Using a design-based research approach for a supplementary instruction programme: A pedagogical intervention during the COVID-19 pandemic

The study focused on the implementation of supplementary instruction as a suitable and effective pedagogical intervention for assisting at-risk students enrolled in an Advanced Research Methodology core course in one of the South African higher education institutions (HEIs). Supplementary instruction (SI) has been purported to be an effective technique for assisting at-risk students undertaking high-risk core modules. The educational challenge of at-risk students in higher education has been worsened by the emergence of the COVID-19 pandemic where high-risk core modules implementing e-learning posed serious challenges for at-risk students thereby negatively affecting pass rates and throughput. The design-based research (DBR) approach was used to guide the design of the intervention and research its effectiveness. The article reports on the design principles that yielded these results. After one cycle of DBR, it was established that SI had a positive impact on the pass rates of this particular course. The article argues that the use of the proposed designed principles in SI interventions has the potential to increase higher mean grades, lower failure and withdrawal rates, and higher retention rates of students. However, this study recommends that further iterations must be undertaken to refine design principles for an SI programme of this nature. The pedagogical significance of the current study in the prevailing circumstances and post COVID-19 pandemic is implementing a robust SI intervention in all core modules at the University of Technology

Decolourisation and degradation of reactive blue 2 by sulphate reducing bacteria (SRB) and zero valent iron in a biosulphidogenic reactor

This work was performed to determine the influence of heat treatment on sewage sludge and addition of zero valent iron (ZVI) on the degradation and decolourisation of an anthraquinone dye, reactive blue 2 (RB 2). A consortium of sulphate reducing bacteria (SRB) in a biosulphidogenic batch reactor with biodigester sludge was used. The latter supplied carbon and augmenting microorganisms. Reactors with heat treated sludge were outperformed by those with unheated sludge for the larger part of the reactor life span. A 75% decolourisation efficiency was achieved within 24 h of inoculation when 4 g ZVI/l were added in an SRB reactor with unheated sludge as opposed to 59% colour removal after four days in the same reactor without ZVI. However, decolourisation was also noted in the presence of ZVI alone, indicating existence of chemical reaction between ZVI and RB 2.Key words: Decolourisation, degradation, reactive blue 2, zero valent iron, sulphate reducing bacteria, sulphidogenic

A Manifesto for (De)growth: Disruptive (De)Growth Repository of Southern Ecosystems

Hunguta formed after the open call for the 2019 Oslo Architecture Triennale, taking the Xitsonga word for 'decrease' as its name. The multidisciplinary collective engages with degrowth practices in the context of the Global South. The project in SubSaharan Africa – developed through months and in dialogue with local communities –,was transformed into an atlas exhibited in Oslo in 2019. Through images, diagrams, and photographs, the collective both tests and challenges degrowth principles in a manifesto on the dynamic repository of southern ecosystems. In doing so, the atlas questions the absolute viability and application of degrowth principles in territories subjected to exploitation and 'slow growth' over decades – if not centuries

Sensitivity analysis and reduction of a dynamic model of a bioproduction of fructo-oligosaccharides

Starting from a relatively detailed model of a bioprocess producing fructo-oligosaccharides, a set of experimental data collected in batch and fed-batch experiments is exploited to estimate the unknown model parameters. The original model includes the growth of the fungus Aureobasidium pullulans which produces the enzymes responsible for the hydrolysis and transfructosylation reactions, and as such contains 25 kinetic parameters and 16 pseudo-stoichiometric coefficients, which are not uniquely identifiable with the data at hand. The aim of this study is, therefore, to show how sensitivity analysis and quantitative indicators based on the Fisher information matrix can be used to reduce the detailed model to a practically identifiable model. Parametric sensitivity analysis can indeed be used to progressively simplify the model to a representation involving 15 kinetic parameters and 8 pseudo-stoichiometric coefficients. The reduced model provides satisfactory prediction and can be convincingly cross validated.The authors thank the financial support from the F.R.S.-FNRS, the Belgium National Fund for the Scientific Research (Research Project 24643.08). C. Nobre thanks the Fundação para a Ciência e Tecnologia for the strategic funding of UID/BIO/04469 /2013 unit.info:eu-repo/semantics/publishedVersio

The Rose Bengal Test in Human Brucellosis: A Neglected Test for the Diagnosis of a Neglected Disease

Brucellosis is a highly contagious zoonosis affecting livestock and human beings. The human disease lacks pathognomonic symptoms and laboratory tests are essential for its diagnosis. However, most tests are difficult to implement in the areas and countries were brucellosis is endemic. Here, we compared the simple and cheap Rose Bengal Test (RBT) with serum agglutination, Coombs, competitive ELISA, Brucellacapt, lateral flow immunochromatography for IgM and IgG detection and immunoprecipitation with Brucella proteins. We tested 208 sera from patients with brucellosis proved by bacteriological isolation, 20 contacts with no brucellosis, and 1559 sera of persons with no recent contact or brucellosis symptoms. RBT was highly sensitive in acute and long evolution brucellosis cases and this related to its ability to detect IgM, IgG and IgA, to the absence of prozones, and to the agglutinating activity of blocking IgA at the pH of the test. RBT was also highly specific in the sera of persons with no contact with Brucella. No test in this study outperformed RBT, and none was fully satisfactory in distinguishing contacts from infected patients. When modified to test serum dilutions, a diagnostic titer >4 in RBT resulted in 87.4% sensitivity (infected patients) and 100% specificity (contacts). We discuss the limitations of serological tests in the diagnosis of human brucellosis, particularly in the more chronic forms, and conclude that simplicity and affordability of RBT make it close to the ideal test for small and understaffed hospitals and laboratories

Isolation of a euryhaline microalgal strain, Tetraselmis sp CTP4, as a robust feedstock for biodiesel production

Bioprospecting for novel microalgal strains is key to improving the feasibility of microalgae-derived biodiesel production. Tetraselmis sp. CTP4 (Chlorophyta, Chlorodendrophyceae) was isolated using fluorescence activated cell sorting (FACS) in order to screen novel lipid-rich microalgae. CTP4 is a robust, euryhaline strain able to grow in seawater growth medium as well as in non-sterile urban wastewater. Because of its large cell size (9-22 mu m), CTP4 settles down after a six-hour sedimentation step. This leads to a medium removal efficiency of 80%, allowing a significant decrease of biomass dewatering costs. Using a two-stage system, a 3-fold increase in lipid content (up to 33% of DW) and a 2-fold enhancement in lipid productivity (up to 52.1 mg L-1 d(-1)) were observed upon exposure to nutrient depletion for 7 days. The biodiesel synthesized from the lipids of CTP4 contained high levels of oleic acid (25.67% of total fatty acids content) and minor amounts of polyunsaturated fatty acids with >= 4 double bonds (< 1%). As a result, this biofuel complies with most of the European (EN14214) and American (ASTM D6751) specifications, which commonly used microalgal feedstocks are usually unable to meet. In conclusion, Tetraselmis sp. CTP4 displays promising features as feedstock with lower downstream processing costs for biomass dewatering and biodiesel refining

Quinine, an old anti-malarial drug in a modern world: role in the treatment of malaria

Quinine remains an important anti-malarial drug almost 400 years after its effectiveness was first documented. However, its continued use is challenged by its poor tolerability, poor compliance with complex dosing regimens, and the availability of more efficacious anti-malarial drugs. This article reviews the historical role of quinine, considers its current usage and provides insight into its appropriate future use in the treatment of malaria. In light of recent research findings intravenous artesunate should be the first-line drug for severe malaria, with quinine as an alternative. The role of rectal quinine as pre-referral treatment for severe malaria has not been fully explored, but it remains a promising intervention. In pregnancy, quinine continues to play a critical role in the management of malaria, especially in the first trimester, and it will remain a mainstay of treatment until safer alternatives become available. For uncomplicated malaria, artemisinin-based combination therapy (ACT) offers a better option than quinine though the difficulty of maintaining a steady supply of ACT in resource-limited settings renders the rapid withdrawal of quinine for uncomplicated malaria cases risky. The best approach would be to identify solutions to ACT stock-outs, maintain quinine in case of ACT stock-outs, and evaluate strategies for improving quinine treatment outcomes by combining it with antibiotics. In HIV and TB infected populations, concerns about potential interactions between quinine and antiretroviral and anti-tuberculosis drugs exist, and these will need further research and pharmacovigilance

Physico-chemical and biotic factors influencing microalgal seed culture propagation for inoculation of a large scale raceway pond

The growth of Chlorella vulgaris in open pond aquatic conditions poses serious challenges due to the interplay of both physico-chemical and biotic factors. We report here the monitoring of physico-chemical and biotic parameters affecting the propagation of C. vulgaris seed culture for inoculation of a large scale raceway pond (300 000 L capacity) in South Africa. The C. vulgarisstrain used for this purpose was isolated from a wastewater maturation pond and characterized for its potential for biomass and lipid production. The isolate was grown aseptically in 4 × 25 L aspirator bottles in BG-11 medium under ambient laboratory conditions and the culture was supplied with filtered air and exposed to 200 µmol photons per m2 per second using Gro-Lux agricultural fluorescent lights. The culture was transferred to a 500 L capacity portable pool under open conditions. This pond was used to further inoculate 3 more portable ponds. Physico-chemical and biotic growth parameters were monitored on a daily basis in the three ponds. The over reliance on fossil fuels will have a major impact on power supply in the near future if renewable sources of energy are not developed at a fast pace. The developed inoculum was subsequently used to inoculate an open raceway pond for large scale biomass production for biodiesel production.Keywords: Biodiesel, biomass, inoculum, lipid, raceway pond, seed cultureAfrican Journal of Biotechnology, Vol 13(31) 3607-361