Mathematics in ancient India

In this series of articles, we intend to have a glimpse of some of the landmarks in ancient Indian mathematics with special emphasis on number theory. This issue features a brief overview of some of the high peaks of mathematics in ancient India. In the next part we shall describe Aryabhata’s general solution in integers of the equationax -by =c. In subsequent instalments we shall discuss in some detail two of the major contributions by Indians in number theory. The climax of the Indian achievements in algebra and number theory was their development of the ingeniouschakravala method for solving, in integers, the equation x² -Dy² = 1, erroneously known as the Pell equation. We shall later describe the partial solution of Brahmagupta and then the complete solution due to Jayadeva and Bhaskaracharya.     

Trends in computer applications in science assessment

Seven computer applications to science assessment are reviewed. Conventional test administration includes record keeping, grading, and managing test banks. Multiple-choice testing involves forced selection of an answer from a menu, whereas constructed-response testing involves options for students to present their answers within a set standard deviation. Adaptive testing attempts to individualize the test to minimize the number of items and time needed to assess a student's knowledge. Figurai response testing assesses science proficiency in pictorial or graphic mode and requires the student to construct a mental image rather than selecting a response from a multiple choice menu. Simulations have been found useful for performance assessment on a large-scale basis in part because they make it possible to independently specify different aspects of a real experiment. An emerging approach to performance assessment is solution pathway analysis, which permits the analysis of the steps a student takes in solving a problem. Virtually all computer-based testing systems improve the quality and efficiency of record keeping and data analysis.     

Alfred Wegener—From continental drift to plate tectonics

What is the nature of the force or mechanism that moves massive continents thousands of miles across? What causes violent earthquakes to displace huge landmasses abruptly? How could great mountain ranges like Himalayas and Alps rise to such incredible heights? What makes earth's interior so restless? Answers to some of these questions may lie in understanding the Earth's interior itself.     

Complementary Approaches to Evaluation of Technology in Science Education

An interesting and relevant case involving two distinct systematic evaluations, traditional as well as somewhat nontraditional, of a science teacher education project with a heavy technology emphasis is discussed. Comparisons of the two separate evaluations of the same project revealed the complexity of evaluating technology projects and the multifaceted ways in which the evaluation endeavor could be approached, and provided an unusual situation and seldom seen opportunity for thinking about such evaluations. Additionally, what some other authors have said about the evaluations of efforts that take advantage of technology in the training of science teachers will also be explored. Evaluators must become active players in guiding the infusion of technology in preservice science programs. If evaluators, don't function to identify what works and what doesn't and what induces the best supportive environment, then who will?     

Giant magnetoresistance

The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter Grünberg for the discovery of giant magnetoresistance (GMR). GMR is achieved in metallic multilayers, where the resistance of the multilayer changes considerably by the application of a magnetic field. This has paved the way for high density data storage in magnetic media. (left) Debakanata Samal is a research scholar at the Deaprtment of Physics at IISc, Bangalore. His research interests are in magnetotransport in oxide multilayers, spintronics. (right) P S Anil Kumar is an Asst. Professor at the Department of Physics, IISc Bangalore. His research interests are in spintronics, magnetic nano-structures, surface-and thin-film magnetism, magnetotransport in metallic multilayers and oxides, and spin-polarized electron scattering.     

Lotka's law and institutional productivity

The present study aims at determining the applicability of Lotka's law, negative binomial distribution and lognormal distribution for institutional productivity, in the same way as it is to authors and their productivity in the field of engineering sciences and the patents filed by industrial firms in laser S&T. The study indicates that non of the three distributions are applicable for institutional productivity in engineering sciences. However, Lotka's law holds good for full as well as truncated set of data for the patents filed by industrial firms.     

Age-Dependent Changes in Glutathione-S-Transferase: Correlation with Total Plasma Antioxidant Potential and Red Cell Intracellular Glutathione

The correlation between antioxidant capacity and oxidative damage during aging has been reported in several tissues in different species. Glutathione-S-transferases (GST) can metabolise endogenous and exogenous toxins and carcinogens by catalysing the conjugation of diverse electrophiles with reduced glutathione (GSH). We observe a significant (P < 0.001) increase in plasma GST activity as a function of human age (r = 0.5675). A significant (P < 0.001) positive correlation (r = 0.8979) is observed between GST activity and total plasma antioxidant potential measured as ferric reducing ability of the plasma (FRAP). GST activity and red cell intracellular GSH also show a significant positive correlation (r = 0.7014). We hypothesize that the increased activity of plasma GST is a manifestation of increased generation of ROS and a concomitant decrease in the level of plasma antioxidant capacity during aging.     

A cloud computing adoption in Indian SMEs: Scale development and validation approach

The purpose of this research article is to identify the critical success criteria/factors that affect the cloud computing adoption and examine structure, reliability and validity of the criteria in the SMEs industry. This study considers nine types of criteria/factors with fifty-one sub-criteria, which have somewhat previously been used, and creates a ranking model that offers decision makers to measure the prior implementation of cloud computing adoption. A questionnaire-based survey research was used to collect data from 110 firms belonging to the SMEs industry in India. In this paper, the data collected was analysed by an integrated approach. Firstly, an Analytic Hierarchy Process approach was applied to find the significant fact of each criterion as the assessable indices of the cloud computing adoption. Secondly, an Exploratory Factor Analysis and Confirmatory Factor Analysis were used to examine structure, reliability and validity of the criteria. The data was tabulated in a Microsoft Excel sheet and then imported in SPSS (Statistical Package for the Social Sciences version 20) for analysis. The findings discovered that ‘Security and Privacy’, ‘Organizational Risk’, ‘Sharing and Collaboration’, ‘Confidentiality’, and ‘Integrity’ have a major effect on the adoption of cloud computing. The research was conducted in the SMEs industry in India, which may limit the generalizability of the findings. The findings and recommendations offer cloud computing service providers as well as users with a better understanding of what affects the cloud computing adoption feature, with a relevant understanding of the current scenario. The research aided in the application of the new technology of cloud computing adoption in the SMEs industry in India through the use of a wide range of criteria. The findings also help organizations study their information technology investments when applying cloud computing.     

Association of Aberrations in One Carbon Metabolism with Intimal Medial Thickening in Patients with Type 2 Diabetes Mellitus

The present work was aimed to study the association of one carbon genetic variants, hyperhomocysteinemia and oxidative stress markers, i.e., serum nitrite, plasma malondialdehyde (MDA) and glutathione (GSH) on intimal medial thickening (IMT) in patients with type 2 diabetes mellitus (T2D). A total number of 76 subjects from ACS Medical College and Hospital, Chennai, India were included in the study, i.e., Group I (n = 42) of T2D and Group II (n = 34) of age- and sex matched healthy controls. The glycated haemoglobin was measured by ion-exchange resin method; plasma homocysteine by Enzyme Linked Immunosorbant Assay method; serum nitrite (nitric oxide, NO), plasma MDA and GSH by spectrophotometric methods; the IMT by high frequency ultrasound. The polymorphisms of one carbon genetic variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism methods. Results indicate that methyltetrahydrofolate homocysteine methyl transferase (MTR) A2756G allele was found to be protective in T2D and the other variants were not significantly associated with T2D. Glutamate carboxypeptidase II (GCP II) C1561T (r = 0.34; p = 0.05) and methylene tetrahydrofolate reductase (MTHFR) C677T (r = 0.35; 0.04) showed positive correlation with plasma homocysteine in T2D cases. In this study, MTR A2756G allele was found to be protective in T2D; GCP II C1561T and MTHFR C677T showed positive association with plasma homocysteine in T2D cases. Among all the genetic variants, MTR A2756G was found influence IMT. RFC 1 G80A and TYMS 5′-UTR 2R3R showed synergistically interact with MTR A2756G in influencing increase in IMT.