Democratising the Classroom for Epistemological Access: The Role of RtL Pedagogy in an Eastern Cape Secondary School, South Africa

Using documentary evidence (learners’ written, DoBE’s curriculum documents, lessons plans, and prescribed workbooks) semi-structured interviews and Reading to Learn pedagogy, to generate data, this paper reports on the positive effect Reading to Learn (RtL) has on literacy development of Grade 10 English First Additional Language learners from a township school in South Africa. The main thrust of this paper is to trace how RtL positively influences literacy development of a cohort of learners whose teaching was informed by Reading to Learn principles. This paper argues that learners whose learning is informed by RtL principles experience accelerated literacy development. The approach is built on the theory of scaffolding proposed by Vygotsky, 1978 and Bruner, 1983; genre theory (Martin, 1985: Christie, 1990); and on the functional model of language developed by Halliday (1985). Systemic functional linguistics was used as the analytical framework; the study situates itself within the critical paradigm, subjective epistemology, and mixed-method research approach. The study revealed that RtL can be part of the solution towards resolving literacy development challenges faced by underprivileged learners in South Africa and other similar environments. Keywords:Reading to Learn pedagogy; scaffolding; systemic functional linguistics; critical paradigm; subjective epistemology and mixed-method. DOI: 10.7176/JEP/13-27-08 Publication date:September 30th 202

Investigation of the parameters governing the performance of jet impingement quick food freezing and cooling systems – a review

Abstract: Jet Impingement Technology (JIT) is a heat transfer enhancement technique. Available literature soundly confirm its wide applications in the cooling of combustion chambers, critical parts of turbines, glass technology, electronic components, drying of paper and textile materials, drying of biomaterials and food preservation. The technology has interesting fluid dynamics and heat transfer properties. Its relative simplicity and low cost, abundance of air, generation of high heat transfer and faster freezing rates have made it a subject of extensive investigations. Several investigations on jet impingement quick food freezing and cooling systems which range from visualization, experimental, computational simulations and or numerical analysis, factorial and mathematical models have been studied. This paper reviews the governing parameters of the jet impingement quick food freezing and cooling systems

Repair of cracks in metals : a review

Abstract: Cracks are surface or subsurface fissures that develop in a material. Propagation energy derived from mechanical, thermal, chemical, and metallurgical effects, or a combination of these may influence crack initiation and growth. Various types of cracks exist in metals and can be categorised as cooling, solidification, centreline, crater, grinding, pickling, heat treatment, machining tears, plating, fatigue, creep, stress corrosion and hydrogen cracks. Cracks can grow and lead to complete fracture of the component posing significant threats to component life and may lead to serious injuries or loss of life. Brittle fracture in metals occurs with little or no visible warning. Discovery of any cracks warrants immediate interventions to arrest the cracks before they propagate to the point of fracture. Several crack detection and repair methods in metals have been developed, characterised and validated through research. This paper reviews the repair techniques of cracks in metals

Synthesis of single-walled carbon nanotubes by the pyrolysis of a compression activated iron (II) phthalocyanine/phthalocyanine metal-free derivative/ferric acetate mixture

This paper reports on the synthesis of single walled carbon nanotubes (SWCNTs) from an activated mixture of iron (II) phthalocyanine, its metal-free derivative and ferric acetate. The powdered mixture was activated by compression into a tablet by applying a force of 300 kN, followed by re-grinding into powder and heating it to high temperatures (1000°C). The activation by compression resulted in more than 50% debundling of SWCNTs as judged by transition electron microscopy. Acid functionalization of the SWCNTs was confirmed by the increase in the D:G ratio from 0.56 to 0.87 in the Raman spectra and the observation of an average of one carboxylic acid group per 13 carbon atoms from thermogravimetric analysis (TGA). TGA also showed that the initial decomposition temperatures for the activated and non-activated mixtures to be 205°C and 245°C, respectively. Hence, activation leads to the lowering of the pyrolysis temperature of the phthalocyanines. X-ray diffraction, electronic absorption and Fourier transform infrared spectra were also employed to characterize the SWCNT

Evaluating distributional regression strategies for modelling self-reported sexual age-mixing

The age dynamics of sexual partnership formation determine patterns of sexually transmitted disease transmission and have long been a focus of researchers studying human immunodeficiency virus. Data on self-reported sexual partner age distributions are available from a variety of sources. We sought to explore statistical models that accurately predict the distribution of sexual partner ages over age and sex. We identified which probability distributions and outcome specifications best captured variation in partner age and quantified the benefits of modelling these data using distributional regression. We found that distributional regression with a sinh-arcsinh distribution replicated observed partner age distributions most accurately across three geographically diverse data sets. This framework can be extended with well-known hierarchical modelling tools and can help improve estimates of sexual age-mixing dynamics

The influence of second-hand cigarette smoke exposure during childhood and active cigarette smoking on crohn’s disease phenotype defined by the montreal classification scheme in a Western Cape population, South Africa

CITATION: Chivese, T., et al. 2015. The influence of second-hand cigarette smoke exposure during childhood and active cigarette smoking on crohn’s disease phenotype defined by the montreal classification scheme in a Western Cape population, South Africa. PLoS ONE, 10(9):1-12, doi:10.1371/journal.pone.0139597.The original publication is available at http://journals.plos.org/plosoneBackground: Smoking may worsen the disease outcomes in patients with Crohn’s disease (CD), however the effect of exposure to second-hand cigarette smoke during childhood is unclear. In South Africa, no such literature exists. The aim of this study was to investigate whether disease phenotype, at time of diagnosis of CD, was associated with exposure to second-hand cigarette during childhood and active cigarette smoking habits. Methods: A cross sectional examination of all consecutive CD patients seen during the period September 2011-January 2013 at 2 large inflammatory bowel disease centers in the Western Cape, South Africa was performed. Data were collected via review of patient case notes, interviewer-administered questionnaire and clinical examination by the attending gastroenterologist. Disease phenotype (behavior and location) was evaluated at time of diagnosis, according to the Montreal Classification scheme. In addition, disease behavior was stratified as ‘complicated’ or ‘uncomplicated’, using predefined definitions. Passive cigarette smoke exposure was evaluated during 3 age intervals: 0–5, 6–10, and 11–18 years. Results: One hundred and ninety four CD patients were identified. Cigarette smoking during the 6 months prior to, or at time of diagnosis was significantly associated with ileo-colonic (L3) disease (RRR = 3.63; 95%CI, 1.32–9.98, p = 0.012) and ileal (L1) disease (RRR = 3.54; 95%CI, 1.06–11.83, p = 0.040) compared with colonic disease. In smokers, childhood passive cigarette smoke exposure during the 0–5 years age interval was significantly associated with ileo-colonic CD location (RRR = 21.3; 95%CI, 1.16–391.55, p = 0.040). No significant association between smoking habits and disease behavior at diagnosis, whether defined by the Montreal scheme, or stratified as ‘complicated’ vs ‘uncomplicated’, was observed. Conclusion: Smoking habits were associated with ileo-colonic (L3) and ileal (L1) disease at time of diagnosis in a South African cohort.Publisher's versio

Spirulina can increase total-body vitamin A stores of Chinese school-age children as determined by a paired isotope dilution technique

Spirulina is an alga rich in high-quality protein and carotenoids. It is unclear whether spirulina can improve the total-body vitamin A stores of school-age children in China with a high prevalence of vitamin A malnutrition. We aimed to evaluate the efficacy of spirulina in improving the total-body vitamin A stores of school-age children in rural areas of China when they consumed spirulina in their daily meals. A total of 228 children (6-11 years) were recruited and randomly divided into three groups supplemented with 4g (containing 4·18µg β-carotene), 2g (containing 2·54µg β-carotene) or 0g spirulina 5d/week for 10 weeks, respectively. Before and after the intervention period, each child was given 0·5mg [2H4]retinyl acetate and [2H8]retinyl acetate, respectively. To assess vitamin A stores, blood samples (3ml) were collected on the third and the twenty-first day after each labelled retinyl acetate dose for a retinol enrichment analysis using a GC mass spectrometer. The concentrations of retinol and β-carotene in serum samples were also determined by using HPLC. After the 10-week intervention, serum β-carotene concentrations of children with 2 or 4g spirulina supplement increased by 0·160 and 0·389µmmol/l, respectively. Total-body vitamin A stores increased significantly, with a median increase of 0·160mmol in children taking 2g spirulina and of 0·279mmol in children taking 4g spirulina. Spirulina is a good dietary source of β-carotene, which may effectively increase the total-body vitamin A stores of Chinese school-age childre

Artificial Intelligence and Amikacin Exposures Predictive of Outcomes in Multidrug-Resistant Tuberculosis Patients

Aminoglycosides such as amikacin continue to be part of the backbone of treatment of multidrug-resistant tuberculosis (MDR- TB). We measured amikacin concentrations in 28 MDR-TB patients in Botswana receiving amikacin therapy together with oral levofloxacin, ethionamide, cycloserine, and pyrazinamide and calculated areas under the concentration-time curves from 0 to 24 h (AUC0 –24). The patients were followed monthly for sputum culture conversion based on liquid cultures. The median duration of amikacin therapy was 184 (range, 28 to 866) days, at a median dose of 17.30 (range 11.11 to 19.23) mg/kg. Only 11 (39%) pa- tients had sputum culture conversion during treatment; the rest failed. We utilized classification and regression tree analyses (CART) to examine all potential predictors of failure, including clinical and demographic features, comorbidities, and amikacin peak concentrations (Cmax), AUC0 –24, and trough concentrations. The primary node for failure had two competing variables, Cmax of \u3c67 mg/liter and AUC0 –24 of \u3c568.30 mg · h/L; weight of \u3e41 kg was a secondary node with a score of 35% relative to the primary node. The area under the receiver operating characteristic curve for the CART model was an R2 �� 0.90 on posttest. In patients weighing \u3e41 kg, sputum conversion was 3/3 (100%) in those with an amikacin Cmax of \u3e67 mg/liter versus 3/15 (20%) in those with a Cmax of \u3c67 mg/liter (relative risk [RR] �� 5.00; 95% confidence interval [CI], 1.82 to 13.76). In all patients who had both amikacin Cmax and AUC0 –24 below the threshold, 7/7 (100%) failed, compared to 7/15 (47%) of those who had these parameters above threshold (RR �� 2.14; 95% CI, 1.25 to 43.68). These amikacin dose-schedule patterns and exposures are virtually the same as those identified in the hollow-fiber system model

Characterization and electrocatalytic behaviour of glassy carbon electrode modified with nickel nanoparticles towards amitrole detection

We report on the synthesis of Ni nanoparticles (NiNPs) and their application in electrocatalysis in comparison with nickel phthalocyanine (NiPc). UV–vis spectroscopy, powder X-ray diffraction, transmission electron microscopy and electron paramagnetic resonance were used in the characterization of NiNPs. Cyclic voltammetry and electrochemical impedance spectroscopy were used in electrocatalytic studies of amitrole on the glassy carbon electrode modified with NiNPs. The apparent and catalytic rate constants for amitrole on the NiNP-GCE were found to be 2.58 × 10−5 cm s−1 and 1.11 × 103 M−1 s−1, respectively