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SoTL: A mechanism for understanding and finding solutions to teaching and learning challenges

  • Authors: Vorster, Jo-Anne E
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/445727 , vital:74419 , https://doi.org/10.36615/sotls.v4i2.149
  • Description: The paper argues that the Scholarship of Teaching and Learning (SoTL) is a necessary strategy for mitigating the many teaching and learning challenges in South African higher education that prevent a large proportion of students from achieving academic success. Research suggests that well-structured and coordinated educational practices that are valued and supported by institutions are crucial for student success. While there exists a very useful body of scholarship on teaching and learning in higher education in South Africa, the persistently high levels of student failure and dropout across the system points to the need for more research into teaching and learning dilemmas in diverse institutional, disciplinary and classroom contexts. I argue that if more academics are to conduct SoTL, it has to be valued and supported by institutions and academic leaders. Even though more SoTL is needed to contribute to solving the many pedagogic dilemmas South African academics encounter, it is counter-productive to expect all academics to conduct SoTL. Rigorous SoTL requires immersion in educational ideas, concepts, theories and research processes. Many academics may not have the time or inclination to work in the area of SoTL, but I suggest that all must be scholarly teachers of their disciplines.
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  • Date Issued: 2020

South Africa’s mohair value chain: institutional framework, governance and the perceptions of management and labour

  • Authors: Heald, Arisa Oka
  • Date: 2020
  • Subjects: Management -- Employee participation , Management -- Employee participation -- South Africa , Agriculture -- South Africa -- History , Mohair industry -- South Africa , Mohair industry -- South Africa -- Employees
  • Language: English
  • Type: text , Thesis , Masters , MSocSci
  • Identifier: http://hdl.handle.net/10962/164669 , vital:41153
  • Description: The primary objective of this research is to understand the ways in which the (working and living) conditions confronting employers and employees on mohair farms are the complex outcome of their position in the global mohair value chain, the nature of the labour process, and the ‘contours of voice’ (i.e., how and why employees voice). These three bodies of literature represent different levels of analysis: at the broadest level, the political economy of the mohair value chain is explained by drawing on the chain literature. This literature has been supplemented, at the level of the production process, by deploying the concepts of labour process theory (LPT), which focus on the control of work processes by management as well as workers’responses to this control. These responses were analysed by incorporating insights from the burgeoning research on employee voice (EV) in an effort to understand the practical ways in which workers on mohair farms articulate their needs and interests. The cross-collination of these three bodies of literature is, to my knowledge, a novel feature of this research on the mohair industry in South Africa, which, in turn, has itself been woefully under-researched. The research design consisted of a qualitative approach in which I used in-depth, semi-structured interviews and focus-group discussions as the primary sources of data collection. The secondary source of data was available publications and documents from the agriculture industry and mohair sector. A qualitative approach acknowledges and gives great insight and meaning into the research topic. Twenty participants were interviewed for my research: six from key organisations within the mohair industry, ten farmers, two mohair farm workers and two mohair shearers. The main findings of the research include the following: first, institutions in South Africa’s mohair industry not only determine (in part) the structure of the mohair value chain but also play a vital role in governing the chain. Each institution and actor plays a significant role in adding value to the mohair product that leads to economic upgrading. Second, understanding the actions of farmers (as employers) by drawing on LPT allows me to show how the systemic pressures of capitalist accumulation compel employers to continuously enhance their control over production – and, by extension, over workers – who, in turn, resist and/or accommodate to these impositions by management. Lastly, the research shows that employee voice at the farm level is complex and contested – not surprisingly, given South Africa’s troubled history – yet, it is increasingly exercised by farm workers and accepted by mohair farmers as a necessary and inescapable means of resolving issues that arise in the employment relationship at the workplace and remaining competitive in a global market.
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  • Date Issued: 2020

South Africa’s student movement: A Rhodes perspective

  • Authors: Knowles, Corinne
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/453535 , vital:75261 , ISBN 9781928232902 , https://jacana.co.za/product/from-ivory-towers-to-ebony-towers-transforming-humanities-curricula-in-south-africa-africa-and-african-american-studies/
  • Description: This edited volume is a significant academic achievement. The book offers a comparatively enriched account of debates in higher education transformation across South African, African, and African-American epistemic contexts. The text offers perspectives on how the humanities could be reformed in the quest to decolonise curriculum and free the higher education from Eurocentrism.” Aslam Fataar, Distinguished Professor, Stellenbosch University, South Africa “The book’s strength came from its diversity of countries, theories, and histories.
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  • Date Issued: 2020

Southern African HIV Clinicians Society guidelines for antiretroviral therapy in adults: 2020 update

  • Authors: David Stead
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/3281 , vital:43293 , https://doi.org/10.4102/sajhivmed.v21i1.1115
  • Description: What is new in the 2020 guidelines update? Key updates ÿ A recommendation for dolutegravir (DTG)-based therapies as the preferred first-line antiretroviral therapy (ART) option (section 11). ÿ Updated guidelines for second- and third-line ART regimens (section 13). ÿ New recommendations on the management of patients on DTG-based therapies who have an elevated viral load (section 12). ÿ A lowering of the threshold for virological failure from 1000 copies/mL to 50 copies/mL (section 8). ÿ A recommendation against routine cluster of differentiation 4 (CD4+) monitoring in patients who are clinically well once the CD4+ count is > 200 cells/μL (section 9). ÿ Updated recommendations for isoniazid preventive therapy (IPT) in human immunodeficiency virus (HIV)-positive patients (section 27). ÿ A recommendation for the use of low-dose prednisone as prophylaxis for paradoxical tuberculosis (TB) immune reconstitution inflammatory syndrome (IRIS) in TB/HIV co-infected patients commencing ART within 1 month of TB therapy (section 26).
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  • Date Issued: 2020

Spatio-temporal variation of the land surface parameters in Temperature, in King Williams Town, Eastern Cape Province, South Africa

  • Authors: Willie, Yanga Adrian
  • Date: 2020
  • Subjects: Environmental sciences
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10353/12106 , vital:39152
  • Description: The world is currently experiencing unprecedented urban growth. The influx of people into urban areas from rural areas is motivated by both economic and social factors such as increased employment opportunities. The latter is a result of, in part, industrialization, and the perceived higher standard of living that is often associated with access to better infrastructure. Surface Heat Island (SHI) is a phenomenon whereby urban areas experience higher surface temperatures than the surrounding rural areas. The presence of the SHI in urban areas has a negative impact not only on city dwellers, but also on the environment and the economy. The development of SHI is often associated with patterns of land use and land cover in urban areas. Numerous methods exist that can be used to study SHI’s. Literature suggests that Land Surface Temperature (LST), derived from satellite imagery, is a proven method that produces reliable results. The aim of this study was to evaluate the SHI in King Williams Town by studying the relationship between land surface temperatures, land cover and land cover indices. The derived indices are the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built up Index (NDBI). These indices were selected because they are representative of the land cover scheme used in the research study. This study was conducted in the King Williams town area between the years 1995 and 2018 the land surface temperature was derived from Landsat ETM + high thermal band data. The findings from this study provide an idea on the correlation between satellite derived land surface temperature and the land modification which occurred during the urbanization of King Williams Town during a 23 year period between1995 and 2018. The built up land category was the most influential in the development of high land surface temperature levels , vegetation had an opposite effect as a series of data sets illustrated that vegetated areas had a iv cooling effect on the surface. Water bodies in the study area had an insignificant effect on the Surface temperature levels while the grass lands weren’t as cooling as the vegetation but provided a cooling environment in the study area .The spatial distribution of areas of high surface temperature (hot spots) was discovered to be concentrated in the urban areas of the study area which is in the northwest region of the study area and correlates to the land cover and land cover indices associated with built up and artificial surfaces. The cooler areas or patches of land with lower values of land surface temperature were distributed on the outskirts of the study area away from the CBD and residential areas. This was the case because of the high concentration of vegetation and thicker grass lands in those regions.
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  • Date Issued: 2020

Species-specific plastic accumulation in the sediment and canopy of coastal vegetated habitats:

  • Authors: Cozzolino, Lorenzo , Nicastro, Katy R , Zardi, Gerardo I , de los Santos, Carmen B
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/149410 , vital:38848 , https://doi.org/10.1016/j.scitotenv.2020.138018
  • Description: Plastic waste has become ubiquitous in ecosystems worldwide. Few, recent studies report evidence of coastal vegetated habitats acting as sink for plastics, yet assessments have been completed either for macro or microplastics and focussing on just one type of vegetated habitat.
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  • Date Issued: 2020

Statutory mergers as contemplated in the Companies Act, 2008: the applicability of the corporate rules contained in section 44 of the Income Tax Act, 1962

  • Authors: Shama, Natalie Anne
  • Date: 2020
  • Subjects: South Africa. Companies Act, 2008 , South Africa. Income Tax Act, 1962 , Consolidation and merger of corporations -- South Africa , Corporation law -- South Africa
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/144767 , vital:38377
  • Description: The purpose of this research is to determine the extent to which a statutory merger in terms of the Companies Act, 2008, may be accommodated by the provisions of an amalgamation transaction in terms of section 44 of the Income Tax Act, 1962. The research method adopted is a legal interpretative research approach. South African company law underwent significant reform with the introduction of the Companies Act, 2008. One of the fundamental areas for reform was the need for a mechanism to appropriately accommodate a corporate merger, and thus, what is referred to as a statutory merger was introduced into South African company law. What is notable is that the statutory merger has been crafted to apply across a variety of circumstances that may arise in commerce, thus offering wide versatility. On the other hand, the tax relief afforded in terms of the corporate roll-over provisions in the Income Tax Act is designed to facilitate corporate transactions on a tax neutral basis, whilst balancing the concessions these measures introduce and the potential for tax avoidance. Consequently, the tax relief applicable to an amalgamation transaction will only apply within strictly prescribed parameters. The research shows an ongoing effort by National Treasury to amend the provisions of the amalgamation transaction to better accommodate a statutory merger, but highlights that there are nevertheless certain conflicting purposes (policy) for each piece of legislation. For these reasons, the focus and parameters of a statutory merger and amalgamation transaction do not align perfectly. The key areas of inconsistency identified in this research are threefold, namely (i) the creation of a new company as a consequence of a statutory merger is not accommodated in an amalgamation transaction; (ii) the process of compensating the shareholders of the amalgamated company in an amalgamation transaction is not clearly contemplated in the statutory merger provisions; and (iii) mergers between a company and its shareholder currently present numerous complexities from both a company law and taxation perspective. The research concludes that the flexibility afforded under the statutory merger is largely minimised for parties who wish to simultaneously enjoy the tax relief afforded under an amalgamation transaction.
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  • Date Issued: 2020

STIP1/HOP regulates the actin cytoskeleton through interactions with actin and changes in actin-binding proteins cofilin and profilin:

  • Authors: Beckley, Samantha Joy , Hunter, Morgan C , Kituyi, Sarah N , Wingate, Ianthe , Chakraborty, Abantika , Schwarz, Kelly , Makhubu, Matodzi P , Rousseau, Robert P , Ruck, Duncan K , de la Mare, Jo-Anne , Blatch, Gregory L , Edkins, Adrienne L
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/165373 , vital:41238 , https://doi.org/10.3390/ijms21093152
  • Description: Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.
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  • Date Issued: 2020

Strategies for rural housing provision in Nkobonkobo Village, Alice, Eastern Cape

  • Authors: Mnqandi, Nomgqibelo Beauty
  • Date: 2020
  • Subjects: Housing, Rural -- South Africa -- Alice Public welfare -- South Africa -- Alice
  • Language: English
  • Type: Thesis , Masters , MDS
  • Identifier: http://hdl.handle.net/10948/49692 , vital:41771
  • Description: South Africa’s history, pre- and post-democracy, has been designed by different laws which moulded the socio-economic conditions of rural communities in numerous ways. The introduction of democracy in the country created a platform for understanding different rights for many citizens; amongst those rights a right to shelter, proper sanitation, and clean water. The provision of housing by the three spheres of government, local, provincial, and national aimed at addressing these rights for all citizens of the country, which is a privilege for both urban and rural communities. Even though provision of houses for the rural poor was not the priority in the first administration of the democratic government, as time progressed, discussions and implementation of the policy on housing provision for rural communities became a strong political debate. The intensity on housing provision for rural houses as from 2010 became more resilient. The objectives of this study firstly viewed the botches of the Department of Human Settlement, Water and Sanitation and the Municipality to monitor and evaluate infrastructural challenges faced by rural communities who became beneficiaries of houses under Rural Development Programme (RDP). The issue of poor sanitation and access to clean water by rural poor even in the fourth and fifth administration was also a concern of the study. The socio-economic factors on the provision of houses for rural housing beneficiaries was also a major apprehension, and support services provided by the relevant stakeholders to rural housing beneficiaries was also a point for discussion. It is therefore imperative that the study evaluate and recommend strategies that can be put in place for improving housing provision for the rural poor and create sustainable human settlements. The Eastern Cape Province is one of the provinces that are battling with backlogs related to housing provision, high unemployment rates, low rural household incomes, and low levels of education more especially to older citizens, which can create a higher risk of crime more especially by the youth. This study, therefore, attempted to highlight cases of poor administration, since it its findings the issue of wasteful expenditure of people’s taxes when houses constructed for community beneficiaries are not occupied. The absence of these important amenities in any community, poor sanitation and a lack of water which creates food insecurities, because there is no agricultural practice, even at a subsistence level and health communities are in danger more especially women and children. In such cases, poverty becomes rife, and health-related issues tend to expand. Similarly, economic growth and social development becomes limited. This treatise was concerned with the strategies used in the provision of rural housing in South Africa, the Eastern Cape Province. The findings further identify that the legislation that was supposed to be employed by the Department of Human Settlement in the provision of rural housing was not considered as a priority, hence there were many flaws identified. The policies applied in other countries, internationally, were suggested to be used as a benchmark for improving housing provision strategies in rural Eastern Cape municipalities. Since the study had adopted a descriptive approach, meaning the use of secondary data, the issue of public participation in any designed development project in rural communities should be as an important aspect of rural development, The Batho Pele Principles as key instrumental legislation in the government should be taken into serious consideration always more especially the principle of consultation. Rigorous debates are also required to produce policies that are informed by evidence in order to build and produce a better future.
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  • Date Issued: 2020

Strategies for the facilitation of implementation of best practice guidelines in operating theatres at public hospitals

  • Authors: Owolabi, Olukemi Olufunmilayo
  • Date: 2020
  • Subjects: Operating rooms—Safety measures
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/46422 , vital:39594
  • Description: Best practice guidelines (BPGs) are the use of scientific evidence to direct patient care and guide clinical care to integrate best patient outcomes. The implementation of BPGs in operating theatre nursing improves patient safety and quality of care and enhances patient outcomes. Although BPGs are crucial, the implementation thereof is not well operationalised in clinical practice, especially in an area such as the operating theatres in public hospitals in the Nelson Mandela Bay Health District(NMHD)in the Eastern Cape Province. The study thus developed strategies that could be used to facilitate the implementation of best practice guidelines in the operating theatres at public hospitals in the NMBHD. Understanding registered nurses’ knowledge, attitudes, and practices (KAP) with regard to implementing BPGs in the operating theatre is important, as it will assist in the development of strategies to facilitate the implementation of BPGs.The study was conducted in three phases. Phase One comprised of a quantitative approach. Data collection was achieved by means of a self-administered questionnaire which was distributed to registered nurses in the operating theatres of public hospitals in the NMBHD. The purpose of the questionnaire was to establish their knowledge, attitude and practice with regard to best practice guidelines and the implementation thereof. Recommendations made by participants for strategies to facilitate the implementation of BPGs in operating theatres were also explored. Descriptive and inferential statistics were utilised to analyse and describe the data. Descriptive statistics were used to describe the profile of the sample, including the demographic data measures of central tendency, for example the mean and standard deviation (SD) and correlation techniques.Chi²analysis was performed to test for significance of the associations between the registered nurses’ demographic variables and their KAP. Data were categorised into three levels, namely lower (score < quartile 1 i.e. bottom 25%). Middle (quartile1 ≤ score ≤quartile i.e. in the middle 50%) and higher (score > quartile 3 i.e. top 25%).Findings from this research study revealed the limited knowledge, attitude and practice of OT nurses about BPGs. During Phase Two an integrative literature review approach was followed in order to identify the best available evidence with regard to the facilitation of the implementation of best practice guidelines in operating theatres. Lastly, Phase Three: strategies that could be used to facilitate the implementation of best practice guidelines in operating theatres were developed. The researcher developed the conceptual framework using the six elements of Dickoff, James and Weidenbach (1968:422). The conceptual framework informed the development of strategies. The strategies are a synthesis of the conclusions drawn from the research findings (phase one and two) and the conceptualization thereof. The strategies were reviewed by six-panel members. Each panel member was supplied with the format for evaluation of the strategies which was based on the criteria established by Chinn and Kramer (2018:156) the results of which included in chapter 7. The researcher ensured that the data obtained was valid and reliable, necessary to assist the researcher to produce quality research. Ethical considerations were maintained throughout. In general, the results of this thesis indicate that the developed strategies that could be used to facilitate the implementation of best practice guidelines, in operating theatres at public hospitals in the NMBHDare unique and could be implemented in theatres in public hospitals. The researcher succeeded in achieving the purpose for this study, because the strategies which are understandable, clear, simple, applicable and significant to operating theatre unit has been developed for use by operating theatre nurses, to facilitate the implementation of best practice guidelines in operating theatres at public hospitals in the NMBHD.
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  • Date Issued: 2020

Strategies to improve employee financial intelligence

  • Authors: Botha, Perine
  • Date: 2020
  • Subjects: Financial literacy
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10948/47486 , vital:40118
  • Description: South African employees are largely indebted, with the majority of their disposable income used to service debt. The potential causes of this problem include the levels of education of individuals, how investors perceive the political climate in the country, levels of disposable income and the spending habits of individuals. This study aims to assist organisations to improve employee financial intelligence by investigating what influences financial intelligence. To ascertain these influences, the respondents’ level of financial literacy is to be determined as well. Financial literacy is assessed by determining a respondents’ knowledge of numeracy, risk diversification, compound interest and inflation. Additional factors such as debt management, saving culture and access to digital information too have an impact on financial literacy. An empirical study, consisting of a questionnaire was conducted among employees of a state-owned enterprise (SOE) in the Eastern Cape Province of South Africa. These employees represent both the management and junior employee profiles. The study found that 75% of the respondents were not financially literate. Financial literacy rates globally are at 51%, however, in a major emerging economy such as South Africa, the rate is between 48% and 51%. The results of the study however indicate that it is much lower than the global average as well as for that of similar developing countries. The results of the study indicate that age, gender, job grade, level of education, access to digital information, a savings culture, budgeting and debt management do not significantly influence financial literacy in the context of SouthAfrica.The research indicates that the respondents are, however, willing to learn and be educated to increase their financial knowledge and awareness. Possible strategies which could assist in improving levels of financial intelligence are:•Financial literacy courses offered by employers;•Research undertaken by employees themselves could increase their financial literacy; Employee wellness programmes, such as debt counselling, could improve the financial literacy of employees;•Completion of online courses would improve the employees’ level of financial literacy;•Budgeting and money management courses;•Financial advisors to be appointed by employers;•Debt counselling of employees.
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  • Date Issued: 2020

String diagrams for modelling functional programming

  • Authors: Motara, Yusuf, M
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/429022 , vital:72554 , https://ieeexplore.ieee.org/abstract/document/9334072
  • Description: It is currently impossible to model functional programs in the same way that UML is used to model object-oriented programs: no analogous graphical notation exists. Unlike object-oriented programs, however, functional programming is built on a solid mathematical basis and it may be possible to adapt graphical notation from the mathematical domain for such modelling. This work examines string diagrams as a way to model certain functional abstractions. A proposed notation is demonstrated in the contexts of equational reasoning and descriptive modelling, and is found to be suitable for both.
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  • Date Issued: 2020

Structural Characterization of Carbonic Anhydrase VIII and Effects of Missense Single Nucleotide Variations to Protein Structure and Function:

  • Authors: Sanyanga, Taremekedzwa Allan , Tastan Bishop, Özlem
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/149670 , vital:38873 , https://doi.org/10.3390/ijms21082764
  • Description: Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues.
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  • Date Issued: 2020

Structure and interaction studies of beta-amyloid in the search for new lead compounds for the treatment of Alzheimer’s disease

  • Authors: Mtini, Onke
  • Date: 2020
  • Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Amyloid beta-protein , Oxidative stress , Protein binding , South African Natural Compounds Database
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/167574 , vital:41493
  • Description: Alzheimer’s disease (AD) is the most devastating neurodegenerative disorder that effects the aging population worldwide. In this study three hypotheses of AD are explored, the β-amyloid cascade hypothesis, the β-amyloid metal binding hypothesis and the oxidative stress hypothesis are explored. In the first case compounds from the South African Natural Compounds Database (SANCDB) are docked to models of β-amyloid fibrils and the properties of these fibrils under pulling simulations are compared to a known small molecule disruptor of β-amyloid, wgx-50. In these simulations SANCDB compounds are identified that disrupt β-amyloid in a similar manner to wgx-50. In these simulations the disruption to the free energy of binding of chains to the fibrils is quantified. For metal binding and oxidative stress hypotheses, problems in simulation arise due to only fragments of β-amyloid being present in the Research Collaboratory for Structural Bioinformatics protein data bank (RCSB PDB), as determined from NMR experiments. In this work, β-amyloid is set up under periodic boundary conditions to simulate a fibril under reasonable computational time. Within these periodic boundary conditions, β-amyloid has been solvated in copper and zinc rich environments and diffusion of these metals around the fibrils has been explored. The localization of these metals (in simulation only using van der Waal’s and electrostatic terms) around the fibril has led us to explore other possible metal binding sites. Metal bound to the infinite fibril has been optimized at the QM/MM level and some of the reactive oxygen species in the presence of the fibril are quantified.
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  • Date Issued: 2020

Study of Star-Forming Regions in the Peculiar Galaxies NGC 660, NGC 1512, NGC 4395, and NGC 4618:

  • Authors: Smirnova, K I , Wiebe, D S , Moiseev, A V , Jozsa, G I G
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/160456 , vital:40447 , https://0-doi.org.wam.seals.ac.za/10.1134/S199034132003013X
  • Description: The star-forming regions (SFRs) in the peculiar galaxies NGC 660, NGC 1512, NGC 4395 and NGC 4618 are studied. The relationships between such characteristics of star forming regions as UV, near- and far-IR fluxes, as well as in the Hα and HI lines, surface brightness in these ranges, and the scatter of the radial velocities of ionized and neutral hydrogen are considered. It is shown that in all the galaxies considered, the IR fluxes from SFRs are less than in the “normal” galaxies, but for different reasons: in the galaxies with signs of recent interaction NGC 660 and NGC 1512, this is due to the low surface brightness of SFRs; in the lopsided galaxies NGC 4395 and NGC 4618, the low brightness of SFRs in the infrared range is due to their compact size. These differences indicate that the star formation process depends not only on the morphological type of a galaxy, but also on many other factors.
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  • Date Issued: 2020

Substituent effect on the photophysical and nonlinear optical characteristics of Si phthalocyanine–Detonated nanodiamond conjugated systems in solution

  • Authors: Matshitse, Refilwe , Nyokong, Tebello
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/186293 , vital:44482 , xlink:href="https://doi.org/10.1016/j.ica.2020.119447"
  • Description: This work reports on the photophysical, nonlinear absorption and optical limiting properties of detonation nanodiamonds (DNDs)-silicon phthalocyanine nanoconjugate systems. Si(IV) hydroxide phthalocyanines employed are: 2,9(10),16(17),23(24)-tetrakis-(4-pyridyloxy) phthalocyaninato (Si(OH)2TPPc), 2,9(10),16(17),23(24)-tetrakis-(4-tert-butyl) phthalocyanato (Si(OH)2TBPc) and phthalocyanato(Si(OH)2Pc). Pcs were covalently linked to nanondiamonds and investigated using 532 nm laser excitation at 7 ns pulses for their optical limiting properties. Si(OH)2TBPc and Si(OH)2Pc gave larger triplet quantum yields when linked to DNDs, while the value decreased for Si(OH)2TPPc in the presence of DNDs due to aggregation. However all Pcs showed enhanced nonlinear optical properties in the presence of DNDs. DNDs-Si(OH)2TPPc and DNDs-Si (OH)2TBPc gave the highest imaginary third-order susceptibility (Im[X(3)]) and hyperpolarizability (γ) at 5.19 × 10−8 and 3.85 × 10−8 esu and 2.66 × 10−27 and 1.97 × 10−27 esu, respectively. DNDs-Si(OH)2TBPc nanoconjugates showed lowest limiting threshold (Ilim) value of 0.01 J.cm−2 relative to 0.09 for DNDs-Si (OH)2TPPc.
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  • Date Issued: 2020

Susceptibility of Staphylococcus aureus to porphyrin-silver nanoparticle mediated photodynamic antimicrobial chemotherapy

  • Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Ovim, James , Amuhaya, Edith K , Nyokong, Tebello
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/186262 , vital:44479 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117158"
  • Description: Photodynamic antimicrobial chemotherapy (PACT) is employed against multi drug resistant Staphylococcus aureus using porphyrins combined with silver nanoparticles to bring about a combined photodynamic effect. We employ Zn-meso-5,10,15,20-tetra(4-pyridyl) (1), Zn-meso-5,10,15,20-tetrathienyl (2), and Zn-meso-5-(4- hydroxyphenyl)- 10,15,20-tris(2-thienyl)(3) porphyrins and their self-assembled conjugates with silver nanoparticles for PACT against Staphylococcus aureus. Complex 3 with nanoparticles was found to perform better resulting in 0% bacterial viability at 60 min.
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  • Date Issued: 2020

Sustainable conflict resolution through community based Water, Sanitation and Hygiene (WASH) Planning in fragile and conflict situations: the case of Somalia

  • Authors: Mafuta, Wonder , Zuwarimwe, Jethro , Kamuzhanje, Joseph , Mwale, Marizvikuru , Chipaike, Ronald
  • Date: 2020
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150241 , vital:38952 , https://0-doi.org.wam.seals.ac.za/10.1177/0021909620928104
  • Description: The study examines the nature of disputes, which are prevalent in water, sanitation and hygiene (WASH) programming and suggests possible conflict management and resolution mechanisms. An online web-based survey, hosted on the popular Survey Monkey platform, was conducted through the Somalia WASH Cluster to 40 ‘active’ member organisations. A response rate of 73% was achieved. Thematic analysis was conducted using NVivo 12. The type of conflicts identified are as follows: visible versus non-visible benefits, emergency versus development focus, the young and the old, insiders versus outsiders, local versus donor priorities and men versus women. The article goes on to suggest possible conflict resolution mechanisms, which include: planning together with communities, continuum programming, setting up early warning systems, harmonisation of institutions managing WASH resources and the development of localised Memorandums of Understanding. It is recommended that the complexities of conflict and fragility require different approaches. The approaches would apply to both relief and developmental WASH programming.
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  • Date Issued: 2020

Symmetry and asymmetry in electrocatalysis: enhancing the electrocatalytic activity of phthalocyanines through synergy with doped graphene quantum dots

  • Authors: Nkhahle, Reitumetse Precious
  • Date: 2020
  • Subjects: Phthalocyanines , Quantum dots , Graphene
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/117585 , vital:34529
  • Description: An exploration on the enhancement of the electrocatalytic activity of phthalocyanines (Pcs) through coupling with a series of graphene quantum dots (GQDs) is undertaken. The preliminary studies using symmetrical Pcs, a cobalt and an iron chloride tetra substituted diethylaminophenoxy Pc (complexes 1 and 2), for the electro-oxidation of nitrite revealed through the various sequential modifications that doped GQDs fare better than their pristine counterparts with respect to improving the electrocatalytic behaviour of Pcs, in particular, the nitrogen-doped GQDs (NGQDs). Following up on this, a series of asymmetric Pc complexes; 2,9,16-tris-(4-tert-butylphenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (3), 2,9,16-tris-(4-tert-butylphenoxy) mono aminophenoxy phthalocyanato cobalt (II) (4), 2,9,16-tris-(3-diethylamino)phenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (5) and 2,9,16-tris-(3-diethylamino)phenoxy) mono aminophenoxy phthalocyanato cobalt (II) (6) was prepared in which push-pull systems were compared to other asymmetric complexes that lack this effect towards the electrocatalytic sensing of hydrazine. All asymmetric complexes (3-6) were π-stacked to the NGQDs while those with an NH2 group (4 and 6), were also covalently linked to the NGQDs. These complexes and their corresponding conjugates were characterized accordingly and applied as electrocatalysts in the oxidation of hydrazine. The electrochemical studies revealed that π π stacking yields better responses (higher sensitivities and lower limits of detection) than covalent linking because there are less forces acting on the graphene network. Covalent linking introduces both tensile and compressive forces which in turn results in an increase in the ID/IG ratio and that is unfavourable for electrocatalysis. In comparing the electrodes composed of the π-stacked conjugates to those altered through sequential modifications, despite the conditions not being the same, it can be inferred that the magnitude of the electrostatic forces between the Pcs and the GQDs also plays a significant role in electrocatalysis. The π-stacked conjugates, owing to the manner in which they were prepared, have stronger electrostatic forces acting between the Pc and GQDs hence they were able to elicit a better electrochemical response than the sequentially modified electrodes. In addition to that, it appears that asymmetric Pcs are better electrocatalysts in comparison to the symmetric Pcs.
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  • Date Issued: 2020

Synergistic effects of temperature and plant quality, on development time, size and lipid in Eccritotarsus eichhorniae

  • Authors: Ismail, Mohannad , Brooks, Margot , Van Baaren, Joan , Albittar, Loulou
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426078 , vital:72312 , xlink:href="https://doi.org/10.1111/jen.12841"
  • Description: Body size is an important biotic factor in evolutionary ecology, since it affects all aspects of insect physiology, life history and, consequently, fitness in ectothermic insects and how species adapt with their environment. It has been linked to tem-perature, with lower temperatures resulting in larger size. In this study, we tested the combined impact of temperature and plant quality on the body size, and de-velopment time from egg to adult of Eccritotarsus eichhorniae (Hemiptera: Miridae), an herbivorous insect used as a biological control agent against the invasive aquatic weed, water hyacinth Eichhornia crassipes (Pontederiaceae). We quantified insect size in individuals exposed to three temperatures (20, 25 and 30°C) combined with three qualities of host plant (high, medium and low) by calculating development time and measuring four traits: tibia length, forewing length, dry body mass and lipid con-tent, and we also determined the wing loading index. The development time, dry body mass and lipid content decreased linearly with increasing temperature and de-creasing plant quality. The decrease in size was the greatest when high temperature interacted with low plant quality. Smaller individuals had proportionately less lipid content. Wing loading decreased significantly with lower quality of host plant, result-ing in individuals likely to have theoretically higher flight ability. The results support the temperature-size rule (TSR) and that plant quality could influence the relationship between development time and the TSR. Results also provide novel evidence for a possible food quality-size rule for both sexes.
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  • Date Issued: 2020
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