kutloana Edward , Manyeruke, Meloddy Hlatini , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240063 , vital:50795 , xlink:href="https://doi.org/10.1016/j.molstruc.2016.05.068"
- Description: This manuscript reports on syntheses of new multi-decker phthalocyanines, namely: bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} cerium(III) (2), tris-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} dicerium(III) (4) and bis-{2,3,9,10,16,10,16,17,23,24-octa(4-tertbutylphenoxy) phthalocyaninato} gadolinium(III) (5). Complex 4 which is a tris phthalocyanine showed better nonlinear optical behavior in solution than 2 which is a bis phthalocyanine, both containing the same central metal, Ce. All the three molecules possess good optical limiting properties judged by the limiting threshold values which ranged from 0.04 to 0.09 J cm−2 with complex 5 embedded in thin films, showing the lowest value of 0.04 J cm−2. Furthermore, nonlinear optical processes responsible for reverse saturable absorption data are investigated.
- Full Text:
- Date Issued: 2016
Synthesis and photophysicochemical properties of BODIPY dye functionalized gold nanorods for use in antimicrobial photodynamic therapy
- Authors: Kubheka, Gugu , Uddin, Imran , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239897 , vital:50778 , xlink:href="https://doi.org/10.1142/S108842461650070X"
- Description: A series of boron dipyrromethene (BODIPY) dyes with properties that are ideal for a good photosensitizer have been prepared. Functionalization with bromine atoms and attachment to gold nanoparticles through a meso-aniline group results in high singlet oxygen quantum yields and low fluorescent quantum yields. Molecular modelling was used to analyze trends in the MO energies of various brominated aniline BODIPY dyes.
- Full Text:
- Date Issued: 2016
Synthesis and physicochemical properties of zinc and indium phthalocyanines conjugated to quantum dots, gold and magnetic nanoparticles
- Authors: Osifeko, Olawale , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188639 , vital:44771 , xlink:href="https://doi.org/10.1016/j.dyepig.2016.04.015"
- Description: This work reports on the conjugation of semiconductors quantum dots (QDs), gold (AuNPs) or Fe3O4 magnetic (MNPs) nanoparticles to 4-(4,6-diaminopyrimidin-2-ylthio) substituted indium or zinc phthalocyanines (Pcs). The QDs and MNPs were linked to the Pcs via an amide bond and by chemisorption unto AuNP surface. There is a general decrease in fluorescence quantum yields of the Pcs in the presence of all the nanoparticles. There is an increase triplet quantum yields for Pcs in the presence of AuNPs and QDs, but not in the presence of MNPs. AuNPs conjugates irrespective of the central atoms have the highest singlet oxygen quantum yield and are more photo-stable than all the other conjugates. MPcs are less photostable in the presence of MNPs.
- Full Text:
- Date Issued: 2016
Synthesis and singlet oxygen production by a phthalocyanine when embedded in asymmetric polymer membranes
- Authors: Mafukidze, Donovan M , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188563 , vital:44765 , xlink:href="https://doi.org/10.1016/j.polymer.2016.10.032"
- Description: 2(3), 9(10), 16(17), 23(24)-Tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (ClInTAPPc, 3) was first conjugated to two different polymers: polystyrene (PS) and polyacrylonitrile (PAN) to form 3-PS and 3-PAN. The conjugates were cast into the corresponding polymers to form membranes represented as 3-PS-membrane and 3-PAN-membrane, respectively. The prepared membranes were characterized using various techniques including scanning electron microscopy and solid state UV/Vis spectroscopy. Singlet oxygen quantum yields were higher for the 3-PS-membrane at 0.51 compared to 3-PAN-membrane at 0.35. The larger singlet oxygen also applies to 3-PS (0.63) compared to 3-PAN (0.38) when in solution.
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- Date Issued: 2016
Synthesis, characterization and electrochemistry of rhodium (iii) complexes of meso-substituted [14] tribenzotriphyrin (2.1. 1)
- Authors: Xue, Zhaoli , Wang, Yemei , Mack, John , Mkhize, Scebi , Nyokong, Tebello , Fang, Yuanyuan , Ou, Zhongping , Kadish, Karl M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241043 , vital:50899 , xlink:href="https://doi.org/10.1039/C6RA03028A"
- Description: A thermal reaction using a series of [14]tribenzotriphyrins(2.1.1) (TriPs, 1a–d) with Rh2(C8H12)Cl2 provides RhIII–TriP complexes (2a–d) in 40−52% yields. The complexes were characterized by mass spectrometry, UV-visible absorption and 1H NMR spectroscopy. Single crystal X-ray analysis reveals that 2b adopts a dome-shaped conformation. The rhodium(III) ion is coordinated by the three pyrrole nitrogen atoms, two chloride ions and the nitrogen atom of an acetonitrile (CH3CN) solvent molecule. The optical spectra can be assigned using Michl's perimeter model. The L and B bands of the 2a–d complexes lie at ca. 600 and 500 nm, respectively, and are markedly red shifted relative to those of 1a–d. A reversible one-electron oxidation and two reversible one-electron reductions are observed in the cyclic voltammograms of 2a–d in CH2Cl2. The redox potentials are consistent with the optical data and the relatively narrow HOMO–LUMO gaps that are predicted in DFT calculations. TD-DFT calculations have been used to assign a third intense spectral band at 375 nm to a higher energy π → π* transition of the [14]tribenzotriphyrin(2.1.1) π-system.
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- Date Issued: 2016
Synthesis, Characterization, and Electronic Structures of Porphyrins Fused with Polycyclic Aromatic Ring Systems
- Authors: Okujima, Tetsuo , Mack, John , Nakamura, Jun , Kubheka, Gugu , Nyokong, Tebello , Zhu, Hua , Komobuchi, Naoki , Ono, Noboru , Yamada, Hiroko , Uno, Hidemitsu , Kobayashi, Nagao
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240360 , vital:50827 , xlink:href="https://doi.org/10.1002/chem.201602213"
- Description: A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels–Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.
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- Date Issued: 2016
Teaching and Learning of ‘Water for Agriculture’in Primary Schools in Lesotho, South Africa and Zimbabwe
- Authors: Pesanayi, Tichaona V , Mashozhera, Farasten , Khitsane, Lintle
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387289 , vital:68222 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152741"
- Description: Teaching youths about the subject of water for agriculture is vital in southern Africa where climate adaptation is imperative. Fresh water is a critical natural resource experiencing dangerous scarcity globally, with climate change and variability being key drivers. Agriculture consumes most of the allocated water in most of the southern African countries, so this sector needs particular water harvesting and conservation education. The Food and Agriculture Organisation (FAO) reported that 93% of cultivated land in southern Africa was rain-fed at the beginning of the 21st century. Drought hinders effective agricultural practices in poor-rainfall areas and is a common feature in most southern African countries. Increasingly frequent drought events affect Lesotho, South Africa and Zimbabwe chronically due to climate variability and change. These three countries have school curricula that carry agricultural and sustainability learning to varying extents. Agriculture is taught as a science subject, and tends to be inclined towards normative technicist approaches at the expense of traditional and innovative sustainability practices. This omission in curriculum development and teaching may miss the opportunity to learn from lessons offered by these traditional and innovative systems that have demonstrated resilience to climate variability and change. This paper explores the opportunities and enablers of sustainability learning and relevance in the primary school agriculture curricula of these three countries. The paper argues for inclusion of sustainable agricultural water learning as an act of educational quality and relevance that reflects 21st century socio-ecological, agro-climate and socioeconomic challenges in southern Africa.
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- Date Issued: 2016
Temperature-dependent performance and potential distribution of Pareuchaetes insulata, a biological control agent of Chromolaena odorata in South Africa
- Authors: Uyi, Osariyekemwen O , Zachariades, Costas , Hill, Martin P , McConnachie, Andrew J
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418067 , vital:71505 , xlink:href="https://doi.org/10.1007/s10526-016-9760-1"
- Description: Despite the release of about 1.9 million individuals of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) in KwaZulu-Natal for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae) in South Africa, the moth probably only established at one of the 30 release sites and its population level is generally low in the field. To determine whether climate incompatibility in South Africa is responsible for the poor performance of P. insulata, the effects of temperature on life-history traits were investigated under several constant temperatures. Although a degree-day model estimated between 3.9 and 10.0 generations of the moth per year in the weed’s invaded range, survival and fecundity declined while development time was prolonged at constant temperatures below 25 °C, indicating that both direct and indirect negative impacts of low winter temperatures, such as increased mortality, slow development and reduced fecundity as well as exposure to natural enemies, may partly explain the poor performance of P. insulata in South Africa.
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- Date Issued: 2016
The effects of silica based nanoparticles on the photophysicochemical properties, in vitro dark viability and photodynamic therapy study of zinc monocarboxyphenoxy phthalocyanine
- Authors: Oluwole, David O , Uddin, Imran , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240371 , vital:50828 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.07.002"
- Description: Aminopropyl triethoxysilane functionalized core SiO2 and core/shell ZnO/SiO2 nanoparticles (NP) were covalently linked to zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc, complex 1) via amide bond formation. The photophysicochemical behavior, in vitro dark viability and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) of the conjugates were studied. The nanoconjugates showed enhanced photophysicochemical behavior as compared to complex 1 alone. Complex 1 showed higher dark toxicity against MCF-7 cells when compared to the conjugates. In the dark, complex 1 accounted for less than 50% viable cells at 28.6 μg/mL and 57.1 μg/mL compared to the conjugates which accounted for more than 50% cell viability at these concentrations. The in vitro dark viability and PDT activity of complex 1 was reduced in the presence of these nanoparticles.
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- Date Issued: 2016
The good African society index
- Authors: Botha, Ferdi
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396194 , vital:69157 , xlink:href="https://doi.org/10.1007/s11205-015-0891-z"
- Description: This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (1) economic sustainability, (2) democracy and freedom, (3) child well-being, (4) environment and infrastructure, (5) safety and security, (6) health and health systems, (7) integrity and justice, (8) education, and (9) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 indicators. Tunisia ranks highest on the GASI, followed by Cape Verde and Botswana. Chad has the lowest GASI score, followed by Central African Republic and Cote d’Ivoire. The GASI is strongly related to the 2012 Human Development Index and Fragile States Index, to a lesser extent, GNI per capita.
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- Date Issued: 2016
The GULLS project: a comparison of vulnerabilities across selected ocean hotspots and implications for adaptation to global change
- Authors: Cochrane, Kevern L , Hobday, Alistair J , Aswani, Shankar , Byfield, Val , Dutra, Leo X , Gasalla, Maria A , Haward, Marcus , Paytan, Adina , Pecl, Gretta T , Popova, Katya , Sainulabdeen, Shyam S , Savage, Candida , Sauer, Warwick H H , van Putten, Ingrid E , Visser, Natascha , TG Team
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422037 , vital:71906
- Description: The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.
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- Date Issued: 2016
The interaction between graphene quantum dots grafted with polyethyleneimine and Au@ Ag nanoparticles
- 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