Covid-19 and the restrictive measures: The national security conundrum for Zimbabwe
- Authors: Mugari, Ishmael , Obioha, Emeka E.
- Date: 2021
- Subjects: COVID-19 (Disease) National security Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6926 , vital:52571 , xlink:href="https://10.1080/10246029.2021.1972015"
- Description: The emergence of the COVID-19 pandemic at the onset of the year 2020 brought unprecedented suffering to humanity. Economic activities in virtually all nations across the globe were brought to a shuddering halt, with the third world suffering the worst effects on the economic front. The health security of nations across the globe was shaken, as nations came to terms with the surging health needs for the infected citizens. In order to grapple with the pandemic, nations took drastic measures, chief among them being the implementation of lockdowns, coupled with harsh restrictions. These measures, however, came at a cost. This paper explores the impacts of the restrictive measures that were implemented by the Zimbabwean government to combat COVID-19 pandemic. The paper interrogates these measures in the context of the national security discourse. In the analysis, the paper also makes reference to South Africa- a more developed nation and Zimbabwe’s neighbour. Keywords: COVID-19 , national security, health security, lockdown
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- Date Issued: 2021
Creating the Ideal Push-Pull System for Electrocatalysis A Comparative Study on Symmetrical and Asymmetrical Cardanol-based Cobalt Phthalocyanines
- Authors: Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:44452 , xlink:href="https://doi.org/10.1002/elan.202060019"
- Description: A symmetrical cardanol-based cobalt phthalocyanine (Pc) along with its asymmetrical acid-based derivatives were synthesized and applied in the electrocatalysis of hydrazine. Despite the inhibition of electron movement by the bulky cardanol-based substituent throughout the series of molecules, an ideal combination of substituents was established in GCE-3 (2,9,16-tris(3- pentadecylphenoxy)-23-mono propionic acid phthalocyanato cobalt (II)) where a limit of detection (LoD) value of 5.10 μM (signal to noise ratio=5) was recorded for the detection of hydrazine. The results obtained serve as an illustration that the combination of electron-donating and electron-withdrawing substituents has a significant influence on the complete functioning of the phthalocyanine molecule(s) being investigated.
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- Date Issued: 2021
Creative Cities and Regional Development: The Case of Makhanda and the Creative City Project
- Authors: Campbell, Guy John
- Date: 2021
- Subjects: To be assigned
- Language: English
- Type: thesis , text , Masters , MCOM
- Identifier: http://hdl.handle.net/10962/174448 , vital:42478
- Description: Thesis (MSc)--Rhodes University, Faculty of Commerce, Economics and Economic History, 2020
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- Date Issued: 2021
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.
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- Date Issued: 2021
Current and future biological control efforts against Solanum mauritianum (Solanaceae) in South Africa
- Authors: Venter, Nic , Cowie, Blair W , Olckers, Terence , Byrnes, Marcus J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414349 , vital:71138 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a14"
- Description: Solanum mauritianum Scop. (Solanaceae), colloquially referred to as bugweed in South Africa, remains a widespread invasive tree of global significance. Although biological control (biocontrol) efforts were undertaken from 1984 -2003 in South Africa, the programme eventually only released two agents, the sap-sucking lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) and flowerbud-feeding weevil Anthonomus santacruzi Hustache (Coleoptera: Curculionidae). To date, these agents have been relatively ineffective in controlling S. mauritianum, largely due to low establishment success due to climatic incompatibility in relation to the widespread distribution of S. mauritianum. This has prompted the revival of S. mauritianum biocontrol research in 2018, with the programme focused largely on sourcing additional agents from climatically suitable regions in the plant’s native range in South America. Climate matching between cooler regions of South Africa and known S. mauritianum sites in South America identified Uruguay as a promising source of new agents. Field collections in Uruguay focused mainly on Anthonomus spp. but included stem-boring and shoot-galling weevils. Low incidence in the field and difficulties in culturing candidate species temporarily precluded research into stem-boring and shoot-galling candidates, but the rearing and assessment of the flowerbud-feeding weevil Anthonomus morticinus Clark (Coleoptera: Curculionidae) is ongoing. Host-specificity testing of A. morticinus has thus far confirmed a narrow host range, suggesting it has potential as a new agent.
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- Date Issued: 2021
Defended subjectivity in service-learning:a psychosocial analysis of students’ talk about service-learning in psychology
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
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- Date Issued: 2021
Design patterns and software techniques for large-scale, open and reproducible data reduction
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
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- Date Issued: 2021
Determinants of Job Satisfaction Among Academics at A Selected Institution of Higher Learning in The Eastern Cape Province of South Africa
- Authors: Mefi, Nteboheng Patricia , Asoba, Samson Nambei
- Date: 2021
- Subjects: Education (Higher) Education (Higher) Computer File , Job Satisfaction Job Satisfaction Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7443 , vital:53976 , https://www.abacademies.org/articles/determinants-of-job-satisfaction-among-academics-at-a-selected-institution-of-higher-learning-in-the-eastern-cape-province-of-sout-13195.html
- Description: Many studies have considered job satisfaction and its antecedents in the profit making sector. These studies have provided a number of factors that influence job satisfaction including autonomy, compensation, growth opportunities, leadership styles, task variety and so on. There are numerous factors that have been discovered to positively influence job satisfaction. Interest in job satisfaction arises from the fact that productivity and other favourable organisational outcomes such as service delivery and quality of outputs have been found to associate with job satisfaction. This study followed a quantitative approach based on a Likert questionnaire to collect data on the antecedents of employee job satisfaction within a Higher Education Institution (HEI) in South Africa. It was established that antecedents of job satisfaction in the HEI resembled closely those established in the literature. It is recommended that HEI should consider factors such as remuneration, task variety, work autonomy, good workplace relations and leadership styles to foster employee motivation. Keywords: Job Satisfaction, Higher Education Institutions, Human Capital, Productivity
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- Date Issued: 2021
Developing Rural Economies through Small to Medium Tourism Enterprise: the case of Matatiele and Cedarville in the Eastern Cape, South Africas
- Authors: Mxunyelwa,Siyabonga , Matarinano, Obert , Vallabh, Dinesh
- Date: 2021
- Subjects: Matatiele, South Africa Small and medium-sized enterprises Small Business Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6015 , vital:45081 , https://www.ijicc.net/index.php/ijicc-editions/2021/226-vol-15-iss-10
- Description: Globally, nations depend on small businesses as engines for economic growth. Small to Medium Tourism Enterprises (SMTEs), as part of the small business sector, are increasingly becoming important in terms of job creation, wealth creation and driving economic growth in smaller rural geographic areas. Utilising a mixed research approach, the paper identifies characteristics of SMTEs in Matatiele and Cedarville with the intention of identifying specific ways in which they can be supported to attain their real potential in enabling economic development in rural environment. Purposive sampling method was used to select respondents and self-administered questionnaires utilised to gather relevant data from managers/owners. The results indicate that the rural tourism is dominated by female-owned enterprises primarily offering accommodation services. Most of the enterprises have been in operation for a period of more than five years which points to potential growth as they are able to survive. The results further show that the businesses that participated in the survey intent employing more full-time employees. Furthermore, the results underscore that there is lack of local government support to promote entrepreneurship in the SMTEs sector particularly those that are located in the rural environment. The findings elucidate the ability of SMTEs to greatly reduce the high unemployment in rural economies if appropriate systems are put in place to support these enterprises. These findings have implications for the national, provincial and local government spheres in South Africa in their quest to create job opportunities in rural areas through entrepreneurship and SMTEs in order to provide impetus to the Eastern Cape Province and South African Economy. This paper
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- Date Issued: 2021
Development and calidation of the psychometric properties underpinning the Kwaito Music Attitude and Perception Scale (KMP)
- Authors: Williams, Akhona
- Date: 2021
- Subjects: Kwaito-music Attitude and Perception , Chronbach's alpha , Kwaito (Music) , Psychotherapy and music -- South Africa , Problem youth -- Rehabilitation -- South Africa , Attitude (Psychology) -- Testing -- South Africa , Perception -- Testing -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172478 , vital:42208
- Description: Music holds a privileged position in enhancing therapeutic well-being, supporting life skills development in youth and adolescents, and shaping cultural identities. As such, music has been closely related to youth culture, especially as it pertains to youth rehabilitation and identity formation. Studies (e.g., Duffy and Fuller, 2000; Miranda et al, 2013; Strayhorn, 2011; Tomasello, 2016) highlight the value of utilising music in youth rehabilitation, and acknowledge the intrinsic value of music to facilitate psychological and social change for individuals who would not otherwise benefit from psycho-education, or other didactic modes of youth rehabilitation. That said, Tyson (2005) developed the RAP music scale to psychometrically validate the underlying constructs of youth’ attitudes and perception of rap music in the United States of America, in order to use the instrument for music-based youth rehabilitation programs. The development of the RAP music scale informed the creation and validation of the Kwaito-music Attitude and Perception (KMP) Scale, the subject of my Masters thesis. Following suggestions from Morrison (2014), my study sought to psychometrically validate the properties of the Kwaito-music Attitude and Perception (KMP) Scale. The KMP was found to be a reliable measure of kwaito music attitudes and perception amongst a sample of South African youth who listen to this genre of music. The internal consistency of the questionnaire revealed a Cronbach’s α (Alpha) value of 0.820. Limitations of the project including reduced factor extraction and sample size constrains are discussed. It is envisioned that results from this study will find resonance with youth-community programs, and rehabilitation projects utilising music as a medium of healing amongst South African youth.
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- Date Issued: 2021
Developments and prospects for biological control of Prosopis (Leguminosae) in South Africa
- Authors: Kleinjan,Catharina , Hoffman, John H , Heystek, F , Ivey, Philip J , Kistensamy, Y
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414360 , vital:71139 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a13"
- Description: South Africa was the first country to deploy biological control (biocontrol) against invasive Prosopis populations. Developments in this regard have been ongoing, and have been reviewed, at approximately 10-year intervals, since 1991. This review spans the period 2011-2020, a timespan globally characterised by increased awareness of the impacts of invasive Prosopis populations, and recognition of the need for improved management. Concerted international collaboration has resulted in enhanced clarity on phylogenetic relationships within the Leguminosae and the phylogenetic placement of Prosopis. These advances have improved the framework for interpreting the host range of potential agents and for evaluating risk. At the outset of the biocontrol programme, in the 1980s, only agents that consumed mature seeds were considered. The intention was to reduce the invasiveness of Prosopis while simultaneously retaining it as a usable resource. The programme was subsequently expanded to investigate agents that prevent pod set or maturation of seed. More recently, potential agents that damage the vegetative growth of the plants have been included in response to recognition in South Africa, that there is no other route to successful management of Prosopis. There is a wealth of largely unexplored potential in this regard.
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- Date Issued: 2021
Disilane-bridged architectures with high optical transparency for optical limiting
- Authors: Feng, Hongjie , Zhou, Zhikuan , May, Aviwe K , Chen, Jiaying , Mack, John , Nyokong, Tebello , Gai, Lizhi , Lu, Hua
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190623 , vital:45011 , xlink:href="https://doi.org/10.1039/D1TC01488A"
- Description: A novel tetraphenylethylene (TPE) architecture that makes use of a disilane bridge was developed to successfully prepare organic optical power limiting (OPL) materials with high transparency. The σ-bridged TPE derivatives exhibit enhanced solid-state emission efficacies up to 4 times that of TPE. Due to the unique σ-electron delocalization, the incorporated Si–Si bridge gives rise to intense nonlinear optics (NLO) properties. These compounds show favorable optical transparency in the visible region, since the σ–π interaction has a relatively minor effect on the absorption properties of TPE. The poly(bisphenol A carbonate) (PBC) thin films of disilane-bridged compounds exhibit significant reverse saturable absorbance (RSA) responses during Z-scan measurements at 532 nm. In contrast, negligible OPL properties were observed in tetrahydrofuran (THF) solution and when a PBC thin film was prepared with TPE. The disilane-bridged molecular system represents a novel and easily prepared architecture for the construction of solid-state optical limiting materials.
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- Date Issued: 2021
Doctors’ practice and attitudes towards red blood cell transfusion at Mthatha Regional Hospital, Eastern Cape, South Africa: A mixed methods study
- Authors: O’Mahony, Don , Adedayo, Temitope , Adeleke, Olukayode
- Date: 2021
- Subjects: Physicians Erythrocytes--Transfusion Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7989 , vital:57871 , xlink:href="https://doi.org/10.4102/phcfm.v13i1.2889"
- Description: Background: Unnecessary blood transfusion exposes recipients to potential harms. Aim: The aim of this study was to describe blood transfusion practice and explore doctors’ attitudes towards transfusion. Setting: A hospital providing level 1 and 2 services. Methods: A mixed-methods study design was used. In the cross-sectional descriptive component, a sample was taken from patients transfused over a 2-month period. Blood use was categorised as for medical anaemia or haemorrhage, and appropriate or not. The qualitative component comprised a purposeful sample for focus group and individual semistructured interviews. Results: Of 239 patients sampled, 62% were transfused for medical anaemia and 38% for haemorrhage. In the medical anaemia group, compliance with age-appropriate transfusion thresholds was 69%. In medical anaemia and haemorrhage, 114 (77%) and 85 (93.4%) of recipients had orders for ≥ 2 red blood cell (RBC) units, respectively. In adults ≥ 18 years old with medical anaemia, 47.1% of orders would have resulted in a haemoglobin (Hb) > 8 g/dL. Six doctors participated in focus group and eleven in individual interviews. There was a lack of awareness of institutional transfusion guidelines, disagreement on appropriate RBC transfusion thresholds and comments that more than one RBC unit should always be transfused. Factors informing decisions to transfuse included advice from senior colleagues, relieving symptoms of anaemia and high product costs. Conclusion: Most orders were for two or more units. In medical anaemia, doctors’ compliance with RBC transfusion thresholds was reasonable; however, almost half of the orders would have resulted in overtransfusion. The attitudes of doctors sampled suggest that their transfusion practice is influenced more by institutional values than formal guidelines. Keywords: red blood cell transfusion; doctors’ attitudes; doctors’ practice; transfusion thresholds; overtransfusion; descriptive study; qualitative study.
- Full Text:
- Date Issued: 2021
Doctors’ practice and attitudes towards red blood cell transfusion at Mthatha Regional Hospital, Eastern Cape, South Africa: A mixed methods study
- Authors: Mabunda, Sikhumbuzo A , O’Mahony, Don , Adedayo, Temitope , Adeleke, Olukayode
- Date: 2021
- Subjects: Physicians Erythrocytes--Transfusion Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7216 , vital:53088 , xlink:href="https://doi.org/10.4102/phcfm.v13i1.2889"
- Description: Background: Unnecessary blood transfusion exposes recipients to potential harms. Aim: The aim of this study was to describe blood transfusion practice and explore doctors’ attitudes towards transfusion. Setting: A hospital providing level 1 and 2 services. Methods: A mixed-methods study design was used. In the cross-sectional descriptive component, a sample was taken from patients transfused over a 2-month period. Blood use was categorised as for medical anaemia or haemorrhage, and appropriate or not. The qualitative component comprised a purposeful sample for focus group and individual semistructured interviews. Results: Of 239 patients sampled, 62% were transfused for medical anaemia and 38% for haemorrhage. In the medical anaemia group, compliance with age-appropriate transfusion thresholds was 69%. In medical anaemia and haemorrhage, 114 (77%) and 85 (93.4%) of recipients had orders for ≥ 2 red blood cell (RBC) units, respectively. In adults ≥ 18 years old with medical anaemia, 47.1% of orders would have resulted in a haemoglobin (Hb) > 8 g/dL. Six doctors participated in focus group and eleven in individual interviews. There was a lack of awareness of institutional transfusion guidelines, disagreement on appropriate RBC transfusion thresholds and comments that more than one RBC unit should always be transfused. Factors informing decisions to transfuse included advice from senior colleagues, relieving symptoms of anaemia and high product costs. Conclusion: Most orders were for two or more units. In medical anaemia, doctors’ compliance with RBC transfusion thresholds was reasonable; however, almost half of the orders would have resulted in overtransfusion. The attitudes of doctors sampled suggest that their transfusion practice is influenced more by institutional values than formal guidelines. Keywords: red blood cell transfusion; doctors’ attitudes; doctors’ practice; transfusion thresholds; overtransfusion; descriptive study; qualitative study.
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- Date Issued: 2021
Does the absence of community involvement underpin the demise of urban neighbourhood parks in the Eastern Cape, South Africa?:
- Authors: Shackleton, Charlie M , Njwaxu, Afrika
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175791 , vital:42624 , https://doi.org/10.1016/j.landurbplan.2020.104006
- Description: Public urban green spaces are essential for urban sustainability and the physical and mental wellbeing of urban residents. Yet in some settings they may face a number of threats, ranging from land transformation and development, through to poor maintenance and vandalism. It has been posited that community engagement is a crucial strategy in addressing or minimising many of these threats. Here we report on the condition of 11 newly created or renovated parks in poorer neighbourhoods of six towns over a three year period, along with in-depth interviews regarding the sentiments of local residents and officials to the (re)creation of the parks and their subsequent deterioration.
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- Date Issued: 2021
Ecological patterns and effectiveness of protected areas in the preservation of Mimusops species’ habitats under climate change
- Authors: Sinasson, Gisèle K S , Shackleton, Charlie M , Teka, Oscar , Sinsin, Brice
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175812 , vital:42626 , https://doi.org/10.1016/j.gecco.2021.e01527 , https://researchdata.ru.ac.za/search?q=:keyword: "Gap analysis"
- Description: Understanding the niche and habitat requirements of useful and threatened species, their shifts under climate change and how well protected areas (PAs) preserve these habitats is relevant for guiding sustainable management actions. Here we assessed the ecological factors underlying the distribution of two multipurpose and threatened species, Mimusops andongensis and M. kummel, in Benin, and potential changes in the suitable habitats covered by PAs, under climate change scenarios. Fifty seven occurrence points were collected for M. andongensis and 81 for M. kummel.
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- Date Issued: 2021
Editorial
- Authors: Rosenberg, Eureta
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/389759 , vital:68481 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/216901"
- Description: This issue of the Southern African Journal of Environmental Education coincides with the start of the 26th United Nations Conference on Climate Change. COP26 in Glasgow is, like its predecessors, a Conference of Parties who will deliberate how to lower global greenhouse emissions and build adaptive capacity so as to reduce the risk and impacts of climate change.
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- Date Issued: 2021
Effect of ultrasonic frequency and power on the sonodynamic therapy activity of cationic Zn (II) phthalocyanines
- Authors: Nene, Lindokuhle C , Sindelo, Azole , Britton, Jonathan , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185737 , vital:44419 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2021.111397"
- Description: We report on the sonodynamic activity of cationic phthalocyanines (Pcs) and the effect of the variation of two parameters: ultrasound frequency and power (Par I (1 MHz, 1 W cm−2), Par II (1 MHz, 2 W cm−2), Par III (3 MHz, 1 W cm−2) and Par IV (3 MHz, 2 W cm−2)) on the efficiency of their reactive oxygen species generation and cancer eradication in vitro thereof. Where Par stands for the various combinations of these parameters. Four Pcs were investigated with substituents bearing diethylamine, ortho- and para-pyridine and morpholine groups. Overall, the para-pyridine and morpholine Pcs showed substantial sono-activity in the various ultrasound parameters with Par I and IV generally showing better singlet oxygen and hydroxyl radicals generation confirmed by electron paramagnetic resonance spectroscopy. In some cases, very high hydroxyl radicals' generation was observed at Par II. Furthermore, the fragmentation of the Pcs after Par II treatments was confirmed using UV–vis and magnetic circular dichroism spectroscopy. The reactive species generation efficacy decreased at Par III for all samples. Ultrasound assisted cytotoxicity of the Pcs was confirmed in vitro using the human (Michigan Cancer Foundation-7) breast cancer cell line.
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- Date Issued: 2021
Efforts towards engaging communities to promote the benefits of biological control research and implementation in South Africa
- Authors: Weaver, Kim N , Hill, Martin P , Byrne, Marcus J , Ivey, Philip J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414428 , vital:71146 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a23"
- Description: In the last decade, biological control in South Africa has evolved from a classical applied science, allied to an extension service, to a more community engagement-based activity. Therefore, capacity building is important for the sustainability of biological control research and its implementation. In South Africa, a broad approach has been taken to build capacity in weed biological control, starting at grass-roots level with primary and secondary school learner programmes, through to developing research capacity at the tertiary level and enhancing technical capacity through adult education. Non-specialists are empowered through access to knowledge. The dissemination of accurate information through the most appropriate outlets has become increasingly important, including non-traditional science communication through the internet and, more importantly, social media, which has the potential to reach a far wider audience. Public understanding of biological control has the potential to contribute significantly to the green and knowledge economies of South Africa, but relies on government support for the sustainability of this discipline.
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- Date Issued: 2021
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.
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- Date Issued: 2021