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Changing curriculum and teaching practice A practical theory for academic staff development

- Clarence, Sherran, van Heerden, Martina

Authors: Clarence, Sherran , van Heerden, Martina
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , book chapter
Identifier: http://hdl.handle.net/10962/445770 , vital:74428 , ISBN 9781003028215 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781003028215-9/changing-curriculum-teaching-practice-sherran-clarence-martina-van-heerden
Description: An underdeveloped aspect of academic staff development research in higher education is using theory to help academic lecturers to understand and inform their practices, so as to better enable student development and learning. This chapter illustrates how a theorized way of talking about teaching and learning, specifically using the LCT dimension of Semantics, both semantic waves and the semantic plane, may create exciting and productive conversations with academic lecturers. Using two ‘vignettes’ drawn from English Studies and Political Studies, the chapter illustrates how teaching practice and curriculum design can be enhanced by using LCT in academic staff development work, and by extension in curriculum design, teaching and assessment practice.
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Date Issued: 2020

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Characterisation of plasmodial transketolases and identification of potential inhibitors: an in silico study

- Boateng, Rita A, Tastan Bishop, Özlem, Musyoka, Thommas M

Authors: Boateng, Rita A , Tastan Bishop, Özlem , Musyoka, Thommas M
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429372 , vital:72605 , xlink:href="https://doi.org/10.1186/s12936-020-03512-1"
Description: Plasmodial transketolase (PTKT) enzyme is one of the novel pharmacological targets being explored as potential anti-malarial drug target due to its functional role and low sequence identity to the human enzyme. Despite this, features contributing to such have not been exploited for anti-malarial drug design. Additionally, there are no anti-malarial drugs targeting PTKTs whereas the broad activity of these inhibitors against PTKTs from other Plasmodium spp. is yet to be reported. This study characterises different PTKTs [Plasmodium falciparum (PfTKT), Plasmodium vivax (PvTKT), Plasmodium ovale (PoTKT), Plasmodium malariae (PmTKT) and Plasmodium knowlesi (PkTKT) and the human homolog (HsTKT)] to identify key sequence and structural based differences as well as the identification of selective potential inhibitors against PTKTs.
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Date Issued: 2020

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Charlie Hebdo as a critical event in a secondary school: Muslim students’ complex positioning in relation to the attack

- Tize, Carola, Berckmoes, Lidewyde, de Jong, Joop, Reis, Ria

Authors: Tize, Carola , Berckmoes, Lidewyde , de Jong, Joop , Reis, Ria
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/156400 , vital:39986 , DOI: 10.1177/1363461520903814
Description: This paper examines responses to the 2015 terror attack on Charlie Hebdo, a French satirical magazine, amongst students in a secondary school in Berlin-Neukölln, Germany. The Charlie Hebdo attack occurred in the final weeks of a 19-month ethnographic study in the community. By analyzing the responses in the school to this critical event, we identify what is at stake for Muslim students.
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Date Issued: 2020

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Chasing Eden: Margaret Atwood’s MaddAddam trilogy and the value of reading in a technological age

- Bosman, Zoë June

Authors: Bosman, Zoë June
Date: 2020
Subjects: Atwood, Margaret, 1939- MaddAddam trilogy , Speculative fiction -- History and criticism , Capitalism in literature , Dystopias in literature , Science fiction -- History and criticism , Technology in literature
Language: English
Type: Thesis , Masters , MA
Identifier: http://hdl.handle.net/10962/145796 , vital:38467
Description: This thesis is focussed on Margaret Atwood’s MaddAddam trilogy: Oryx and Crake (2003) The Year of the Flood (2009) and MaddAddam (2013). Detailing Atwood’s own specifications as to why these texts should be categorised as works of speculative fiction, the thesis examines how this literary genre, and Atwood’s MaddAddam trilogy in particular, is uniquely capable of encouraging readers to interrogate critically the socio-economic, environmental, and ethical problems to which she, and the contemporary reader, bear witness in the present technological age. With reference to Atwood’s essays and critical writings, Darko Suvin’s Metamorphoses of Science Fiction, and Wolfgang Iser’s The Act of Reading, this project explores the value of reading speculative fiction and details how Atwood has constructed the fictional, yet plausible, possible future world of her trilogy by extrapolating our current scientific capabilities, environmental challenges, and political configurations to their logical conclusions. It explores the close relationship that exists between the near-future world of Atwood’s texts and the contemporary context from which she has drawn her subject matter, and argues that the trilogy demonstrates graphically the long-term consequences of capitalism, sustainability, and the doctrine of human exceptionalism, which this project, following Yuval Harari, defines as orthodox guiding narratives: fictions that humanity has created, and which structure our perception of reality and guide our behaviour. The project maintains that Atwood’s trilogy presents the reader with a hypothetical future that looks towards and beyond the end of contemporary technological society in order to urge her reader to imagine, and actualize, alternatives to the scenarios that these texts depict. The most significant question Atwood’s texts ask is whether contemporary technological society is willing and able to transform in order to avert the ecological apocalypse that is the logical conclusion to the Anthropocene?
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Date Issued: 2020

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Chemical archeoceanography:

- Albarede, Francis, Thibon, Fanny, Blichert-Toft, Janne, Tsikos, Harilaos

Authors: Albarede, Francis , Thibon, Fanny , Blichert-Toft, Janne , Tsikos, Harilaos
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/149065 , vital:38801 , https://doi.org/10.1016/j.chemgeo.2020.119625
Description: Elemental fluxes to the ocean are expected to increase with the surface area of continental exposure to weathering and atmospheric PCO2. The record of phosphorus in sediments, which has no notable source within the ocean, and the radiogenic strontium isotopes in Archean carbonates indicate that, prior to the Great Oxidation Event (GOE), subaerial expanses represented only about 20% of the modern continental surface area, i.e. 7% of the surface of the Earth. Because these simple first-order observations, in contrast to the low oxygen content of the pre-GOE atmosphere, have so far received only little attention in the appraisal of the marine chemistry of the early Earth, a reassessment of the chemistry of the pre-GOE ocean is warranted. Here we discuss some of the geochemical cycles of the Archean world, including protons, alkalinity, electrons, and other electrolytes, and attempt to build a first conceptual framework for Chemical Archeoceanography.
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Date Issued: 2020

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Chemical constituents, antioxidant and cytotoxicity properties of Leonotis leonurus used in the folklore management of neurological disorders in the Eastern Cape, South Africa

- Tonisi, Sipho, Okaiyeto, Kunle, Hoppe, Heinrich C, Mabinya, Leonard V, Nwodo, Uchechukwu U, Okoh, Anthony I

Authors: Tonisi, Sipho , Okaiyeto, Kunle , Hoppe, Heinrich C , Mabinya, Leonard V , Nwodo, Uchechukwu U , Okoh, Anthony I
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429384 , vital:72606 , xlink:href="https://doi.org/10.1007/s13205-020-2126-5"
Description: In the present study, we evaluated the phytochemical compounds and antioxidant properties of chloroform, ethanol and acetone extracts for leaves and flowers of Leonutus leonurus (L. leonurus) alongside with their cytotoxic effects on human cervical carcinoma (HeLa) cell lines. The phytochemical compounds present in the leaves and flowers of L. leonurus included; phenolics, flavonoids and alkaloids. Their radicals scavenging effects against 2, 2-diphenyl-1-picrylhydrazyl [DPPH] 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) [ABTS·+], hydrogen peroxide, nitric oxide as well as metal chelating activities showed dose-dependent activities. Gas chromatography-mass spectrometry (GCMS) analyses revealed the presence of important bioactive compounds, which are associated with antioxidant; and the extracts exhibited toxicity effect against HeLa cells. The findings from this study divulge extracts of L. leonurus as prospective sources of antioxidant and anticancer agents; and hence, further study on their neuroprotective potentials becomes imperative.
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Date Issued: 2020

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Child marriage as a hindrance to the realisation of child rights in Zimbabwe: consolidated approaches towards eradication

- Ndhlovu, Ntandokayise

Authors: Ndhlovu, Ntandokayise
Date: 2020
Subjects: Teenage marriage Children's rights
Language: English
Type: Thesis , Doctoral , LLD
Identifier: http://hdl.handle.net/10353/18359 , vital:42256
Description: Child marriage is defined as any marriage where one of the spouses is younger than 18 years old. A number of deep, complex, interrelated and interlinked factors are responsible for the practice in Zimbabwe and elsewhere. These include the weak enforcement of existing laws, legal contradictions, slow alignment of laws to the Constitution and international child rights, entrenched harmful religious and cultural practices, and acute poverty. It was at the fulcrum of this dissertation thus to examine the unfair limitations caused by child marriage, on the realisation and enjoyment of child rights in Zimbabwe. The United Nations International Children’s Emergency Fund reported an estimated 31 percent prevalence of the scourge in the country. These percentages translate to millions of children, and the numbers could be on the rise. Child marriage has intense consequences for the realisation and enjoyment of rights by many children in Zimbabwe. Of note, child marriage ends childhoods. It impairs the children’s right to education, minimises their economic opportunities and fair chances in life, and increases their vulnerability to domestic violence, marital rape and sexually transmitted diseases. The grave ramifications of child marriage, in terms of the realisation of child rights have led to a number of international, regional and national efforts to curb this scourge. However, owing to an array of multifaceted and complex causes, the practice remains highly prevalent in Zimbabwe. After decades of side-lining, child rights in Zimbabwe, have finally gained constitutional protection under the 2013 Constitution. While the comprehensive protection of child rights as justiciable rights is an acceptable standard, a plethora of practices such as child marriage are a practical and real threat to the realisation of these rights. Therefore, it is incumbent upon Zimbabwe to ensure that child rights as stipulated in the Constitution are respected, promoted, protected and fulfilled. The elimination of child marriage is a daunting yet possible task. Through desktop based qualitative research, this dissertation ascertained the main drivers of the practice in the country, and its impact on the realisation of fundamental child rights in Zimbabwe. The study further explored the contribution, as well as the insufficiencies of International and African Human Rights systems, to the protection of children from child marriage. It also assesses the prospects and challenges of the existing domestic (legislative and constitutional norms) in protecting child rights in the Southern African country. The impetus behind this iii examination is to recommend a comprehensive and holistic effort to curb child marriage and suggest a consolidated legal and non-legal approach to end it
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Date Issued: 2020

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Chirema Chine Mazano Chinotamba Chakazendama Madziro

- Mapondera, Wallen

Authors: Mapondera, Wallen
Date: 2020
Subjects: Art, Zimbabwean , Art -- Economic aspects -- Zimbabwe , Artists -- Zimbabwe , Takadiwa, Moffet , Nyandoro, Gareth , Clottey, Serge Attiku , Mapondera, Wallen -- Exhibitions
Language: English
Type: text , Thesis , Masters , MFA
Identifier: http://hdl.handle.net/10962/147457 , vital:38638
Description: This mini-thesis has developed as a practice-based supporting document to the exhibition Chirema Chine Mazano Chinotamba Chakazendama Madziro. The exhibition responds to how people become innovative in finding alternative means of survival and staying relevant in an economically depressed country. Zimbabwe is often the first country that comes to mind when people talk about hyperinflation; the situation was and still is intolerable, but somehow its citizens find means to pull through. Unemployment and poverty are the main causes of physical and mental problems for an individual. With this thesis, I highlight the innovations employed by Zimbabweans as a way of keeping themselves busy. I approach this through analysing the Zimbabwean general public’s creative reactions, and by tracing Zimbabwean visual artists’ use of found objects as a reaction to the country’s economic hardships. As people have been pushed to find alternative ways of survival, Zimbabwean artists in particular also shifted from using conventional art materials due to their unavailability. They began to redefine what art material is by employing objects in their artworks that previously had a non-art function. As such, there is a growing need to recognise, classify and document the shifts and establish platforms to generate growth of these innovations. In this minithesis I discuss my own practice, and I analyse the works of Moffat Takadiwa, Gareth Nyandoro and Serge Attiku Clottey.
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Date Issued: 2020

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Choreographies of protest performance as recruitment to activism and the movement of perception during the 2015 re-emergence of student activism at Rhodes University

- Qoza, Phiwokazi

Authors: Qoza, Phiwokazi
Date: 2020
Subjects: College students -- Political activity -- South Africa , Student protesters -- South Africa , Student movements -- South Africa , Higher education and state -- South Africa , Performance art -- Political aspects -- South Africa , Protest songs -- South Africa
Language: English
Type: text , Thesis , Masters , MA
Identifier: http://hdl.handle.net/10962/141692 , vital:37997
Description: It has been argued that individuals participate in activism due to an identification with the preferences and interests of an emerging group of actors or in solidarity with a pre-existing network that has resorted to a number of protest repertoires in order to make claims or demands. Additionally, an emerging instance of protest is often linked to an image of previous protest events through the employment of a combination of master frames which function as discursive articulation of the encounter in familiar terms, creating a frame resonance which recruits adherents and constituents. To understand why some bystanders to protest transcended to actors in protest and the development of frames within a protest cycle, a performance ethnography is employed to observe and analyse choreographies of protest which took place at an institution of higher education in South Africa during the 2015 re-emergence of wide-spread student activism. It is found that in encountering an atmosphere of protest there emerged a relation of feeling, referred to as “feeling the vibe or atmosphere”, which those who became protest performers resolved in ways which increased their capacity to act in favour of co-constituting that atmosphere. During the encounter between the bystander body and the atmosphere of protest, non-linear somatic communication, characterised by active and passive gestures and postures, occurred through which protest performers developed contact and connection with other bodies as a result of the displacement of space. This thesis suggests that participation in activism can be about going with the flow of movement in an uncertain and ambiguous moment and is not limited to an identification with the pre-existing organization of preferences and interests as a frame of resonance emerges to signify somatic communication which differentiated bodies in the duration of protest performance. Therefore, this thesis uses the theory of affect to situate student activism in-between the politics of performance and the performance of politics whereupon the rhythm of song creates an opening for the kinaesthetic to create form from spontaneous movement of the body as an event of the movement of perception and the perception of movement.
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Date Issued: 2020

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Climate modelling suggests a review of the legal status of Brazilian pepper Schinus terebinthifolia in South Africa is required:

- Martin, Grant D, Magengelele, Nwabisa L, Paterson, Iain D, Sutton, Guy F

Authors: Martin, Grant D , Magengelele, Nwabisa L , Paterson, Iain D , Sutton, Guy F
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/148606 , vital:38754 , https://doi.org/10.1016/j.sajb.2020.04.019
Description: Brazilian pepper (Schinus terebinthifolia) is a tree native to subtropical South America that was introduced into South Africa in the early 1900s as an ornamental plant. The tree has since escaped cultivation and has invaded ruderal and pristine habitats along the eastern coast of South Africa. Brazilian Pepper is also one of the most problematic invasive alien plants in Florida, USA. We modelled the climatically suitable area for this species in South Africa using MaxEnt, with five distinct datasets: incorporating both the native and the invaded range of the species, as well as different backgrounds.
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Date Issued: 2020

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Climate responsive innovation within the agricultural curriculum and learning system

- Van Staden, Wilma

Authors: Van Staden, Wilma
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/389744 , vital:68479 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/186598"
Description: The purpose of this paper is to outline the climate responsive innovation process within the agricultural innovation system of the North West Province, South Africa. The focus was on the embedded curriculum and learning activity system and its responses to social-ecological and earth system changes influenced by climate change. It outlines the barriers and processes hampering curriculum and learning innovations towards climate-smart responsiveness, and also examines the processes required to initiate micro and macro innovations. This paper focusses on how actors within the system can initiate curriculum innovation and climate responsiveness through micro innovations when supported and how this can lead to macro innovations. The system experienced various barriers during the innovation process and overcame many challenges during the journey towards climate-smart responsiveness through the identification of contradictions within the system, developing tools to assist in the transitioning process and expansion in the social-spatial dimension by establishing a learning network within the surrounding communities. The research indicated that the catalysing of the curriculum and learning system required specific tools, time and the understanding of the importance of micro-level innovation.
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Date Issued: 2020

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Clinically established biodegradable long acting injectables

- Nkanga, Christian I, Fisch, Andreas, Rad-Malkshahi, Mazda, Romic, Marieta D, Kittel, Birgit, Ullrich, Thomas, Wang, Jing, Krause, Rui W M, Adler, Sabine, Lammers, Twan, Hennink, Wim E, Ramazani, Farshad

Authors: Nkanga, Christian I , Fisch, Andreas , Rad-Malkshahi, Mazda , Romic, Marieta D , Kittel, Birgit , Ullrich, Thomas , Wang, Jing , Krause, Rui W M , Adler, Sabine , Lammers, Twan , Hennink, Wim E , Ramazani, Farshad
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/193386 , vital:45327 , xlink:href="https://doi.org/10.1016/j.addr.2020.11.008"
Description: Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.
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Date Issued: 2020

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Cloud computing for competitive advantage: A case of rural SMEs in the Eastern Cape Province of South Africa

- Mpongwana , Mbongo Mhlanga

Authors: Mpongwana , Mbongo Mhlanga
Date: 2020
Subjects: Cloud computing -- Economic aspects , Business enterprises -- South Africa -- Eastern Cape
Language: English
Type: Thesis , Masters , MBA
Identifier: http://hdl.handle.net/10948/50415 , vital:42166
Description: The emergence of new ICTs over the past decades has had a substantial impact on commerce and to societies in general. However, the high costs and the relevant skills and expertise that are associated with the implementation and maintenance of the latest ICTs impedes SMEs from taking full advantage of their use. The introduction and adoption of cloud computing has addressed some of these challenges for SMEs. Despite this, SMEs in rural South Africa have not fully adopted or realized the advantages of cloud computing, which could be owing to a number of factors.The aim of this study was to explore how rural SMEs in the Eastern Cape Province of South Africa can leverage on the capabilities of cloud computing for competitive advantage. The study adopted an interpretivist, quantitative approach to identifying the enablers and barriers of cloud computing adoption. The research population was defined as all the SMEs that operate outside of Buffalo City and Nelson Mandela Bay Metropolitan Municipalities. Convenience and snowball sampling techniques were used as non-probability sampling methods. Data was collected from the participants using a structured self-administered online questionnaire. The Technology-Organization-Environment framework was used as a basis in formulating the research theoretical framework, focusing on technological, organizational and environmental elements that could potentially influence adoption of cloud computing by rural SMEs. Microsoft Power BI was used to present demographic information as well as descriptive statistics for the factors included in the proposed research model. IBM SPSS 22 was used for correlation and linear regression analysis. The review of related literature revealed that access to markets, access to finance, inadequate public infrastructure and lack of skilled resources are some of the major challenges that rural SMEs face. This study found seven of the statistically examined factors to be significant predictors of cloud adoption by rural Eastern Cape SMEs. These are market demand, use of online-based marketing, having formal business plans, reliable electricity, awareness of SaaS, use of basic Internet-based services such as email and websites as well as Internet costs.
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Date Issued: 2020

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Co-loading of isoniazid-grafted phthalocyanine-in-cyclodextrin and rifampicin in crude soybean lecithin liposomes: Formulation, spectroscopic and biological characterization

- Nkanga, Christian I, Roth, Michael, Walker, Roderick B, Noundou, Xavier S, Krause, Rui W M

Authors: Nkanga, Christian I , Roth, Michael , Walker, Roderick B , Noundou, Xavier S , Krause, Rui W M
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/183481 , vital:43999 , xlink:href="https://doi.org/10.1166/jbn.2020.2880"
Description: An inclusion complex of isoniazid-grafted phthalocyanine with gamma-cyclodextrin (Complex) was co-encapsulated with rifampicin (RIF) in crude soybean lecithin liposomes using a heating method. The encapsulation efficiency (%EE) of the Complex-RIF co-loaded liposomes (Rif-Complex-Lips) was determined using UV-Vis spectrophotometry. Rif-Complex-Lips formulations were evaluated using dynamic light scattering, transmission electron microscopy (TEM), 1H-NMR, absorption and emission spectroscopy. Dialysis was used for drug release study in two different media, pH 6.4 and 7.4. HeLa cells were used to assess potential cytotoxicity, and the uptake by lung fibroblasts and epithelial cells was investigated using fluorescence microscopy. The particle size and Zeta potential of Rif-Complex-Lips were approximately 594 nm and –50 mV. Spectroscopic analyses demonstrated molecular distribution of the cargo within the lipid core, and encapsulation efficiency of 58% for Complex and 86% for RIF. TEM analysis unveiled the existence of spherical nanoparticles in our samples, indicating the presence of liposomes. Rif-Complex-Lips exhibited much higher release rates for both INH and RIF at pH 6.4 compared to those tested at pH 7.4. In addition, there was no cytotoxicity on HeLa cells, but remarkable Rif-Complex-Lips internalization by peripheral lung fibroblasts and epithelial cells. Hence, Rif-Complex-Lips are promising vehicles for intracellular delivery of antimicrobial drugs.
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Date Issued: 2020

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Coastal engineers embrace nature: characterizing the metamorphosis in hydraulic engineering in terms of Four Continua

- Slinger, Jill H, Vreugdenhil, Heleen S I

Authors: Slinger, Jill H , Vreugdenhil, Heleen S I
Date: 2020
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/163846 , vital:41076 , https://doi.org/10.3390/w12092504
Description: Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.
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Date Issued: 2020

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Coherent detection of data and timing signals over optical fiber for telescope networks

- Nfanyana, Ketshabile

Authors: Nfanyana, Ketshabile
Date: 2020
Subjects: Fiber optics , Very large array telescopes
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10948/49226 , vital:41612
Description: Telescope networks are increasingly being developed with networks such as the SKA telescope demanding the use of high-end technology to be incorporated. These networks require accurate clock signals to be transported to antennas as well as massive data to be transported from individual parabolic array antennas to a central computer for data analysis. To achieve this, optical fiber technology forms the backbone of these networks, proving high speed transmission and required bandwidth. For a distributed telescope network, coherent detection technology serves as the ideal optical fiber technology candidate for transport of information to a correlator. Use of this technology constitutes too many benefits. Sensitivity of the system is improved, and advanced modulation formats can be employed thereby improving spectral efficiency. Furthermore, coherent detection allows for digital signal processing algorithms to be employed for equalization of transmission impairments such as chromatic dispersion (CD), polarization mode dispersion (PMD), phase noise and nonlinear effects in the electrical domain. CD equalization is performed in the time or frequency domain using digital filters which suppress the fibers dispersion effectively. PMD equalization is usually performed in the time domain through the use of adaptive filters which employ algorithms such as least mean squares (LMS) and constant modulus algorithm (CMA). These algorithms further equalize residual CD. In mitigation of phase noise (carrier phase recovery), feed-forward and feedback carrier phase algorithms are used. Fiber nonlinearities and other impairments are compensated using the digital backpropagation algorithm which solves for the Manakov equation and nonlinear Schrödinger equation (NLSE). Distribution of stable clock signals to individual antennas is an important aspect of telescope networks. Clock signals are used to drive the digitizers and time stamping of received antenna information. These clock signals can be distributed using coherent detection technology by phase modulating the clock so as to provide inherent phase modulation robustness to noise through the fiber. In this thesis, we present coherent detection of non-return-to-zero pseudorandom binary sequence (PRBS-7) using binary phase shift keying (BPSK) through 26.6 km non-zero dispersion shifted fiber (NZDSF) at 10 Gbps. Digital signal processing for equalization of CD and PMD was performed offline using MATLAB software. For residual CD and PMD equalization, the LMS algorithm was used. The performance of the system, bit error rate (BER), was compared with that of an intensity modulated on-off keying (OOK) signal at the same bit rate. Basing on receiver sensitivity performance of OOK at 10-9 bit error rate, BPSK achieved superior performance with receiver sensitivity improvements of 18.37 dB and 13.89 dB attained for back-to-back and transmission over fiber, respectively. Phase modulation transmission of a 4 GHz clock signal was also conducted. Frequency instability, Allan variance and phase noise, of phase modulated clock was compared with that of intensity modulated clock. Moreover, we present an all optical clock generation scheme using frequency heterodyning technique. Allan variance values in the range of 10-10 were attained. The frequency instability of this clock generation scheme was quantified using the spectrum analyzer method. Furthermore, an all-photonic technique for data latency tracking of 5G networks over optical fiber is presented. The technique is spectrally efficient and is able to track latency down to the nano second timescale.
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Date Issued: 2020

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Combination ecosystem green engineering and early life history processes to enhance the intertidal biodiversity in the Port of East London

- Mafanya, Sandisiwer

Authors: Mafanya, Sandisiwer
Date: 2020
Subjects: Biotic communities -- South Africa -- East London , Perna -- Ecology --South Africa -- South Africa-- East London , Mexilhao mussel -- Ecology -- South Africa -- East London , Habitat (Ecology) -- Modification -- South Africa -- East London , Benthic animals -- Effect of habitat modification on -- South Africa -- East London , Harbors -- Environmental aspects -- South Africa -- East London
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/166376 , vital:41357
Description: Marine coastal ecosystems are highly impacted by anthropogenic activities, including the development of, and practices within, harbours and/or ports. Artificial structures associated with harbours have a different chemical composition, texture and orientation than that of the natural benthic habitats they have replaced, and are therefore not generally favourable for the settlement and occurrence of indigenous species. Attempts are being made to identify what structures and materials can be used to aid in the rehabilitation of native species within harbours. The aim of this study was to investigate the effects of utilising environmentally-friendly artificial structures (tiles) with varying complexity (crevices and ridges with different depths) with ecological engineers (the indigenous bivalve Perna perna), on the associated benthic biodiversity within an international port in South Africa (Port of East London). The objectives of the study were to test the effects of artificial habitat complexity and the presence of bivalves on 1) the growth, mortality and biomass of a selected model species of ecosystem engineer (P. perna), and 2) the associated intertidal biodiversity. Tiles seeded with bivalves (P. perna) were deployed at two sites in the Port of East London and monitored monthly over a period of 12 months (November 2016-October 2017) to assess survival, growth and associated biodiversity. Environmental variables were also measured every month. The results of the three-way repeated measures ANOVAs indicated that tile treatment (especially high complexity of 2.5 and 5 cm) had an effect on the diversity of mobile species, length, height and biomass of the bivalves used as model ecosystem engineer, indicating the potentials for protection from wave dislodgement and refuge provision. Treatment (especially flat tiles) also had an effect on sessile/sedentary species diversity, indicating the greater proportion of space provided by these non-complex tiles. In addition, month had an effect on the mortality, height and biomass of the bivalves. Mortality was highest in October 2017, while the growth in height and biomass of P. perna were largest in January and October 2017 respectively. The use of artificial tiles also had a positive effect on the survival, growth, and biomass of bivalves (especially the length, weight and dry weight in 2.5 cm and 5 cm complexity). Additionally, this research investigated patterns of settlement and recruitment of the local bivalve population (P. perna) in the Port of East London and adjacent natural coastline to understand the early life history temporal and spatial dynamics of this model ecosystem engineer species. Settlement and recruitment were assessed every month by deploying and replacing artificial collectors for a total period of 19 months (November 2016-May 2018). The results of the two-way ANOVAs indicated that month and site (port vs natural) had an effect on settlement and recruitment of bivalves. Settlement and recruitment of bivalves were highest in July 2017 (port) and March 2018 (natural rocky shore). This study has highlighted that the use of artificial concrete tiles with increased complexity, as well as the investigation of the early stages of mussel populations could be important to consider in a framework of rehabilitation of urban coastal environments such as the Port of East London. Ecological engineering (in terms of increased complexity and heterogeneity) has indeed the potentials to be incorporated in South African programmes aiming at improving natural biodiversity in coastal urban environments. Nonetheless, the spatio-temporal variability of early driver of mussel populations (settlement and recruitment) is also an important feature to be closely monitored if biodiversity in South African coastal armouring is to be enhanced effectively and in the long term.
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Date Issued: 2020

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Combination of CTec2 and GH5 or GH26 Endo-Mannanases for Effective Lignocellulosic Biomass Degradation

- Malgas, Samkelo, Pletschke, Brett I

Authors: Malgas, Samkelo , Pletschke, Brett I
Date: 2020
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429397 , vital:72607 , xlink:href="https://doi.org/10.3390/catal10101193"
Description: Among endo-mannanases, glycoside hydrolase (GH) family 26 enzymes have been shown to be more catalytically active than GH5 enzymes on mannans. However, only GH5 endo-mannanases have been used for the formulation of enzyme cocktails. In this study, Bacillus sp.-derived GH5 and GH26 endo-mannanases were comparatively analysed biochemically for their synergistic action with a commercial cellulase blend, CTec2, during pre-treated lignocellulose degradation. Substrate specificity and thermo-stability studies on mannan substrates showed that GH26 endo-mannanase was more catalytically active and stable than GH5. GH26 also exhibited higher binding affinity for mannan than GH5, while GH5 showed more affinity for lignocellulosic substrates than GH26. Applying the endo-mannanases in combination with CTec2 for lignocellulose degradation led to synergism with a 1.3-fold increase in reducing sugar release compared to when CTec2 was used alone. This study showed that using the activity of endo-mannanases displayed with model substrates is a poor predictor of their activity and synergism on complex lignocelluloses.
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Date Issued: 2020

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Combining DNA barcoding and morphology to identify larval fishes from the nearshore environment off the south-east coast of South Africa

- Somana, Zinzi Sinazo

Authors: Somana, Zinzi Sinazo
Date: 2020
Subjects: Fishes -- Larvae -- South Africa -- Identification , Fishes -- Genetics -- Research -- Technique , Fishes -- South Africa -- Classification , Genetic markers
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/144605 , vital:38362
Description: The early life history stages of most marine fish species are undescribed. The problem is, most of these fishes have pelagic larvae which are minute, delicate forms. Linking the larval stage to an adult counterpart is extremely challenging as larvae are morphologically different from the adults. Historically, larval fish identification relied solely on distinguishing morphological characteristics and meristic measurements, which has resulted in taxonomic confusion and misidentification. The introduction of the deoxyribonucleic acid (DNA) barcoding technique as an alternative approach has been successful in positively identifying larval fishes. The correct identification of larval specimens is the key to a better understanding of larval ecology, which underpins the success of any adult fish population. This study aimed to positively identify larval fishes of the south-east coast of South Africa using morphological characteristics and DNA barcoding. Larval and eggs specimens for this study were collected from the shallow nearshore waters of the south-east coast of South Africa. A total of 177 larval specimens were used for morphological analysis. Body shape, gut shape, pigmentation and morphometric measurements (such as body depth, preanal length and total body length) were used to identify each specimen to the family level. In addition, a fragment of mitochondrial cytochrome c oxidase subunit 1 gene (COI) was adopted for sequencing to identify larval fish specimens and fish eggs. Sequences generated from this study were compared to those in the Barcode of Life Database (BOLD). When there were no close matches to a sequence, the GenBank nucleic acid sequence database, maintained by the National Center for Biotechnology Information (NCBI), was used as an alternative. A total of 18 different families were identified through morphology. Seventy-seven of the 177 larval specimens were not subjected to morphological identification due to physical damage. The majority of larvae identified using morphological characteristics belonged to either the Sparidae, Tripterygiidae or Gobiesocidae fish families. Through DNA barcoding, 12 fish families, 16 genera and 18 different species were identified. Ten DNA barcodes (categorised as ‘no match’) from 10 different larval specimens were not identified through any of the online databases. Therefore, the 2% threshold value was used to identify members of the same species. The K2P genetic distance relationships were calculated among the no match sequences and downloaded probability matches from NCBI. This resulted in two unknown specimens assigned to the Blenniidae and Gobiidae. All other taxa were identified to species level, except specimens representing the Gobiidae and Tripterygiidae families. Based on the K2P genetic distances Gobiidae representatives were categorised as members of the Caffrogobius genus. Twenty-eight barcodes represented specimens from the Tripterygiidae. DNA barcode data from COI was analysed using the standard phylogenetic procedures in MEGA6 to examine relationships and differentiation among sequences. These could not be identified to the lowest taxonomic rank due to limited sequence data to compare them with. The sequence data from these specimens gave different results in the two online databases. BOLD results were to family level (Tripterygiidae) and NCBI to the species level (Clinidae: Pavoclinus profundus). Results in this study confirmed the efficiency of the DNA barcoding technique in species level identification of fish larvae. The evidence from genetic barcodes of the Tripterygiidae specimens, supported by morphological characteristics, suggests the need for thorough research to identify the individuals to the species level. The fact that this study identified taxonomically problematic Gobiidae and Tripterygiidae specimens suggests that studies similar to this may highlight additional diversity and help to resolve the taxonomy of other species in these families. However, the lack of reference sequence data from the adult specimens, and especially those with cryptic diversity, were both shortcomings for the positive identification of larvae. With that being said, it shows the necessity for more research to be conducted on barcoding of larvae in general as to accommodate all kinds of species from biodiversity to economic perspectives.
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Date Issued: 2020

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