Genetic Variant XRCC1 rs1799782 (C194T) and Risk of Cancer Susceptibility in Indian Population: A Meta-analysis of Case–Control Studies

X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. Several studies have reported contradictory results for XRCC1 exon 6 C>T (rs1799782) gene polymorphism and cancer risk in Indian population has provided inconsistent results. Therefore, we have performed this meta-analysis to evaluate the relationship between XRCC1 exon 6 C>T gene polymorphism and risk of cancer by published studies. We searched PubMed and Google scholar web databases to cover all studies published on association between XRCC1 exon 6 C>T gene polymorphism and cancer risk. The meta-analysis was carried out and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to appraise the strength of association. In order to derive a more precise estimation of the association, A total of 3197 confirmed cancer cases and 3819 controls were included from eligible seventeen case-controls studies. Results from overall pooled analysis demonstrated suggested that that variant allele (T vs. C: OR 1.301, 95% CI 1.003–1.688, p = 0.047) was associated with the risk of overall cancer. Other genetic models; heterozygous (TC vs. CC: OR 1.108, 95% CI 0.827–1.485, p = 0.491), homozygous (TT vs. CC: OR 1.479, 95% CI 0.877–2.493, p = 0.142), dominant (TT+TC vs. CC: OR 1.228, 95% CI 0.899–1.677, p = 0.196) and recessive (TT vs. TC+CC: OR 1.436, 95% CI 0.970–2.125, p = 0.071) did not reveal statistical association. Publication bias observation was also considered and none was detected during the analysis. The present meta-analysis suggested that the variant allele T of XRCC1 exon 6 gene polymorphism was associated with the risk of cancer. It is therefore pertinent to confirm this finding in a large sample size to divulge the mechanism of this polymorphism and cancer risk in Indian population.     

Aerobasics —An introduction to aeronautics

The structure of an airplane holds it together in flight without significant deformation due to flight loads. It contributes to about a quarter of the airplane take-off structure weight results in an equal increase in disposable load (fuel or payload) and thus contributes significantly to improved performance or economy. Thus great pains are taken by the designers to make an airplane structure as light as possible consistent with strength and stiffness. This structure is primarily of semi-monocoque design. This implies that it is designed as a hollow stiffened shell in which the skin contributes a major share to its strength and stiffness. In this article, we describe the general principles of design of this type of structure. We indicate the nature of flight loads the structure has to resist and the design concepts which ensure that the structure is safe during the life of an airplane.     

Genetic Variant Arg399Gln G>A of XRCC1 DNA Repair Gene Enhanced Cancer Risk Among Indian Population: Evidence from Meta-analysis and Trial Sequence Analyses

The X-ray repair cross-complementation group 1 (XRCC1) gene plays an important role in base excision repair pathway. Several studies have reported contradictory results for XRCC1 exon 10 (Arg399Gln, G23990A, rs25487) gene polymorphism and cancer risk in Indian population, making it difficult to interpret them. Therefore, we have conducted a meta-analysis to evaluate the more precise association between XRCC1 exon 10 G>A gene polymorphism and risk of cancer by published studies. We searched PubMed (Medline) and Google scholar web databases to cover all studies published on association between XRCC1 exon 10 G>A gene polymorphism and cancer risk until August 2016. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to appraise the strength of association. Heterogeneity, publication bias and sensitivity analysis were also assessed. Twenty-five published studies had fulfilled the inclusion criteria comprising 4131 confirmed cancer cases and 5013 controls. When all studies were polled together, overall significant association was found between XRCC1 exon 10 G>A polymorphism and cancer risk in variant allele carrier (A vs. G: OR 1.217, 95% CI 1.056–1.402, p = 0.007), homozygous (AA vs. GG: OR 1.359, 95% CI 1.036–1.783, p = 0.027), dominant (AA+AG vs. GG OR 1.208, 95% CI 1.006–1.450, p = 0.043) and recessive (AA vs. AG+GG: OR 1.315, 95% CI 1.029–1.680, p = 0.029) genetic models. Further sensitivity analysis supported the stability of our result by showing similar ORs before and after removal of a single study. The present meta-analysis suggested that the XRCC1 exon 10 G>A polymorphism contribute cancer risk in Indian population, and supports that individuals with risk allele A and AA genotype are at higher risk of developing cancer.     

Development and Demonstration of Multidimensional IRT-Based Internal Measures of Differential Functioning of ltems and Tests

This article defines and demonstrates a framework for studying differential item functioning (DIF) and differential test functioning (DTF) for tests that are intended to be multidimensional The procedure introduced here is an extension of unidimensional differential functioning of items and tests (DFIT) recently developed by Raju, van der Linden, & Fleer (1995). To demonstrate the usefulness of these new indexes in a multidimensional IRT setting, two-dimensional data were simulated with known item parameters and known DIF and DTE The DIF and DTF indexes were recovered reasonably well under various distributional differences of Os after multidimensional linking was applied to put the two sets of item parameters on a common scale. Further studies are suggested in the area of DIF/DTF for intentionally multidimensional tests.     

Farmers’ participation in extension programs and technology adoption in rural Nepal: a logistic regression analysis

Purpose: This paper examines the factors affecting farmers’ participation in extension programs and adoption of improved seed varieties in the hills of rural Nepal.

Methodology/approach: Cross-sectional farm-level data were collected during July and August 2014. A sample of 198 farm households was selected for interviewing by using a multistage, random sampling technique. We employed a logistic regression model, frequency counts, and percentages to analyze the data.

Findings: Adoption decisions were mainly affected by extension-related variables – training, membership in a farmers’ group, and off-farm employment. Extension participation was found to be influenced by socioeconomic variables – age, education, household size, and distance to the extension office. Our findings reveal that distance to the extension office and off-farm employment limited participation in extension activities and adoption, respectively, and education, household size, and group membership stimulated participation in extension programs.

Practical implications: Recognition of the determinants of farmers’ participation in extension services and innovation adoption ensures that targeted extension approaches are used to address these factors in various stages of planning, delivering, and evaluating extension programs.

Theoretical implications: Innovation adoption follows a systematic decision-making process. Although personal characteristics are important, widespread use of new technology requires a conducive social and institutional context. Because contexts vary by country or region, extension services providers should create institutions favorable for innovation adoption within a social system.

Originality/value: This research is original and highly valuable to identify the factors associated with extension participation and innovation adoption in the rural hilly region of Nepal. This also provides a new direction to operationalize farmer-oriented policies of agricultural extension and so can be helpful for agricultural policy-makers in devising programs of extension services.     

Aerobasics — An introduction to aeronautics

Modern aircraft are designed for the utmost in performance and safety as the penalty for any shortfalls in these areas is very heavy. Thus they incorporate many complex systems and subsystems, each developed using advanced scientific concepts and manufacturing methods. Aircraft design is undertaken by a group of design engineers, each with a specialized knowledge about a few subsystems but only a rough understanding of the whole aircraft. This rough overall understanding of the concepts and principles based on which an aircraft is organized is a vital element of a design engineer’s toolbox. It helps him perform his own specialized task such that it fits in the complete design seamlessly. This comprehensive knowledge is not easily acquired from modern technical literature which is voluminous and primarily caters to special interest groups. An attempt has been made here to gather this knowledge and present it concisely as a series of articles, so that it will serve as a broad general introduction to aircraft engineering. This material should be useful not only to fresh engineers entering the aeronautical industry but also to students in all relevant branches of engineering. It is also likely to be of general interest to any scientifically inclined reader as a source of basic information in a number of aeronautical disciplines. The general philosophy adopted here is best summarized by the following quote from the Panchatantra: “Knowledge indeed is unlimited, but life is short and there are many obstacles to the acquisition of knowledge. Therefore one must grasp the essential knowledge leaving out much detail ….”     

Levels of plasma soluble complement receptor 1 (sCR1) in normal Indian adult population

A decrease in the membrane anchored erythrocyte complement receptor 1 (CR1) is reported as an acquired phenomenon in a number of inflammatory and autoimmune diseases with concomitant rise in soluble CR1 (sCR1) levels in plasma. There is a need to establish the normal range of sCR1 in Indian adults to assess the function and disease association of this protein. The plasma sCR1 levels of 50 healthy individuals have been estimated by an indigenously developed sandwich ELISA. sCR1 levels from 26 patients suffering from nephropathies had also been assayed which was much higher than the normal controls. This observation suggests sCR1 as a potential market for the assessment of disease activity in nephropathies.     

GTR component of planetary precession

Even as the theory of relativity is more than a hundred years old, it is not within easy reach of undergraduate students. These students have an insatiable urge to learn more about it even if the full machinery of the tools required to study the same is not within their comfortable reach. The recent detection of gravitational waves has only augmented their enthusiasm about the General Theory of Relativity (GTR), developed just over a hundred years now, encapsulated in Einstein’s Field Equations. The GTR provided a consistent formulation of the theory of gravity, removed the anomalies in the Newtonian model, and predicted spectacular natural phenomena which eventual experiments have testified to. This pedagogical article retraces some of the major milestones that led to the GTR and presents a simple numerical simulation of the GTR advance of the perihelion of planetary motion about the sun.     

‘Time: What is it That it can be Measured?’

Experiments with the simple pendulum are easy, but its motion is nevertheless confounded with simple harmonic motion. However, refined theoretical models of the pendulum can, today, be easily taught using software like CALCODE. Similarly, the cycloidal pendulum is isochronous only in simplified theory. But what are theoretically equal intervals of time? Newton accepted Barrow’s even tenor hypothesis, but conceded that ‘equal motions’ did not exist – the refutability of Newtonian physics is independent of time measurement. However, time measurement was the key difficulty in reconciling Newtonian physics with electrodynamics. On Poincaré’s criterion of convenience, equal intervals of time ought be so defined as to make the enunciation of physics simple. Hence he postulated constancy of the speed of light. (The Michelson–Morley experiment was not critical.) The theory of relativity followed. But does there exist a proper clock?