What can we learn from the electromagnetic spectrum?

Electromagnetic radiation is all around us, and essential for the survival of all lifeforms. It provides valuable information about the physical world around us, feeds us by providing energy to plants, allows us to maintain human metabolism, and cures us of various diseases. This article deals with the various properties of electromagnetic radiation, its sources and detectors, its nature, and its uses. A brief discussion on the absorption spectrum of the Earth’s atmosphere and the atmospheric windows, and celestial objects seen through optical and radio telescopes is also provided.     

`Emergency Education': The Missing Dimension in Education Policy

Large numbers of children regularly experience educational disruption because of natural disasters. Donor and rehabilitation agencies, using an ‘emergency education’ framework, have usually addressed the immediate needs of such children and longer-term educational reconstruction. However, the imperative of continuous educational access to all children, and the need for resource and curricular policies to deal with frequent disruption, call for the inclusion of an emergency education dimension in traditional educational policy. This article outlines the features of such a dimension by drawing on the experiences of an earthquake rehabilitation effort in India (2001-02). Policies that target an improved post-crisis educational system create an opportunity to redress past disadvantages. Helping local educational institutions build capacities in curriculum development and continuing education of emergency personnel is crucial. Some new features highlighted include tracking local demographic shifts with the help of local leaders and the use of innovative teachers to handle children’s immediate recreational needs. This revised version was published online in August 2006 with corrections to the Cover Date.     

Single‐sex schooling and labour market outcomes

One quarter of the 1958 British Birth cohort attended single‐sex secondary schools. This paper asks whether sex‐segregated schooling had any impact on the experience of gender differences in the labour market in mid‐life. We examine outcomes at age 42, allowing for socio‐economic origins and abilities measured in childhood. We find no net impact of single‐sex schooling on the chances of being employed in 2000, nor on the horizontal or social class segregation of mid‐life occupations. But we do find a positive premium (5%) on the wages of women (but not men), of having attended a single‐sex school. This was accounted for by the relatively good performance of girls‐only school students in post‐16 qualifications, not by the wider range of subjects studied by both girls and boys at single‐sex schools. Men’s labour market attainments were more closely related to attending private schools and to parental class, suggesting that the intergenerational transmission of advantage, while not related to coeducation, is related to gender.     

The longitudinal relationship between generalized self-efficacy and physical activity in school-aged children

Our understanding of the longitudinal relationship between generalized self-efficacy (GSE) and physical activity in children and youth is limited. The purpose of this study was to investigate the effect of GSE towards physical activity on sedentary behaviours and physical activity in school-aged children over time. A total of 2278 nine-year-old children (1120 girls and 1158 boys) were recruited at baseline and followed for seven waves of data collection from 2005 to 2008. All children completed questionnaires at each wave assessing their GSE (adequacy, predilection, and enjoyment), sedentary behaviours, free play, and organized activity. Mixed-effects models were used to estimate changes in physical activity and GSE within individuals over time, controlling for gender and motor ability. The results showed that participation in free play significantly increased over time, whereas organized activity significantly decreased over the same period. Children with high perceived adequacy and predilection had higher free play and organized activity participation relative to other children over time. However, the effect of perceived adequacy diminished over time, while the gaps between groups with different levels of predilection widened over time. While sedentary behaviours were lower over time in children with high predilection, these behaviours were consistently higher in children with high enjoyment. The differences in sedentary behaviours between groups increased over time for both predilection and enjoyment. This study highlights the importance of different components of GSE on physical activity participation. In addition, interventions targeting the enhancement of predilection may facilitate physical activity and reduce sedentary behaviours.     

LP(a) phenotypes and levels in angiographically proven coronary heart disease patients and controls

Lipoprotein Lp(a) excess has been identified as a powerful predictor of premature atherosclerotic vascular diseases. To evaluate this in a North-Indian population, 130 CAD patients and 130 controls were analyzed. The size of the apo(a) phenotypic isoforms was inversely proportional to Lp(a) concentrations. The mean concentration of Lp(a) in the CAD patients was 42±34 mg/dl whereas in the normal subjects it was much lower, 27±27 mg/dl. 157 subjects out of the total 260 subjects showed plasma levels of >20mg/dl. The frequency of high Lp(a) levels was much higher in patients(73%) than controls (43%). These data suggest (1) that there is heterogeneity of the Lp(a) polymorphism, (2) Higher Lp(a) levels were found in patients than in the controls, (3) Patients showed 1.5 fold increase in Lp(a) levels as compared to the controls. We conclude that low molecular weight apo(a) isoforms are significantly associated with increased risk of CAD in the North-Indian population.     

Separating genuine cases of reading disability from reading deficits caused by predominantly inattentive ADHD behavior

Conventional methods of differentiating reading disability (RD) caused by deficits in decoding skills or comprehension from poor reading performance caused by inconsistent attention associated with attention-deficit/hyperactivity disorder (ADHD) have produced equivocal results. This study presents a model of differential diagnosis of attentional problems and RD that differs from these conventional approaches. The new diagnostic procedure uses intraindividual differences seen in the performance of at-risk learners on tasks related to reading that vary in their sensitivity to the sustained attention required for successful performance. The hypothesis is that children with inconsistent attention would perform more poorly on tests that require sustained attention, such as listening comprehension, than on tests that are more tolerant of inattention, such as reading comprehension. Such differences would not be seen in the test scores of children who have only RD, because their performance is determined more by the difficulty level of the reading tests than by the degree of sensitivity of the task to attention. The validity of this new model was evaluated by determining the capability of the differences seen in the scores of tests that differ in their sensitivity to sustained attention to predict the degree of inconsistency in sustained attention as measured by a continuous performance test. The data obtained from 39 children who are at risk for RD suggest that this is a viable model.     

Oxidative stress and disturbance in antioxidant balance in beta thalassemia major

Repeated blood transfusion in beta thalassemia major patients may lead to peroxidative tissue injury by secondary iron overload. In the present study, 72 children with beta thalassemia major were included. Serum levels of total lipid peroxides, Iron, Total Iron Binding Capacity, Copper, Zinc, Vitamin E, plasma Total Antioxidant Capacity, activity of Erythrocyte Superoxide Dismutase, were measured. The findings were compared with 72 age matched healthy controls irrespective of sex. A significant increase in the levels of lipid peroxide and Iron (p<0.001), whereas, significant decrease in the levels of vitamin-E, Total Antioxidant Capacity and Total Iron Binding Capacity (p<0.001) was observed. Serum Zinc was significantly increased (p<0.001) with significant decrease in the levels of copper (p<0.001). Non Significant increase in the activity of Erythrocyte Superoxide Dismutase (p>0.05) was found in the patients when compared with controls. This suggest that oxidative stress and reduced antioxidant defense mechanism play an important role in pathogenesis of beta thalassemia major.