Learner-centric MOOC model: a pedagogical design model towards active learner participation and higher completion rates

Educational technology research and development - MOOCs support the global need of learning resources with large impact through online access and no geographical boundaries. However, pedagogical...     

Refrigerants for vapour compression refrigeration systems

With the mandate of Montreal Protocol banning ozone depleting substances, and Kyoto Protocol later on curtailing the use of substances which contribute to global warming, conventional refrigerants are to be replaced by environment-friendly working fluids. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are being substituted by hydrofluorocarbons (HFCs), hydrofluorooelifins (HFOs), and a variety of mixtures. In view of the global warming potential of these newly synthesized refrigerants, the recent trend is to go back to the originally used natural fluids such as ammonia, carbon dioxide, hydrocarbons, water vapour, etc. In this article, various issues related to this changeover of refrigerants being used in vapour compression refrigeration systems are discussed.     

Circulating levels of cell adhesion molecules in hypertension

Hypertension causes complications such as coronary atherosclerosis and thrombosis wherein inflammatory factors play significant role. In the present study inflammatory molecules such as cell adhesion molecules (CAMs); endothelial (E)-selectin, platelet (P)-selectin, intercellular CAM-1 (ICAM-1), vascular CAM-1 (VCAM-1) and platelet endothelial CAM-1 (PECAM-1) were analysed in subjects newly diagnosed with hypertension with no secondary cause against normotensive healthy individuals. In each group 57 subjects were recruited and soluble (s) levels of CAMs were analysed by ELISA. As compared to controls median of sE-selectin (49.2%, P=0.001), sP-selectin (54.3%, P=0.001), and sICAM-1 (18.9%, P=0.012) were significantly elevated in hypertensive subjects. Significant negative correlation was observed of sP-selectin (spearman rank correlation coefficient (rs) =−0.345, p=0.027) and sPECAM-1 (rs =−0.446, p=0.003) with age in hypertension group. Hypertension may increase expression of certain CAMs while younger hypertensives in addition are also at increased risk of atherothrombosis.     

The legacy of Radium

The discovery of radium, its use in radiation therapy for cancer and its modern replacements are described.     

Matrix metalloproteinase-3 (MMP-3) -1612 5A/6A promoter polymorphism in coronary artery disease in Indian population

Matrix metalloproteinases (MMPs) play important role in the pathogenesis of coronary artery disease (CAD). 5A allele of -1612 5A/6A polymorphism of MMP-3 is associated with two fold higher activity than 6A allele. Present study was designed to analyse the association of this polymorphism with CAD in Indian population. Subjects included in the study were patients with stable angina (n=35), unstable angina (n=53), patients with recent event of myocardial infarction (MI) (MI Group-1, n=56) and patients at presentation of the acute MI (MI Group-2, n=49). Controls were healthy individuals (n=99). Genotyping of MMP-3 5A/6A polymorphism was carried out by PCR-based restriction digestion method. The genotype distribution of patient groups did not deviate from controls. Serum MMP-3 levels were significantly elevated at presentation of the acute MI by 36.8% (P=0.031) as compared to controls and more associated with 6A genotype suggesting discrepancy between in vitro transfection experiment and peripheral MMP-3 levels.     

Universal Design for Learning in Pre-K to Grade 12 Classrooms: A Systematic Review of Research

Some researchers have characterized Universal Design for Learning (UDL) as a promising framework to provide diverse students with access to the general education curriculum, but to what extent and how have UDL-based interventions fulfilled that promise? The purpose of this review was to analyze studies that investigated impacts of UDL-based instruction on academic and social outcomes for pre-K to grade 12 students. For the 13 studies that qualified for our review, we analyzed how researchers applied UDL principles as well as outcomes and efficacy of UDL-based interventions. Results of this analysis suggest that overall, UDL-based instruction has the potential to increase engagement and access to general education curriculum for students with disabilities, and improve students’ academic and social outcomes. However, we found mixed results; the efficacy of UDL-based interventions varied considerably within and across many studies, with effect sizes ranging from small to large. In addition, we found that although authors noted that their interventions were UDL-based, there was considerable variance in how authors reported connections between specific UDL guidelines and components of their interventions.     

The Development of Quantum Mechanics

A historical account of the development of quantum mechanics, and the roles played by many outstanding physicists, their views and philosophical attitudes is presented. Ingenious and path-breaking experiments that helped this development along are highlighted. Ideas and notions that initially arose in the course of discussions on foundations of quantum mechanics and later paved the way for the emergence of the field of Quantum Information Science and Technology are briefly touched upon.