The Weight of Time: Time influences on overweight and obesity in women

We know that adults’ weight increases with age, at least until around the age of 55 years or older. Recent National Australian surveys show that men and women of all age groups were heavier in 2000 than in 1995 or 1990. These studies also found that a greater proportion of people of all ages were overweight or obese in 2000 than in the previous surveys. These studies also suggested that different generations, also known as ‘birth cohorts’, had different patterns of weight gain. These birth cohort influences mean that the year a person is born and the unique set of experiences people born at that time experience, have an effect on weight gain patterns. People born at other times experience different conditions and have different weight gain patterns. Some birth cohorts or ‘generations’ are well-known, such as the ‘baby boomer’ generation, or pre-war generation. For example, Australians born in the first three decades of the twentieth century experienced World War I and II and the Great Depression during their childhood and early adult life. During these times food was scarce and everyday life required high levels of physical activity. This group overall had lower body weights than more recent generations, meaning they were less at risk of becoming obese. Australians born after 1980 were born into an advanced technological society with greater availability of food, a vastly increased range of food products and increasing serving sizes. At the same time, levels of physical activity in everyday life have been decreasing. Together these factors produce an obesogenic environment. The three National Health surveys, conducted by the Australian Bureau of Statistics for the Australian Institute of Health and Welfare in 1990, 1995 and 2000, produced data which the NSW Centre for Overweight and Obesity has analyzed to find out what effects three time factors -- ageing, the time of the surveys and birth cohort, have on body mass index (BMI) and the prevalence of overweight and obesity. [Note – BMI used as the indicator of weight status, where BMI = weight (kg)/height2 (M2)] This report provides an overview of key findings of the analyses of the effects of these three time factors on female weight patterns. The complete findings have been published in a comprehensive technical report. The results from the analysis of the effect of birth cohorts have been used to predict the mean body mass index of women in NSW in 2010. The graphs in this report show the results for women, and the results for men are available in a separate document. The overall patterns and implications for men are generally similar to those for women. NS

The Weight of Time: Time influences on overweight and obesity in men

We know that adults’ weight increases with age, at least until around the age of 55 years or older. Recent National Australian surveys show that men and women of all age groups were heavier in 2000 than in 1995 or 1990. These studies also found that a greater proportion of people of all ages were overweight or obese in 2000 than in the previous surveys. These studies also suggested that different generations, also known as ‘birth cohorts’, had different patterns of weight gain. These birth cohort influences mean that the year a person is born and the unique set of experiences people born at that time experience, have an effect on weight gain patterns. People born at other times experience different conditions and have different weight gain patterns. Some birth cohorts or ‘generations’ are well-known, such as the ‘baby boomer’ generation, or pre-war generation. For example, Australians born in the first three decades of the twentieth century experienced World War I and II and the Great Depression during their childhood and early adult life. During these times food was scarce and everyday life required high levels of physical activity. This group overall had lower body weights than more recent generations, meaning they were less at risk of becoming obese. Australians born after 1980 were born into an advanced technological society with greater availability of food, a vastly increased range of food products and increasing serving sizes. At the same time, levels of physical activity in everyday life have been decreasing. Together these factors produce an obesogenic environment. The three National Health surveys, conducted by the Australian Bureau of Statistics for the Australian Institute of Health and Welfare in 1990, 1995 and 2000, produced data which the NSW Centre for Overweight and Obesity has analyzed to find out what effects three time factors -- ageing, the time of the surveys and birth cohort -- have on body mass index (BMI) and the prevalence of overweight and obesity. [Note – BMI used as the indicator of weight status, where BMI = weight (kg)/height2 (M2)] This report provides an overview of key findings of the analyses of the effects of these three time factors on male weight patterns. The complete findings have been published in a comprehensive technical report. The results from the analysis of the effect of birth cohorts have been used to predict the mean body mass index of men in NSW in 2010. The graphs in this report show the results for men but the results for women are available. The overall patterns and implications for women are generally similar to those for men

The role of fundamental solution in Potential and Regularity Theory for subelliptic PDE

In this survey we consider a general Hormander type operator, represented as a sum of squares of vector fields plus a drift and we outline the central role of the fundamental solution in developing Potential and Regularity Theory for solutions of related PDEs. After recalling the Gaussian behavior at infinity of the kernel, we show some mean value formulas on the level sets of the fundamental solution, which are the starting point to obtain a comprehensive parallel of the classical Potential Theory. Then we show that a precise knowledge of the fundamental solution leads to global regularity results, namely estimates at the boundary or on the whole space. Finally in the problem of regularity of non linear differential equations we need an ad hoc modification of the parametrix method, based on the properties of the fundamental solution of an approximating problem

Wake interaction in offshore wind farms with mesoscale derived inflow condition and sea waves

Numerical simulation is an indispensable tool for the design and optimization of wind farms layout and control strategies for energy loss reduction. Achieving consistent simulation results is strongly related to the definition of reliable weather and sea conditions, as well as the use of accurate computational fluid dynamics (CFD) models for the simulation of the wind turbines and wakes. Thus, we present a case study aiming to evaluate the wake-rotor interaction between offshore multi-MW wind turbines modelled using the Actuator Line Model (ALM) and realistic wind inflow conditions. In particular, the interaction between two DTU10 wind turbines is studied for two orientations of the upstream turbine rotor, simulating the use of a yaw-based wake control strategy. Realistic wind inflow conditions are obtained using a multi-scale approach, where the wind field is firstly computed using mesoscale numerical weather prediction (NWP). Then, the mesoscale vertical wind profile is used to define the wind velocity and turbulence boundary conditions for the high-fidelity CFD simulations. Sea waves motion is also imposed using a dynamic mesh approach to investigate the interaction between sea waves, surface boundary layer, and wind turbine wakes and loads

On the Hausdorff volume in sub-Riemannian geometry

For a regular sub-Riemannian manifold we study the Radon-Nikodym derivative of the spherical Hausdorff measure with respect to a smooth volume. We prove that this is the volume of the unit ball in the nilpotent approximation and it is always a continuous function. We then prove that up to dimension 4 it is smooth, while starting from dimension 5, in corank 1 case, it is C^3 (and C^4 on every smooth curve) but in general not C^5. These results answer to a question addressed by Montgomery about the relation between two intrinsic volumes that can be defined in a sub-Riemannian manifold, namely the Popp and the Hausdorff volume. If the nilpotent approximation depends on the point (that may happen starting from dimension 5), then they are not proportional, in general.Comment: Accepted on Calculus and Variations and PD

Harnack inequality for fractional sub-Laplacians in Carnot groups

In this paper we prove an invariant Harnack inequality on Carnot-Carath\'eodory balls for fractional powers of sub-Laplacians in Carnot groups. The proof relies on an "abstract" formulation of a technique recently introduced by Caffarelli and Silvestre. In addition, we write explicitly the Poisson kernel for a class of degenerate subelliptic equations in product-type Carnot groups

Potential theory results for a class of PDOs admitting a global fundamental solution

We outline several results of Potential Theory for a class of linear par-tial differential operators L of the second order in divergence form. Under essentially the sole assumption of hypoellipticity, we present a non-invariant homogeneous Harnack inequality for L; under different geometrical assumptions on L (mainly, under global doubling/Poincar\ue9 assumptions), it is described how to obtainan invariant, non-homogeneous Harnack inequality. When L is equipped with a global fundamental solution \u393, further Potential Theory results are available (such as the Strong Maximum Principle). We present some assumptions on L ensuring that such a \u393 exists

Recommendations of the 2007 Healthy Lifestyle Forum to Help Combat Childhood Obesity

Senator Guy Barnett has held eight Healthy Lifestyle Forums to Help Combat Childhood Obesity since entering the Senate in 2002. The most recent forum, held on 20 June 2007 at Australian Parliament House Canberra, brought together approximately 60 concerned members of health care, academia, industry and public health to develop useful interventions and ideas for fighting childhood obesity. This report details the recommendations of the groups convened. They were asked to consider actions in the key areas of: clinical/health care system monitoring/benchmarking infant and early childhood schools and the wider community, and industry and private sector solutions

Low-speed preconditioning for strongly coupled integration of Reynolds-averaged Navier–Stokes equations and two-equation turbulence models

Computational fluid dynamics codes using the density-based compressible flow formulation of the Navier–Stokes equations have proven to be very successful for the analysis of high-speed flows. However, solution accuracy degradation and, for explicit solvers, reduction of the residual convergence rates occur as the local Mach number decreases below the threshold of 0.1. This performance impairment worsens remarkably in the presence of flow reversals at wall boundaries and unbounded high-vorticity flow regions. These issues can be resolved using low-speed preconditioning, but there exists an outstanding problem regarding the use of this technology in the strongly coupled integration of the Reynolds-averaged Navier–Stokes equations and two-equation turbulence models, such as the k − ω shear stress transport model. It is not possible to precondition only the RANS equations without altering parts of the governing equations, and there did not exist an approach for preconditioning both the RANS and the SST equations. This study solves this problem by introducing a turbulent low-speed preconditioner of the RANS and SST equations that does not require any alteration of the governing equations. The approach has recently been shown to significantly improve convergence rates in the case of a one-equation turbulence model. The study focuses on the explicit multigrid integration of the governing equations, but most algorithms are applicable also to implicit integration methods. The paper provides all algorithms required for implementing the presented turbulent preconditioner in other computational fluid dynamics codes. The new method is applicable to all low- and mixed-speed aeronautical and propulsion flow problems, and is demonstrated by analyzing the flow field of a Darrieus wind turbine rotor section at two operating conditions, one of which is characterized by significant blade/vortex interaction. Verification and further validation of the new method is also based on the comparison of the results obtained with the developed density-based code and those obtained with a commercial pressure-based code