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The effects of the composition and structure of quantum dots combined with cobalt phthalocyanine and an aptamer on the electrochemical detection of prostate specific antigen

  • Authors: Nxele, Siphesihle R , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/185002 , vital:44315 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109407"
  • Description: The ability to functionalize and modify graphene-based quantum dots has also allowed for the tuning of their activity in different applications. A comparative study is carried out in this work where a prostate specific aptamer (PSA) and cobalt phthalocyanine molecule are combined with graphene quantum dots (GQDs), nitrogen doped graphene quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) in order to determine the effects of quantum dots type (and therefore composition) on the electrocatalytic ability of the sensor to detect the analyte of interest. For the detection of prostate-specific antigen, electrochemical impedance spectroscopy (EIS) is employed to determine detection limits as well as sensitivity and selectivity of the aptasensors. Results showed a good performance of all sensors fabricated with the NGQDs based aptasensor showing the best performance with a detection limit of 1.54 pM in EIS as well as negligible interference in mixed samples. This electrode was further verified in spiked human serum samples and good recovery and low detection limits were determined, putting this aptasensor in good stead as a reliable, efficient PSA aptasensor.
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  • Date Issued: 2021

The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials

  • Authors: Mpeta, Lekhetho Simon
  • Date: 2021
  • Subjects: Phthalocyanines , Nanostructured materials , Electrocatalysis , Nanoparticles , Environmental chemistry , Electrodes , Organic wastes -- Purification
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/172191 , vital:42174 , 10.21504/10962/172191
  • Description: Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.
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  • Date Issued: 2021

The electrochemical detection of prostate specific antigen on glassy carbon electrode modified with combinations of graphene quantum dots, cobalt phthalocyanine and an aptamer

  • Authors: Nxele, Siphesihle R , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/185013 , vital:44316 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2021.111462"
  • Description: Herein, a novel aptasensor is developed for the electrochemical detection of prostate specific antigen (PSA) on electrode surfaces modified using various combinations of a Cobalt phthalocyanine (CoPc), an aptamer and graphene quantum dots (GQDs). Electrochemical impedance spectroscopy (EIS) as well as differential pulse voltammetry (DPV) are employed for the detection of PSA. In both analytical techniques, linear calibration curves were observed at a concentration range of 1.2–2.0 pM. The glassy carbon electrode where CoPc and GQDs are placed on the electrode when non-covalently linked followed by addition of the aptamer (GQDs-CoPc(ππ)-aptamer (sequential)) showed the best performance with a limit of detection (LoD) as low as 0.66 pM when using DPV. The detection limits were much lower than the dangerous levels reported for PSA in males tested for prostate cancer. This electrode showed selectivity for PSA in the presence of bovine serum albumin, glucose and L-cysteine. The aptasensor showed good stability, reproducibility and repeatability, deeming it a promising early detection device for prostate cancer.
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  • Date Issued: 2021

The first record of Omosita nearctica Kirejtshuk (Coleoptera, Nitidulidae) in South Africa, with the first description of its mature larva

  • Authors: Williams, Kirstin A , Clitheroe, Crystal-Leigh , Villet, Martin H , Midgley, John M
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440640 , vital:73799 , https://africaninvertebrates.pensoft.net/article/58842/
  • Description: Sap beetles of the genus Omosita Erichson are stored-product pests that are also associated with carrion, potentially making them biosecurity risks and forensic tools. The discovery of a specimen of the Nearctic species Omosita nearctica Kirejtshuk in South Africa prompted an investigation a decade later to determine if this species had established itself in the country, which was confirmed by the collection of further breeding specimens that also facilitated the first description of mature larvae of O. nearctica. A new key to adults of all Omosita species is presented.
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  • Date Issued: 2021

The hermeneutics of recovery

  • Authors: Kong, Camillia , Campbell, Megan , Kpobi, Lily , Swartz, Leslie , Atuire, Caesar
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/302554 , vital:58207 , xlink:href="https://doi.org/10.1177/13634615211000549"
  • Description: The widespread use of faith-based and traditional healing for mental disorders within African contexts is well known. However, normative responses tend to fall within two camps: on one hand, those oriented towards the biomedical model of psychiatry stress the abuses and superstition of such healing, whilst critics adopting a more ‘local’ perspective have fundamentally challenged the universalist claims of biomedical diagnostic categories and psychiatric treatments. What seemingly emerges is a dichotomy between those who endorse more ‘universalist’ or ‘relativist’ approaches as an analytical lens to the challenges of the diverse healing strands within African contexts. In this article, we draw upon the resources of philosophy and existing empirical work to challenge the notion that constructive dialogue cannot be had between seemingly incommensurable healing practices in global mental health. First, we suggest the need for much-needed conceptual clarity to explore the hermeneutics of meaning, practice, and understanding, in order to forge constructive normative pathways of dialogue between seemingly incommensurable values and conceptual schemas around mental disorder and healing. Second, we contextualise the complex motives to emphasise difference amongst health practitioners within a competitive healing economy. Finally, we appeal to the notion of recovery as discovery as a fruitful conceptual framework which incorporates dialogue, comparative evaluation, and cross-cultural enrichment across divergent conceptualisations of mental health.
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  • Date Issued: 2021

The impact of labour legislation on selected small firms in Mbombela (Nelspruit)

  • Authors: Dlamini, Sikhulile Blessing
  • Date: 2021
  • Subjects: Labor laws and legislation -- South Africa , Small business -- Law and legislation-- South Afric , Small business -- South Africa -- Mbombela -- Case studies
  • Language: English
  • Type: text , Thesis , Masters , MSocSci
  • Identifier: http://hdl.handle.net/10962/170781 , vital:41959
  • Description: This study uses the theoretical framework of industrial relations pluralism, to study and analyse the impacts of labour legislation on six small firms (employing less than 50 workers) based in Mbombela (formerly Nelspruit), Mpumalanga province, South Africa. The analysis is based on the viewpoints of six managers and how they see the impacts of labour legislation on their respective firms. The analysis is aided by utilising theory and literature to make sense of the manager perspectives on the topic. Also, utilising a qualitative research design to collect and analyse the data, the study presents diverse findings in terms of how the participants perceived and experienced certain types of legislation. Some managers believed that the benefits of labour legislation outweighed the costs. While others believed the exact opposite. At an overall level, the study revealed that most of the participants were not as severely affected by labour legislation as might be expected; given the scarcity of resources in most small firms. This was partly because of various coping strategies and practices (mostly involving the use of informal procedures) that were adopted by the firms. Also, some small firms who aimed at expanding their businesses strategised to adopt some formal procedures and practices in order to easily absorb labour legislation and subsequently mordenise their businesses in the process. While a few firms persisted with more informal customs as they appeared cost-effective and necessary in their particular market positioning.
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  • Date Issued: 2021

The impact of poverty reduction strategies during COVID-19 in South Africa

  • Authors: Maxwell, Sentiwe
  • Date: 2021
  • Subjects: Poverty , Service delivery
  • Language: English
  • Type: lecture , text
  • Identifier: http://hdl.handle.net/11260/6307 , vital:45366
  • Description: This article focuses on investigating the impact of poverty reduction strategies during Covid 19 in improving the quality of lives of the people in our local municipalities, in relation to interventions that have been implemented by the South African government to address poverty. The purpose of the article is to understand the situation in our municipalities and come up with recommendations that will assist government to enhance delivery of poverty reduction strategy in order to improve the quality of life of the rural poor communities. The findings on this article show that; whilst significant progress has been made to address poverty through policy and legal frameworks and through implementation of poverty reduction strategies and programmes, there is a general consensus in literature that poverty is still widespread in South Africa and that activities put in place to reduce and eradicate it are not sufficiently translating into required outputs necessary for desired outcomes which ultimately impact on poverty. The study has identified the gaps that exist in service delivery as well as the challenges faced by government in effectively impacting on poverty through its poverty reduction programmes. Based on the findings the study has made recommendations that will assist government to enhance service delivery so that poverty reduction strategies are conducted in an effective and efficient, integrated and coordinated manner which will cause government to achieve its desired outcomes.
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  • Date Issued: 2021

The impact of the COVID-19 pandemic on accessing HIV care: A case report

  • Authors: Kaswa, Ramprakash
  • Date: 2021
  • Subjects: COVID-19 Pandemic, 2020- HIV (Viruses) Diseases Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/7291 , vital:53107 , xlink:href="https://doi.org/10.4102/safp.v63i1.5344"
  • Description: The coronavirus disease 2019 (COVID-19) pandemic has had an enormous impact on the provision of human immunodeficiency virus (HIV) services amongst people living with HIV. Many people have adopted different health-seeking behaviour in alignment with the lockdown provisions during the COVID-19 pandemic. These lockdown regulations have had a huge impact on healthcare access for people on chronic medication. The disruption of antiretroviral therapy (ART) has a profound effect on HIV-associated morbidity and mortality. The impact on HIV programmes as a result of the interruption in ART could be bigger than the HIV pandemic alone. Keywords: COVID-19; pandemic; HIV; ART; lockdown; morbidity and mortality.
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  • Date Issued: 2021

The improved antibacterial efficiency of a zinc phthalocyanine when embedded on silver nanoparticle modified silica nanofibers

  • Authors: Mapukata, Sivuyisiwe , Britton, Jonathan , Osifeko, Olawale L , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/185784 , vital:44423 , xlink:href="https://doi.org/10.1016/j.pdpdt.2020.102100"
  • Description: This work reports on the fabrication and modification of electrospun polymer free silica nanofibers (SiO2 NFs) with the aim of creating heterogeneous antibacterial catalysts. The optical and photophysical properties of the obtained NFs i.e. bare SiO2, Ag-SiO2, Pc-SiO2 and Pc@Ag-SiO2 NFs (Pc = phthalocyanine) were compared and reported. The singlet oxygen quantum yields of the Pc-SiO2 and Pc@Ag-SiO2 NFs were also quantified and found to be 0.08 and 0.12, respectively, in water. All the modified SiO2 NFs were found to possess photoactivity against S. aureus with the most effective being the Pc@Ag-SiO2 NFs due to the synergy between the Pc and Ag nanoparticles. The bare SiO2 NFs do not exhibit any antibacterial activity while the Ag-SiO2 and Pc@Ag-SiO2 NFs were found to also exhibit dark toxicity. The generated photocatalysts are attractive because they are active against bacteria and they are easily retrievable post-application. The nanocatalysts reported herein are therefore feasible candidates for real-life antibacterial applications.
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  • Date Issued: 2021

The influence of biophysical and socio-economic factors on the effectiveness of private land conservation areas in preventing natural land cover loss across South Africa

  • Authors: Shumba, Tafadzwa , de Vos, Alta , Biggs, Reinette , Esler, Karen J , Clements, Hayley S
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/415940 , vital:71302 , xlink:href="https://doi.org/10.1016/j.gecco.2021.e01670"
  • Description: There is increasing interest in the potential of private land conservation areas (PLCAs) as a complementary biodiversity conservation strategy to state-owned protected areas. However, there is limited understanding of how the diverse social-ecological contexts of PLCAs influence their effectiveness in conserving biodiversity. Here, we investigated how the effectiveness of South African PLCAs in conserving biodiversity varied across social-ecological contexts, using natural land cover as a proxy. Social-ecological contexts were represented by biophysical and legal factors (distance to towns and roads, elevation, slope, terrain ruggedness, rainfall, PLCA size, distance to state-owned national parks, and presence of legal protection) and, for a subset of commercially-operated PLCAs, management factors (adopted business model, and profitability).
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  • Date Issued: 2021

The influence of citrus orchard age on the ecology of entomopathogenic fungi and nematodes

  • Authors: Albertyn, Sonnica , Moore, Sean D , Marsberg, Tamryn , Coombes, Candice A , Hill, Martin P
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/417790 , vital:71486 , xlink:href="https://doi.org/10.1080/09583157.2020.1830949"
  • Description: A three-year survey of the ecology of entomopathogenic nematodes (EPN) and entomopathogenic fungi (EPF) was undertaken on soils from citrus orchards of different ages to determine the influence of orchard age on the ecology of entomopathogenic fungi and nematodes. The influence of mulch and irrigation method on the occurrence of EPN and EPF was also determined. Most of the isolates recovered (n = 810) were Beauveria sp. (87.88% of all isolates), followed by Metarhizium sp. (11.87% of all isolates). Only 0.24% of soil samples collected during this study tested positive for EPN. All EPN isolates recovered were Heterorhabditis bacteriophora. No significant differences in EPF occurrence were recorded between orchards under drip and micro-sprinkler irrigation. EPF occurrence was significantly lower (P = 0.016) in orchards covered by mulch (31.85% ± 2.07% occurrence) than in orchards with no covering (38.57% ± 1.57% occurrence). EPF occurrence of 40.33 ± 2.13% was highest in non-bearing orchards, followed by mature orchards (nine years or older) (36.76 ± 2.05% of samples) with the lowest EPF occurrence of 25.30 ± 2.02% reported in juvenile orchards (four to eight years old). Juvenile orchards sustain significantly less EPF than mature and non-bearing orchards because of the combined negative impact of less favourable environmental conditions (lower shade density) and fungicide applications.
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  • Date Issued: 2021

The invasion ecology of Pontederia cordata L. (Pontederiaceae) in South Africa

  • Authors: Wansell, Sage Nora-Lee
  • Date: 2021
  • Subjects: Plant invsions -- South AFrica , Invasive plants -- Ecology -- South Africa , Pontederiaceae -- South AFrica
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/172433 , vital:42200
  • Description: Pontederia cordata L. (Pontederiaceae) is a tristylous invasive macrophyte – originating from North and South America – that has caused detrimental environmental, agricultural and socio-economic impacts in South Africa (SA). This novel study investigates the invasive ecology of P. cordata in SA by determining population genetics, pollination ecology and floral traits. Preliminary field surveys suggest that only one of three tristylous forms of P. cordata is invading SA and no seeds have been observed in any invasive populations. This study therefore determined the population genetics, mode of spread of P. cordata in SA and possible reasons for the lack of seed production, as well as providing suggestions for future control and management strategies. Inter Simple Sequence Repeats of leaf samples from invasive populations in SA and the native range of the United States of America (USA) were performed to determine the population genetics of P. cordata. The clarification of population structure of an alien invasive plant can provide insight into founder effects, introduction events and modes of spread and is important for the development of management plans such as biological control. Results from the genetic analyses indicated that P. cordata populations have low genetic diversity within and amongst invasive populations in comparison to native populations. This suggests that high gene flow and sexual reproduction is not present in invasive populations, and that only a single or very few introductory events have occurred in SA. Furthermore, invasive P. cordata populations shared the highest genetic similarity with native samples from Belle Haven, Virginia, USA, and thus further sampling and future genetic surveys should be conducted in this area to identify source populations to survey for potential biological control agents. Following these findings, I investigated whether sexual reproduction and seed production is absent from invasive P. cordata populations in SA as speculated. Floral traits from populations throughout all the invaded provinces were measured and, along with pollen grain measurements, it was determined that only short-morphed plants are present in SA. It was speculated that the absence of native pollinators in the invasive range may be responsible for the absence of sexual reproduction. However, a pollination study confirmed the presence of generalist insect pollinators. Thereafter, artificial pollination experiments on 8 865 flowers were conducted to determine whether an incompatibility system was present which prevented seed production. No seeds were produced and it was concluded that illegitimate pollination of the short-morphed plants prevented seed production and rhizomes are responsible for the invasion of P. cordata throughout SA. The implications of these findings and possible management strategies such as biological control is discussed in Chapter 4. These findings suggest that control programmes should target the plants rhizomes to prevent and reduce spread. Preventing the introduction of medium- and long-morphed plants into SA is crucial to prevent P. cordata from producing seeds and intensifying invasion further through both asexual and sexual spread.
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  • Date Issued: 2021

The nature of violence in South African universities African universities: The politics of process

  • Authors: Mutongoza, Bonginkosi Hardy https://orcid.org/0000-0002-2939-1274
  • Date: 2021
  • Subjects: Education, Higher -- Political aspects , Universities and colleges -- South Africa , Campus violence
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10353/27909 , vital:70816
  • Description: The high levels of violence that plague South Africa’s universities are symptomatic of an education system that is under attack, with institutions of higher learning not reflecting the peacefulness and safety which are oftentimes associated with the pursuit of learning. While violence in societies and educational institutions globally continues to intensify in viciousness and frequency, this is especially worrisome for South Africa, a country regarded as one of the most violent in the world. South African education institutions are admittedly extremely violent, yet there are relatively few mechanisms to enable the verification of trends in violence, or to cross-reference and compare incidents, thus making the reduction of violence problematic. The contention is that the general outlook of violence at educational institutions appears to echo the relentless violence which haunts South African communities in general. Against this background, the current study sought to explore the nature of violence in South African universities. To achieve this, the study was guided by an exploration of student and staff experiences of violence in universities, the causes of violence in such sites, and the recording thereof. Underpinned by a pragmatist paradigm, this study utilised a mixed-methods approach to ‘get under the skin’ of the problem of violence in universities. Within the mixed-methods approach, the study employed a single-phase convergent design, which enabled the researcher to reach comprehensive conclusions on violence in universities, by merging and comparing qualitative and quantitative datasets. In the quantitative phase of the study, a simple random sampling technique was used to select a total of 1 776 students and 250 staff, while 32 students and four staff were conveniently sampled during the qualitative phase. The data for this study were collected using an online survey in the quantitative phase, and semi-structured interviews and document reviews in the qualitative phase. The findings of this investigation revealed that violence happened in six main configurations, namely student-on-student violence, staff-on-student violence, staff-on-staff violence, student-on-staff violence, self-directed violence, and protest-related violence. In addition, the findings revealed diverse causes of violence in universities, chief of which were alcohol and drug abuse, poor security, the abuse of power or authority, impunity, and psychosocial factors, among others. Factors that impeded the recording of violence in universities included the normalisation of violence, a lack of consequences for the perpetrators, a lack of procedural awareness, cronyism and brotherhoods, and a lack of protection from reprisal for reporting perpetrators. The production of violence in South African universities was also found to be significantly shaped by wider structures that included sexuality, gender, age, socioeconomic status, and race and ethnicity. These structures were found to be prominent in increasing the likelihood of violence being perpetrated. Based on the reported findings, the study moved to recommend that, in order to reduce experiences of violence in South African universities, institutions adopt multidimensional approaches to combatting this scourge. The fact that violence was noted to occur in multiple configurations, means multiple viewpoints are required to reduce and ultimately combat it. This calls for a multi-stakeholder approach that transcends a reliance on the traditional university policymakers, and a concerted consultative process to formulate and renew policies that can help to address university violence. The study further recommended that reporting structures be decentralised at universities, in a bid to improve the smoothness of related processes. In this respect, it will be essential for universities to consider setting up anonymous reporting platforms online, to move with the times and ensure more urgent responses, as opposed to a continued reliance on present systems that are replete with red tape. Additionally, universities may consider outsourcing divisions that deal with violence reporting, to minimise conflicts of interest when dealing with such cases. The researcher concluded that violence in universities threatens the very purpose of tertiary education – members of the university community must be able to freely pursue their aspirations in peaceful environments. As such, for as long as campuses experience violence in any of its varied forms, a proverbial dark cloud will forever frustrate the quest for quality and transformative education that has the potential to reverse-engineer inequality, poverty, and underdevelopment in South Africa, as contemplated in various development plans. , Thesis (PhD) -- Faculty of Education, 2021
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  • Date Issued: 2021

The need for an urban ecology of the Global South

  • Authors: Shackleton, Charlie M , Cilliers, Sarel S , du Toit, Marie J , Davoren, Elandre
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/433744 , vital:72998 , ISBN 978-3-030-67650-6 , https://doi.org/10.1007/978-3-030-67650-6_1
  • Description: Urban ecology is a key discipline in guiding urban development, sustainability and consequently human wellbeing. However, most urban ecological research has, and continues to be, undertaken in the Global North, and thus urban ecological methods, principles and frameworks are dominated by contributions and understandings from the Global North. However, there are a multitude of local- and national-scale contextual differences between the Global North and the Global South that limit or question the universal application of Global North perspectives and knowledge. This chapter lays the foundation for the rest of the book in two ways. First, it explores the development and definitions of the terms ‘urban ecology’ and ‘Global South’. Second, it presents the major biophysical and socio-economic contextual characteristics of Global South towns and cities that differentiate them from those in the Global North. These contextual differences need to be accounted for in urban ecological research, theory and application towards the development of an urban ecology that is more relevant for the Global South, and when conjoined with understandings from the Global North allow for the exploration and development of truly universal urban ecology principles and frameworks.
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  • Date Issued: 2021

The perception of police officers towards corruption in South African police services: a case study of Polokwane cluster policing area in Limpopo Province

  • Authors: Rathogwa, Emmah Mufanadzo
  • Date: 2021
  • Subjects: Corruption , Police corruption , Police misconduct
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/27314 , vital:66935
  • Description: The 1996 National Crime Prevention Strategy identified corruption within the criminal justice sector as the greatest threat to the governance of security. Police corruption has been a huge obstacle within the South African Police Service’s endeavours to tackle improper activities of police officers. A general definition of corruption is “use of public office for private gain”; this includes bribery and extortion, which involves at least two parties, and other types of malfeasance that a public official can carry out alone, including fraud and embezzlement. The corruption of police officers impinges on the capacity and ability of the entire force in ensuring that all citizens abide by the law. This study explored the perceptions of police officers towards corruption activities in South African Police Services (SAPS) within the Polokwane Cluster (Capricorn District) Policing Area in Limpopo province. In this study, a qualitative research design was used. The researcher used purposive sampling to select participants. For collection of data, semi-structured interviews were used where the researcher interviewed police officers within the Polokwane Cluster Capricorn District Policing Area. The researcher conducted fifty 50 interviews with five police officers from 10 police stations within the Polokwane Cluster Capricorn District Policing Area, namely: Botlokwa, Lebowakgomo, Polokwane,Westernburg, Seshego, Mankweng, Mashashane, Matlala, Mogwadi and Zebediela police stations. In addition, secondary sources were used where the researcher relied on documents from the Independent Police Investigations IPID on statistics on police corruption, among other scales of measurements. For the analysis of data, thematic content analysis was used to analyse the data collected through interviews whilst document analysis was used for analysing data collected from secondary sources. The findings gathered in this study revealed that police corruption is widespread within the Polokwane Cluster Capricorn District Policing Area in Limpopo province due some police officers’ fear of victimisation of their families or loved ones if they expose corrupt acts by other police officers. Furthermore, corruption of the South African Police Services personnel has been reported where potential police recruits are required to pay bribes for them to be placed for the job. Weak leadership within the South African police service and poor policy formulation and implementation have been identified by participants to be some of the main determinants of corruption within the South African Police Services. As a recommendation to counter the adverse effects of police corruption, a number of strategies have been formulated in this study such as the establishment of vibrant anticorruption mechanisms. It is essential for the government to recall passionate former police officials to investigate all the corrupt officials. The South African government should establish a very sophisticated anti-corruption body independent from the SAPS to spearhead the strategy to combat corruption. The recruitment of police personnel should culminate into hiring individuals who would see the police job as a calling and do it passionately. They should firstly target people who choose police related courses are already studying courses in crime investigation from grassroots level. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2021
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  • Date Issued: 2021

The photodynamic activities of the gold nanoparticle conjugates of phosphorus (V) and gallium (III) A3 meso-triarylcorroles

  • Authors: Soy, Rodah C , Babu, Balaji , Mack, John , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/184978 , vital:44313 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109631"
  • Description: The synthesis and characterization of series of P(V) and Ga(III) A3 triarylcorrole complexes with 4-methylthiophenyl (2a, 3a), thien-3-yl (2b, 3b) and thien-2-yl (2c, 3c) meso-groups are reported along with the physicochemical and photodynamic activity properties of the dyes and their gold nanoparticle (AuNP) conjugates. The Ga(III) corrole series have lower fluorescence quantum yields and higher singlet oxygen quantum yields than the analogous P(V) complexes. Upon conjugation to AuNPs, the fluorescence quantum yields of the P(V) and Ga(III) corroles decrease, while the singlet oxygen quantum yields increase due to an external heavy atom effect. The P(V) and Ga(III) corroles exhibit relatively low in vitro dark cytotoxicity, which was further enhanced upon conjugation to AuNPs. The P(V) complexes and their AuNP conjugates display more favorable PDT activity properties upon illumination with a Thorlabs 625 nm light-emitting diode (288 J cm−2) with phototoxicity indices > 18.5 and 20.8, respectively, for the meso-thienyl-substituted 2b-AuNP and 2c-AuNP conjugates. Optical spectroscopy analyses demonstrate that this can be attributed to there being significantly less aggregation due to the presence of two trans-hydroxy axial ligands.
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  • Date Issued: 2021

The photophysicochemical properties and photodynamic therapy activity of Schiff base substituted phthalocyanines doped into silica nanoparticles and conjugated to folic acid

  • Authors: Magadla, Aviwe , Babu, Balaji , Sen, Pinar , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/185407 , vital:44384 , xlink:href="https://doi.org/10.1016/j.poly.2021.115227"
  • Description: This work explores the synthesis, photophysicochemical properties and photodynamic activity (PDT) of tetrakis [N,N’–bis (4-(diethylamino)benzylidene) amino)propan-2-yl)oxy) phthalocyaninato] Zn (II) (3) and tetra-phenoxy N,N-dimethyl-4-((methylimino) Zn (II) (4) when the encapsulated into silica nanoparticles (SiNPs) followed by conjugation of folic acid (FA). The synthesised complexes and their doped analogues are examined for their PDT activity using MCF-7 cells. All the complexes showed dark toxicity that is >80%. The folic acid conjugates, MPc@SiNPs-FA showed greater photocytoxicity against MCF-7 cells upon irradiation with laser light.
  • Full Text:
  • Date Issued: 2021

The politics of postgraduate education: supervising in a troubled world

  • Authors: McKenna, Sioux
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/434502 , vital:73069 , ISBN 9781991201225 , https://www.google.co.za/books/edition/The_Global_Scholar/KvQ3EAAAQBAJ?hl=enandgbpv=0
  • Description: In our rapidly globalising world, "the global scholar" is a key concept for reimagining the roles of academics at the nexus of the global and the local. This book critically explores the implications of the concept for understanding postgraduate studies and supervision. It uses three conceptual lenses - "horizon", "currency" and "trajec-tory" - to organise the thirteen chapters, concluding with a reflection on the implica-tions of Covid-19 for postgraduate studies and supervision. Authors bring their perspectives on the global scholar from a variety of contexts, including South Afri-ca, Australia, the United States, the United Kingdom, Chile, Germany, Cyprus, Kenya and Israel. They explore issues around policy, research and practice, sharing a con-cern with the relation between the local and the global, and a passion for advancing postgraduate studies and supervision.
  • Full Text:
  • Date Issued: 2021

The potential conflict of interest associated with the management of Rosa rubiginos L. (Rosehip) in South Africa

  • Authors: Westwood, Timothy
  • Date: 2021
  • Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/172458 , vital:42204
  • Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
  • Full Text:
  • Date Issued: 2021

The potential influence of commercial plant nurseries in shaping the urban forest in South Africa

  • Authors: Arnoldi, Marco , Shackleton, Charlie M
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/398408 , vital:69409 , xlink:href="https://doi.org/10.1016/j.ufug.2021.127254"
  • Description: A substantial portion of urban green infrastructure is under private tenure in residents’ and business/corporate gardens. Therefore, the ways that urban residents manage their gardens can influence the type, quantity and quality of ecosystem services and disservices in urban areas. Plant nurseries are a major source of trees for urban residents, and so the types of trees and species that nurseries stock influence the composition of private gardens. Consequently, this study aimed to examine the roles that plant nurseries play in shaping the urban forest in South Africa. To do so, an online and direct questionnaire was used to gather data from 30 nurseries across 19 urban centres in South Africa. The main questions included species selection criteria, customer tree inquiries, best-selling tree species, attitudes towards increasing urban tree cover and diversity and whether they think climate change will affect the selection of species to stock. The results show that there is a strong preference for indigenous trees, which were also most commonly listed as best-sellers. Non-native species that were commonly sold were ones that provided provisioning services, particularly edible fruits. Drought tolerance influenced selection criteria and customer demand. Vachellia spp. and Olea europaea were commonly inquired about and most commonly listed amongst the best-sellers. Nursery owners valued the importance of increasing tree cover and diversity in urban areas, listing many perceived benefits for doing so. We conclude that there is a clear preference for indigenous tree species by customers and nursery owners, which in time could increase the proportion and cover of native species.
  • Full Text:
  • Date Issued: 2021
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