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Evaluating the establishment of a new water hyacinth biological control agent in South Africa

  • Authors: Miller, Benjamin E , Coetzee, Julie A , Hill, Martin P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/451399 , vital:75046 , http://dx.doi.org/10.17159/2254-8854/2023/a15613
  • Description: Megamelus scutellaris Berg (Hemiptera: Delphacidae) is the most recent of nine biological control agents developed to manage invasive water hyacinth, Pontederia (= Eichhornia) crassipes Mart.(Pontederiaceae), in South Africa. More than a million M. scutellaris have been mass-reared and released since the first introduction of the agent into South Africa in 2013, successfully establishing overwintering populations at 32 sites in seven of the nine provinces. Establishment has also been recorded at seven of these sites through natural dispersal from sites where they had established. Inundative releases, where large numbers of M. scutellaris are released regularly, have resulted in excellent establishment, and caused a significant reduction in water hyacinth cover in areas where, historically, biological control seemed unlikely due to excessive eutrophication. Although M. scutellaris has established well throughout South Africa through classical biological control methods, this study also showed that inundative releases of biological control agents over multiple seasons results in the most effective control of the weed, especially at cool temperate and eutrophic sites.
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  • Date Issued: 2023

Evaluation of the antibacterial activity of gallic acid anchored phthalocyanine-doped silica nanoparticles towards Escherichia coli and Staphylococcus aureus biofilms and planktonic cells

  • Authors: Magadla, Aviwe , Openda, Yolande Ikala , Mpeta, Lekhetho S , Nyokong, Tebello
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/360424 , vital:65087 , xlink:href="https://doi.org/10.1016/j.pdpdt.2023.103520"
  • Description: In this work, we have described the synthesis of phthalocyanine complexes Zn(II) tetrakis 4-(5-formylpyridin-2-yl)oxy) phthalocyanine (2), Zn(II) tetrakis-1 butyl 4-(2-(6- (tetra-phenoxy)pyridin-3-yl) vinyl)pyridin-1-ium phthalocyanine (3) and Zn(II) tetrakis 1 butyl 5-(2-(1-butylpyridin-1-ium-4-yl)vinyl)-2-(tetra-phenoxy)pyridin-1-ium phthalocyanine (4). The effect of a varying number of charges when the Pc complexes are alone or grafted in gallic acid (GA) tagged silica nanoparticles on photodynamic antimicrobial chemotherapy (PACT) is investigated toward Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli) in both planktonic and biofilm forms. Complex 4, bearing a total of 8 cationic charges, displayed the highest activity with log CFU (colony forming units) values of 8.60 and 6.42 against E.coli and S.aureus biofilms, respectively. The surface stability of E.coli and S.aureus biofilms in the presence of 4 and its conjugate was analyzed using cyclic voltammetry. Scanning electron microscopy (SEM) and Raman spectra are also used to study the conformational and biochemical changes within biofilm upon subjecting them to PACT.
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  • Date Issued: 2023

Examining the implementation of the Department of Social Development’s fatherhood strategy by FAMSA

  • Authors: Sishuba, Thozama Alicia
  • Date: 2023
  • Subjects: Grahamstown (South Africa) , Eastern Cape (South Africa) , South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/27618 , vital:69320
  • Description: This study aimed to exam the implementation of the Department of Social Development’s Fatherhood Strategy by Families South Africa (FAMSA) Eastern Cape. FAMSA is a non-profit organization providing vital services to people in families while providing them with psychosocial and emotional support. FAMSA has been in existence since 1954. To achieve this aim, the study’s objectives were underpinned by understanding the implementation of the Department of Social Development’s Fatherhood Strategy in Buffalo City Metro, establishing FAMSA’s response to the implementation of the Department of Social Development’s Fatherhood Strategy as well as exploring the challenges faced by FAMSA in implementing the Department of Social Development’s Fatherhood Strategy. A qualitative research methodology was implemented to gather information from FAMSA and DSD. Findings from literature revealed that the fatherhood strategy has been a concern worldwide evidenced by the high levels of father-child non-residency. Data from this study revealed that FAMSA had been implementing the programme effectively regardless of numerous challenges that include funding human resources. Conclusively, a lot must be done to advocate for fatherhood. Recommendations also point to the need for several interventions which need to be done in research, social work practice and also policy formulation and development. , Thesis (MA) -- Faculty of Social Sciences and Humanities, 2023
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  • Date Issued: 2023

Feminism and women in African philosophy

  • Authors: Etieyibo, Edwin , Tabensky, Pedro
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/453305 , vital:75244 , https://doi.org/10.1080/02580136.2023.2283674
  • Description: In this preamble, we highlight some of the more recent work on gender and sexuality in African philosophy. We do this as a way of introducing the special issue on “African Philosophy, Women, and Feminism”. In particular, we outline and highlight the trajectory and intellectual landscape of several discussions on women and feminism in African philosophy in the issue, and in this way, build on some previous work on gender, women, sexuality and African philosophy.
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  • Date Issued: 2023

Fruits of the city: The nature, nurture and future of urban foraging

  • Authors: Sardeshpande, Mallika , Shackleton, Charlie M
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/402259 , vital:69835 , xlink:href="https://doi.org/10.1002/pan3.10428"
  • Description: Urban foraging is a global informal phenomenon which has been investigated in the Global North more than oth-er parts of the world. Characterising the nature of urban foraging in the Global South is imperative given the rapid urbanisation and sustainable development priorities in the region. In this study, we interviewed 80 urban forag-ers in four cities in the eastern coastal region of South Af-rica, with an aim to understand the nature of urban forag-ing in a developing nation context. We asked foragers about their initiation to and motivations for foraging, their logistics, yields and associated activities, descriptions of their foraging grounds, and if and how they had changed, and what they envisage as an ideal future for foraging.
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  • Date Issued: 2023

Gender and Culture Shock at University: Perspectives of First-Year Male Students From a Public University in South Africa

  • Authors: Aiseng, Kealeboga
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/453392 , vital:75250 , ISBN 9781668469613 , DOI: 10.4018/978-1-6684-6961-3.ch006
  • Description: The chapter seeks to embark on a qualitative study with first-year male students from a public university in South Africa to understand their adjustment and adapting to university life due to challenges with gender and sexuality matters that they face. The authors is mostly interested in male students as they are the usual perpetrators of gender and sexuality offences in universities. With this chapter, the author wants to understand the experiences of these students as they transition from one world (their hometowns) to another (university campuses). Of interest in this study is that some of the students at this university come from previously disadvantaged backgrounds: villages, townships, and farmsteads. Some of them have gone through traditional rites of passage such as initiation schools; others come from patriarchal backgrounds and heteronormative backgrounds.
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  • Date Issued: 2023

Governing pregnancy in the Global South: the case of post-apartheid South Africa

  • Authors: du Plessis, Ulandi , Macleod, Catriona I
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/441212 , vital:73867 , xlink:href="https://doi.org/10.1080/13698575.2023.2249943"
  • 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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  • Date Issued: 2023

Grandmothers of the sea: Stories and lessons from five Xhosa ocean elders

  • Authors: Francis, Buhle , McGarry Dylan K
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/433926 , vital:73010 , ISBN 9781003355199 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781003355199-12/grandmothers-sea-buhle-francis-dylan-mcgarry
  • Description: We surface a historical, political, spiritual, economic and cultural analysis made by five Xhosa Grandmothers based in the Eastern Cape, regarding their entangled relationship with the Ocean. A nuanced, complex relationship with the ocean and the politics of natural resource management in South Africa emerged from our interviews, as scholar-activists, with these Grandmothers, and this chapter attempts to explore how a gendered upbringing, with its associated roles and responsibilities, have created a unique relationship with the ocean that must be understood in all its nuanced and complex facets. We explore how the identities and values of these Xhosa Grandmothers are relationally entangled with the ocean and politics of South Africa, and explore the deep ecological knowledge that they hold, yet is shamelessly ignored. Through their own renderings, we unpack the rich understanding of marine species, customary rights, ocean policy and governance practices that impact, impede and complicate their lives. Working with first-hand accounts (stories translated from Xhosa), the Grandmothers provide a nuanced and brazen analysis of the status quo of ocean governance, ocean literacy and policy. They unpack what interventions are needed, and call for a response that recognises Grandmothers as central to South Africa’s wellbeing, a health that sits precariously with the complex realities of older women’s entangled and diverse vulnerabilities. Finally, the firsthand accounts and analyses made by the Grandmothers, offer a politically rigorous contribution to the field of hydrofeminism, one told in their own way, using their own idiomatic rendering, with their own metaphors and figurations.
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  • Date Issued: 2023

Historical diversification of Pseudonympha Wallengren, 1857 (Lepidoptera: Nymphalidae: Satyrinae).

  • Authors: van Steenderen, Clarke J M , Pringle, Ernest L , Villet, Martin H
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/442182 , vital:73965 , https://doi.org/10.1080/00222933.2023.2257373
  • Description: The butterfly genus Pseudonympha and several related genera are endemic to southern Africa. Although many of the species are montane, some inhabit the arid interior of South Africa, offering an opportunity to study the palaeobiogeography of this biome. Morphological data (for all species of Pseudonympha and allied African and Asian genera) and molecular data (WG and COI genes for nine of the 15 species of Pseudonympha and all of the southern African endemic genera of Ypthimina) were compiled. Phylogenetic analysis indicated that Pseudonympha apparently originated in the Cape Fold Mountains about 15 Mya ago and spread steadily eastwards and northwards along the Great Escarpment during the aridification of the region, perhaps assisted by orogeny in the east and oceanic cooling in the west. Aridification cycles seem to have intermittently isolated some early lineages in elevated habitats in the interior, so that those lineages show lower speciation rates (or perhaps higher extinction rates) than those in the east. Four species delineation techniques indicated that some species are taxonomically oversplit. Based on genetic polyphyly and morphological similarity, we propose that the status of P. swanepoeli be reduced to that of a subspecies of P. varii, such that all the north-eastern populations from Harrismith to Tzaneen fall under P. varii swanepoeli van Son stat. n., and all the southern populations fall under P. varii varii van Son stat. n. Ultimately, the diversification of both of these lineages seems tied to their host plants’ response to aridification brought on by continental drift and orogeny. Sympatric organisms (eg cicadas) with biologies focused around different resources (eg savanna trees) show other patterns of diversification. The phylogenetic analysis of the subtribe Ypthimina also supports the monophyly of Paternympha, paraphyly of Ypthima, recognition of Thymipa Moore stat. rev. as a phylogenetic independent genus, and new relationships for Strabena.
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  • Date Issued: 2023

History matters: Societal acceptance of deep-sea mining and incipient conflicts in Papua New Guinea

  • Authors: van Putten, Ingrid , Aswani, Shankar , Boonstra, W.J , De la Cruz-Modino, R , Das, Jewel , Glaser, Marion , Heck, Nadine , Narayan, Siddharth , Paytan, Adina , Selim, Samiya , Vave, Ron
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/391453 , vital:68653 , xlink:href="https://doi.org/10.1007/s40152-023-00318-0"
  • Description: New marine industries that develop and grow in response to the changing demand for their products have the potential to exert pressure on fragile marine environments. These emerging industries can benefit local communities but equally can have negative environmental and socio-cultural impacts. The development of new and emerging industries, like deep seabed mining (DSM), requires the acceptance and involvement of local communities. Yet, the history of marine exploitation is imbued with conflicts between industries and local communities. This paper presents a DSM case study in Papua New Guinea (PNG) to stimulate debate around the potential for conflict in the pursuit of resource extraction from the deep sea and the social and environmental harm that these extractions can cause. We do so by first presenting a timeline of local and extra-local events and enabling conditions that form the development background for the DSM Solwara 1 project in PNG. We then undertake a media narrative analysis to consider the contribution of aspects of social acceptability to this highly complex and multi-scale conflict. We find that the lack of (or a decrease in) social acceptability contributed to the conflict situation and ultimately the demise of the Solwara 1 project. Extra-locally, the initial development was positively framed around solutions for decarbonisation using new technology. Over time, actions by international NGOs, financial issues related to foreign companies, and asymmetry in the power balance between the Pacific Island nation and global businesses played a role in growing negative perceptions of acceptability. Historical experiences with prior environmental mining disasters, together with sea tenure governance challenges, and a lack of community and stakeholder acceptance also contributed to the demise of the project. Untangling and debating these complex interactions provides context and reasons for the tension between the lack of societal acceptance at a local scale and the perceived need for DSM products in the global North for innovative technologies and decarbonising societies. Better understanding these interactions and tensions can help emerging industries navigate a future blue economy.
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  • Date Issued: 2023

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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  • Date Issued: 2023

Impact assessment of genetically modified TELA® Bt. maize variety adoption on yield, household income, technical efficiency and food security: a case of maize farmers in Limpopo and Mpumalanga Provinces, South Africa.

  • Authors: Mailula, Lesiba Pertunia
  • Date: 2023
  • Subjects: Food security , Farmers -- Training of , Seed technology -- Economic aspects
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/28266 , vital:74040
  • Description: The agricultural sector is widely recognized as a crucial factor for promoting sustainable economic development, reducing poverty, and ensuring food security in developing countries. However, in Africa, the agricultural sector continues to underperform, with growth rates falling behind the population growth, this can be attributed to various challenges, including climate change and pest infestation. This has over the years weakened the defence of crops leading to the disruptions in crop production and food security. As such, calls have been made that adoption of the agricultural technology may promote food security through high yields. This is because agricultural technology crops have improved varieties such as drought tolerance and pest resistance traits. However, adoption of improved agricultural technology in Africa has been very sluggish amongst smallholder farmers, particularly for GM seed, this is due to the on-going controversies and compliance requirements regarding GM technologies. The controversies are raised by the unknown benefits and risks associated with the adoption of GM seeds technology. Furthermore, there are mixed benefits associated with GM technology adoption as well as methodological and data gaps associated with assessment of GM impact on the farmer’s welfare. In 2016, five Bt. maize varieties trademarked TELA were developed through the WEMA project. Trials were approved and launched with smallholder farmers in various countries in Africa, and South Africa is not an exception. Several smallholder maize farmers have accessed the TELA Bt. maize varieties through local seed companies and have been producing it for the past seasons. Yet, no study that has been conducted on the impact of the GM TELA Bt. maize technology adoption on yield, income, food security and technical efficiency, hence, a need for such a study. The primary data was collected from 289 183 TELA Bt. and 106 non-TELA Bt. smallholder farmers in Mpumalanga and Limpopo provinces using convenience and snowball sampling techniques. Data were analysed using various analytical tools that included descriptive statistics, gross margin analysis, Household Dietary Diversity Score, Stochastic Frontier Model and the Propensity Score Matching, modelled through the Probit regression model. These tools were utilised to address the objectives. The descriptive statistics show that the TELA Bt. maize variety yielded 61.1 percent more maize output as compared to non-TELA Bt. maize farmers, with an average of 691kg ha and 429kg ha, respectively. The gross margin analysis showed higher subsequent income for the TELA Bt. maize farmers R2 834.93 compared to R2 124.96 for the non-TELA Bt. maize farmers. The results of the HDDS showed a marginal effect of TELA Bt. maize seed technology on food diversity. The average HDDS scores were 8.4 and 7.5 for the TELA Bt. and non-TELA Bt. maize farmers, respectively. The Stochastic Frontier Analysis SFA results revealed that both the TELA Bt. maize farmers and non-TELA Bt. maize farmers were technically inefficient. However, the TELA Bt. maize farmers were better-off than their counterparts, with mean technical efficiency scores of 0.416 and 0.328, respectively. The Propensity Score Matching PSM using the Probit model revealed that gender 0.6064, number of years in farming 0.0099 credit 1.1438 and market access 0.4427 had a positive and significant influence on the decision taken by the farmers to adopt TELA Bt. maize seed technology. However, access to extension services was found to have a negative and significant impact on the adoption of TELA Bt. maize seed technology. The Average Treatment Effect of the Treated ATT using the Nearest Neighbour Matching algorithm indicated that adoption of TELA Bt. maize technology improved farmers’ yields by 254.3kg, income by 0.36 cents and technical efficiency by 8.6 percent. There was no significant relationship observed between adoption of the GM technology and food security. Generally, the results from this study imply that adoption of GM TELA Bt. maize seed technology improves farmers’ yields, income, technical efficiency, as well as food security. The study therefore, recommends increased awareness of the GM seed technology benefits to farmers, coupled with training and capacity development to enhance adoption of seed technology towards improved farmers’ welfare. In addition, there is a need for sustained Research and Development investments towards GM seed technologies to enhance maize productivity and technical efficiency of the farmers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
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  • Date Issued: 2023

Impact of Access and Benefit Sharing implementation on biological control genetic resources

  • Authors: Mason, Peter G , Barratt, Barbara I P , Mc Kay, Fernando , Klapwijk, Johannette N , Silvestri, Luciano C , Hill, Martin P , Hinz, Hariet L , Sheppard, Andy , Brodeur, Jacques , Vitorino, Marcello Diniz , Weyl, Philip S R , Hoelmer, Kim A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/418013 , vital:71501 , xlink:href="https://doi.org/10.1007/s10526-023-10176-8"
  • Description: The third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the use of genetic resources was further developed when the Nagoya Protocol on Access and Benefit Sharing came into effect in 2014. Interpretation of how this agreement is being implemented is wide-ranging and there are implications for biological control. A survey of biological control workers indicated that while some countries have facilitated access to biological control genetic resources, requirements in other countries have impeded biological control implementation. There was consensus that benefits to provider countries should be in the form of supporting local research communities. There was also agreement that the free use and exchange of biological control genetic resources has provided benefits to the global community, including to both providers and recipients of the agents. It is recommended that consideration of the free use and exchange principal should be a key element of Access and Benefit Sharing measures for the future.
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  • Date Issued: 2023

Impact of relaxing flood policy interventions on fish production: lessons from earthen pond‑based farmers in Southwest Nigeria

  • Authors: Adewale, Isaac Olutumise
  • Date: 2023
  • Language: English
  • Type: text , Article
  • Identifier: http://hdl.handle.net/11260/9169 , vital:73018
  • Description: These days, aquatic (fish) welfare is a major issue and a significant component that affects fish output. Although numerous factors can be involved, climate-induced floods are one of the most critical limiting factors in the aquaculture and fisheries industry’s development. Understanding the extent of losses and damages caused by floods at the farm level will thereby exacerbate pre-emptive policy responses. Thus, the impact of floods on fish production by focusing on catfish earthen pond-based farmers in Southwest Nigeria is presented. A survey is conducted for 150 fish farms in the region. A marginal treatment effects (MTE) approach is employed to determine the heterogeneity across the households and the policy-relevant treatment effects (PRTE). The results show significant heterogeneity in the effects of floods on fish production, considering both observed and unobserved characteristics of the farmers. It is shown that flood significantly increases output loss. Furthermore, farmers with high propensity scores to flood tend to have a high likelihood of incurring output loss. The estimates of PRTE reveal that relaxing policy strategies, such as access to climate information and climate-related training and workshops, would significantly exacerbate output loss due to flood incidences. Thus, intensifying awareness and sensitization on climate change policies will address the flood menace and still increase food production.
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  • Date Issued: 2023

Impact of sustainable tax revenue and expenditure on the achievement of sustainable development goals in some selected African countries

  • Authors: Kola, Benson Ajeigbe
  • Date: 2023
  • Language: English
  • Type: text , Article
  • Identifier: http://hdl.handle.net/11260/9234 , vital:73024
  • Description: Abstract The study examined the impact of Sustainable Tax Revenue and Expenditure on the achievement of Sustainable Development Goals in African countries using secondary data. The dataset was extracted from the World Development Indicators database. The large gap between developed and developing countries when comparing the probability of them achieving the SDGs was the main motivation behind this study. Data retrieved from 45 countries comprised of both African and developed countries for the period 2010–2020 was analyzed using the Generalized Method of Moments technique. The results revealed that the coefficients of grants received, various forms of taxes, and other revenue have a positive effect on economic growth but a negative effect on poverty and unemployment for African and developed countries. This finding suggests that improvements in tax revenue generation, grants and other revenue accumulation across different sources boost economic performance and the welfare of individuals in the analyzed countries. The outcome is an indication that accumulating more grants from different sources will help to achieve sustainable development, improve financial stability, contributes to the economic growth and development in these countries. This study can guide policymakers, governments, international institutions, revenue bodies such as SARS and other stakeholders in their various planning and other decision-making endeavors. Governments and other policymakers must ensure the efficient generation and sustainable utilization of revenue generated from taxes and other revenues to spur the growth and development of their countries. They should have Growth-Sustainability-Oriented Fiscal Adjustment Programs and Sustainable Government Expenditure that can help push and redirect governments to achieve the SDGs in Africa.
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  • Date Issued: 2023

In silico substrate-binding profiling for SARS-CoV-2 Main protease (Mpro) using Hexapeptide substrates

  • Authors: Zabo, Sophakama , Lobb, Kevin A
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452711 , vital:75164 , xlink:href="https://doi.org/10.3390/v15071480"
  • Description: The SARS-CoV-2 main protease (Mpro) is essential for the life cycle of the COVID-19 virus. It cleaves the two polyproteins at 11 positions to generate mature proteins for virion formation. The cleavage site on these polyproteins is known to be Leu-Gln↓(Ser/Ala/Gly). A range of hexapeptides that follow the known sequence for recognition and cleavage was constructed using RDKit libraries and complexed with the crystal structure of Mpro (PDB ID 6XHM) through extensive molecular docking calculations. A subset of 131 of these complexes underwent 20 ns molecular dynamics simulations. The analyses of the trajectories from molecular dynamics included principal component analysis (PCA), and a method to compare PCA plots from separate trajectories was developed in terms of encoding PCA progression during the simulations. The hexapeptides formed stable complexes as expected, with reproducible molecular docking of the substrates given the extensiveness of the procedure. Only Lys-Leu-Gln*** (KLQ***) sequence complexes were studied for molecular dynamics. In this subset of complexes, the PCA analysis identified four classifications of protein motions across these sequences. KLQ*** complexes illustrated the effect of changes in substrate on the active site, with implications for understanding the substrate recognition of Mpro and informing the development of small molecule inhibitors.
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  • Date Issued: 2023

Inclusion complexation and liposomal encapsulation of an isoniazid hydrazone derivative in cyclodextrin for pH-dependent controlled release

  • Authors: Safari, Justin B , Mona, Lamine B , Sekaleli, Bafokeng T , Avudi, Bénite K , Isamura, Bienfait K , Mukubwa, Grady K , Salami, Sodeeq A , Mbinze, Jérémie K , Lobb, Kevin A , Krause, Rui W M , Nkanga, Christian I
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452727 , vital:75166 , xlink:href="https://doi.org/10.1016/j.jddst.2023.104302"
  • Description: Tuberculosis, a predominantly pulmonary pathology, is currently the deadliest infection worldwide. Its treatment is based on combination therapy involving selected antimicrobials including Isoniazid. However, physicochemical properties of isoniazid negatively affect the clinical performance of current tuberculosis regimens, causing drug resistance development and increasing mortality rates. Liposomal encapsulation improves antituberculosis drug delivery; however, nano-formulation of isoniazid remains challenging due to its small molecular size and high hydrophilicity. Therefore, this study aimed to derivatize isoniazid and formulate a controlled delivery system using the concept of drug-in-cyclodextrins-in-liposomes to enhance drug biopharmaceutical properties. A prodrug of isoniazid was synthesized and screened for its ability to form stable complexes with α, β, and γ cyclodextrins. A selected inclusion complex with β-cyclodextrin was encapsulated in liposomes and assessed for controlled release of isoniazid. Successful formation of a 1:1 complex was established and characterized, followed by molecular modeling studies to demonstrate strength of the interactions within the complex and predicted complex structure. The inclusion complex was successfully encapsulated in liposomes using the thin film hydration method and the ethanol injection ultrasonic dispersion, with the latter giving the best results. These findings demonstrate the potential.
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  • Date Issued: 2023

Information extraction model from Ge’ez texts

  • Authors: Gebeyehu, Seffi , Wolde, Worke , Shibeshi, Zelalem S
  • Date: 2023
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/429176 , vital:72565 , 10.11591/ijeecs.v30.i2.pp787-795
  • Description: Nowadays, voluminous and unstructured textual data is found on the Internet that could provide varied valuable information for different institutions such as health care, business-related, training, religion, culture, and history, among others. A such alarming growth of unstructured data fosters the need for various methods and techniques to extract valuable information from unstructured data. However, exploring helpful information to satisfy the needs of the stakeholders becomes a problem due to information overload via the internet. This paper, therefore, presents an effective model for extracting named entities from Ge'ez text using deep learning algorithms. A data set with a total of 5,270 sentences were used for training and testing purposes. Two experimental setups, i.e., long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM) were used to make an empirical evaluation with training and a testing split ratio of 80% to 20%, respectively. Experimental results showed that the proposed model could be a practical solution for building information extraction (IE) systems using Bi-LSTM, reaching a training, validation, and testing accuracy as high as 98.59%, 97.96%, and 96.21%, respectively. The performance evaluation results reflect a promising performance of the model compared with resource-rich languages such as English.
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  • Date Issued: 2023

Inhibiting human dipeptidyl peptidase IV using cannabinoids and Leonotis leonurus extracts as a potential therapy for the management of diabetes

  • Authors: Mkabayi, Lithalethu , Viljoen, Zenobia , Lobb, Kevin A , Pletschke, Brett I , Frost, Carminita L
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/452745 , vital:75167 , xlink:href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1773924"
  • Description: Diabetes is a chronic metabolic disorder that has been shown to affect a growing number of people worldwide. Controlling blood glucose levels is one of the possible strategies to treat type 2 diabetes mellitus (T2DM). It has been established that the inhibition of dipeptidyl peptidase IV (DPP-IV) prolongs the activity of incretin hormones, which serve as key stimulators of insulin secretion and regulation of blood glucose levels. Although several synthetic DPP-IV inhibitors are available, there is still a need for naturally sourced inhibitors that have fewer to no undesirable side effects. In this study, cannabinoids and Leonotis leonurus aqueous extracts were evaluated for their inhibitory effects against recombinant human DPP-IV. Their potential inhibition mechanism was explored using in vitro and in silico approaches. All tested cannabinoids and L. leonurus aqueous extracts showed significant inhibitory activity against DPP-IV. Phytochemical analysis of L. leonurus extract indicated the presence of diterpenoids and alkaloids, which might contribute to the inhibitory activity. In molecular docking studies, among different constituents known in L. leonurus, luteolin and marrubiin showed binding energy of -7.2 kcal/mol and cannabinoids (cannabidiol, cannabigerol, cannabinol and Δ9-tetrahydrocannabinol) showed binding energies ranging from -6.5 to -8.2 kcal/mol. Molecular dynamics revealed that all tested compounds formed stable complexes with the enzyme during 100 ns simulation, indicating that they are good ligands. This study provided preliminary evidence for the potential application of the selected cannabinoids and L. leonurus in maintaining glucose homeostasis, suggesting that they could be suitable therapeutic candidates for managing T2DM.
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  • Date Issued: 2023

International agreement for the use and exchange of classical biological control genetic resources: a practical proposal

  • Authors: Mason, Peter G , Mc Kay, Fernando , Silvestri, Luciano C , Hill, Martin P , Weyl, Philip S R , Hinz, Hariet L , Brodeur, Jacques , Vitorino, Marcello Diniz , Barratt, Barbara I P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/418025 , vital:71502 , xlink:href="https://doi.org/10.1007/s10526-023-10177-7"
  • Description: The Nagoya Protocol on Access and Benefit Sharing (ABS) was implemented to further develop the third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Interpretation of this agreement is wide-ranging and there is concern that if ABS measures are poorly implemented biological control and the resultant public good will be greatly impeded. The ethos of multilateral use and exchange of genetic resources used in classical biological control will be particularly affected. In the spirit of the fair and equitable sharing of benefits arising out of the utilization of genetic resources, we propose a simple practical solution in the form of an international agreement on the use and exchange of classical biological control genetic resources.
  • Full Text:
  • Date Issued: 2023
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