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Violence against women who sell sex in eastern and southern Africa: a scoping review

  • Authors: Macleod, Catriona I , Reynolds, John H , Delate, Richard
  • Date: 2024
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/441380 , vital:73881 , xlink:href="https://doi.org/10.1177/15248380231160847"
  • Description: Women who sell sex (WSS) are vulnerable to violence. We present a scoping review of the last decade of research on the prevalence and incidence of, factors associated with, and services regarding violence against WSS in Eastern and Southern African (ESA). A systematic search of various databases resulted in 20 papers being reviewed. Inclusion criteria, applied by the first two authors, were as follows: empirical papers, key research problem is violence against WSS, and conducted in ESA countries. The lifetime prevalence of violence revealed in the studies ranged from 21% to 82%. A pattern of generalized violence against WSS from paying clients, male partners, strangers, family members, friends/acquaintances, and the authorities emerged. Factors associated with violence included the context within which the sex work occurs, alcohol use, type of sex exchange interactions, and personal factors (low education, low income, marriage, youth, high client volume, time in sex work, forced sexual debut, and internalized sex work stigma). WSS seldom access services after violence. Evaluations of two programs, a woman-focused HIV intervention, and the Diagonal Interventions to Fast-Forward Reproductive Health project, showed improvements in gender-based violence services. Findings suggest that targeted programmes should be paired with improving general health services and focus on promoting collective agency among WSS.
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Asymmetrical zinc phthalocyanine conjugated to various nanomaterials for applications in phototransformation of organic pollutants and photoinactivation of bacteria

  • Authors: Mgidlana, Sithi , Openda, Yolande Ikala , Nyokong, Tebello
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/360344 , vital:65081 , xlink:href="https://doi.org/10.1016/j.molstruc.2022.134850"
  • Description: Zinc phthalocyanine (ZnPc) complexes are linked to metallic nanoparticles covalently via amide and ester bonds. The photocatalytic activity of the conjugates of ZnPc complexes with NiWO4, Ag2WO4, CoWO4 and Ag-Fe3O4 nanoparticles are evaluated for photodegradation of methylene blue, tetracycline, and dibenzothiophene. The photocatalytic efficiencies of the prepared phthalocyanine complexes increased in the presence of nanoparticles. This work also reports on the photodynamic antimicrobial chemotherapy activity of these materials against Staphylococcus aureus (S. aureus) bacteria. The results indicate that Ag2WO4 based nanoconjugates exhibit high antimicrobial activity with higher log reduction compared to NiWO4, CoWO4 and Ag-Fe3O4 based materials.
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Crystal structure, Hirshfeld surface analysis and computational studies of (E)-2, 2-dimethyl-4-styryl-2, 3-dihydro-1H-benzo [b][1, 4] diazepine

  • Authors: Odame, Felix , Madanhire, T , Hosten, Eric C , Lobb, Kevin A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452677 , vital:75161 , xlink:href="https://doi.org/10.48317/IMIST.PRSM/morjchem-v11i3.40773"
  • Description: The crystal structure, Hirshfeld surface analysis, and computational studies of (E)-2,2-dimethyl-4-styryl-2,3-dihydro-1H-benzo[b][1,4]diazepine have been presented. The compound crystallized in the monoclinic space group P21/c with 8 molecules in it unit cell. A comparison of the experimental and computed bond lengths and bond angles showed good agreement among the results with varying deviations from each other. A discussion of the Hirshfeld surface analysis of the compound have been carried out to provide insight into the structural properties of the compound.
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Host-specificity testing of the leaf-feeding flea beetle, Phenrica guerini, a biological control agent for the invasive alien cactus, Pereskia aculeata

  • Authors: Dixon, Elizabeth , Paterson, Iain D , Muskett, Phillippa C , McConnachie, Andrew
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/417687 , vital:71478 , xlink:href="https://doi.org/10.1080/09583157.2023.2214342"
  • Description: Pereskia aculeata Miller (Cactaceae) is an environmentally damaging invasive alien plant in South Africa and Australia. The flea-beetle, Phenrica guerini Bechyné (Coleoptera: Chrysomelidae), has been used in South Africa as a biological control agent against the plant for more than 30 years but updated host-specificity testing was required to determine its suitability as an agent in Australia. No-choice larval survival tests were conducted on 26 test plant species from 11 families, with survival to the adult stage only being recorded on the target weed, P. aculeata. No-choice oviposition testing with adult P. guerini was conducted on six test plant species. No adult feeding was recorded on any test plants and significantly more eggs were oviposited on P. aculeata (158.8 SE ± 21.4) than on Talinum caffrum (5.2 SE ± 5.2), which was the only test plant on which they oviposited. The adults survived on average 27 days longer on P. aculeata than on any test plant species. In a multiple-choice trial that included all three species that supported any larval feeding as well as P. aculeata, oviposition and feeding was only recorded on target weed. Phenrica guerini is suitably host specific for consideration in Australia as a biological control agent against P. aculeata.
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The importance of long-term post-release studies in classical biological control: Insect–plant monitoring and public awareness of water hyacinth management (Pontederia crassipes) in Dique Los Sauces, Argentina

  • Authors: Faltlhauser, Ana C , Jiménez, Nadia L , Righetti, Tomas , Visintin, Andrés M , Torrens, Javier , Salinas, Nicolás A , Mc Kay, Fernando , Hill, Martin P , Cordo, Hugo A , Sosa, Alejandro J
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/424828 , vital:72187 , xlink:href="https://doi.org/10.1111/eea.13355"
  • Description: Several components of classical biological control (CBC) programmes are necessary to assess the success of the management strategy (e.g., post-release monitoring) and also help prevent reintroductions or resurgences of invasive species (e.g., public awareness). Water hyacinth, Pontederia (= Eichhornia) crassipes (Mart.) Solms (Pontederiaceae) is an aquatic plant naturally distributed in the north-eastern region of the Del Plata basin in Argentina. In the 1960s it was introduced into the Dique Los Sauces reservoir located outside of its native range in La Rioja Province, in western Argentina, where it became invasive. The natural enemy, Neochetina bruchi Hustache (Coleoptera: Curculionidae), was intentionally introduced in 1974 to control the weed. To assess the success of this CBC programme, a long-term post-release study was conducted. Between 1965 and 2023, we monitored plant coverage, estimated N. bruchi densities, and quantified the associated damage by reanalysing previously published data and incorporating new sampling. We also conducted an online survey to analyse public knowledge and perception about this programme. Water hyacinth coverage fluctuated from its first record in 1965 (maximum coverage 90%) until the control of germinated plants (coverage 0%) in 2018. The plant decline was accompanied by an increase in the weevil population. In our survey, out of 325 respondents only a small group of mostly middle-aged and elderly people knew that the restoration had been achieved through a management strategy and even fewer were aware of the biocontrol approach taken. Respondents who had a positive approach to biological control were more aware of the management plan than respondents who had neutral or negative opinions. Neochetina bruchi has played a key factor in the control of P. crassipes. The intrinsic dynamics of these populations, the dormant seed bank, and the lack of public awareness support the need for long post-release evaluations including outreach campaigns to make a sustainable successful management programme.
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The prevalence, uses and cultural assimilation of shrub and tree invasive alien plants in a biodiversity hotspot along the Wild Coast, South Africa

  • Authors: Wootton, Oscar , Shackleton, Charlie M
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/401314 , vital:69725 , xlink:href="https://doi.org/10.1080/26395916.2023.2216804"
  • Description: Invasive alien plant species (IAPS) frequently offer both ecosystem services and disservices to rural communities with high livelihood dependency on local landscapes. However, biocultural relationships with IAPS may go deeper than just provisioning uses, as they may be assimilated into local belief systems manifest in them becoming embedded in cultural constructions such as naming, stories, songs and ceremonies. It is likely that IAPS that are culturally assimilated will represent a greater conflict of interest in the face of proposed controls of IAPS in biodiversity hotspots where conservation priorities are frequently deemed paramount by external agencies. Using a mixed-methods approach we undertook roadside surveys of 17 selected IAPS along the 250 km Wild Coast section of the Maputaland-Pondoland-Albany biodiversity hotspot, accompanied by questionnaire interviews with 48 local people. The mean number of IAPS per site was four, ranging from zero (only one site) to ten, and local inhabitants deemed the abundance of all but one of the species to be increasing. All species had been in the region for decades, had a vernacular name, and all but one had direct consumptive uses. Species with multiple uses were more widely recognised. However, there was only marginal incorporation of the IAPS into stories, songs and ceremonies, although medicinal uses of some IAPS were for cultural/spiritual needs rather than physical ailments per se. These results show that despite widespread use, there was as yet relatively limited cultural assimilation of the IAPS in the Wild Coast region.
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The trophic position and isotopic niche of a cryptogenic tube-building polychaete in a protected clear-water estuarine bay

  • Authors: van Rensburg, Hendre , Richoux, Nicole B , Simon, Carol A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454404 , vital:75341 , xlink:href="https://doi.org/10.1016/j.ecss.2023.108549"
  • Description: The Knysna Estuary is a large, clear-water embayment and one of the most important estuaries for conservation in southern Africa. The estuary is detritus-dominated and the benthic food webs have low diversities of carnivores, which may make the estuary vulnerable to invasions through the empty niche hypothesis. In the last two decades, the Knysna Estuary has experienced an increase in the population of the cryptogenic and apparently omnivorous estuarine moonshine worm (Diopatra aciculata). Our goal was to describe the trophic role of D. aciculata. We measured carbon and nitrogen stable isotopes in all the common macrophytes and macroinvertebrates across four seasons to 1) establish the isotopic landscapes of three disparate sites within the Knysna Estuary where D. aciculata occurs, 2) establish whether the trophic level of D. aciculata matches those of other common macroinvertebrates, and 3) establish whether the isotopic niche of D. aciculata overlaps with those of syntopic macroinvertebrates. Communities at the different sites differed in food web width, most likely due to differences in primary producer diversity. Our findings suggested that D. aciculata is a facultative carnivore, and some sub-populations are sustained primarily by animal tissues. Isotopic niche overlap analysis showed that direct competition with other common macroinvertebrate consumers is doubtful and D. aciculata occupies a unique niche within the estuary.
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Assessing climate risk to support urban forests in a changing climate

Assessing the electrocatalytic activity of a localized push-pull system in cobalt phthalocyanine/graphene quantum dot hybrids

  • Authors: Nkhahle, Reitumetse , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229909 , vital:49722 , xlink:href="https://doi.org/10.1016/j.matchemphys.2022.125842"
  • Description: In this study, two cobalt phthalocyanines (asymmetric complex 1) and symmetric (complex 2) were synthesized and conjugated to nitrogen-doped graphene quantum dots (NGQDs) through covalent and non-covalent means to create Co phthalocyanine (CoPc)-NGQDs hybrid systems. The CoPcs and conjugates were applied as electrode modifiers on a glassy carbon electrode in the electrochemical sensing of nitrite. Of the CoPcs alone, complex 1 performed better than complex 2 regarding the limits of detection (LoD) recorded (5.74 μM for 1 and 15.1 μM for 2). Regarding the conjugates/nanocomposites, the π-π stacked conjugate derived from complex 2 (2πNGQDs) demonstrated highly favourable electrochemical potential with an LoD value of 0.70 μM. The nanocomposites fashioned from complex 1 were marred by a reduced loading which rendered the conjugates poor electrochemical sensors. These observations however do not disqualify GQDs as complementary nanomaterials to phthalocyanines but rather shed light on seeking alternative routes to increasing the Pc loading in conjugates (more so in π-π stacked conjugates).
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Ecosystem for 4th industrial revolution to accelerate sustainable development goals in the South Africa’,‘n context: a conceptual framework

  • Authors: Diale, Dineo , Kanakana-Katumba, Mukondeleli G , Maladzhi, Rendani W , von der Ohe, Hartmut
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/450592 , vital:74963 , xlink:href="https://ieomsociety.org/proceedings/2022nigeria/11.pdf"
  • Description: Contextualizing technology and digitalization in a period of having to meet sustainable development goals (SDGs), requires a paradigm shift which calls for collaboration from multiple stakeholders. The current turbulent environment requires an investigation into ways of adopting the Fourth Industrial Revolution (4IR) as a pertinent mechanism for accelerating sustainable development goals. The need to formulate a conceptual framework and adapt it to the South African context, requires careful mapping of the elements of 4IR, the relevant infrastructure and resources There has been perceptions instigating resistance towards the SDGs, hence the need to develop the conceptual framework. The exploratory research method fitted well as its nature a systematic review to effect and respond to the abovementioned investigation. The study reviewed about 70 articles of which 53 of those were peerreviewed articles within 4th industrial revolution in South Africa as set for ecosystem. Due to limited research on the topic, possible impacting variables that added immeasurable value were explored as contributing factors the study. Both reviewed literature and government archive on 4th industrial revolution revealed how the ecosystems of 4IR accelerated the achievement of SDGs in South Africa. The study further singled smart factories, smart cities, integrated systems, green technologies, cybernetics, the internet of people, the internet of energy, and the internet of things as contributing factors towards 4IR. The recommended the applicability of the ecosystems onto the South African context to advance innovation agenda to achieve green energy, sustainable water provision, waste management, trade in low-carbon products, cleaner and greener technologies, green buildings, green chemistry and sustainable transport, as well as improved air quality.
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Exploring the community structure of Afrotropical macroinvertebrate traits and ecological preferences along an agricultural pollution gradient in the Kat River, Eastern Cape, South Africa

  • Authors: Akamagwuna, Frank C , Odume, Oghenekaro N , Richoux, Nicole B
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454334 , vital:75336 , xlink:href="https://doi.org/10.1016/j.ecolind.2022.108570"
  • Description: Agricultural activities impact riverine ecosystem structure, function, and processes. In the Afrotropical regions, research on agricultural effects on macroinvertebrate trait distribution is sparse. In this study, we investigated the spatial and temporal changes in the community structure of macroinvertebrate traits along an agricultural disturbance gradient in an Afrotropical River system. Physicochemical variables were sampled alongside macroinvertebrates at eight sites in the dry (winter and spring) and wet (summer and autumn) periods of 2018–2019. We grouped the sites into four categories using the percentage of agricultural land-use cover within each drainage area. Our results showed that agricultural pollution exhibited varying effects on traits and ecological preferences, with traits such as a predatory lifestyle, medium body-size (>10–20 mm), active swimming, possession of spiracles and haemoglobin, and adult aquatic life stage increasing with the pollution gradient. These traits were positively associated with nutrients (PO4+-P, NO2+-N, NH4+-N and NO3+-N), salinity, turbidity and temperature and were deemed tolerant of agricultural pollution. Shredding, crawling, and a preference for macrophytes as food showed strong positive associations with the least disturbed sites and were negatively associated with increasing nutrients, salinity, turbidity and water temperature. As such, these three traits were considered sensitive to agricultural pollution. The identified indicator traits can be used to predict the survival and distribution patterns of organisms under the impact of agriculture-induced stress.
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Fuelwood Production and Carbon Sequestration in Public Urban Green Spaces in Bulawayo, Zimbabwe

  • Authors: Ngulani, Thembelihle , Shackleton, Charlie M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/438757 , vital:73497 , xlink:href="https://doi.org/10.3390/f13050741"
  • Description: Understanding tree species autecology and population structure supports effective conservation actions. Of particular importance are multipurpose trees that provide non-timber forest products (NTFPs). We assessed the population structures and morphologies of two species of NTFP trees in the genus Mimusops across bioclimatic zones in Benin by sampling 288 plots within 11 forests. Structural characteristics were compared between species, forests and zones. Correlations were also observed between Mimusops tree regeneration density, tree features and ecological characteristics. The density of trees ≥5 cm and of regeneration and mean tree height were higher for M. andongensis (within more protected forest) than M. kummel (in forests with access to people), while the highest mean diameter was observed for M. kummel. Tree and regeneration densities and mean height were greatest in the humid zone of Benin, whilst the largest mean diameter was obtained in the sub-humid zone. The results showed significant correlations between regeneration density and soil properties for M. andongensis but not for M. kummel. The correlations between tree morphology and soil characteristics were weak for both species. Ecological characteristics, along with the species’ functional traits and pressures, are important factors related to the observed differences between the species. All diameter classes were represented, and the population seemed more stable in the more protected forest relative to other forests. Mimusops trees with a diameter of 5–15 cm represented more than 30% of this species in most forests; this suggests, for M. kummel, whose trees flower when quite small (≥6 cm dbh), that there are sufficient reproductive trees. Thus, as a long-lived species, its populations could be maintained even with low/episodic recruitment. However, we found no regeneration in many forests and climate change could threaten populations. Therefore, it is important to investigate regeneration growth and dynamics, seed production and germination of the species in relation to the biophysical conditions and disturbances experienced by Mimusops stands.
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Improving signer-independence using pose estimation and transfer learning for sign language recognition

  • Authors: Marais, Marc , Brown, Dane L , Connan, James , Boby, Alden
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/463406 , vital:76406 , xlink:href="https://doi.org/10.1007/978-3-031-35644-5"
  • Description: Automated Sign Language Recognition (SLR) aims to bridge the com-munication gap between the hearing and the hearing disabled. Com-puter vision and deep learning lie at the forefront in working toward these systems. Most SLR research focuses on signer-dependent SLR and fails to account for variations in varying signers who gesticulate naturally. This paper investigates signer-independent SLR on the LSA64 dataset, focusing on different feature extraction approaches. Two approaches are proposed an InceptionV3-GRU architecture, which uses raw images as input, and a pose estimation LSTM architecture. MediaPipe Holistic is implemented to extract pose estimation landmark coordinates. A final third model applies augmentation and transfer learning using the pose estimation LSTM model. The research found that the pose estimation LSTM approach achieved the best perfor-mance with an accuracy of 80.22%. MediaPipe Holistic struggled with the augmentations introduced in the final experiment. Thus, looking into introducing more subtle augmentations may improve the model. Over-all, the system shows significant promise toward addressing the real-world signer-independence issue in SLR.
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In vitro photoinactivation of S. aureus and photocatalytic degradation of tetracycline by novel phthalocyanine-graphene quantum dots nano-assemblies

  • Authors: Openda, Yolande Ikala , Mgidlana, Sithi , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229895 , vital:49721 , xlink:href="https://doi.org/10.1016/j.jlumin.2022.118863"
  • Description: A novel asymmetrical zinc (II) phthalocyanine (Pc) 4 bearing three dimethoxy groups and one carboxyl group was linked to glutathione capped graphene quantum dots (GQDs) by the reaction of carboxylic acid substituent on Pc 4 with the amino group on the GQDs. On the other side, the symmetrical Pc analog 3 was linked to the same nanoparticles through π-π interactions. The as-formed nano-photosensitizers were fully characterized by spectroscopic methods and their photophysicochemical properties were investigated as well. Photodynamic antimicrobial chemotherapy was performed on the planktonic cells of S. aureus strain. And the results show that these nano assemblies were able to completely inhibit the metabolic activity of the resistant bacteria strain S. aureus with a 10.26 log reduction in the viable count. Again, asymmetrical Pc showed higher photocatalytic activity compared to the symmetrical complex with higher kobs and fast initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model. The target conjugates showed all the advantages of two different groups existing on a single entity.
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Iterative Refinement Versus Generative Adversarial Networks for Super-Resolution Towards Licence Plate Detection

  • Authors: Boby, Alden , Brown, Dane L , Connan, James
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/463417 , vital:76407 , xlink:href="https://link.springer.com/chapter/10.1007/978-981-99-1624-5_26"
  • Description: Licence plate detection in unconstrained scenarios can be difficult because of the medium used to capture the data. Such data is not captured at very high resolution for practical reasons. Super-resolution can be used to improve the resolution of an image with fidelity beyond that of non-machine learning-based image upscaling algorithms such as bilinear or bicubic upscaling. Technological advances have introduced more than one way to perform super-resolution, with the best results coming from generative adversarial networks and iterative refinement with diffusion-based models. This paper puts the two best-performing super-resolution models against each other to see which is best for licence plate super-resolution. Quantitative results favour the generative adversarial network, while qualitative results lean towards the iterative refinement model.
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Lessons from COVID-19 for wildlife ranching in a changing world

  • Authors: Clements, Hayley S , Child, Matthew F , Lindeque, Lehman , Lunderstedt, Kyra , de Vos, Alta
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/415886 , vital:71297 , xlink:href="https://doi.org/10.1038/s41893-022-00961-1"
  • Description: The COVID-19 pandemic provided an opportunity to assess the impacts of a global disturbance on conservation land uses and learn from responses to the crisis to enable more resilient conservation systems. To understand socio-economic responses of diverse wildlife working lands to COVID-19, we surveyed owners and managers of 78 private wildlife ranches (wildlife working lands), 23 agricultural farms (conventional working lands) and six public protected areas (conventional conservation lands) in South Africa. Most protected areas lost more than 75% of their revenues during 2020, while most agricultural farms lost less than 10%. The impact on wildlife ranches was more varied. Ranches with more diverse activities, particularly mixed wildlife–agriculture systems, lost less revenue, shifting their activities from those heavily impacted (international ecotourism, trophy hunting) to those less afected (for example, wildlife meat, livestock). This adaptive capacity suggests that wildlife-based enterprises could represent key ecosystem-based adaptations, providing lessons for integrated global policies that seek to incorporate private land models in the 2030 Biodiversity Framework.
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Reaction of Perrhenate with Phthalocyanine Derivatives in the Presence of Reducing Agents and Rhenium Oxide Nanoparticles in Biomedical Applications

  • Authors: Ntsimango, Songeziwe , Gandidzanwa, Sendibitiyosi , Joseph, Sinelizwi V , Hosten, Eric C , Randall, Marvin , Edkins, Adrienne L , Khene, Samson M , Mashazi, Philani N , Nyokong, Tebello , Abrahams, Abubak’r , Tshentu, Zenixole R
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/300257 , vital:57910 , xlink:href="https://doi.org/10.1002/open.202200037"
  • Description: A novel alternative route to access rhenium(V)−phthalocyanine complexes through direct metalation of metal-free phthalocyanines (H2Pcs) with a rhenium(VII) salt in the presence of various two-electron reducing agents is presented. Direct ion metalation of tetraamino- or tetranitrophthalocyanine with perrhenate (ReO4−) in the presence of triphenylphosphine led to oxidative decomposition of the H2Pcs, giving their respective phthalonitriles. Conversely, treatment of H2Pcs with ReO4− employing sodium metabisulfite yielded the desired ReVO−Pc complex. Finally, reaction of H2Pcs with ReO4− and NaBH4 as reducing agent led to the formation of rhenium oxide (RexOy) nanoparticles (NPs). The NP synthesis was optimised, and the RexOy NPs were capped with folic acid (FA) conjugated with tetraaminophthalocyanine (TAPc) to enhance their cancer cell targeting ability. The cytotoxicity profile of the resultant RexOy−TAPc−FA NPs was assessed and found to be greater than 80 % viability in four cell lines, namely, MDA−MB-231, HCC7, HCC1806 and HEK293T. Non-cytotoxic concentrations were determined and employed in cancer cell localization studies. The particle size effect on localization of NPs was also investigated using confocal fluorescence and transmission electron microscopy. The smaller NPs (≈10 nm) were found to exhibit stronger fluorescence properties than the ≈50 nm NPs and exhibited better cell localization ability than the ≈50 nm NPs.
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Time-dependent characterization of graphene quantum dots and graphitic carbon nitride quantum dots synthesized by hydrothermal methods

  • Authors: Nxele, Siphesihle Robin , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/230917 , vital:49831 , xlink:href="https://doi.org/10.1016/j.diamond.2021.108751"
  • Description: We report on the facile synthesis of graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and graphitic carbon nitride quantum dots (gCNQDs) by the bottom-up hydrothermal synthetic process. The time is varied to study its effects on the structural, hydrodynamic and optical properties of these nanostructures. The techniques used to characterize these nanostructures were transmission electron microscopy, X-ray diffractometry, dynamic light scattering, and zetametry (zeta potential), and by energy dispersive X-ray, UV/vis, fluorescence, Fourier transform infrared, Raman and X-ray photoelectron spectroscopies. For gCNQDs and NGQDs, Raman spectroscopy showed an increase in disorder with synthesis time, indicating introduction of more triazine groups for the former and increase in doping with the N atoms for the latter, hence higher temperatures are recommended. For GQDs, Raman spectra showed an increase in the spatial order of the π-conjugated structure with synthesis time. Considering all the techniques employed in this work, the synthesis times of 6h and 8 h are recommended for GQDs and NGQDs.
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Towards SDG 15.3: The biome context as the appropriate degradation monitoring dimension

  • Authors: Xoxo, Sinetemba , Mantel, Sukhmani K , de Vos, Alta , Mahlaba, Bawinile , le Maître, David , Tanner, Jane L
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/415961 , vital:71304 , xlink:href="https://doi.org/10.1016/j.envsci.2022.07.008"
  • Description: Accurate and reliable estimation of terrestrial ecosystem degradation is critical to meeting the challenge of reversing land degradation. Remote sensing data (especially land productivity dynamics) is commonly used to estimate land degradation, and this study uses the TRENDS.EARTH toolbox for the period covering 2000–2018, demonstrating the benefit of tracking the degradation process (SDG 15.3.1) at a biophysical unit. Contributing to the country’s SDG 15.3.1 monitoring, anthropogenic degradation was estimated based on RESTREND land productivity, biome-specific land cover trends, and soil organic carbon (SOC) stocks. Underlying degradation was evaluated by reclassifying a 28-year national land cover change dataset to match the UNCCD land cover legend. Analysis results indicate that land productivity changes (especially in stable grasslands, afforested, and cropland areas) mainly influenced the degradation status of the biome (19.9% degraded and 25.6% improvement). Global datasets also suggest that land cover and SOC had a minimal contribution (more than 2%) to anthropogenic degradation dynamics in the biome between 2000 and 2018. The GIS analysis showed that long-term, the major contributors to the biome’s underlying 9% anthropogenic degradation were woody proliferation into the Grassland Biome, urban expansion, and wetland drainage.
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Ubuntu among the ‘born frees’: Exploring the transmission of social values through community engagement in South Africa

  • Authors: Willmore, Stephanie B , Day, Randal , Maistry, Savathrie M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426564 , vital:72363 , xlink:href="https://doi.org/10.1177/00208728221086151"
  • Description: Ubuntu was recently adopted as the first theme for the 2020–2030 global agenda for social work, and yet little research is available to explore how it is transmitted and implemented in communities. The authors present findings of a qualitative study conducted in an academic setting in South Africa, where the transmission of Ubuntu was discussed among 30 young adult ‘born frees’. Students seemed to embrace principles of Ubuntu as a whole; however, economic, social and cultural strains are documented as obstacles to its pragmatic application. Implications of community engagement through service learning as a means of strengthening Ubuntu are discussed.
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