Advances in the regulation of weed biological control in South Africa
- Authors: Ivey, Philip J , Hill, Martin P , Zachariades, Costas
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416819 , vital:71388 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a24"
- Description: Regulation of biological control (biocontrol) is essential to ensure its continued safety and to enhance its acceptability as a key contributor to the management of damaging invasive alien plants in South Africa. Local researchers were concerned that regulators may become risk averse and over-cautious, thus preventing introductions of safe biocontrol agents, as bureaucratic impediments have contributed to the decline in the number of biocontrol releases in several other countries. In South Africa, the introduction of a transparent and inclusive review process has averted these concerns. Legislation in South Africa enables departments concerned with protecting environmental and agricultural resources, to work together to regulate potential risks. An interdepartmental committee, advised by independent specialists, facilitate the review of research into the safety of potential biocontrol agents. Regulators have reviewed and timeously assessed 26 potential biocontrol agents between 2013 and 2020. This has ensured that the considerable benefits from safe biocontrol agents are available for management of some of South Africa’s worst invasive alien plants. We review the system in South Africa and suggest possible improvements to the regulatory framework.
- Full Text:
- Date Issued: 2021
Applying a student curriculum discourse in higher education teaching and learning
- Authors: Mndzebele, Samuel , McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187417 , vital:44633 , xlink:href="https://doi.org/10.1080/18146627.2013.786210"
- Description: Indications of poor quality in students’ written work necessitated the need for deeper investigations aimed at designing and applying appropriate teaching/learning and assessment innovations in the course curriculum. The project-exercise engaged a conceptual-explorative approach through: reviews/investigations; educational diagnosis; design/application of innovations and evaluation processes. In addition to other challenges, diagnosed problems included: students’ ignorance on key curriculum components; imbalance in teaching/learning and assessment tasks engaging all 3-learning domains; less intensiveness of the e-learning mode; and superficial formative feedback. Included a “Student-Curriculum-Discourse” self-tutorial guide, and tasks alignment of the teaching/learning and assessment. Learners’ performance can be improved through a curriculum-discourse self-tutorial exercise, complemented with: intellectual, social, experiential, and emotional structures. Both educators and learners share specific responsibilities in the teaching/learning environment. There is need to expand/probe the theoretical dimension within which the on-line distance education occurs.
- Full Text:
- Date Issued: 2013
Best practices in the use and exchange of microorganism biological control genetic resources
- Authors: Mason, Peter G , Hill, Martin P , Smith, David , Silvestri, Luciano C , Weyl, Philip S R , Brodeur, Jacques , Vitorino, Marcello Diniz
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417927 , vital:71495 , xlink:href="https://doi.org/10.1007/s10526-023-10197-3"
- Description: The Nagoya Protocol actions the third objective of the Convention on Biological Diversity and provides a framework to effectively implement the fair and equitable sharing of benefits arising out of the use of genetic resources. This includes microorganisms used as biological control agents. Thus biological control practitioners must comply with access and benefit-sharing regulations that are implemented by countries providing microbial biological control agents. A review of best practices and guidance for the use and exchange of microorganisms used for biological control has been prepared by the IOBC Global Commission on Biological Control and Access and Benefit-Sharing to demonstrate commitment to comply with access and benefit-sharing requirements, and to reassure the international community that biological control is a very successful and environmentally safe pest management strategy that uses biological resources responsibly and sustainably. We propose that best practices include the following elements: collaboration to facilitate information exchange about the availability of microbial biological control agents and where they may be sourced; freely sharing available knowledge in databases about successes and failures; collaborative research with provider countries to develop capacity; and production technology transfer to provide economic opportunities. We recommend the use of model concept agreements for accessing microorganisms for scientific research and non-commercial release into nature where access and benefit-sharing regulations exist and where regulations are not restrictive or do not exist. We also recommend a model agreement for deposition of microbial biological control agents into culture collections.
- Full Text:
- Date Issued: 2023
Characterization and physicochemical studies of the conjugates of graphene quantum dots with differently charged zinc phthalocyanines
- Authors: Matshitse, Refilwe , Sekhosana, Kutloano E , Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189227 , vital:44829 , xlink:href="https://doi.org/10.1080/00958972.2017.1387652"
- Description: Unsubstituted zinc phthalocyanine (ZnPc), 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]-phthalocyanine (ZnTPPcQ) and Zn tetrasulfo phthalocyanine (ZnTSPc) were non-covalently (electrostatic and/or π–π interaction) attached to graphene quantum dots (GQDs) to form GQDs-Pc nanoconjugates. Relative to Pcs alone, the presence of GQDs improved the triplet quantum yields with the following values: GQDs-ZnPc (0.73), GQDs-ZnTPPcQ (0.76) and GQDs-ZnTSPc (0.67). Respective Förster resonance energy transfer (FRET) efficiencies were calculated to be 0.81, 0.80 and 0.28. However, singlet oxygen generating abilities of the as-synthesized nanoconjugates were relatively low due to the screening effect of GQDs and quenching in water. This study shows that, the type of Pc, loading and solvent used are among the vital properties to consider when constructing GQD-nanoconjugate systems with optimal triplet quantum yield properties and investigation of their physicochemical properties.
- Full Text:
- Date Issued: 2017
Collaborative stewardship in multifunctional landscapes: toward relational, pluralistic approaches
- Authors: Cockburn, Jessica J , Cundell, Georgina , Shackleton, Sheona E , Rouget, Mathieu , Zwinkels, Marijn , Cornelius, Susanna A , Metcalfe, Liz , Van den Broek, D
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/390297 , vital:68535 , xlink:href="https://doi.org/10.5751/ES-11085-240432"
- Description: Landscape stewardship offers a means to put social-ecological approaches to stewardship into practice. The growing interest in landscape stewardship has led to a focus on multistakeholder collaboration. Although there is a significant body of literature on collaborative management and governance of natural resources, the particular challenges posed by multifunctional landscapes, in which there are often contested interests, require closer attention. We present a case study from South Africa to investigate how collaborative stewardship can be fostered in contested multifunctional landscapes. We conducted this research through an engaged transdisciplinary research partnership in which we integrated social-ecological practitioner and academic knowledge to gain an in-depth understanding of the challenges of fostering collaboration. We identified five overarching factors that influence collaboration: contextual, institutional, social-relational, individual, and political-historical. Collaborative stewardship approaches focused on the development of formal governance institutions appear to be most successful if enabling individual and social-relational conditions are in place. Our case study, characterized by high social diversity, inequity, and contestation, suggests that consensus-driven approaches to collaboration are unlikely to result in equitable and sustainable landscape stewardship in such contexts. We therefore suggest an approach that focuses on enhancing individual and social-relational enablers. Moreover, we propose a bottom-up patchwork approach to collaborative stewardship premised on the notion of pluralism. This would focus on building new interpersonal relationships and collaborative capacity through small collective actions. Taking a relational, pluralistic approach to fostering collaborative stewardship is particularly important in contested, socially heterogeneous landscapes. Drawing on our study and the literature, we propose guiding principles for implementing relational, pluralistic approaches to collaborative stewardship and suggest future research directions for supporting such approaches.
- Full Text:
- Date Issued: 2019
Consider the unexpected: Scaling ESD as a matter of learning
- Authors: Mickelsson, Martin , Kronlid, David O , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182438 , vital:43830 , xlink:href="https://doi.org/10.1080/13504622.2018.1429572"
- Description: This article aims to introduce a view of scaling as a learning process. In the article we discuss the concept of ‘scaling up’ or ‘scaling’ of Education for Sustainable Development (ESD) activities on the basis of how ‘scaling up’ ESD is highlighted in the UNESCO Global Action Programme (GAP) on ESD. Drawing on a Deweyan theory of learning as processes of transactional encounters, the article presents a conceptual framework of scaling-ESD-activities-as-learning. This conceptual framework is intended to have implications for ESD policy and ESE research. The theoretical specifications and practical implications presented are results of data collected using a participatory research approach (Re-Solve) and an abductive analysis. In this article, we argue that viewing scaling as a learning process enables a nuanced notion of scaling ESD-activities. This should be seen in relation to (a) complex sustainability challenges, (b) ethical aspects, (c) a more attentive and strict approach to scaling in ESD policy and (d) addressing questions of significant importance to scaling research.
- Full Text:
- Date Issued: 2019
Constellations, technicality, iconisation and Eskom: A case from South Africa’s Business Day
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385350 , vital:68010 , xlink:href="https://doi.org/10.2989/16073614.2022.2040369"
- Description: This article uses Legitimation Code Theory (LCT) and systemic functional linguistics (SFL) to explore interactions between various resources for building economic and political knowledge in a 2015 article from Business Day, a South African newspaper, concerning the country’s energy crisis. We use LCT to observe how three constellations are built in the article: a ‘developmental state’ constellation; a ‘neo-liberal’ constellation; and another underarticulated constellation that selectively draws ideas from both the preceding constellations. These constellations are built through the unfolding of the text using various linguistic resources, which we describe using SFL, including technicality and iconisation. We identify instances where words are charged with both ideational and axiological meaning concurrently, challenging existing understandings of the process of iconisation.
- Full Text:
- Date Issued: 2022
Crossing the border from candidate to supervisor: The need for appropriate development
- Authors: Motshoane, Puleng , McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185876 , vital:44442 , xlink:href="https://doi.org/10.1080/13562517.2021.1900814"
- Description: Postgraduate education has grown enormously worldwide, which has led to supervisors being expected to take on a supervisor's role immediately upon graduation. But crossing the border from being a doctoral candidate to becoming a doctoral supervisor entails significant shifts in identity and an understanding of postgraduate pedagogy and institutional expectations. This paper argues that supervision development opportunities are crucial, but they need to be contextualised and include critical key agents with some institutional authority if they are to be deemed worthwhile and effect change. An online survey completed by 186 participants from across institutional types and disciplines in South Africa is analysed using Archer's social realism to provide insights into how emerging supervisors are currently supported. The resultant recommendations on supervision development could contribute to more confident border crossing by emerging supervisors.
- Full Text:
- Date Issued: 2021
Cultural historical activity theory, expansive learning and agency in permaculture workplaces
- Authors: Mukute, Mutizwa
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386474 , vital:68145 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122818"
- Description: This paper reports on how Cultural Historical Activity Theory was used to identify and analyse contradictions; model and implement solutions in the learning and practice of permaculture at one school and its community in Zimbabwe. This is one of three sustainable agriculture workplace learning sites being examined in a wider study on change-oriented learning and sustainability practices (Mukute, 2009). It gives a brief background to permaculture and the School and Colleges Permaculture Programme (SCOPE) in Zimbabwe. The paper focuses on how contradictions were used as sources of learning and development leading to ‘real life expansions’. This demonstrates and reflects on the value of an interventionist research theory and methodology employed in the study to enhance participants’ agency in sustainable agriculture workplaces.
- Full Text:
- Date Issued: 2009
Curriculating powerful knowledge for public managers and administrators
- Authors: McKenna, Sioux , Harran, Marcelle , Lück, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187160 , vital:44575 , xlink:href="https://doi.org/10.1080/18146627.2019.1652103"
- Description: Public Management and Public Administration are important professions for an emerging democracy such as South Africa. They operate as the interface between state and public and are responsible for enacting many of the government's policies and social initiatives. Concerns about a lack of capacity in the sector suggest that those in these roles may be unable to meet the demands of the workplace. This article reports on a study that responded to calls for the curriculum to address such concerns by interrogating the knowledge structures of Public Management and Public Administration programmes in higher education. Interviews, textbooks and course guides were analysed to illuminate the forms of knowledge being legitimated in curricula. The study found that the focus on knowledge, skills and processes might be at the expense of a focus on the development of particular attributes or dispositions in the knowers. Furthermore, the knowledge level focus was limited in that it was highly contextualised and “light” on theory, raising questions about the acquisition of powerful knowledge needed for good governance and critical engagement in the public sector. The study recommends that both programmes include more conceptual knowledge; exposure to critical powerful forms of knowledge; and the development of particular attributes and dispositions.
- Full Text:
- Date Issued: 2020
Deep Palmprint Recognition with Alignment and Augmentation of Limited Training Samples
- Authors: Brown, Dane L , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440249 , vital:73760 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
Deep palmprint recognition with alignment and augmentation of limited training samples
- Authors: Brown, Dane L , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/464074 , vital:76473 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
Depth and habitat determine assemblage structure of South Africa’s warm-temperate reef fish
- Authors: Heyns-Veale, Elodie R , Bernard, Anthony T F , Richoux, Nicole B , Parker, Daniel M , Langlois, T J , Harvey, E S , Götz, Albrecht
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456035 , vital:75477 , xlink:href="https://doi.org/10.1007/s00227-016-2933-8"
- Description: Depth and habitat are important predictors of fish assemblage structure, yet current no-take marine protected area (MPA) networks are generally limited to providing refuge for fish species that inhabit shallow waters and may exclude deep habitats essential to exploited populations. To ensure MPA efficacy at the design, uptake and management levels, baseline data on fish populations associated with deep nearshore reefs are needed. This study employed baited remote underwater stereo-video systems to investigate fish habitat associations at shallow (11–25 m) and deep (45–75 m) reef sites in the Tsitsikamma National Park MPA, South Africa. The compositions of fish assemblages at shallow and deep reef sites were significantly different. Specifically, rare species, juveniles and low trophic level species dominated the shallow reef, while deep reef assemblages were characterised by large, sexually mature and predatory fish. The body size of abundant species was also correlated with depth, with larger individuals being more abundant on deeper reefs. Habitat types were identified according to a habitat classification system established in a previous study, which resulted in four broad depth separated habitat types (defined by macrobenthos and environmental variables). Canonical analysis of principle coordinates (CAP) indicated that habitat type was a good categorical predictor of the observed fish assemblages. The CAP analysis determined that 86 % of the samples were correctly assigned to the habitat type from which they were collected, indicating that specific fish assemblages were associated with distinct habitat types. This study highlights the importance of protecting both shallow and deep reefs, not only to ensure the conservation of particular fish assemblages, but also to provide protection for all stages of the life cycle of fish species.
- Full Text:
- Date Issued: 2016
Developing biosensors in developing countries: South Africa as a case study
- Authors: Fogel, Ronen , Limson, Janice L
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431661 , vital:72794 , xlink:href="https://doi.org/10.3390/bios6010005"
- Description: A mini-review of the reported biosensor research occurring in South Africa evidences a strong emphasis on electrochemical sensor research, guided by the opportunities this transduction platform holds for low-cost and robust sensing of numerous targets. Many of the reported publications centre on fundamental research into the signal transduction method, using model biorecognition elements, in line with international trends. Other research in this field is spread across several areas including: the application of nanotechnology; the identification and validation of biomarkers; development and testing of biorecognition agents (antibodies and aptamers) and design of electro-catalysts, most notably metallophthalocyanine. Biosensor targets commonly featured were pesticides and metals. Areas of regional import to sub-Saharan Africa, such as HIV/AIDs and tuberculosis diagnosis, are also apparent in a review of the available literature. Irrespective of the targets, the challenge to the effective deployment of such sensors remains shaped by social and economic realities such that the requirements thereof are for low-cost and universally easy to operate devices for field settings. While it is difficult to disentangle the intertwined roles of national policy, grant funding availability and, certainly, of global trends in shaping areas of emphasis in research, most notable is the strong role that nanotechnology, and to a certain extent biotechnology, plays in research regarding biosensor construction. Stronger emphasis on collaboration between scientists in theoretical modelling, nanomaterials application and or relevant stakeholders in the specific field (e.g., food or health monitoring) and researchers in biosensor design may help evolve focused research efforts towards development and deployment of low-cost biosensors.
- Full Text:
- Date Issued: 2016
Diversity and Endemism of Southern African Gekkonids Linked with the Escarpment Has Implications for Conservation Priorities
- Authors: Nicolau, Gary K , Edwards, Shelley
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/461506 , vital:76208 , xlink:href="https://doi.org/10.3390/d15020306"
- Description: South Africa is recognised for its high reptile diversity and endemism, specifically among lizards. Phylogenetic diversity, endemism, and richness can have clear implications or raise important questions in a range of fields, and most urgently in conservation. Among squamate reptiles, these indices are very commonly associated with high temperatures and topographic heterogeneity. Indeed, mountainous biogeography has been a critical driver in the radiation of the family Gekkonidae within the subregion. Here, we assess the species richness, diversity, and endemism of Gekkonidae species inhabiting South Africa, Lesotho, and Eswatini, accounting for phylogenetic relationships. We also employ the CANAPE method to identify regions that have neo- and/or paleoendemics. Southern African gekkonids appear to be most diverse and show high levels of endemism in three regions of Southern Africa: the northwestern Richtersveld, the escarpment running west to southeast, and the northeastern escarpment in the Limpopo province. Implications for conservation priorities are discussed.
- Full Text:
- Date Issued: 2023
Effects of covalent versus non-covalent interactions on the electrocatalytic behavior of tetracarboxyphenoxyphthalocyanine in the presence of multi-walled carbon nanotubes
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188271 , vital:44740 , xlink:href="https://doi.org/10.1080/00958972.2017.1303679"
- Description: Tetracarboxyphenoxy phthalocyanine was covalently linked to multi-walled carbon nanotubes and the conjugate was used for modification of glassy carbon electrodes for the detection of hydrogen peroxide. The electrocatalytic behavior was examined by cyclic voltammetry, square wave voltammetry, and rotating disk electrode. The results show that covalent linking is attractive in terms of high detecting currents, low overpotential, and high catalytic rate constants. Very low detection limits were observed with CoTCPhPc-DAMN-MWCNT(linked)-GCE at 0.33 nM. The resulting catalytic rate constant was 1.1 × 103 M−1s−1.
- Full Text:
- Date Issued: 2017
Effects of pluronic silica nanoparticles on the photophysical and photodynamic therapy behavior of triphenyl-p-phenoxy benzoic acid metalloporphyrins
- Authors: Managa, Muthumuni , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239698 , vital:50756 , xlink:href="https://doi.org/10.1080/00958972.2016.1236372"
- Description: 5, 10, 15, Triphenyl-20-p-phenoxy benzoic acid porphyrins (P) containing Zn (ZnP), Ga (GaP), and Si (SiP) were synthesized and conjugated to pluronic-silica (PluS) nanoparticles (NPs) where the fluorescence and singlet oxygen generating behavior of the porphyrins were investigated. The highest singlet oxygen quantum yield (ΦΔ) was obtained for ZnP. When the porphyrins were conjugated to the PluS NPs, the ΦΔ was quenched and fluorescence was enhanced. The pore size of the NPs upon conjugation decreased from 18.9 nm for PluS NPs to 2.4 nm (for ZnP as an example) as determined by applying the Brunauer–Emmett–Teller method. The porphyrin complexes and their conjugates were tested for their photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. It was found that ZnP and its conjugate showed the highest PDT activity. The p > 0.05 indicated that ZnP is significantly different than GaP and SiP.
- Full Text:
- Date Issued: 2016
Electrocatalytic Activity of Cobalt Phthalocyanines Revisited: Effect of the Number of Oxygen Atoms and Conjugation to Carbon Nanomaterials
- Authors: Ndebele, Nobuhle , Mgidlana, Sithi , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185700 , vital:44416 , xlink:href="https://doi.org/10.1007/s12678-021-00670-x"
- Description: The synthesis and characterization of tetrakis[4(4-acetlyphenoxy)phthalocyanato] cobalt (II) (1) are presented. Complex 1 together with the reported tetrakis dimethyl 5-(phenoxy)-isophthalatephthalocyaninato] cobalt (II) (2) are conjugated to carbon-based nanomaterials: graphene quantum dots (GQDs) and single-walled carbon nanotubes (SWCNTs) via π-π stacking, taking advantage of the π electrons on the graphitic structure of the nanomaterial as well as on the aromatic rings of the Co phthalocyanines (CoPcs). The electrocatalytic behaviour of the CoPcs, GQDs, SWCNTs and their respective conjugates towards the electrochemical oxidation of catechol was studied. The electrocatalytic probes were drop-dried onto the electrode surface of the glassy carbon electrode (GCE). The electrochemical oxidation of catechol was studied using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Complex 2 when linked to GQDs gave the lowest oxidation peak potentials of 0.33 V. Low catechol detection limits (LOD) of 0.057 µM was obtained for complex 2 with SWCNT. Thus, complex 2 containing more oxygen atoms outperformed complex 1 with less oxygen atoms. The CoPcs on their own showed moderate electrocatalytic behaviour, hence showing the importance of conjugating them to the carbon nanomaterials. SWCNT-based electrodes performed better than GQDs, and an improvement in the LoDs, sensitivity and the catalytic rate was observed upon conjugation.
- Full Text:
- Date Issued: 2021
Environment and sustainability education in a changing South Africa: A critical historical analysis of outline schemes for defining and guiding learning interactions
- Authors: O'Donoghue, Rob B
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373634 , vital:66708 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122749"
- Description: This paper examines how, in response to emerging risk, methodological narratives for conservation (CE), environmental (EE) and now sustainability education (ESD) were constituted in diverse settings within a changing South African state. After documenting an awareness creation perspective underpinning early extension and experiential activities, the study examines shaping social processes and changing outline schemes for defining and guiding planned learning interactions (methodology) within the broadening field into the present day. The critical historical analysis developed in the study reflects a well-documented shift from early topdown (intervention/extension) to more participatory approaches (collaborative engagement/stewardship). A situated process-mapping of changing orientations also reveals characterising methodological features across the contours of an increasingly diverse field of conservation, environment and sustainability education.
- Full Text:
- Date Issued: 2007
Explaining people's perceptions of invasive alien species: A conceptual framework
- Authors: Shackleton, Ross T , Richardson, David M , Shackleton, Charlie M , Bennett, Brett , Crowley, Sarah L , Dehnen-Schmutz, Katharina , Estévez, Rodrigo A , Fischer, Anke , Kueffer, Christoph , Kull, Christian , Marchante, Elizabete , Novoa, Ana , Potgieter, Luke J , Vass, Jetske , Vas, Anna S , Larson, Brendon
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181356 , vital:43726 , xlink:href="https://doi.org/10.1016/j.jenvman.2018.04.045"
- Description: Human perceptions of nature and the environment are increasingly being recognised as important for environmental management and conservation. Understanding people's perceptions is crucial for understanding behaviour and developing effective management strategies to maintain, preserve and improve biodiversity, ecosystem services and human well-being. As an interdisciplinary team, we produced a synthesis of the key factors that influence people's perceptions of invasive alien species, and ordered them in a conceptual framework. In a context of considerable complexity and variation across time and space, we identified six broad-scale dimensions: (1) attributes of the individual perceiving the invasive alien species; (2) characteristics of the invasive alien species itself; (3) effects of the invasion (including negative and positive impacts, i.e. benefits and costs); (4) socio-cultural context; (5) landscape context; and (6) institutional and policy context. A number of underlying and facilitating aspects for each of these six overarching dimensions are also identified and discussed. Synthesising and understanding the main factors that influence people's perceptions is useful to guide future research, to facilitate dialogue and negotiation between actors, and to aid management and policy formulation and governance of invasive alien species. This can help to circumvent and mitigate conflicts, support prioritisation plans, improve stakeholder engagement platforms, and implement control measures.
- Full Text:
- Date Issued: 2019