339 research outputs found

    Procedures for democratic planning: Issues and proposals.

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    A risk management approach to pillar extraction in the Central Appalachian coalfields

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    Central Appalachian coal reserves are a valuable natural resource in high demand, both domestically and internationally. The need for this resource necessitates recovery a high percentage of the coal reserves. The mining technique that is most often utilized to extract Central Appalachian coal at high recovery rates involves the development of entries and cross-cuts within the coal seam and the subsequent removal of the coal pillars that remain. The practice of extracting coal pillars is commonly referred to as pillaring or retreat mining.;The problem associated with pillar extraction is the additional safety risk posed to miners during pillar extraction. This thesis, will investigate the application of pillaring in Central Appalachia, and based on this investigation, develop a risk management-based strategy that targets personnel performance-based risk, in order to improve the ability of safety trainers to tailor training programs to the needs of pillaring sections.;Several conclusions have been determined in this thesis. Although pillaring has its roots in antiquated mining methods, current technology and mining practices have made this form of mining highly modernized. This modernization of the pillaring process has made great strides towards improving safety. However, current fatality trends suggest that work still needs to be done to control the residual risk that is not controlled by modern machinery and mining practices. Fatalities and accidents almost always have a personnel performance related component. These performances that have been identified in previous fatal accidents are still commonly observed in Central Appalachia. The risk management based strategy developed in this thesis can successfully identify and quantify risk associated with personnel performance. This ability to quantitatively assess performance based risk can have a significant impact on the ability of safety managers to train the workforce, and therefore, should have a positive impact on pillaring safety in Central Appalachia

    Federal Tax Restructuring and State and Local Governments: An Introduction to the Issues and the Literature

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    This short Article briefly outlines some of the issues inherent in substituting a comprehensive consumption tax for the existing federal personal and corporate income taxes. It addresses the effects of federal tax restructuring on state and local governments based on state reliance on the federal income tax infrastructure, as well as outlining other major issues for states and localities. The authors recommend that Congress consider the impact of tax reform on state and local governments as among the two or three most important issues it must study as it explores restructuring the federal tax system

    Loneliness and Schizotypy Are Distinct Constructs, Separate from General Psychopathology

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    Loneliness is common in youth and associated with a significantly increased risk of psychological disorders. Although loneliness is strongly associated with psychosis, its relationship with psychosis proneness is unclear. Our aim in this paper was to test the hypothesis that loneliness and schizotypal traits, conveying risk for schizophrenia spectrum disorders, are similar but separate constructs. Pooling data from two non-clinical student samples (N = 551) we modeled the structure of the relationship between loneliness and trait schizotypy. Loneliness was assessed with the University of California, Los Angeles Loneliness Scale (UCLA-3), whilst negative (Social Anhedonia) and positive (Perceptual Aberrations) schizotypal traits were assessed with the Wisconsin Schizotypy Scales-Brief (WSS-B). Fit statistics indicated that the best fitting model of UCLA-3 scores comprises three correlated factors (Isolation, Related Connectedness, and Collective Connectedness), consistent with previous reports. Fit statistics for a two factor model of positive and negative schizotypy were excellent. Next, bi-factor analysis was used to model a general psychopatholgy factor (p) across the three loneliness factors and separate negative and positive schizotypy traits. The results showed that all items (except 1) co-loaded on p. However, with the influence of p removed, additional variance remained within separate sub-factors, indicating that loneliness and negative and positive trait schizotypy are distinct and separable constructs. Similarly, once shared variance with p was removed, correlations between sub-factors of loneliness and schizotypal traits were non-significant. These findings have important clinical implications since they suggest that loneliness should not be conflated with the expression of schizotypy. Rather, loneliness needs to be specifically targeted for assessment and treatment in youth at risk for psychosis

    Correlates of physical activity and sedentary time in young adults: The Western Australian Pregnancy Cohort (Raine) Study

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    Background: The socioecological model proposes a wide array of factors that influence behaviours. There is a need to understand salient correlates of these activity behaviours in a specific population. However, few studies identified socio-demographic, behavioural, physical, and psychological correlates of objectively-assessed physical activity and sedentary time in young adults. Methods: This was a cross-sectional analysis of participants in the Raine Study (a pregnancy cohort started in 1989). Australian young adults (mean 22.1 years ± SD 0.6) wore Actigraph GT3X+ accelerometers on the hip 24 h/day for seven days to assess moderate-to-vigorous physical activity (MVPA) and sedentary time (n = 256 women, n = 219 men). Potential correlates were assessed via clinical assessment and questionnaire and included socio-demographic variables (ethnicity, relationship status, work/study status, education, mothers education), health behaviours (food intake, alcohol consumption, smoking status, sleep quality), and physical and psychological health aspects (anthropometrics, diagnosed disorders, mental health, cognitive performance). Backwards elimination (p < 0.2 for retention) with mixed model regressions were used and the gender-stratified analyses were adjusted for demographic variables, waking wear time and number of valid days. Results: Increased time spent in MVPA was associated with: being single (IRR 1.44 vs in a relationship living together, 95%CI: 1.17, 1.77, p =.001) in women; and better sleep quality in men (lower scores better IRR 0.97, 95%CI: 0.93, 1.00). Less time spent sedentary was associated with: lower mother's education (- 32.1 min/day, 95%CI -52.9, 11.3, p = 0.002 for having mother with no university degree vs at least a baccalaureate degree) and smoking (- 44.3 min/day, 95%CI: - 72.8, - 15.9, p =.0002) for women; lower education status (- 32.1 min/day, 95%CI: -59.5, - 4.8, p = 0.021 for having no university degree vs at least a baccalaureate degree) and lower depression scores in men (- 2.0, 95%CI: - 3.5, - 0.4, p = 0.014); more alcoholic drinks per week for women (- 1.9 min/day, 95%CI: -3.1, - 0.6, p = 0.003) and men (- 1.0, 95%CI: -1.8, - 0.3, p = 0.007). Conclusions: Less desirable correlates were associated with positive levels of activity in young Australian adult women and men. Interventions to increase MVPA and decrease sedentary activity in young adults need to specifically consider the life stage of young adults

    Motor subtype as a predictor of future working memory performance in idiopathic Parkinson\u27s disease

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    Parkinson’s disease is a progressive neurodegenerative disorder associated with reduced spatial and verbal working memory ability. There are two established motor subtypes of PD, tremor dominant (TD) and postural instability and gait difficulty (PIGD). This study used structural equation modelling to explore the longitudinal relationship between the two subtypes and working memory assessed at a 2-year follow-up. The study comprised 84 males and 30 females (N = 114), aged between 39 and 85 (M = 64.82, SD = 9.23) with confirmed PD. There was no significant relationship between motor subtype at Time 1 and working memory at Time 2. Postural symptom severity at Time 1 predicted Time 2 spatial working memory for the PIGD subtype (p = .011) but not the TD subtype. Tremor symptoms were not associated with Time 2 working memory in either subtype. Predictive significance of Time 1 postural symptoms only in the PIGD subtype suggests an interaction between symptom dominance (subtype) and symptom severity that future subtyping should consider. This study demonstrates a predictive relationship between postural difficulties and working memory performance assessed at a 2-year follow-up. Establishing physical symptoms as predictors of cognitive change could have significant clinical importance

    P092 improving postgraduate psychology students’ sleep and insomnia knowledge with a sleep education workshop

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    Abstract Introduction Trainee psychologists receive limited sleep and insomnia education during postgraduate study. This study examined the delivery of a sleep psychology training workshop for postgraduate psychology students and examined changes in sleep knowledge from pre- to post-workshop. Methods A 6-hour Sleep Psychology Workshop was delivered to postgraduate psychology students around Victoria. Online pre- and post-workshop questionnaires were used to evaluate changes in sleep psychology knowledge and collect feedback on the workshop. Results The participants were 187 students (82% female, M age = 32), most of whom were in their 5th year of psychology training (69%) and had not received any sleep education during their postgraduate studies at the date of the intervention (77%). Students’ sleep knowledge significantly improved after workshop completion (pre: 56% vs. post: 80% correct), t(107)= -21.41, p < .001. Students provided positive feedback about the workshop, with 96% rating the workshop as excellent/very good and 86% reporting that they would recommend the workshop to other postgraduate students. Overall, 94% of students agreed/strongly agreed that the sleep psychology workshop improved their confidence to manage sleep disturbances in their future psychology practice. Discussion Postgraduate psychology students require sleep and insomnia education. This study demonstrates that students’ sleep psychology knowledge can improve after a 6-hour sleep education and training workshop and provides initial positive feedback about the benefits of sleep and insomnia education for postgraduate students

    Attention and fluctuating attention in patients with dementia with lewy bodies and alzheimer disease

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    Background: Attentional deficits are described in the consensus clinical criteria for the operationalized diagnosis of dementia with Lewy bodies (DLB) as characteristic of the condition. In addition, preliminary studies have indicated that both attentional impairments and fluctuation of attentional impairments are more marked in patients with DLB than in patients with Alzheimer disease (AD), although neuropsychological function has not previously been examined in a large prospective cohort with confirmed diagnostic accuracy against postmortem diagnosis. Methods: A detailed evaluation of attention and fluctuating attention was undertaken in 155 patients with dementia (85 with DLB and 80 with AD) from a representative hospital dementia case register and 35 elderly controls using the Cognitive Drug Research Computerized Assessment System for Dementia Patients computerized neuropsychological battery. Operationalized clinical diagnosis was made using the consensus criteria for DLB and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for AD. High levels of sensitivity and specificity have been achieved for the first 50 cases undergoing postmortem examination. Results: The groups were well matched for severity of cognitive impairments, bur the AD patients were older (mean age, 80 vs 78 years) and more likely to be female (55 vs 40). Patients with DLB were significantly more impaired than patients with AD on all measures of attention and fluctuating attention (for all comparisons, t � 2.5, P<.001), and patients from both dementia groups were significantly more impaired than elderly controls for all comparisons other than cognitive reaction time, which was significantly more impaired in DLB patients than controls but was comparable in controls and AD patients. There were, however, significant associations between the severity of cognitive impairment and the severity of both attentional deficits and fluctuations in attention. Conclusions: This large prospective study confirms that slowing of cognitive processing, attention, and fluctuations of attention are significantly more pronounced in DLB and AD patients, although fluctuating attention is common in patients with moderate-to-severe AD. Deficits of cognitive reaction rime appear to be specific to DLB, except in severe dementia. A detailed evaluation of attentional performance could make an important contribution to differential diagnosis, although the results need to be interpreted within the context of the overall severity of cognitive deficits

    Double Quantum Dots as Detectors of High-Frequency Quantum Noise in Mesoscopic Conductors

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    We propose a measurement set-up for detecting quantum noise over a wide frequency range using inelastic transitions in a tunable two-level system as a detector. The frequency-resolving detector consists of a double quantum dot which is capacitively coupled to the leads of a nearby mesoscopic conductor. The inelastic current through the double quantum dot is calculated in response to equilibrium and non-equilibrium current fluctuations in the nearby conductor, including vacuum fluctuations at very low temperatures. As a specific example, the fluctuations across a quantum point contact are discussed.Comment: 4 pages, 4 figures. Final version to appear in Physical Review Letter

    Mesoscopic Stern-Gerlach device to polarize spin currents

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    Spin preparation and spin detection are fundamental problems in spintronics and in several solid state proposals for quantum information processing. Here we propose the mesoscopic equivalent of an optical polarizing beam splitter (PBS). This interferometric device uses non-dispersive phases (Aharonov-Bohm and Rashba) in order to separate spin up and spin down carriers into distinct outputs and thus it is analogous to a Stern-Gerlach apparatus. It can be used both as a spin preparation device and as a spin measuring device by converting spin into charge (orbital) degrees of freedom. An important feature of the proposed spin polarizer is that no ferromagnetic contacts are used.Comment: Updated to the published versio
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