Influence of school community and fitness on prevalence of overweight in Australian school children

AbstractThe study objectives were (1) to determine the variation in prevalence of overweight between school communities, (2) to evaluate the relationship between cardiorespiratory fitness and the probability of being overweight among different school communities, and (3) to test whether this relationship varies between school communities. Using a repeated cross-sectional design, data from 31,424 (15,298 girls, 16,126 boys) Australian school children who had objective assessments of body composition and physical performance were used. Ninety-one schools located across 5 states and territories were included. Independent samples were taken across 12 school years (2000–2011). Analysis used generalised linear mixed models in R with a two-level hierarchical structure—children, nested within school communities. Predictor variables considered were: level 1—gender, age, cardiorespiratory fitness and year of measurement; level 2—school community. A total of 24.6% of the children were overweight and 69% were of low fitness. Variation in the prevalence of overweight between school communities was significant, ranging from 19% to 34%. The probability of being overweight was negatively associated with increasing cardiorespiratory fitness. The relationship was steepest at low fitness and varied markedly between school communities. Children of low fitness had probabilities of being overweight ranging between 26% and 75% depending on school community, whereas those of high fitness had probabilities of <2%. Our findings suggest that most might be gained from a public health perspective by focusing intervention on the least fit children in the worst-performing communities

Effect of rapid solidification on the microstructure and microhardness of BS1452 grade 250 hypoeutectic grey cast iron

Containerless solidification of low alloyed commercial grey cast iron in two different cooling media (N2 and He) using a 6.5 m high vacuum drop-tube have been investigated. Both the conventionally cooled, as-cast alloy and the rapidly cooled drop-tube samples were characterized using SEM, XRD and Vickers microhardness apparatus. The estimated range of cooling rates are 200 K s−1 to 16,000 K s−1 for N2 cooled droplets and 700 K s−1 to 80,000 K s−1 for He cooled droplets (in each case for 850 μm and 38 μm diameter droplets respectively). Microstructural analysis reveals that the as-received bulk sample displayed a graphitic structure while the rapidly cooled samples display decreasing amounts of α-Fe as the cooling rate increases. At moderate cooling rates α is replaced with γ and Fe3C, while at higher cooling rates with α′. Microhardness increase with cooling rate but cannot be mapped uniquely onto cooling rate, suggesting undercooling also influences the mechanical properties

Default Risk and Equity Returns: A Comparison of the Bank-Based German and the U.S. Financial System

In this paper, we address the question whether the impact of default risk on equity returns depends on the financial system firms operate in. Using an implementation of Merton's option-pricing model for the value of equity to estimate firms' default risk, we construct a factor that measures the excess return of firms with low default risk over firms with high default risk. We then compare results from asset pricing tests for the German and the U.S. stock markets. Since Germany is the prime example of a bank-based financial system, where debt is supposedly a major instrument of corporate governance, we expect that a systematic default risk effect on equity returns should be more pronounced for German rather than U.S. firms. Our evidence suggests that a higher firm default risk systematically leads to lower returns in both capital markets. This contradicts some previous results for the U.S. by Vassalou/Xing (2004), but we show that their default risk factor looses its explanatory power if one includes a default risk factor measured as a factor mimicking portfolio. It further turns out that the composition of corporate debt affects equity returns in Germany. Firms' default risk sensitivities are attenuated the more a firm depends on bank debt financing

Rapid solidification morphologies in Ni3Ge: Spherulites, dendrites and dense-branched fractal structures

Single-phase β-Ni3Ge has been rapidly solidified via drop-tube processing. At low cooling rates (850–300 μm diameter particles, 700–2800 K s−1) the dominant solidification morphology, revealed after etching, is that of isolated spherulites in an otherwise featureless matrix. At higher cooling rates (300–75 μm diameter particles, 2800–25,000 K s−1) the dominant solidification morphology is that of dendrites, again imbedded within a featureless matrix. As the cooling rate increases towards the higher end of this range the dendrites display non-orthogonal side-branching and tip splitting. At the highest cooling rates studied (25,000 K s−1), dense-branched fractal structures are observed. Selected area diffraction analysis in the TEM reveals the spherulites and dendrites are a disordered variant of β-Ni3Ge, whilst the featureless matrix is the ordered variant of the same compound. We postulate that the spherulites and dendrites are the rapid solidification morphology and that the ordered, featureless matrix grew more slowly post-recalescence. Spherulites are most likely the result of kinetically limited growth, switching to thermal dendrites as the growth velocity increases. It is extremely uncommon to observe such a wide range of morphologies as a function of cooling rate in a single material

Evidence for an extended transition in growth orientation and novel dendritic seaweed structures in undercooled Cu-8.9 wt%Ni

A melt encasement (fluxing) technique has been used to systematically study the microstructural development and velocity-undercooling relationship of a Cu-8.9 wt%Ni alloy at undercoolings up to 235 K. A complex series of microstructural transitions have been identified with increasing undercooling. At the lowest undercoolings a 〈1 0 0〉 type dendritic structure gives way to an equiaxed grain structure, consistent with the low undercooling region of grain refinement observed in many alloys. At intermediate undercoolings, dendritic growth returns, consisting of dendrites of mixed 〈1 0 0〉 and 〈1 1 1〉 character. Within this region, 8-fold growth is first observed at low undercoolings, indicating the dominance of 〈1 0 0〉 character. As undercooling is increased, 〈1 1 1〉 character begins to dominate and a switch to 6-fold growth is observed. It is believed that this is an extended transition region between 〈1 0 0〉 and 〈1 1 1〉 dendrite growth, the competing anisotropies of which are giving rise to a novel form of dendritic seaweed, characterised by its containment within a diverging split primary dendrite branch. At higher undercoolings it is suggested that a transition to fully 〈1 1 1〉 oriented dendritic growth occurs, accompanied by a rapid increase in growth velocity with further increases in undercooling. At the highest undercooling achieved, a microstructure of both small equiaxed grains, and large elongated grains with dendritic seaweed substructure, is observed. It is thought that this may be an intermediate structure in the spontaneous grain refinement process, in which case the growth of dendritic seaweed appears to play some part

Using participatory workshops to assess alignment or tension in the community for minimally invasive tissue sampling prior to start of child mortality surveillance: lessons From 5 sites across the CHAMPS network

The Child Health and Mortality Prevention Surveillance (CHAMPS) program is a 7-country network (as of December 2018) established by the Bill &amp; Melinda Gates Foundation to identify the causes of death in children in communities with high rates of under-5 mortality. The program carries out both mortality and pregnancy surveillance, and mortality surveillance employs minimally invasive tissue sampling (MITS) to gather small samples of body fluids and tissue from the bodies of children who have died. While this method will lead to greater knowledge of the specific causes of childhood mortality, the procedure is in tension with cultural and religious norms in many of the countries where CHAMPS works - Bangladesh, Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa. Participatory Inquiry Into Community Knowledge of Child Health and Mortality Prevention (PICK-CHAMP) is a community entry activity designed to introduce CHAMPS to communities and gather initial perspectives on alignments and tensions between CHAMPS activities and community perceptions and priorities. Participants' responses revealed medium levels of overall alignment in all sites (with the exception of South Africa, where alignment was high) and medium levels of tension (with the exception of Ethiopia, where tension was high). Alignment was high and tension was low for pregnancy surveillance across all sites, whereas Ethiopia reflected low alignment and high tension for MITS. Participants across all sites indicated that support for MITS was possible only if the procedure did not interfere with burial practices and rituals