272 research outputs found

    Potential uses of health promotion competencies

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    Projects in Australia and internationally over the past two decades have sought to define and clarify competencies required to work in health promotion. It is now apparent that such competencies are very useful to health promotion practice. However, to date little attempt has been made to describe those uses.More than 200 health promotion practitioners throughout Australia were engaged in workshops to explore and define potential uses of health promotion competencies. The suggestions from these 10 workshops are summarised in eight categories of uses.Agreed health promotion competencies have potential to impact on recruitment, training, employment policy and health promotion practice

    Giant Oscillations of Acoustoelectric Current in a Quantum Channel

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    A theory of d.c. electric current induced in a quantum channel by a propagating surface acoustic wave (acoustoelectric current) is worked out. The first observation of the acoustoelectric current in such a situation was reported by J. M. Shilton et al., Journ. Phys. C (to be published). The authors observed a very specific behavior of the acoustoelectric current in a quasi-one-dimensional channel defined in a GaAs-AlGaAs heterostructure by a split-gate depletion -- giant oscillations as a function of the gate voltage. Such a behavior was qualitatively explained by an interplay between the energy-momentum conservation law for the electrons in the upper transverse mode with a finite temperature splitting of the Fermi level. In the present paper, a more detailed theory is developed, and important limiting cases are considered.Comment: 7 pages, 2 Postscript figures, RevTeX 3.

    Effectiveness of a Home-Based Postal and Telephone Physical Activity and Nutrition Pilot Program for Seniors

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    Objective. To evaluate the effectiveness of a 12-week home-based postal and telephone physical activity and nutrition pilot program for seniors. Methods. The program was delivered by mailed material and telephone calls. The main intervention consisted of a booklet tailored for seniors containing information on dietary guidelines, recommended physical activity levels, and goal setting. Dietary and walking activity outcomes were collected via a self-administered postal questionnaire pre- and postintervention and analysed using linear mixed regressions. Of the 270 seniors recruited, half were randomly selected for the program while others served as the control group. Results. The program elicited favourable responses. Postintervention walking for exercise/recreation showed an average gain of 27 minutes per week for the participants in contrast to an average drop of 5 minutes for the controls (P<.01). Little change was evident in errand walking for both groups. The intervention group (n=114) demonstrated a significant increase in fibre intake (P<.01) but no reduction in fat intake (P>.05) compared to controls (n=134). Conclusions. The participants became more aware of their health and wellbeing after the pilot program, which was successful in increasing time spent walking for recreation and improving fibre intake

    Reducing Attrition in Physical Activity Programs for Older Adults

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    This study investigated attrition in a 6-month physical activity intervention for older adults. The program was based on the social-cognitive theory incorporating self-efficacy factors. Two hundred forty-eight insufficiently active 65- to 74-year olds were recruited from the Australian federal electoral roll. The intervention comprised walking and strength and flexibility exercises and was conducted in 30 local neighborhoods where the participants resided. Characteristics of individuals lost to attrition (n = 86, 35%) were compared with those of programcompleters (n = 162, 65%). Logistic-regression analysis showed that those lost to attrition came from areas of lower socioeconomic status, were overweight and less physically active, and had lower walking self-efficacy scores and higher loneliness scores. The results suggest that early assessment of these characteristics should be undertaken to identify individuals at risk of attrition, to improve retention, and to avoid potential bias

    Core health promotion competencies for Australia 2007

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    Four hundred health promotion practitioners throughout Australian completed an on-line survey on Health Promotion Competencies for Australia at the end of 2005. This was followed by a series of workshops throughout Australia in 2006 to identify practical uses of the competencies and to determine a set of core competencies of health promotion practice in Australia. Many of the participants requested information about the results of the study. This brief report has been produced to describe the process and the final result. In addition more detailed accounts are contained in two articles that are being prepared for publication

    Consumers’ responses to front-of-pack labels that vary by interpretive content

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    Previous research has shown that front-of-pack labels (FoPLs) can assist people to make healthier food choices if they are easy to understand and people are motivated to use them. There is some evidence that FoPLs providing an assessment of a food’s health value (evaluative FoPLs) are easier to use than those providing only numerical information on nutrients (reductive FoPLs). Recently, a new evaluative FoPL (the Health Star Rating (HSR)) has been introduced to Australia and New Zealand. The HSR features a summary indicator, differentiating it from many other FoPLs being used around the world. The aim of this study was to understand how consumers of all ages use and make sense of reductive FoPLs and evaluative FoPLs including evaluative FoPLs with and without summary indicators. Ten focus groups were conducted in Perth, Western Australia with adults (n=50) and children aged 10-17 years (n=35) to explore reactions to one reductive FoPL (the Daily Intake Guide), an existing evaluative FoPL (multiple traffic lights), and a new evaluative FoPL (the HSR). Participants preferred the evaluative FoPLs over the reductive FoPL, with the strongest preference being for the FoPL with the summary indicator (HSR). Discussions revealed the cognitive strategies used when interpreting each FoPL (e.g., using cut offs, heuristics, and the process of elimination), which differed according to FoPL format. Most participants reported being motivated to use the evaluative FoPLs (particularly the HSR) to make choices about foods consumed as part of regular daily meals, but not for discretionary foods consumed as snacks or deserts. The findings provide further evidence of the potential utility of evaluative FoPLs in supporting healthy food choices and can assist policy makers in selecting between alternative FoPL formats

    A numerical investigation of a piezoelectric surface acoustic wave interaction with a one-dimensional channel

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    We investigate the propagation of a piezoelectric surface acoustic wave (SAW) across a GaAs/AlX_XGa1X_{1-X}As heterostructure surface, on which there is fixed a metallic split-gate. Our method is based on a finite element formulation of the underlying equations of motion, and is performed in three-dimensions fully incorporating the geometry and material composition of the substrate and gates. We demonstrate attenuation of the SAW amplitude as a result of the presence of both mechanical and electrical gates on the surface. We show that the incorporation of a simple model for the screening by the two-dimensional electron gas (2DEG), results in a total electric potential modulation that suggests a mechanism for the capture and release of electrons by the SAW. Our simulations suggest the absence of any significant turbulence in the SAW motion which could hamper the operation of SAW based quantum devices of a more complex geometry.Comment: 8 pages, 8 figure

    Quantized charge transport through a static quantum dot using a surface acoustic wave

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    We present a detailed study of the surface acoustic wave mediated quantized transport of electrons through a split gate device containing an impurity potential defined quantum dot within the split gate channel. A new regime of quantized transport is observed at low RF powers where the surface acoustic wave amplitude is comparable to the quantum dot charging energy. In this regime resonant transport through the single-electron dot state occurs which we interpret as turnstile-like operation in which the traveling wave amplitude modulates the entrance and exit barriers of the quantum dot in a cyclic fashion at GHz frequencies. For high RF powers, where the amplitude of the surface acoustic wave is much larger than the quantum dot energies, the quantized acoustoelectric current transport shows behavior consistent with previously reported results. However, in this regime, the number of quantized current plateaus observed and the plateau widths are determined by the properties of the quantum dot, demonstrating that the microscopic detail of the potential landscape in the split gate channel has a profound influence on the quantized acoustoelectric current transport.Comment: 9 page

    Acoustoelectric current and pumping in a ballistic quantum point contact

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    The acoustoelectric current induced by a surface acoustic wave (SAW) in a ballistic quantum point contact is considered using a quantum approach. We find that the current is of the "pumping" type and is not related to drag, i.e. to the momentum transfer from the wave to the electron gas. At gate voltages corresponding to the plateaus of the quantized conductance the current is small. It is peaked at the conductance step voltages. The peak current oscillates and decays with increasing SAW wavenumber for short wavelengths. These results contradict previous calculations, based on the classical Boltzmann equation.Comment: 4 pages, 1 figur

    New advances in Raman study of polyvinylchloride structure

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    In this work we investigated Raman spectra of a number of industrial grades of polyvinylchloride powder and films, prepared from solutions in tetrahydrofuran and acetophenone. The number and spectral characteristics of the Raman lines in the spectral regions of the C-Cl stretching vibrations and in the region of the C-H and CH2 stretching vibrations were evaluated
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