Electrode modification using nanocomposites of electropolymerised cobalt phthalocyanines supported on multiwalled carbon nanotubes
- Authors: Nyoni, Stephen , Mashazi, Philani N , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188730 , vital:44780 , xlink:href="https://doi.org/10.1007/s10008-015-2985-6"
- Description: A polymer of tetra(4)-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II) (CoPyPc) has been deposited over a multiwalled carbon nanotube (MWCNT) platform and its electrocatalytic properties investigated side by side with polymerized cobalt tetraamino phthalocyanine (CoTAPc). X-ray photoelectron spectroscopy, scanning electron microscopy and cyclic voltammetry studies were used for characterization of the prepared polymers of cobalt phthalocyanine derivatives and their nanocomposites. L-Cysteine was used as a test analyte for the electrocatalytic activity of the nanocomposites of polymerized cobalt phthalocyanines and multiwalled carbon nanotubes. The electrocatalytic activity of both polymerized cobalt phthalocyanines was found to be superior when polymerization was done on top of MWCNTs compared to bare glassy carbon electrode. A higher sensitivity for L-cysteine detection was obtained on CoTAPc compared to CoPyPc.
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Elucidating Latent Mechanistic Complexity in Competing Acid-Catalyzed Reactions of Salicylaldehyde-Derived Baylis–Hillman Adducts
- Authors: Olomola, Temitope O , Klein, Rosalyn , Caira, Mino, R , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442596 , vital:74010 , https://doi.org/10.1021/acs.joc.5b02372
- Description: 1H NMR-based kinetic studies have revealed the latent mechanistic complexity of deceptively simple hydrochloric acid-catalyzed reactions of salicylaldehyde-derived Baylis–Hillman adducts. Reactions conducted at 0 °C afforded 2-(chloromethyl)cinnamic acid derivatives as the major products and the corresponding 3-(chloromethyl)coumarin derivatives as the minor products. In reactions conducted in refluxing acetic acid, however, the 3-(chloromethyl)coumarin derivatives are the sole products. Variable-temperature 1H NMR analysis permitted the determination of the rate constants and kinetic parameters involved in the pseudo-first-order formation of (Z)-2-(chloromethyl)-3-(2-hydroxyphenyl)-2-propenoic acid. The kinetic data clearly preclude the operation of classical kinetic versus thermodynamic control and indicate the operation of three independent reaction pathways. Theoretical studies of these pathways undertaken at the B3LYP/6-31G(d) level permitted rationalization of the experimental data and provided insights into the possible mechanism of the enzymic E–Z isomerization and cyclization of (E)-cinnamic acid analogues to afford coumarins.
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Encompassing the relative non-target risks from agents and their alien plant targets in biological control assessments
- Authors: Downey, Paul O , Paterson, Iain D
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417940 , vital:71496 , xlink:href="https://doi.org/10.1007/s10526-016-9744-1"
- Description: Criticisms about the safety of biological control of alien plants has resulted in a risk-averse approach, where the risks posed by the agent are paramount and the risks posed by the alien plant are neglected. We argue that the risk associated with non-target damage from agents needs to be assessed relative to that of their target alien plants. A literature review of the non-target risks associated with biological control agents was undertaken in terms of the risk to native species from agents relative to the risk to native species from their alien plant targets. We then developed a framework that compares the consequence with the likelihood of non-target damage for both agents and their targets to provide an overall risk rating. Assessments of the risk of damage from both agents and their target alien plants will enable researchers, managers and policy makers to better assess the risks from biological control.
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Enhanced nonlinear optical responses of zinc diaminopyrimidin-2-ylthio phthalocyanine conjugated to AgxAuy alloy nanoparticles
- Authors: Bankole, Owolabi M , Osifeko, Olawale L , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240382 , vital:50829 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.06.025"
- Description: In this article, the photophysical and nonlinear optical (NLO) characterizations of diaminopyrimidin-2-ylthio phthalocyaninatozinc (II) (2) before and after conjugation to AgxAuy nano-alloys are discussed. Phthalocyanines-AgxAuy (2-AgxAuy) composites showed enhanced triplet state and nonlinear optical behaviour when compared to free phthalocyanine. Optical limiting (OL) responses of the samples were evaluated using Z-scan technique at 532 nm and 10 ns in dimethyl sulfoxide. Reverse saturable absorption (RSA), which is a direct consequence of triplet absorption of already excited molecules was observed as the dominant mechanism responsible for nonlinearity of the samples. By virtue of the magnitude of absorption coefficients and other NLO optical parameters estimated in this work, 2-AgxAuy composites were found to exhibit stronger optical limiting responses than unconjugated phthalocyanine. The large third-order susceptibilities of the composites make them suitable materials for attenuating modern laser radiations, and also found useful in various optical applications.
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Enhancing Life Sciences Teachers’ Biodiversity Knowledge
- Authors: Tshiningayamwe, Sirkka A N
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387991 , vital:68296 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152733"
- Description: In the last two decades, South Africa has made efforts to integrate biodiversity content in its Life Sciences curriculum; however its implementation lacks systemic coherence. This is due to ineffective professional development approaches. This paper provides insights into how Life Sciences teachers in the Eastern Cape can be supported through professional learning communities (PLCs) as a potential approach to enhancing their biodiversity knowledge. PLCs are communities that provide the setting and necessary support for groups of classroom teachers to participate collectively in determining their own developmental trajectories, and to set up activities that will drive their development. The case study presented in this paper is part of a broader qualitative PhD study which explored the functionings and conversion factors in biodiversity teacher PLCs in South Africa. Drawing on teachers’ and facilitators’ experiences and the observation of the PLC approaches, the capability approach was used to analyse the functionings and conversion factors that enhance teachers’ biodiversity knowledge. The paper highlights that for PLCs to be effective approaches for professional development, they need to be aligned to teachers’ valued functionings. It also reveals that different conversion factors enable teachers’ achievements of valued functionings in the PLC. The paper aims to contribute to wider policies on capacity building for teachers.
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Enigmatic tissue in the orobranchial chamber of cardinalfishes of the genus Siphamia (Perciformes, Apogonidae)
- Authors: Gon, Ofer , Pinchuck, Shirley C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443297 , vital:74106 , https://hdl.handle.net/10520/EJC196540
- Description: An unusual tissue covering the tongue and occasionally part of the gill chamber of many species of the Indo-Pacific cardinalfish genus Siphamia is described and compared with an earlier description of a similar tissue found in the cichlid species Alcolapia grahami inhabiting lakes of the African Rift Valley. Species of both genera are mouth brooders. The Siphamia tissue is globular and its cells are oblong, whereas the A. grahami tissue is single-layered, with larger, columnar cells. The tissues of both have the characteristics of a mucosa and show evidence of active synthesis. While ion regulation has been proposed for the A. grahami tissue, the function of the Siphamia tissue is unknown, but a role in feeding, or antibiotic or appetite-suppressing functions have been suggested.
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Entomopathogenic fungi as control agents of Thaumatotibia leucotreta in citrus orchards: field efficacy and persistence
- Authors: Coombes, Candice A , 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/10962/417956 , vital:71497 , xlink:href="https://doi.org/10.1007/s10526-016-9756-x"
- Description: Entomopathogenic fungal isolates Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) strain G Ar 17 B3 and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) strain FCM Ar 23 B3 have been identified as effective control agents of the important citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) wandering fifth instars under laboratory conditions. This study is the first report on the ability of these isolates to persist and reduce T. leucotreta infestation in commercial citrus orchards in South Africa. A reduction in pest infestation of between 28 and 82 % upon trial completion was reported. Both isolates were recovered from soil samples collected five months post-application with high host density and moderate to high soil moisture favouring recovery. Low soil moisture negatively influenced the persistence of both isolates and the control efficiency of B. bassiana. These results provide evidence and support for the future use of these isolates against T. leucotreta thus warranting further investigation.
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Ericoid fungal inoculation of blueberry under commercial production in South Africa
- Authors: Bizabani, Christine , Fontenla, Sonia , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448610 , vital:74746 , https://doi.org/10.1016/j.scienta.2016.06.029
- Description: Ericoid mycorrhizal (ERM) fungi are known to enhance growth of plants belonging to the Ericaceae family. However, the outcomes of root-fungal associations in this family are influenced by several factors such as soil nutrient status, climatic conditions, host variety and fungal partner. The aim of this study was (i) to determine whether symbiotic fungal structures form in roots of Misty (Vaccinium corymbosum) and Brightwell (V. ashei) blueberry varieties, following inoculation with Leohumicola, Oidiodendron maius and Meliniomyces fungal species, and (ii) evaluate inoculation effects on the growth of blueberry varieties. The study was conducted for 60 weeks under commercial production conditions at Amathole Berries, Sutterheim, South Africa. All three fungi were isolated from Erica plants growing naturally in Albany Centre of Endemism of South Africa. All ERM formed mycorrhizal structures characteristic of typical ericoid colonisation in the roots of both Misty and Brightwell. However, percentage colonisation was low. The highest colonisation percentage, 20.4%, was observed in Misty inoculated with Oidiodendron maius. Colonisation was significantly different compared to un-inoculated controls in the Misty variety. In both varieties inoculated with either Leohumicola or Meliniomyces did not improve (p > 0.05) shoot growth and biomass. All fungal species improved root biomass in Misty but not in Brightwell. This indicates that ERM inoculation may potentially benefit plant of Misty and that responses to ERM inoculation vary between blueberry varieties.
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Expanding reproductive justice through a supportability reparative justice framework: the case of abortion in South Africa
- Authors: Macleod, Catriona I
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443680 , vital:74143 , xlink:href="https://doi.org/10.1080/13691058.2018.1447687"
- Description: Theoretical refinement of the concept of reproductive justice has been called for. In this paper, I propose the use of a supportability reparative justice approach. Drawing on intra-categorical intersectionality, the supportability aspect starts from the event of a pregnancy to unravel the interwoven embodied and social realities implicated in women experiencing pregnancy as personally supportable/unsupportable, and socially supported/unsupported. The reparative justice aspect highlights the need for social repair in the case of unsupportable pregnancies and relies on Ernesto Verdeja’s critical theory of reparative justice in which he outlines four reparative dimensions. Using abortion within the South African context, I show how this framework may be put to use: (1) the facilitation of autonomous decision-making (individual material dimension) requires understanding women within context, and less emphasis on individual-driven ‘choice’; (2) the provision of legal, safe state-sponsored healthcare resources (collective material dimension) demands political will and abortion service provision to be regarded as a moral as well as a healthcare priority; (3) overcoming stigma and the spoiled identities (collective symbolic dimension) requires significant feminist action to deconstruct negative discourses and to foreground positive narratives; and (4) understanding individual lived experiences (individual symbolic dimension) means deep listening within the social dynamics of particular contexts.
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Fluorescence behavior of nanoconjugates of graphene quantum dots and zinc phthalocyanines
- 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.
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Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells
- 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.
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Focus on 'the family'?: how South African family policy could fail us
- Authors: Morison, Tracy , Lynch, Ingrid , Macleod, Catriona I
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446244 , vital:74484 , xlink:href="https://hsrc.ac.za/uploads/pageContent/7505/HSRC%20POLICY%20BRIEF%2011%20-%20MORISON%20Family%20policy_PRESS%20(2).pdf"
- Description: In the past decade South African policymakers have increasingly focused on families as sites of state intervention. To date, several family policies have been developed to support societal well-being and cohesion. The most recent policy document is the White Paper on Families in South Africa (DSD 2012), which aims to facilitate the mainstreaming of a family perspective into all government policy-making. Family policies are intended to provide support, enhance family members’ wellbeing, strengthen family relationships, and help families address social challenges, such as economic instability. Their ultimate aim is to ensure a safe and socially cohesive society (Robila 2014). A core concern, therefore, is with promoting ‘stable, healthy families’. This concern is valid in South Africa since many families experienced a profound lack of stability under apartheid and today instability is brought about by various socio-economic changes, especially the HIV and AIDS epidemic.
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Fundisa for Change teacher professional development programme
- Authors: Tshiningayamwe, Sirkka A
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432999 , vital:72922 , xlink:href="https://eeasa.org.za/wp-content/uploads/2017/05/EEASA-Bullitin-vol-43.pdf"
- Description: Environment and sustainability content has been integrated into the South African curricula documents, including the past ones. This integration was followed by initiatives which aimed at supporting teachers to implement environmental knowledge and action in the curriculum. For example, the Learning for Sustainability project was piloted in Gauteng and Mpumalanga province between the year 1997 and 2000. The project followed a three pillar approach of integrating environmental education in the curriculum: teacher development, curriculum development and materials development. As part of the project, a spiral model approach to teacher professional development was introduced.
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Generation of New Ecotoxicity Data for Salts Using Indigenous South African Freshwater Macroinvertebrate: Updating the National Salts Toxicity Database
- Authors: Mensah, Paul K , Mgaba, Ntombekhaya , Griffin, Neil J , Odume, Oghenekaro N , Palmer, Carolyn G
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437854 , vital:73417 , ISBN 978-1-4312-0747-3 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV%20353.pdf
- Description: Scherman and Palmer (2013) reviewed the historical and current trends of Environmental Water Quality (EWQ) in South Africa. Based on the review, they identified research gaps for which they proposed a co-ordinated set of projects that need to be commissioned and executed to fill these gaps. These co-ordinated set of projects include update of TEACHA (Tool for Ecological Aquatic Chemical Habitat Assessment); update of the national salt toxicity database; integration of Resource Directed Measures (RDM) components (ie Ecological Reserve, Re-source Quality Objectives (RQOs) and Classification); integrating water quality and quantity; evaluation of the RDM participatory process based on research and current understandings of complex social-ecological systems and ecosystem services; and integrating RDM and SDC (Source Direct Control) to ensure coherent link between the two. The overarching aim of the above set of projects is to support implementa-tion of the National Water Resource Strategy 2 (NWRS2). Therefore, the main objective of this project to contribute to addressing the second research gap listed above (ie updating the national salt toxicity data-base). Noting that the database contains only data on single salts with nothing on salt mixtures, the project also generated binary salt mixtures data for the database, in addition to generating data for single salts.
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Graphene quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as fluorescence “turn-on” nanosensors
- 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.
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HealthMessenger: an e-Health service to support ICT deployments in poor areas
- Authors: Gremu, Chikumbutso , Terzoli, Alfredo , Tsietsi, Mosiuoa
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430609 , vital:72703 , 10.1109/ISTAFRICA.2016.7530632
- Description: Development and implementation of appropriate e-services as well as revenue generation are key to deploying and sustaining ICT installa-tions in poor areas in developing countries. The area of e-Health is a promising area for e-Services that are important to populations in poor areas and health service organisations that are already spending mon-ey on different health initiatives in these areas. This paper discusses an e-Health service that facilitates dissemination of health information to people living in poor areas and that is subsequently used to generate revenue to support deployment and development of ICT in the areas. The tool was developed within the context of the Siyakhula Living Lab (SLL), a multi-stakeholder operation that promotes ICT for Development in the Eastern Cape Province of South Africa. Creation of health con-tent for the e-health service and its subsequent consumption happen in two different environments from a technological and social point of view. To enable this to happen, the e-service comprises two component applications that run in a peer-to-peer fashion. The component that is used to disseminate content for end-user consumption is called the HealthMessenger. The HealthMessenger is hosted on an environment called TeleWeaver, an application integration platform developed within the SLL to host software applications targeting people living in poor ar-eas. The platform is customised to support services with a revenue generation component.
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Heat accumulation and development rate of massed maggots of the sheep blowfly, Lucilia cuprina (Diptera: Calliphoridae)
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442168 , vital:73964 , https://doi.org/10.1016/j.jinsphys.2016.09.009
- Description: Blowfly larvae aggregate on exposed carcasses and corpses and pass through three instars before wandering from the carcass and pupating. The developmental landmarks in this process can be used by forensic entomologists to estimate the time since the insects colonised the carcass, which sets a minimum post mortem interval. Large aggregations of feeding larvae generate a microclimate with temperatures up to 15 °C above ambient conditions, which may accelerate larval development and affect forensic estimates of post-mortem intervals. This study investigated the effects of heat accumulated by maggot masses of Lucilia cuprina at aggregations of 20, 50 and 100 larvae, each at incubation temperatures of 18 °C, 24 °C and 30 °C, using body length and life stage as developmental indicators. Aggregation temperatures reached up to 18.7 °C above ambient temperature, with significant effects of both size and temperature of the aggregation on the development time of its larvae. Survivorship was highest for all life stages at 24 °C, which is near the developmental optimum of L. cuprina. The results of this study provide a broadly applicable method of quantifying heat accumulation by aggregations of a wide range of species of forensic importance, and the results obtained from such studies will demonstrate that ambient temperature cannot be considered the only source of heat that blowfly larvae experience when they develop on a carcass. Neglect of temperatures within larval aggregations will result in an overestimation of post-mortem intervals and thus have far-reaching medicolegal consequences.
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Heterogeneity in virulence relationships between Cryptophlebia leucotreta granulovirus isolates and geographically distinct host populations: Lessons from codling moth resistance to CpGV-M
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline M , Moore, Sean D
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417998 , vital:71500 , xlink:href="https://doi.org/10.1007/s10526-016-9728-1"
- Description: In South Africa, the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV) is used to control the citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). However, the risk associated with continuous application of a single active ingredient is resistance. In order to manage resistance should it occur in field populations of T. leucotreta in South Africa, five new CrleGV genotypes from geographically distinct insect populations which were shown to exhibit some degree of phenotypic variation were recovered and genetically characterized. In droplet bioassays using seven CrleGV isolates against five T. leucotreta populations, some isolates were found to show higher virulence to some host populations than others. There were marked differences in the LD50 values of isolates and the number of occlusion bodies required per larva ranged between 0.79 and 3.12. The significance of these findings with respect to the application of CrleGV biopesticides and the management of resistance is discussed.
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How content analysis may complement and extend the insights of discourse analysis: An example of research on constructions of abortion in South African newspapers 1978–2005
- Authors: Feltham-King, Tracey , Macleod, Catriona I
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446258 , vital:74485 , xlink:href="https://doi.org/10.1177/1609406915624575"
- Description: Although discourse analysis is a well-established qualitative research methodology, little attention has been paid to how discourse analysis may be enhanced through careful supplementation with the quantification allowed in content analysis. In this article, we report on a research study that involved the use of both Foucauldian discourse analysis (FDA) and directed content analysis based on social constructionist theory and our qualitative research findings. The research focused on the discourses deployed, and the ways in which women were discursively positioned, in relation to abortion in 300 newspaper articles, published in 25 national and regional South African newspapers over 28 years, from 1978 to 2005. While the FDA was able to illuminate the constitutive network of power relations constructing women as subjects of a particular kind, questions emerged that were beyond the scope of the FDA. These questions concerned understanding the relative weightings of various discourses and tracing historical changes in the deployment of these discourses. In this article, we show how the decision to combine FDA and content analysis affected our sampling methodology. Using specific examples, we illustrate the contribution of the FDA to the study. Then, we indicate how subject positioning formed the link between the FDA and the content analysis. Drawing on the same examples, we demonstrate how the content analysis supplemented the FDA through tracking changes over time and providing empirical evidence of the extent to which subject positionings were deployed.
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Impacts of HIV/AIDS on food consumption and wild food use in rural South Africa
- Authors: Ncube, Keitometsi , Shackleton, Charlie M , Swallow, Brent M , Dassanayake, Wijaya
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180412 , vital:43385 , xlink:href="https://doi.org/10.1007/s12571-016-0624-4"
- Description: HIV/AIDS can affect household food consumption in many ways, including through reductions in availability and quality of labour, reductions in earned income, and increased expenditure on medications. In rural South Africa, these negative effects can be buffered by social safety net programs provided by government and collection of wild foods. Despite some acknowledgement of the potential safety net role of wild foods, however, their contribution relative to other food sources in the context of HIV/AIDS remains underexplored. Here we report empirical findings from two rural communities in the Eastern Cape province of South Africa. Qualitative and quantitative methods were used to characterise food sources, intake and calories from 68 HIV/AIDS afflicted households and 87 non-afflicted households every quarter over 12 months. Results show that diets were moderately well-balanced though limited in variety, with cereal items contributing 52 % to total calorie intake. The bulk of food consumed by households was purchased, with supplementation from own production, collected wild vegetables and collected wild fruits. Up to 20 % of respondents from both HIV/ AIDS afflicted and non-afflicted households had insufficient daily caloric intake. Multivariate analyses show that, all else equal, individuals living in households afflicted by HIV/AIDS consumed fewer calories, had less diverse diets, and were more dependent on wild foods than those living in non-afflicted households. Given the detrimental effects of HIV/AIDS on income and home production, wild foods represent a free and readily available food source for vulnerable households.
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