The impact of school tobacco policies on student smoking in Washington State, United States and Victoria, Australia

This paper measures tobacco polices in statewide representative samples of secondary and mixed schools in Victoria, Australia and Washington, US (N = 3,466 students from 285 schools) and tests their association with student smoking. Results from confounder-adjusted random effects (multi-level) regression models revealed that the odds of student perception of peer smoking on school grounds are decreased in schools that have strict enforcement of policy (odds ratio (OR) = 0.45; 95% CI: 0.25 to 0.82; p = 0.009). There was no clear evidence in this study that a comprehensive smoking ban, harsh penalties, remedial penalties, harm minimization policy or abstinence policy impact on any of the smoking outcomes.

Maximum likelihood estimation for rician distributed data in analytical q-ball imaging

Analytical q-ball imaging is widely used for reconstruction of orientation distribution function (ODF) using diffusion weighted MRI data. Estimating the spherical harmonic coefficients is a critical step in this method. Least squares (LS) is widely used for this purpose assuming the noise to be additive Gaussian. However, Rician noise is considered as a more appropriate model to describe noise in MR signal. Therefore, the current estimation techniques are valid only for high SNRs with Gaussian distribution approximating the Rician distribution. The aim of this study is to present an estimation approach considering the actual distribution of the data to provide reliable results particularly for the case of low SNR values. Maximum likelihood (ML) is investigated as a more effective estimation method. However, no closed form estimator is presented as the estimator becomes nonlinear for the noise assumption of the Rician distribution. Consequently, the results of LS estimator is used as an initial guess and the more refined answer is achieved using iterative numerical methods. According to the results, the ODFs reconstructed from low SNR data are in close agreement with ODFs reconstructed from high SNRs when Rician distribution is considered. Also, the error between the estimated and actual fiber orientations was compared using ML and LS estimator. In low SNRs, ML estimator achieves less error compared to the LS estimator.

Promoting a team ball game (Lifeball) to older people : who does this game attract and who continues?

Issue addressed: To describe the demographic and health-related characteristics (physical activity, self-reported health status, quality of life and falls history) of older people who enroll in a team-based game, Lifeball, and examine associations between continuation and participant characteristics. Reasons for stopping, participants' perceptions of the game and changes in health-related characteristics over 12 months were examined.

Methods: Telephone surveys were conducted with a cohort of Lifeball players at: baseline, soon after commencing playing and 12 months later.

Results: At baseline, participants were aged 40 to 96 years (mean 67). Most were female (84%), in good to excellent health (86%) and reported being sufficiently (>150 minutes per week) physically active (69%). Almost half (43%) were still playing 12 months later (continuers). Continuers were more likely to perceive Lifeball had helped them to: feel fitter and healthier (91%); improve their social life (73%); and be more active (53%). No significant changes in continuers' physical activity, self-reported health status and quality of life measures were reported. The main reason for stopping playing was illness/injury unrelated to Lifeball.

Conclusions: Lifeball mainly appealed to healthy, active older people.

Mary De Garis

The thesis is a biographical study of the life and times of Dr Mary De Garis, (1881-1963) an early medical woman. It examines her extensive writing, her research on childbirth and her modernising of the Geelong Hospital in the 1920s and 1930s. Her life illuminates Australian women in the first half of the twentieth century.

Rural adolescent alcohol, tobacco, and illicit drug use: a comparison of students in Victoria, Australia, and Washington State, United States

Purpose: There are inconsistent research findings regarding the impact of rurality on adolescent alcohol, tobacco, and illicit substance use. Therefore, the current study reports on the effect of rurality on alcohol, tobacco, and illicit
drug use among adolescents in 2 state representative samples in 2 countries, Washington State (WA) in the United States and Victoria (VIC) in Australia.
Participants: The International Youth Development Study (IYDS) recruited representative samples of students from Grade 7 (aged 12 to 13 years) and Grade 9 (aged 14 to 15) in both states. A total of 3,729 students responded to questions about alcohol, tobacco, cannabis, and other illicit substance use (n_VIC = 1,852; n_WA = 1,877). In each state, males and females were equally represented and ages ranged from 12 to 15 years.
Methods: Data were analyzed to compare lifetime and current (past 30 days) substance use for students located in census areas classified as urban, large or small town, and rural. Findings were adjusted for school clustering and
weighted to compare prevalence at median age 14 years.
Findings: Rates of lifetime and current alcohol, tobacco, and cannabis use were significantly higher in rural compared to urban students in both states (odds ratio for current substance use = 1.31).
Conclusions: In both Washington State and Victoria, early adolescent rural students use substances more frequently than their urban counterparts. Future studies should examine factors that place rural adolescents at risk for alcohol, tobacco, and illicit drug use.

Growth of V2O5 nanorods from ball-milled powders and their performance in cathodes and anodes of lithium-ion batteries

The two-stage procedure of ball milling and annealing in air represents a prospective method of preparing nanorods of V₂O₅ with electrochemical properties suitable for the application in lithium-ion batteries. Commercially purchased V₂O₅ powder is milled in a ball mill as the first step of the synthesis. The as-milled precursor is subsequently annealed in air to produce the morphology of nanorods via solid-state recrystallization. We have recently investigated intermediate stages of the formation of nanorods, and this paper summarizes the synthesis method including the description of the current understanding of the growth mechanism. The obtained V₂O₅ nanorods have been assessed as an electrode material for both anodes and cathodes of lithium-ion batteries. When used in cathodes, the nanorods demonstrate a better retention of capacity upon cycling than that of the commercially available powder of V₂O₅. When used in anodes, the performances of nanorods and the reference V₂O₅ powder are similar to a large extent, which is related to a different operating mechanism of V₂O₅ in anodes. The experimentally observed capacity of V₂O₅ nanorods in an anode has stabilized at the level of about 450 mAh/g after few cycles.

Maximum-likelihood based estimation for Q-ball imaging using diffusion-weighted MRI data

Q-ball imaging has been presented to reconstruct diffusion orientation distribution function using diffusion weighted MRI. In this thesiis, we present a novel and robust approach to satisfy the smoothness constraint required in Q-ball imaging. Moreover, we developed an improved estimator based on the actual distribution of the MR data.

Risk and protective factors for adolescent substance use in Washington State, the United States and Victoria, Australia : a longitudinal study

Purpose
To compare the levels of risk and protective factors and the predictive influence of these factors on alcohol, tobacco, and cannabis use over a 12-month follow-up period in Washington State in the United States and in Victoria, Australia.

Method
The study involved a longitudinal school-based survey of students drawn as a two-stage cluster sample recruited through schools, and administered in the years 2002 and 2003 in both states. The study used statewide representative samples of students in the seventh and ninth grades (n = 3,876) in Washington State and Victoria.

Results
Washington State students, relative to Victorian students, had higher rates of cannabis use but lower rates of alcohol and tobacco use at time 1. Levels of risk and protective factors showed few but important differences that contribute to the explanation of differences in substance use; Washington State students, relative to Victorian students, reported higher religiosity (odds ratio, .96 vs. .79) and availability of handguns (odds ratio, 1.23 vs. 1.18), but less favorable peer, community, and parental attitudes to substance use. The associations with substance use at follow-up are generally comparable, but in many instances were weaker in Washington State.

Conclusions
Levels of risk and protective factors and their associations with substance use at follow-up were mostly similar in the two states. Further high-quality longitudinal studies to establish invariance in the relations between risk and protective factors and substance use in adolescence across diverse countries are warranted.

Large-scale mechanical peeling of boron nitride nanosheets by low-energy ball milling

Mechanical cleavage by Scotch tape was the first method to produce graphene and is still widely used in laboratories. However, a critical problem of this method is the extremely low yield. We have tailored ball milling conditions to produce gentle shear forces that produce high quality boron nitride (BN) nanosheets in high yield and efficiency. The in-plane structure of the BN nanosheets has not been damaged as shown by near edge X-ray absorption fine structure measurements. The benzyl benzoate acts as the milling agent to reduce the ball impacts and milling contamination. This method is applicable to any layered materials for producing nanosheets.

The impact of school suspension on student tobacco use : a longitudinal study in Victoria, Australia, and Washington State, United States

Context: School suspension may have unintended consequences in contributing to problem behaviors, including dropping out from school, substance use, and antisocial behavior. Tobacco use is an early-onset problem behavior, but prospective studies of the effects of suspension on tobacco use are lacking.

Method: Longitudinal school-based survey of students drawn as a two-stage cluster sample, administered in 2002 and 2003, in Washington State, United States, and Victoria, Australia. The study uses statewide representative samples of students in Grades 7 and 9 (N = 3,599). Results: Rates of tobacco use were higher for Victorian than Washington State students. School suspension remained a predictor of current tobacco use at 12-month follow-up, after controlling for established risk factors including prior tobacco and other drug use for Grade 7 but not Grade 9 students.

Conclusions: School suspension is associated with early adolescent tobacco use, itself an established predictor of adverse outcomes in young people. Findings suggest the need to explore process mechanisms and alternatives to school suspensions as a response to challenging student behavior in early adolescence.