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Nature and source of suspended particulate matter and detritus along an austral temperate river–estuary continuum, assessed using stable isotope analysis

- Dalu, Tatenda, Richoux, Nicole B, Froneman, P William

Authors: Dalu, Tatenda , Richoux, Nicole B , Froneman, P William
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/68012 , vital:29181 , https://doi.org/10.1007/s10750-015-2480-1
Description: Publisher version , Ecologists are interested in the factors that control, and the variability in, the contributions of different sources to mixed organic materials travelling through lotic systems. We hypothesized that the source matter fuelling mixed organic pools in a river–estuary continuum varies over space and time. Samples of the mixed organic pools were collected along a small temperate river (Kowie River) in southern Africa during early and late spring, summer and winter. The C:N ratios of suspended particulate matter (SPM) collected during summer and winter indicated that the lower reaches of the system had similar organic matter contributions. Stable isotope analysis in R revealed that aquatic macrophytes were significant contributors to SPM in the upper reaches. Bulk detritus had large allochthonous matter components in the lower reaches, and contributions of aquatic macrophytes and benthic algae were high (>50%) in the upper to middle reaches. The evaluation of organic matter contributions to SPM and detritus along the river–estuary continuum provided a baseline assessment of the nature and sources of potential food for consumers inhabiting different locations during different seasons. Incorporating SPM and detritus spatio-temporal variations in food web studies will improve our understanding of carbon flow in aquatic systems.
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Date Issued: 2016

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On luminescence stimulated from deep traps using thermally-assisted time-resolved optical stimulation in α-Al2O3: C

- Nyirenda, Angel N, Chithambo, Makaiko L, Polymeris, G S

Authors: Nyirenda, Angel N , Chithambo, Makaiko L , Polymeris, G S
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/124627 , vital:35639 , https://doi.org/10.1016/j.radmeas.2016.01.016
Description: We report a study of charge transfer mechanisms of electrons stimulated optically from very deep traps, also known as donor traps, in α-Al2O3:C. The investigations were carried out using thermally-assisted time-resolved optical stimulation, thermoluminescence and by way of residual thermoluminescence from the main electron trap. When the charges are optically stimulated from the deep traps, they are redistributed via the conduction band to the main electron trap and the shallow trap from where they are optically or thermally released for recombination at luminescence centres. The luminescence is strongly quenched at high measurement temperature as evident by very short luminescence lifetimes at these temperatures. The main peak due to residual thermoluminescence is located at a higher temperature than the conventional main peak.
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Date Issued: 2016

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Partnerships and parents–relationships in tutorial programmes

- Layton, Delia M, McKenna, Sioux

Authors: Layton, Delia M , McKenna, Sioux
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66699 , vital:28983 , ISSN 1469-8366 , https://doi.org/10.1080/07294360.2015.1087471
Description: The tutorial system is considered to be a useful pedagogical intervention to improve student retention, particularly in the context of a first-year student’s experience of entering university. For these novice students to achieve academic success, it is important that they are given access to the subject-specific knowledge and practices in their different disciplines, that is, that they acquire ‘epistemological access’. A recent study of the tutorial system in a South African university (Layton, D.M. [2013]. A social realist account of the tutorial system at the University of Johannesburg (Unpublished doctoral dissertation). Rhodes University, Grahamstown), sought to discover to what extent tutorials were discursively constructed as being about the enablement of epistemological access. This paper focuses on two discourses that emerged from the study – the parent discourse and the partnership discourse. Both discourses were concerned with relationships between key stakeholders in the tutorial programme. Given that tutorials are considered to be spaces in which more intimate learning can take place than in the anonymous environment of the large lecture hall, an interrogation of the relationships fostered in tutorials is important. The parent discourse, in which students were positioned as ‘kids’ needing care, was supportive of new students but ran the risk of being patronising and reductionist. The partnerships discourse, in which tutors and academics were seen to be working together towards the common goal of student success, was seen to be enabling of epistemological access. But it required a commitment to teaching endeavours that was in tension with the institutional focus on research. Through a social realist analysis of the two discourses constructing relationships in the tutorial system, we conclude that these discourses have the power to both constrain and enable the extent to which the tutorial system can be a site of epistemological access.
Full Text: false
Date Issued: 2016

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Payment of taxes, refunds and SARS’ collection powers

- Arendse, Jacqueline A, Clegg, David, Williams, Robert C

Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
Date: 2016
Subjects: To be catalogued
Language: English
Type: text , book chapter
Identifier: http://hdl.handle.net/10962/131264 , vital:36547 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
Description: The Tax Administration Act and the various tax Acts administered by the Commissioner contain specific provisions dealing with the payment and recovery of tax, which are explained in this chapter.
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Date Issued: 2016

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Pedagogy for fostering criticality, reflectivity and praxis in a course on teaching for lecturers

- Quinn, Lynn, Vorster, Jo-Anne

Authors: Quinn, Lynn , Vorster, Jo-Anne
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66590 , vital:28967 , https://doi.org/10.1080/02602938.2015.1066756
Description: publisher version , Using the concepts of criticality, reflectivity and praxis, the paper presents an analysis of our reflections on participants’ responses to the assessment requirements for a course for lecturers on teaching. The context in which the course is being taught has changed considerably in the last few years in terms of the mode of delivery, as well as the number and diversity of participants. Our analysis has generated insights into ways in which the course is not meeting all the learning needs of the participants, nor preparing them adequately to demonstrate, in writing, their learning. Using insights gained, we suggest pedagogic processes and strategies for ensuring that the course focuses on both writing to learn and learning to write; and for assisting participants to acquire the practices to demonstrate their learning in written assessment tasks, using the requisite literacy including criticality, reflectivity and praxis.
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Date Issued: 2016

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Politics at a distance from the state: radical, South African and Zimbabwean praxis today

- Helliker, Kirk D, van der Walt, Lucien

Authors: Helliker, Kirk D , van der Walt, Lucien
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/71364 , vital:29837 , https://doi.org/10.1080/02589001.2016.1240792
Description: For decades, most anti-capitalist and anti-imperialist movements identified radical social transformation with the capture of state power. The collapse of supposedly enabling states led recently to a crisis of left and working class politics. But this has also opened space for the rediscovery of society-centred, anti-capitalist modes of bottom-up change, labelled as ‘at a distance’ politics. These modes have registered important successes in practice, such as the Zapatistas in Mexico, and have involved strands of anarchism and syndicalism, and autonomist Marxism. This article, an introduction to a collection of papers emerging from a 2012 conference of academics and activists in South Africa, aims to help articulate an understanding of social transformation from below that has been analytically and politically side-lined not only in South Africa (and Zimbabwe), but globally. In doing so, it provides a preliminary attempt to map and create a dialogue between three major positions within the broad category of ‘at a distance’ politics.
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Date Issued: 2016

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Possible futures for science and engineering education

- Blackie, Margaret, Le Roux, Kate, McKenna, Sioux

Authors: Blackie, Margaret , Le Roux, Kate , McKenna, Sioux
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66796 , vital:28994 , ISSN 1573-174X , https://doi.org/10.1007/s10734-015-9962-y
Description: Publisher version , From Introduction: The understanding that the science, engineering, technology and mathematics disciplines (STEM) have a significant and directly causal role to play in economic productivity and innovation has driven an increased focus on these fields in higher education. Innovation in this context is a shorthand for the harnessing of the knowledge economy and the provision of products with novel significant ‘added value’. The assumption in both developed and developing economies alike is that STEM will drive national growth (World Bank 2002; UNESCO 2009), and this impacts on demands that universities provide competent graduates in sufficient numbers. However, exactly what ‘competency’ might mean in this context is open to debate.
Full Text: false
Date Issued: 2016

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Purification and characterization of β-mannanase from Aspergillus terreus and its applicability in depolymerization of mannans and saccharification of lignocellulosic biomass

- Soni, Hemant, Rawat, Hemant Kumar, Kango, Naveen

Authors: Soni, Hemant , Rawat, Hemant Kumar , Kango, Naveen
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66167 , vital:28912 , https://doi.org/10.1007/s13205-016-0454-2
Description: publisher version , Aspergillus terreus FBCC 1369 was grown in solid-state culture under statistically optimized conditions. β-Mannanase was purified to apparent homogeneity by ultrafiltration, anion exchange and gel filtration chromatography. A purification factor of 10.3-fold was achieved, with the purified enzyme exhibiting specific activity of 53 U/mg protein. The purified β-mannanase was optimally active at pH 7.0 and 70 °C and displayed stability over a broad pH range of 4.0–8.0 and a 30 min half-life at 80 °C. The molecular weight of β-mannanase was calculated as ~49 kDa by SDS-PAGE. The enzyme exhibited K m and V maxvalues of 5.9 mg/ml and 39.42 µmol/ml/min, respectively. β-Mannanase activity was stimulated by β-mercaptoethanol and strongly inhibited by Hg2+. The β-Mannanase did not hydrolyze mannobiose and mannotriose, but only mannotetraose liberating mannose and mannotriose. This indicated that at least four mannose residues were required for catalytic activity. Oligosaccharide with a degree of polymerization (DP) three was the predominant product in the case of locust bean gum (16.5 %) and guar gum (15.8 %) hydrolysis. However, the enzyme liberated DP4 oligosaccharide (24 %) exclusively from konjac gum. This property can be exploited in oligosaccharides production with DP 3–4. β-Mannanase hydrolyzed pretreated lignocelluloses and liberated reducing sugars (% theoretical yield) from copra meal (30 %). This property is an important factor for the bioconversion of the biomass.
Full Text: false
Date Issued: 2016

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Registration, returns, assessments and records

- Arendse, Jacqueline A, Clegg, David, Williams, Robert C

Authors: Arendse, Jacqueline A , Clegg, David , Williams, Robert C
Date: 2016
Subjects: To be catalogued
Language: English
Type: text , book chapter
Identifier: http://hdl.handle.net/10962/131060 , vital:36520 , https://store.lexisnexis.co.za/products/silke-on-tax-administration-skuZASKUPG1440
Description: This chapter covers the administrative provisions dealing with the requirements for certain persons to register with SARS, the submission of tax returns, the raising of assessments and the maintenance of records.
Full Text: false
Date Issued: 2016

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Revisiting cellulase production and redefining current strategies based on major challenges

- Kuhad, Ramesh Chander, Deswal, Deepa, Sharma, Sonia, Bhattacharya, Abhishek, Jain, Kavish Kumar, Kaur, Amandeep, Pletschke, Brett I, Singh, Ajay, Karp, Matti

Authors: Kuhad, Ramesh Chander , Deswal, Deepa , Sharma, Sonia , Bhattacharya, Abhishek , Jain, Kavish Kumar , Kaur, Amandeep , Pletschke, Brett I , Singh, Ajay , Karp, Matti
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66142 , vital:28909 , https://doi.org/10.1016/j.rser.2015.10.132
Description: publisher version , Lignocellulosic biomass has been considered as an important and sustainable source of renewable energy. Cellulose constitutes the major component of the lignocellulosic biomass and also offers maximum recalcitrance towards its fullest utilization. The enzymatic breakdown of cellulose is achieved through cellulases. Diverse forms of microbes including fungi, bacteria, actinomycetes and yeast are known to produce cellulases that have found extensive application in various industries. Due to the current global political unrest over oil prices and the threat of global warming following combustion of fossil fuels, the paradigm of research is now focused on biofuel production from plant biomass. Conventional approaches have not been economically feasible for meeting the demands of the industry. This review provides an update regarding the status of present microbial cellulase production technologies and research with special reference to solid state fermentation and different molecular techniques such as mutagenesis, metabolic engineering and heterologous gene expression of cellulases from different microbial domains with improved catalytic and stability properties. Metagenomic and genomic studies for mining of novel cellulase genes in addition to screening of culturable strains using conventional methods have been advanced. In addition the bottlenecks associated with cellulase production and how the future research needs to be directed to provide a comprehensive technology for the production of cellulases with novel traits for application at an industrial level without economic constraints are discussed.
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Date Issued: 2016

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Sarqaquinoic acid and related synthetic naphthoquinones inhibit the function of Hsp90

- Chiwakata, M, de la Mare, Jo-Anne, Edkins, Adrienne L, Beukes, Denzil R

Authors: Chiwakata, M , de la Mare, Jo-Anne , Edkins, Adrienne L , Beukes, Denzil R
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66324 , vital:28933 , https://doi.org/10.1055/s-0036-1596751
Description: publisher version , Heat shock protein 90 (Hsp90) is of critical importance in the proper folding of numerous proteins, including those involved in cancer. Consequently, there is significant interest in the discovery and development of Hsp90 inhibitors as anticancer drugs. In this study, we investigated the ability of sargaquinoic acid (SQA) and selected naphthoquinone derivatives to inhibit Hsp90 function. SQA was isolated and purified from Sargassum incisifolium while the naphthoquinones were synthesised via a straightforward sequence incorporating a Diels-Alder reaction between benzoquinone derivatives and myrcene followed by coupling with substituted alkyl or arylamines. Hsp90 inhibition was assessed by a client protein degradation assay. At a concentration of 1µM, SQA showed almost complete inhibition of Hsp90 but only moderate antiproliferative effects (IC50 658µM) against a Hs578T breast cancer carcinoma cell line. Interestingly, the most potent synthetic aminonaphthoquinone inhibited Hsp90 function by 50% at a concentration of 1µM but showed much improved activity against the Hs578T cell line (IC50 0.32µM). Furthermore, unlike geldanamycin, none of the compounds tested upregulates Hsp70 suggesting that these compounds may bind to the C-terminal end of Hsp90.
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Date Issued: 2016

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SASO and Black Consciousness, and the shift to congress politics

- Badat, Saleem

Authors: Badat, Saleem
Date: 2016
Language: English
Type: book chapter , text
Identifier: http://hdl.handle.net/10962/59755 , vital:27645 , http://witspress.co.za/catalogue/students-must-rise/
Description: Students Must Rise 98 Chapter 8 SASO and Black Consciousness, and the shift to congress politics I n 1960, demonstrators protesting against pass laws were killed and injured by police at Sharpeville. Soon afterwards, the apartheid government declared a state of emergency. Over 11 000 political activists were detained, and repressive new laws, police raids, arrests, bannings, and torture were used to crush political opposition to apartheid. The African National Congress (ANC) and Pan Africanist Congress (PAC) were banned, and many leaders of the ANC and PAC were arrested and imprisoned , and hundreds fled into exile. For many white South Africans, the rest of the 1960s were a time of economic boom, political calm, prosperity, and rising living standards. Some blacks took the opportunity to accumulate wealth, power, and privilege through the Bantustans that the apartheid government established as part of its separate development programme. For most blacks, it was a period of great economic exploitation, extensive political and social control, fear, and demoralisation. It was difficult to see how there could be any political challenge to white minority rule. Anti-apartheid organisations faced immediate repression. They also had to overcome black people’s fear and demoralisation, which stood in the way of mobilising opposition against apartheid. The emergence of the South African Students’ Organisation and Black Consciousness Despite many problems, the South African Students’ Organisation (SASO) was formed as an exclusively black university and college student organisation in 1968. It escaped immediate state repression, and developed a following among students at the Saleem Badat SASO and Black Consciousness, and the shift to congress politics 99 universities reserved for blacks. Thereafter, the ideology of Black Consciousness (BC) was developed and other BC organisations were formed, resulting in the BC movement. SASO saw its challenge as the ‘assertion, manifestation and development of a sense of awareness politically, socially and economically among the black community’.1 It emphasised black ‘group cohesion and solidarity’ as ‘important facets of Black Consciousness’, the need for ‘the totality of involvement of the oppressed people’, and for BC ‘to be spread to reach all sections of the black community’.2 SASO began community development, literacy, education, media, culture, and sports projects, which aimed to help black communities to determine and realise their own needs. They were seen as a means to win the trust of people and to educate and mobilise them.3 Projects instilled the idea of self-reliance, seen as important for achieving freedom, in members and communities. SASO created a favourable political climate for various organisations to emerge.
Full Text: false
Date Issued: 2016

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Seeing yourself in a new light: crossing the threshold to “researcher"

- Clarence, Sherran

Authors: Clarence, Sherran
Date: 2016
Language: English
Type: book chapter , text
Identifier: http://hdl.handle.net/10962/61390 , vital:28021 , http://www.africansunmedia.co.za/Sun-e-Shop/tabid/78/ProductId/385/Default.aspx , http://dx.doi.org/10.17613/M6WW52
Description: Writing, and the thinking, reading and analytical process that writers engage with to make writing possible, is transformative, and doctoral students in the social sciences especially tend to write themselves into their new identities as ‘doctors’ and recognised researchers. Much has been written in recent years about doctoral writing, including many advice books on how to write a ‘big-book’ or similar doctoral thesis into being. While some of the journal articles and books are helpful, and provide useful accounts of the complex challenges of writing a doctoral thesis, many of the advice books in particular focus more on the text itself, with the writer oddly under-accounted for. Recent research on, for example, doctoral writing groups and doctoral identity speaks into this gap helpfully, but much of it is written in contexts other than South Africa, and much of it is written for rather than by students going through or having recently completed a PhD process. This chapter contributes to a growing body of research and reflection on the role of writing itself in the process of becoming a ‘doctor’. Building on relevant blog posts and critical reflection through a research journal on my own transformative doctoral writing process at a South African university, this chapter will reflect on how challenging yet also potentially thrilling the writing process can be during a PhD. Readers will hopefully find in this chapter useful insights into their own process of becoming a doctor, and ideas for making their own ‘writing and becoming’ process more engaging and rewarding.
Full Text: false
Date Issued: 2016

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South African perceptions of the good life twenty years into democracy

- Moller, Valerie

Authors: Moller, Valerie
Date: 2016
Language: English
Type: text , book
Identifier: http://hdl.handle.net/10962/67215 , vital:29060 , https://doi.org/10.1007/978-3-319-20568-7_15
Description: publisher version , South Africa celebrated 20 years of democracy in 2014. In 1994, life satisfaction among all South Africans peaked following the first open non-racial elections. Since that time, only some 45–55 % of the total population, on average, state that they are satisfied. Drawing on Alex Michalos’ classic Multiple Discrepancy Theory (MDT), this chapter explores the needs, expectations, aspirations and perceptions of progress among black South Africans, who were promised a better life under democracy by the new government they voted for in 1994. Findings suggest that expectations raised by the new government in the early years of democracy, coupled with a strong sense of entitlement to state services and welfare in later years, are among the strongest drivers of life satisfaction 20 years into democracy. South Africa’s democracy project is still a work in progress and black South Africans continue to hope for a better life in the future.
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Date Issued: 2016

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Stromatolite microbial communities as a source of new bioactive secondary metabolites

- Flatt, P M, Damarjanan, C, Isamonger, E, Kalinski, Jarmo-Charles J, Dorrington, Rosemary A, McPhail, Kerry L

Authors: Flatt, P M , Damarjanan, C , Isamonger, E , Kalinski, Jarmo-Charles J , Dorrington, Rosemary A , McPhail, Kerry L
Date: 2016
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/65871 , vital:28851 , https://doi.org/10.1055/s-0036-1596638
Description: publisher version , Stromatolites represent some of the earliest microbial communities on Earth. They are formed by accretion and precipitation of layered calcium carbonate structures that result from the metabolic activity of complex microbial communities and the geochemical conditions of their environment. Modern stromatolite communities include aerobic heterotrophs, sulphide-oxidizing bacteria, sulphate-reducing bacteria, fermentative bacteria and cyanobacteria. Phylogenetic analyses revealed the presence of new and known cyanobacterial taxa related to known producers of biologically active secondary metabolites in tufa stromatolites along the South African southeast coast [1]. Prompted us to investigate their potential for producing novel bioactive secondary metabolites. A series of three tide pools provided the opportunity to collect stromatolites along a vertical transect from pool A (highest elevation, low nitrogen input, fresh water), pool B (within high tide zone, brackish water) and pool C (within tidal zone). The microbial community in pool A is particularly distinct. Chemical extracts of stromatolites from different pools have been profiled by LC-MS/MS and the data subjected to molecular spectral networking using the GnPS platform [2] in order to establish the diversity and biological potential of the microbial metabolome that is being expressed within each of these microhabitats. Correlation of the phylogenetic and secondary metabolomic data is expected to guide the isolation of new natural products with biomedical relevance.
Full Text: false
Date Issued: 2016

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