Changes in body composition as determinants of longitudinal changes in bone mineral measures in 8 to 26 year old female twins

Between 1990 and 1998, we conducted a longitudinal study of 286 female twins aged 8 to 25 years at baseline (60 monozygotic (MZ) pairs, 44 dizygotic (DZ) pairs and 78 unpaired twins), measured on average 2.4 times (range 2–6) with an average of 1.8 years between measurements (range 0.7–6.7 years). Areal bone mineral density (ABMD) at the lumbar spine, total hip and femoral neck, total body bone mineral content (BMC), total body soft tissue composition (lean mass and fat mass) were measured by dual-energy X-ray absorptiometry, and height and menarchial status were also recorded. Median annual changes in height were negligible at 4 years post-menarche. During the “linear growth” period up to 4 years post-menarche, ABMD at the lumbar spine, total hip and femoral neck increased with annual change in lean mass by 1.7 (S.E. 0.1), 1.4 (0.1) and 1.0 (0.1) percent per kilogram per year, respectively (all p<0.001), independently of changes in fat mass or height. During the “post-linear growth” period, ABMD at the total hip and femoral neck increased with annual change in fat mass by 0.3 (0.1) and 0.5 (0.1) percent per kilogram per year (all p<0.01), independent of change in lean mass. Annual changes in total body BMC were associated with annual changes in lean mass (1.9 (0.2) percent per kilogram), in fat mass (1.3 (0.2) percent per kilogram) and in height (0.7) (0.2) percent per centimeter) during linear growth, and in fat mass (1.0 (0.1)) and lean mass (0.6 (0.1)) percent per kilogram post-linear growth (all p<0.001). We conclude that changes in bone mineral measures are strongly associated with changes in lean mass during linear growth, while post-linear growth, changes in fat mass are the predominant, although weaker, predictor. These findings suggest that the strong cross-sectional association between bone mineral measures and lean mass is established during growth and development, and that fat mass emerges as a more powerful determinant of bone change in healthy adult females.

Corporate ethics and trust in intra-corporate relationships, an in-depth and longitudinal case description

Theoretically, a contribution of this article is the pinpointed connection between corporate ethics and trust in intra-corporate relationships. Furthermore, it contributes to a conceptual framework that distinguishes between the constructs of business ethics and corporate ethics. The authors also provide a grounded conceptual framework of corporate ethics and trust. The principal dyadic determinants of corporate ethics in intra-corporate relationships are interpreted to be management behaviour versus employee perception of that behaviour. Empirically, the contribution is an in-depth and longitudinal case description that underpins the topic and the discussion provided in the article.

Increasing central adiposity: the Nepean longitudinal study of young people aged 7-8 to 12-13y

BACKGROUND: Estimates of the prevalence of overweight and obesity in young people are typically based on body mass index (BMI). However, BMI may not indicate the level of central adiposity. Waist circumference has therefore been recommended to identify young people at risk of morbidity associated with central adiposity.

OBJECTIVE: To investigate (a) change in total and central adiposity between 7–8 and 12–13 y (b) agreement between classifying young people as overweight or obese based on total adiposity and central adiposity, and (c) risk factors associated with the development of total and central adiposity.

DESIGN: Anthropometric measurements were taken on 342 children in 1996/97 and 5 y later. Risk factors examined included birth weight, physical activity, TV viewing, pubertal status, parental adiposity, diet and socio-economic status.

RESULTS: Between 7–8 and 12–13 y indices of central adiposity increased more than total adiposity; waist circumference z-score increased by (means.d.) 0.740.92 and BMI z-score increased by 0.180.67. At 12–13 y there was moderate agreement between the two measures of adiposity (weighted kappa=0.64). However, waist circumference identified a greater number of young people as overweight or obese compared to BMI (41.2 vs 29.3%, P<0.001). Adiposity status at 7–8 y, maternal obesity, and pubertal stage were the strongest predictors of BMI status at 12–13 y. Risk factors associated with increased central adiposity were similar.

CONCLUSIONS: Overweight and obesity, as measured by waist circumference, is a bigger problem than is currently assessed by BMI. Targeting known risk factors for total adiposity may be an appropriate strategy for preventing increased central adiposity.

Technical and scale efficiency of Islamic banking operations in Malaysia: an empirical investigation with a longitudinal perspective

Against the background of increasing competition from globalization and the trend towards consolidation, diversification and rationalization, the study of efficiency is most relevant in the Malaysian Islamic banking context, where all domestic commercial banks operate Islamic banking schemes. Using the non-parametric method of Data Envelopment Analysis (DEA), this study investigates the recent efficiency of the Malaysian Islamic Banking system. The attributions of technical efficiency (utilization of capacity) and scale efficiency (optimality of scale achieved) are identified. Further, Islamic Banking Schemes operating under the dual banking system of foreign and domestic commercial banks were benchmarked to the country's two full-fledged Islamic banks to provide insight of the relative efficiencies. Amidst an overall improvement in TE and SE, it was noted that foreign banks (FB) increased efficiency levels to achieve full efficiency over the six-year period, and domestic banks (DB) followed by smaller improvement while the fully-fledged Islamic banks (FFIE) experienced a general decline in efficiency which was solely attributed to scale inefficiency. The findings provide useful guidelines for policy implications and may also assist banks concerned with their strategic planning with regard to the future of Islamic banking.

Longitudinal surveys of Australian youth : active citizenship and the secondary school experience : community participation rates of Australian youth

LSAY is a research program that follows young Australians as they move through secondary school, into further education or training, and into the labour market and adult life. This website provides access to the electronic full text versions of LSAY research reports, from 1996 to present.

How schooling, and particular schools, make a difference: values, identities and futures in longitudinal study

Just over a decade ago the authors set out to select and follow a range of young people from the age of 12 and their end of primary or first days in secondary school, to the age of 18 when most of them had embarked on the first steps of the post-school lives. Students from four different types of schools were chosen: a Melbourne high school, a high school in a Victorian regional city, a large non-government school, and a secondary school that had once been a technical school. The students were interviewed twice a year about their views of self, of school, of the future. In this article the authors discuss two aspects of the study: what sense did they get of schools and their effects on the subjectivities being formed by young people today? And, what sense did the authors get of how gender is working in young lives now? The article outlines some of the findings in relation to these two issues.

A longitudinal study of body change strategies among children

This study was designed to examine changes in body image and strategies to lose weight and increase muscles among 443 children (207 boys, 236 girls) aged 8-12 years over 16 months. Boys were more likely than girls to receive messages from sociocultural influences to increase msucles, and to adopt strategies to increase muscles. The strongest infuences were Body Mass Index, media and mothers, and to a lesser extent fathers and best friend. Girls were focused on losing weight, whereas boys were focused on both incrasing muscle and losing weight. The implications of these findings for preventative eductation programs are discussed.