Dynamic Resonance Effects in the Statistical Distributions of Asteroids and Comets

Some principles in the distribution of Centaurs and the "Scattered Disk" objects, as well as the Kuiper belt objects for its semi-major axes, eccentricities and inclinations of the orbits have been investigated. It has been established, that more than a half from them move on the resonant orbits and that is what has been predicted earlier. The divergence of the maximum in the observable distribution of the objects of the Kuiper belt for the semi-major axes with an exact orbital resonance has been interpreted.Comment: 7 pages, 5 figures, 1 table. International Conference "100 years since Tunguska phenomenon: Past, present and future", (June 26-28, 2008. Russia, Moscow), International Conference "Modern problems of astronomy" (August 12-18, 2007, Ukraine, Odessa

A Survey for Outer Satellites of Mars: Limits to Completeness

We surveyed the Hill sphere of Mars for irregular satellites. Our search covered nearly the entire Hill Sphere, but scattered light from Mars excluded the inner few arcminutes where the satellites Phobos and Deimos reside. No new satellites were found to an apparent limiting red magnitude of 23.5, which corresponds to radii of about 0.09 km using an albedo of 0.07.Comment: 5 figures (1 color), 2 Tables, to appear in AJ Nov. 200

Occupational noise: auditory and non-auditory consequences

Occupational noise exposure accounts for approximately 16% of all disabling hearing losses, but the true value and societal costs may be grossly underestimated because current regulations only identify hearing impairments in the workplace if exposures result in audiometric threshold shifts within a limited frequency region. Research over the past several decades indicates that occupational noise exposures can cause other serious auditory deficits such as tinnitus, hyperacusis, extended high-frequency hearing loss, and poor speech perception in noise. Beyond the audiogram, there is growing awareness that hearing loss is a significant risk factor for other debilitating and potentially life-threatening disorders such as cardiovascular disease and dementia. This review discusses some of the shortcomings and limitations of current noise regulations in the United States and Europe

Lorentz Beams

A new kind of tridimensional scalar optical beams is introduced. These beams are called Lorentz beams because the form of their transverse pattern in the source plane is the product of two independent Lorentz functions. Closed-form expression of free-space propagation under paraxial limit is derived and pseudo non-diffracting features pointed out. Moreover, as the slowly varying part of these fields fulfils the scalar paraxial wave equation, it follows that there exist also Lorentz-Gauss beams, i.e. beams obtained by multipying the original Lorentz beam to a Gaussian apodization function. Although the existence of Lorentz-Gauss beams can be shown by using two different and independent ways obtained recently from Kiselev [Opt. Spectr. 96, 4 (2004)] and Gutierrez-Vega et al. [JOSA A 22, 289-298, (2005)], here we have followed a third different approach, which makes use of Lie's group theory, and which possesses the merit to put into evidence the symmetries present in paraxial Optics.Comment: 11 pages, 1 figure, submitted to Journal of Optics

Towards understanding the availability of physiotherapy services in rural Australia

Introduction: A recent exploration of factors affecting rural physiotherapy service provision revealed considerable variation in services available between communities of the study. Multiple factors combined to influence local service provision, including macro level policy and funding decisions, service priorities and fiscal constraints of regional health services and capacity and capabilities at the physiotherapy service level. The aim of this article is to describe the variation in local service provision, the factors influencing service provision and the impact on availability of physiotherapy services. Methods: A priority-sequence mixed methods design structured the collection and integration of qualitative and quantitative data. The investigation area, a large part of one Australian state, was selected for the number of physiotherapy services and feasibility of conducting site visits. Stratified purposive sampling permitted exploration of rural physiotherapy with subgroups of interest, including physiotherapists, their colleagues, managers, and other key decision makers. Participant recruitment commenced with public sector physiotherapists and progressed to include private practitioners, team colleagues and managers. Surveys were mailed to key physiotherapy contacts in each public sector service in the area for distribution to physiotherapists, their colleagues and managers within their facility. Private physiotherapist principals working in the same communities were invited by the researcher to complete the physiotherapy survey. The survey collected demographic data, rural experience, work setting and number of colleagues, services provided, perspectives on factors influencing service provision and decisions about service provision. Semi-structured interviews were conducted with consenting physiotherapists and other key decision makers identified by local physiotherapists. Quantitative survey data were recorded in spreadsheets and analysed using descriptive statistics. Interviews were recorded and transcribed verbatim, with transcripts provided to participants for review. Open-ended survey questions and interview transcripts were analysed thematically. Results: Surveys were received from 11/25 (44%) of facilities in the investigation area, with a response rate of 29.4% (16/54) from public sector physiotherapists. A further 18 surveys were received: five from principals of private physiotherapy practices and 13 from colleagues and managers. Nineteen interviews were conducted: with 14 physiotherapists (nine public, five private), four other decision makers and one colleague. Three decision makers declined an interview. The variation in physiotherapy service availability between the 11 communities of this study prompted the researchers to consider how such variation could be reflected. The influential factors that emerged from participant comments included rurality and population, size and funding model of public hospitals, the number of public sector physiotherapists and private practices, and the availability of specialised paediatric and rehabilitation services. The factors described by participants were used to develop a conceptual framework or index of rural physiotherapy availability. Conclusions: It is important to make explicit the link between workforce maldistribution, the resultant rural workforce shortages and the implications for local service availability. This study sought to do so by investigating physiotherapy service provision within the rural communities of the investigation area. In doing so, varying levels of availability emerged within local communities. A conceptual framework combining key influencing factors is offered as a way to reflect the availability of physiotherapy services

The Anti-Coincidence Detector for the GLAST Large Area Telescope

This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LAT first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and 4 sides of the LAT tracking detector, requiring a total active area of ~8.3 square meters. The ACD detector utilizes plastic scintillator tiles with wave-length shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997.Comment: 33 pages, 19 figure

Towards understanding the availability of physiotherapy services in rural Australia

Introduction: A recent exploration of factors affecting rural physiotherapy service provision revealed considerable variation in services available between communities of the study. Multiple factors combined to influence local service provision, including macro level policy and funding decisions, service priorities and fiscal constraints of regional health services and capacity and capabilities at the physiotherapy service level. The aim of this article is to describe the variation in local service provision, the factors influencing service provision and the impact on availability of physiotherapy services. Methods: A priority-sequence mixed methods design structured the collection and integration of qualitative and quantitative data. The investigation area, a large part of one Australian state, was selected for the number of physiotherapy services and feasibility of conducting site visits. Stratified purposive sampling permitted exploration of rural physiotherapy with subgroups of interest, including physiotherapists, their colleagues, managers, and other key decision makers. Participant recruitment commenced with public sector physiotherapists and progressed to include private practitioners, team colleagues and managers. Surveys were mailed to key physiotherapy contacts in each public sector service in the area for distribution to physiotherapists, their colleagues and managers within their facility. Private physiotherapist principals working in the same communities were invited by the researcher to complete the physiotherapy survey. The survey collected demographic data, rural experience, work setting and number of colleagues, services provided, perspectives on factors influencing service provision and decisions about service provision. Semi-structured interviews were conducted with consenting physiotherapists and other key decision makers identified by local physiotherapists. Quantitative survey data were recorded in spreadsheets and analysed using descriptive statistics. Interviews were recorded and transcribed verbatim, with transcripts provided to participants for review. Open-ended survey questions and interview transcripts were analysed thematically. Results: Surveys were received from 11/25 (44%) of facilities in the investigation area, with a response rate of 29.4% (16/54) from public sector physiotherapists. A further 18 surveys were received: five from principals of private physiotherapy practices and 13 from colleagues and managers. Nineteen interviews were conducted: with 14 physiotherapists (nine public, five private), four other decision makers and one colleague. Three decision makers declined an interview. The variation in physiotherapy service availability between the 11 communities of this study prompted the researchers to consider how such variation could be reflected. The influential factors that emerged from participant comments included rurality and population, size and funding model of public hospitals, the number of public sector physiotherapists and private practices, and the availability of specialised paediatric and rehabilitation services. The factors described by participants were used to develop a conceptual framework or index of rural physiotherapy availability. Conclusions: It is important to make explicit the link between workforce maldistribution, the resultant rural workforce shortages and the implications for local service availability. This study sought to do so by investigating physiotherapy service provision within the rural communities of the investigation area. In doing so, varying levels of availability emerged within local communities. A conceptual framework combining key influencing factors is offered as a way to reflect the availability of physiotherapy services

Detecting the harmonics of oscillations with time-variable frequencies

A method is introduced for the spectral analysis of complex noisy signals containing several frequency components. It enables components that are independent to be distinguished from the harmonics of nonsinusoidal oscillatory processes of lower frequency. The method is based on mutual information and surrogate testing combined with the wavelet transform, and it is applicable to relatively short time series containing frequencies that are time variable. Where the fundamental frequency and harmonics of a process can be identified, the characteristic shape of the corresponding oscillation can be determined, enabling adaptive filtering to remove other components and nonoscillatory noise from the signal. Thus the total bandwidth of the signal can be correctly partitioned and the power associated with each component then can be quantified more accurately. The method is first demonstrated on numerical examples. It is then used to identify the higher harmonics of oscillations in human skin blood flow, both spontaneous and associated with periodic iontophoresis of a vasodilatory agent. The method should be equally relevant to all situations where signals of comparable complexity are encountered, including applications in astrophysics, engineering, and electrical circuits, as well as in other areas of physiology and biology