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.

Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study

BACKGROUND: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear.

OBJECTIVE: We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women.

DESIGN: We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y. Analyses were performed on 3 data sets: study 1, 83 female twin pairs (21 monozygous and 62 dizygous) aged (x +/- SD) 42.2 +/- 15.5 y who were discordant for ever having been pregnant beyond 20 wk; study 2, 498 twin pairs aged 42.3 +/- 15.0 y; and study 3, 1354 individual twins, their siblings, and family members.

RESULTS: In study 1, there were no significant within-pair differences in unadjusted BMD or BMD adjusted for age, height, and fat mass at the lumbar spine or total-hip or in total-body bone mineral content (BMC; kg) (paired t tests). In study 2, there was no significant within-pair difference in measures of bone mineral or body composition related to the within-pair difference in number of pregnancies. In study 3, subjects with 1 or 2 (n = 455) and > or = 3 pregnancies (n = 473) had higher adjusted lumbar spine BMD (2.9% and 3.8%, respectively; P = 0.001) and total-body BMC (2.2% and 3.1%; P < 0.001) than did nulliparous women (n = 426). Parous women who breast-fed had higher adjusted total-body BMC (2.6%; P = 0.005), total-hip BMD (3.2%; P = 0.04), and lower fat mass (10.9%; P = 0.01) than did parous non-breast-feeders.

CONCLUSION: We found no long-term detrimental effect of pregnancy or breast-feeding on bone mineral measures.

Extending construction linkage measures by the consideration of the impact of capital

Construction linkage is a well-established research field. However, a significant limitation in previous linkage research is that the flow of capital goods is not addressed. Using the OECD input-output tables, this research first generates a new input-output model considering capital as an intermediate factor. Using the new model, the construction linkages are recalculated and investigated in order to evaluate further the role of construction in national economies. The findings verify that traditional construction linkages were extremely underestimated in previous research. Furthermore, the effect of capital on construction shows a declining trend over the examined period. After considering the effect of capital, most values and rankings of backward and forward linkages show a decreasing trend, which confirms the declining role of the construction sector with economic maturity.

Linkage measures of the real estate sector considering the effect of capital

A significant limitation in previous linkage relevant research is that the flow of capital goods is not addressed. Using the OECD input-output tables, this research first generates a new input-output model considering capital as an intermediate factor. Using the new model, the real estate linkages are re-calculated and investigated in order to evaluate appropriately the impact of the real estate sector on national economies. The findings verify that the linkages of the real estate sector were extremely underestimated in previous research. A correct linkage measure of the real estate sector can contribute to produce correct information corresponding to the sectors responsible for the economic growth during the period under study and provide substantial contributions towards guiding the appropriate strategies for future economic development.

Equity indicators: measures of socio-economic status at an Australian university

After reviewing relevant literature on socio-economic status (SES) and the ways in which it is used for higher education institutional research and policy, a detailed data analysis of Victoria University (Australia) student data was undertaken. Between 10,000 and 15,000 domestic student addresses were ‘geocoded’ to Australian Bureau of Statistics (ABS) collection district level. A survey of individual reenrolling 2001 students that included parental occupation and education data was also analysed. The most important findings were: (1) The debate for practical reasons tends to focus on area versus individual measures, but SES is a richer and more complex subject and must be acknowledged as such. (2) It is apparent that VU’s student catchment is on average of lower SES than the Melbourne average, using various area measures of SES, including the DEST-Martin indicators. (3) There is only a very small difference between average area SES measures at the collection district and the postcode level. In practical terms this means that the postcode method is adequate, as well as being cheaper and more efficiently obtained, for analyses at an aggregated (or average) level. (4) Individual surveys of students do not prima facie add to the quality of aggregated institution level SES results delivered by area analyses. This again suggests that the postcode method is best for practical reasons.

Standardizing anthropometric measures in children and adolescents with new functions for egen

A new function for egen has been developed to allow transformation of child anthropometric data to z-scores using the LMS method and the reference data available from the 1990 British Growth Reference and the 2000 US CDC Growth Reference. An additional function allows for children to be categorized according to body mass index (weight/height ²) using international cutoff points recommended by the Childhood Obesity Working Group of the International Obesity Taskforce. Copyright 2004 by StataCorp LP.

Parents with psychosis : a pilot study examining self-report measures related to family functioning

The aims of this study were to examine the utility of various self-report instruments related to family functioning in families where a parent has a psychotic disorder, and to explore associations between these instruments and symptoms in the parent. Twenty-one parents with a psychotic disorders participated in the study. All participants were able to complete the questionnaires and the majority of parents reported levels of parental competence in the average range. Most parents (90%) perceived themselves to be effective parents, however 30% reported low levels of satisfaction with the parenting role. There were significant associations between objective measures of negative symptoms and self-report scores related to problems in ways of coping, and problems with parent-child interactions. Many individuals with psychosis were able to report areas of perceived need related to their role as parents and to the functioning of their families, however there are several limitations in the use of these instruments in this setting.

Plagiarism – can preventative measures and a commitment to the value of learning by academics and students reduce plagiarism in classrooms?

Plagiarism is an interruptive act in the teaching and learning value chain. This paper analyses the impact of both plagiarism and effective assessment in the learning value chain. Effective assessment is the positive outcome. Plagiarism negates or breaks the chain. Anecdotal evidence suggests the incidences of plagiarism are increasing in faculties across the Queensland University of Technology (QUT), and where every subject/unit outline includes a statement and warning to students of the penalties of this activity, deterrence tools do not overcome the harmful impact of plagiarism on the teacher/student learning relationship. A working party established in 2000 in the Faculty of Business at QUT, examined the literature, university policies, teaching and learning practices, and examples of plagiarism and penalties in order to identify the wider learning and assessment issues surrounding plagiarism and options for action and policy. A three-semester study of acts of plagiarism and wide consultation with staff presented the working party with an opportunity to develop a set of preventative measures, and also exposed the legal, cultural and accountability issues of diverse attitudes and values.

The paper presents the findings and recommendations from the investigation, and also proposes an interpretation of marketing theory of the impact of plagiarism on the teaching and learning value chain.