Using electronic portfolios to promote reflective thinking in language teacher education

This study aimed at investigating the role of electronic portfolios in fostering pre‐service teachers’ reflective thinking. The research was conducted with pre‐service English language teachers enrolled in a practicum course in an undergraduate teacher education programme in Turkey. The data were collected through e‐portfolios and interviews. The findings revealed that e‐portfolios gave participants a sense of ownership, fostered reflecting thinking, supported collaboration and allowed them to make connections between theory and practice. With the on‐going nature of the e‐portfolio, participants had the chance of developing and reviewing their portfolio artefacts whenever and wherever they wanted. Therefore, electronic portfolios allowed teacher candidates to reflect more on their own work and thus engage in on‐going professional development.     

Increasing Glucose Concentrations Interfere with Estimation of Electrolytes by Indirect Ion Selective Electrode Method

The estimation of electrolytes like sodium (Na⁺), potassium (K⁺) and chloride (Cl⁻) using direct and indirect ion-selective electrodes (ISE) is a routine laboratory practice. Interferents like proteins, triglycerides, drugs etc. are known to affect the results. The present study was designed to look into the effect of increasing glucose concentrations on estimation of Na⁺, K⁺ and Cl⁻ by direct and indirect ISE. Pooled sera was mixed with glucose stock solution (20 g/dL) prepared in normal saline to obtain glucose concentrations ranging from ~100 to ~5000 mg/dL. Na⁺, K⁺ and Cl⁻ levels were estimated by direct and indirect ISE analyzers and results were statistically analysed using ANOVA and Pearson’s correlation. Similar experiment was also performed in 24 h urine sample from healthy subjects. Significant difference was observed between Na⁺ and Cl⁻ measurements by direct and indirect ISE, with indirect ISE values being consistently higher than direct ISE. Besides this, significant difference was observed amongst Na⁺ and Cl⁻ values from baseline values obtained by indirect ISE at glucose concentrations ≥2486 mg/dL. However, no such difference was observed with direct ISE. Na⁺ and Cl⁻ estimation by indirect ISE showed significant negative correlation with glucose concentration, more so, above ~2000 mg/dL. K⁺, however, showed no significant difference with varying glucose. Similar results were observed in 24 h urine samples with a significant difference observed amongst Na⁺ and Cl⁻ values at ≥2104 mg/dL glucose. Thus we conclude that high glucose concentrations interfere significantly in estimation of Na⁺ and Cl⁻ by indirect ISE in serum as well as urine.

Electronic supplementary material

The online version of this article (doi:10.1007/s12291-015-0522-0) contains supplementary material, which is available to authorized users.     

Effect of surface acoustic waves on the viability, proliferation and differentiation of primary osteoblast-like cells

Surface acoustic waves (SAWs) have been used as a rapid and efficient technique for driving microparticles into a three-dimensional scaffold matrix, raising the possibility that SAW may be effective in seeding live cells into scaffolds, that is, if the cells were able to survive the infusion process. Primary osteoblast-like cells were used to specifically address this issue: To investigate the effects of SAW on the cells’ viability, proliferation, and differentiation. Fluorescence-labeled osteoblast-like cells were seeded into polycaprolactone scaffolds using the SAW method with a static method as a control. The cell distribution in the scaffold was assessed through image analysis. The cells were far more uniformly driven into the scaffold with the SAW method compared to the control, and the seeding process with SAW was also significantly faster: Cells were delivered into the scaffold in seconds compared to the hour-long process of static seeding. Over 80% of the osteoblast-like cells were found to be viable after being treated with SAW at 20 MHz for 10–30 s with an applied power of 380 mW over a wide range of cell suspension volumes (10–100 μℓ) and cell densities (1000–8000 cells∕μℓ). After determining the optimal cell seeding parameters, we further found that the treated cells offered the same functionality as untreated cells. Taken together, these results show that the SAW method has significant potential as a practical scaffold cell seeding method for tissue and orthopedic engineering.     

Multiplication on ℝn

In 1843 Hamilton discovered the quaternions and in the same year Graves found an algebra with 8 basis elements. So, mathematicians knew the division algebra structures (over ℝ) on ℝ, ℝ², ℝ⁴ and ℝ⁸ in the first half of the 19th century itself. It took more than 100 years to prove that these are all the division algebras over ℝ. This follows from a theorem of Adams (which we will discuss in Part 2). In this part we also discuss ‘vector products’ on ℝ³ and ℝ⁷ and Hurwitz’s theorem on ‘sums of squares formulae’     

Multiplication on ℝn

In the first part of this article we discussed the nonexistence of division algebra structures and vector products on ℝⁿ. We now show how results fromtopology can be used to prove the results in the first article.While the discussion in the first part of the article required only elementary mathematics, this (second) part requires notions from basictopology, with which, we hope, many students at the M Sc level are familiar.     

Hyperhomocysteinemia, as an Independent Risk Factor for Retinal Venous Occlusion in an Indian Population

Total plasma homocysteine was analysed in 64 cases of retinal vein occlusion (RVO) of which 24 cases of central retinal vein occlusion (CRVO) and 40 cases of branch retinal vein occlusion (BRVO) and compared with 45 age and sex matched control. Homocysteine was significantly increased in RVO cases in respect to control (P < 0.001). Analysis also revealed that prevalence of rise of plasma homocysteine was more in cases of CRVO (OR = 13) than that of BRVO (OR = 5.03).