The association between sedentary leisure and physical activity in middle-aged adults

Aim The aim of this study was to examine the association between time spent in sedentary leisure and physical activity level in mid-aged men and women

Identifying patterns of item missing survey data using latent groups: An observational study

Objectives: To examine whether respondents to a survey of health and physical activity and potential determinants could be grouped according to the questions they missed, known as ‘item missing’. Design: Observational study of longitudinal data. Setting: Residents of Brisbane, Australia. Participants: 6901 people aged 40–65 years in 2007. Materials and methods: We used a latent class model with a mixture of multinomial distributions and chose the number of classes using the Bayesian information criterion. We used logistic regression to examine if participants’ characteristics were associated with their modal latent class. We used logistic regression to examine whether the amount of item missing in a survey predicted wave missing in the following survey. Results: Four per cent of participants missed almost one-fifth of the questions, and this group missed more questions in the middle of the survey. Eighty-three per cent of participants completed almost every question, but had a relatively high missing probability for a question on sleep time, a question which had an inconsistent presentation compared with the rest of the survey. Participants who completed almost every question were generally younger and more educated. Participants who completed more questions were less likely to miss the next longitudinal wave. Conclusions: Examining patterns in item missing data has improved our understanding of how missing data were generated and has informed future survey design to help reduce missing data

An assessment of juvenile Atlantic cod distribution and growth using diver operated stereo-video surveys

Protecting juvenile fish habitat is of particular importance for their survival. However, in many cases fish habitat requirements are poorly understood. Stereo-video methods can provide non-destructive quantitative information on fish abundance and size in relation to their surrounding environment. Stereo-video SCUBA transects were conducted during daylight hours from June to September 2013 within a proposed Marine Protected Area (MPA) in the Firth of Clyde, west of Scotland. More juvenile Atlantic cod Gadus morhua of size range 6 – 11 cm were observed in substrata containing mixed gravel, including maerl, than in boulder-cobble substrata with high algal cover, or sand with low density seagrass. Community composition was significantly different between substratum types. A decrease in G. morhua abundance was observed over the period of data collection. Over time, mean and variance in fish size increased, indicating multiple recruitment events. Protecting mixed gravel substrata could be a beneficial management measure to support the survival and recruitment of juvenile G. morhua, other substrata might be important at night given their diel migratory behaviour. Stereo-video cameras provide a useful non-destructive fisheries independent method to monitor species abundance and length measurements

An assessment of juvenile Atlantic cod distribution and growth using diver operated stereo-video surveys

Protecting juvenile fish habitat is of particular importance for their survival. However, in many cases fish habitat requirements are poorly understood. Stereo-video methods can provide non-destructive quantitative information on fish abundance and size in relation to their surrounding environment. Stereo-video SCUBA transects were conducted during daylight hours from June to September 2013 within a proposed Marine Protected Area (MPA) in the Firth of Clyde, west of Scotland. More juvenile Atlantic cod Gadus morhua of size range 6 – 11 cm were observed in substrata containing mixed gravel, including maerl, than in boulder-cobble substrata with high algal cover, or sand with low density seagrass. Community composition was significantly different between substratum types. A decrease in G. morhua abundance was observed over the period of data collection. Over time, mean and variance in fish size increased, indicating multiple recruitment events. Protecting mixed gravel substrata could be a beneficial management measure to support the survival and recruitment of juvenile G. morhua, other substrata might be important at night given their diel migratory behaviour. Stereo-video cameras provide a useful non-destructive fisheries independent method to monitor species abundance and length measurements

Solid molecular hydrogen: The Broken Symmetry Phase

By performing constant-pressure variable-cell ab initio molecular dynamics simulations we find a quadrupolar orthorhombic structure, of $Pca2_1$ symmetry, for the broken symmetry phase (phase II) of solid H2 at T=0 and P =110 - 150 GPa. We present results for the equation of state, lattice parameters and vibronic frequencies, in very good agreement with experimental observations. Anharmonic quantum corrections to the vibrational frequencies are estimated using available data on H2 and D2. We assign the observed modes to specific symmetry representations.Comment: 5 pages (twocolumn), 4 Postscript figures. To appear in Phys. Rev. Let

Longitudinal Associations Between Bicycling and Having Dependent Children, in Middle-Aged Men and Women

Bicycling has multiple health benefits. Child-rearing may influence bicycling, but little is known about the impact of this between men’s and women’s bicycling, or of number and ages of children on bicycling. This study examined the longitudinal associations between having dependent children and bicycling for transportation and recreation over 4 years among mid-aged men and women. Data were from the HABITAT study (Australia). We analysed data from three survey waves (2007, 2009, 2011) using multilevel logistic regression stratified by gender (n = 7758). Findings indicate that having dependent children was associated with bicycling for transportation and recreation in contrasting ways for men and women. The odds of bicycling were higher in men with ≥2 children aged under 18y than men without children (transportation: OR = 1.93, 95% CI: 1.26, 2.98; recreation: OR = 2.37, 95% CI: 1.67, 3.37). Over time, the odds of recreational bicycling were lower in women with ≥2 children than women without children (OR = 0.83, 95% CI: 0.73, 0.93). However, for both men and women, the odds of recreational bicycling were higher in those with children aged 6–12y than those with younger or older children (men: OR = 1.86, 95% CI: 1.39, 2.49; women: OR = 1.79, 95% CI: 1.31, 2.46). Interventions to promote bicycling must therefore consider gendered differences in bicycling for travel and active leisure, and family circumstances. An opportunity to promote bicycling might be to target parents with children aged 6–12y

Time-Lapse Acoustic Imaging of Mesoscale and Fine-Scale Variability within the Faroe-Shetland Channel

We describe and analyze the results of a three‐dimensional seismic (i.e. acoustic) reflection survey from the Faroe‐Shetland Channel that is calibrated with near‐coincident hydrographic and satellite observations. 54 vertical seismic transects were acquired over a period of 25 days. On each transect, a 250‐‐400 m band of reflections is observed within the water column. Hydrographic measurements demonstrate that this reflective band is caused by temperature variations within the pycnocline that separates warm, near‐surface waters of Atlantic origin from cold, deep waters which flow southward from the Nordic Seas. Tilting of reflective surfaces records geostrophic shear between these near‐surface and deep waters. Measurements of temporal changes of pycnoclinic depth and of reflection tilt are used to infer the existence of an anticyclonic vortex that advects northeastward. Comparison with satellite measurements of sea‐surface temperature and height suggests that this vortex is caused by meandering of the Continental Slope Current. A model of a Gaussian vortex is used to match seismic and satellite observations. This putative vortex has a core radius of 20—30 km and a maximum azimuthal velocity of 0.3‐‐0.4 m s‐1. It translates at 0.01‐‐0.1 m s‐1. Within the pycnocline, diapycnal diffusivity, K , is estimaed by analyzing the turbulent spectral subrange of tracked reflections. K varies between 10‐5.7 and 10‐5.0 m 2 s‐1 in a pattern that is broadly consistent with translation of the vortex. Our integrated study demonstrates the ability of time‐lapse seismic reflection surveying to dynamically resolve the effects that mesoscale activity has upon deep thermohaline structure on scales from meters to hundreds of kilometers.Natural Environment Research Council (NERC) Engineering and Physical Science Research Council 794 Program Grant EP/K034529/

Modelling seabed sediment physical properties and organic matter content in the Firth of Clyde

High quality quantitative maps of seabed sedimentary physical and geochemical properties have numerous research and conservation applications, including habitat and ecosystem modelling, marine spatial planning and ecosystem service mapping. However, such maps are lacking for many ecologically and economically important marine areas. Using legacy data supplemented by measurements from recent benthic surveys, modelled hydrodynamic variables and high resolution bathymetry, quantitative maps for the top 10 cm of seabed sediment were generated via a combination of statistical and machine-learning techniques for the Firth of Clyde, a semi-enclosed coastal sea on the west coast of Scotland. The maps include sediment fractions of mud, sand and gravel, whole-sediment median grain size, sediment permeability and porosity, rates of natural seabed abrasion, and sediment particulate organic carbon and nitrogen content. Properties were mapped over an unstructured grid, so that very high resolutions were achieved close to the coastlines, where sediments may be expected to be spatially heterogeneous. Overall, the maps reveal extensive areas of very low sediment permeability coupled with low rates of natural seabed disturbance. Moreover, muddy sediments in the inner Firth of Clyde, Inchmarnock Water and the sea lochs are enriched in organic carbon and nitrogen relative to the sediments of the outer Firth of Clyde. As a demonstration of the value of these maps, the standing stock of organic carbon and nitrogen in the surficial sediments of the Clyde was calculated. The Clyde stores 3.42 and 0.33 million tonnes of organic carbon and nitrogen in the top 10 cm of seabed sediment, respectively, substantially contributing to Scotland’s coastal and shelf blue carbon stocks

Association Between Overweight or Obesity and Household Income and Parental Body Mass Index in Australian Youth: Analysis of the Australian National Nutrition Survey, 1995

This study is a secondary data analysis based on the 1995 Australian National Nutrition Survey (NNS). A random subsample of 1581 school children aged 7 15 years old from the NNS was studied. The results show the prevalence of overweight, obesity and combined overweight and obesity was 10.6 20.9%, 3.7 7.2% and 15.6 25.7%, respectively. The odds ratio of overweight or obese boys with highest household income was significantly smaller than those with the lowest household income. The proportion of combined overweight and obesity in children whose parents were overweight or obese was significantly greater compared with those whose parents were not. The trend of increasing prevalence of overweight or obesity among children with increasing parental body mass index (BMI) was significant after adjusting for age except the trend of father's BMI for boys. This study provided baseline data on the recent prevalence of overweight or obesity of Australian school children using new international absolute BMI cut-off points. It indicated that young school girls (7 9 years) were more likely to be overweight or obese compared with boys, the prevalence rates of overweight or obesity in older boys (13 15 year) was significantly greater than in other age groups while in girls it was the opposite. The boys with lowest household income ($0 17 500) were more likely to be overweight or obese compared with those with the highest household income (greater than$67 500). Having parents especially mothers who were overweight or obese may increase the risk of children being overweight or obese

HABITAT: A longitudinal multilevel study of physical activity change in mid-aged adults

Purpose. To explore the role of the neighborhood environment in supporting walking Design. Cross sectional study of 10,286 residents of 200 neighborhoods. Participants were selected using a stratified two-stage cluster design. Data were collected by mail survey (68.5% response rate). Setting. The Brisbane City Local Government Area, Australia, 2007. Subjects. Brisbane residents aged 40 to 65 years. Measures. Environmental: street connectivity, residential density, hilliness, tree coverage, bikeways, and street lights within a one kilometer circular buffer from each resident’s home; and network distance to nearest river or coast, public transport, shop, and park. Walking: minutes in the previous week categorized as < 30 minutes, ≥ 30 < 90 minutes, ≥ 90 < 150 minutes, ≥ 150 < 300 minutes, and ≥ 300 minutes. Analysis. The association between each neighborhood characteristic and walking was examined using multilevel multinomial logistic regression and the model parameters were estimated using Markov chain Monte Carlo simulation. Results. After adjustment for individual factors, the likelihood of walking for more than 300 minutes (relative to <30 minutes) was highest in areas with the most connectivity (OR=1.93, 99% CI 1.32-2.80), the greatest residential density (OR=1.47, 99% CI 1.02-2.12), the least tree coverage (OR=1.69, 99% CI 1.13-2.51), the most bikeways (OR=1.60, 99% CI 1.16-2.21), and the most street lights (OR=1.50, 99% CI 1.07-2.11). The likelihood of walking for more than 300 minutes was also higher among those who lived closest to a river or the coast (OR=2.06, 99% CI 1.41-3.02). Conclusion. The likelihood of meeting (and exceeding) physical activity recommendations on the basis of walking was higher in neighborhoods with greater street connectivity and residential density, more street lights and bikeways, closer proximity to waterways, and less tree coverage. Interventions targeting these neighborhood characteristics may lead to improved environmental quality as well as lower rates of overweight and obesity and associated chromic disease