8,745 research outputs found

    Is subjective social status a more important determinant of health than objective social status? Evidence from a prospective observational study of Scottish men

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    Both subjective and objective measures of lower social position have been shown to be associated with poorer health. A psychosocial, as opposed to material, aetiology of health inequalities predicts that subjective social status should be a stronger determinant of health than objective social position. In a workplace based prospective study of 5232 Scottish men recruited in the early 1970s and followed up for 25 years we examined the association between objective and subjective indices of social position, perceived psychological stress, cardiovascular disease risk factors and subsequent health. Lower social position, whether indexed by more objective or more subjective measures, was consistently associated with an adverse profile of established disease risk factors. Perceived stress showed the opposite association. The main subjective social position measure used was based on individual perceptions of workplace status (as well as their actual occupation, men were asked whether they saw themselves as “employees”, “foremen”, or “managers”). Compared to foremen, employees had a small and imprecisely estimated increased risk of all cause mortality, whereas managers had a more marked decreased risk. The strongest predictors of increased mortality were father's manual as opposed to non-manual occupation; lack of car access and shorter stature, (an indicator of material deprivation in childhood). In the fully adjusted analyses, perceived work-place status was only weakly associated with mortality. In this population it appears that objective material circumstances, particularly in early life, are a more important determinant of health than perceptions of relative status. Conversely, higher perceived stress was not associated with poorer health, presumably because, in this population, higher stress was not associated with material disadvantage. Together these findings suggest that, rather than targeting perceptions of disadvantage and associated negative emotions, interventions to reduce health inequalities should aim to reduce objective material disadvantage, particularly that experienced in early life

    Individual employment histories and subsequent cause specific hospital admissions and mortality: a prospective study of a cohort of male and female workers with 21 years follow up

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    It is a widely held view that the labour market is demanding increased levels of flexibility, and that this is causing greater psychosocial stress among employees.1 Such stress may affect health, either through neuroendocrine pathways, or through increases in behaviours linked with poor health.2 Previously we presented evidence linking an unstable employment history, as measured by a greater number of job changes and shorter duration of current job, with a greater prevalence of smoking and greater alcohol consumption, in male and female workers.3 4 Despite this, we did not observe clear detrimental effects of such instability on health related physiological measures (body mass index, diastolic blood pressure, cholesterol, and lung function), nor on current cardiovascular health (electrocardiogram determined ischaemia and reported symptoms of angina). Finding work is easier for healthy persons, and those persons who need to find work repeatedly will be particularly likely to drop out of the workforce if their health deteriorates. Consequently, an occupational cohort, upon which our previous work was based, is least likely to include people of poor health with an unstable work history. If such people are underrepresented, attempts to determine the association between health and individual work histories will mislead. This study links the same cohort to information on the hospitalisations and deaths experienced over a 21 year follow up period. While those people whose health deteriorated before the enrolment of this cohort must remain poorly represented, these prospective data permit unbiased observation of those cases who experienced ill health subsequently, whether or not this resulted in an exit from the workforce. We hypothesise that an employment history characterised by frequent job changes, whatever the motivation for those changes, will require the person to be more focused on work, and less focused on maintaining personal health, with consequent poorer health for such people

    Psychological stress and cardiovascular disease: empirical demonstration of bias in a prospective observational study of Scottish men

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    Objectives: To examine the association between self perceived psychological stress and cardiovascular disease in a population where stress was not associated with social disadvantage. Design: Prospective observational study with follow up of 21 years and repeat screening of half the cohort 5 years from baseline. Measures included perceived psychological stress, coronary risk factors, self reported angina, and ischaemia detected by electrocardiography. Setting: 27 workplaces in Scotland. Participants: 5606 men (mean age 48 years) at first screening and 2623 men at second screening with complete data on all measures Main outcome measures: Prevalence of angina and ischaemia at baseline, odds ratio for incident angina and ischaemia at second screening, rate ratios for cause specific hospital admission, and hazard ratios for cause specific mortality. Results: Both prevalence and incidence of angina increased with increasing perceived stress (fully adjusted odds ratio for incident angina, high versus low stress 2.66, 95% confidence interval 1.61 to 4.41; P for trend <0.001). Prevalence and incidence of ischaemia showed weak trends in the opposite direction. High stress was associated with a higher rate of admissions to hospital generally and for admissions related to cardiovascular disease and psychiatric disorders (fully adjusted rate ratios for any general hospital admission 1.13, 1.01 to 1.27, cardiovascular disease 1.20, 1.00 to 1.45, and psychiatric disorders 2.34, 1.41 to 3.91). High stress was not associated with increased admission for coronary heart disease (1.00, 0.76-1.32) and showed an inverse relation with all cause mortality, mortality from cardiovascular disease, and mortality from coronary heart disease, that was attenuated by adjustment for occupational class (fully adjusted hazard ratio for all cause mortality 0.94, 0.81 to 1.11, cardiovascular mortality 0.91, 0.78 to 1.06, and mortality from coronary heart disease 0.98, 0.75 to 1.27). Conclusions: The relation between higher stress, angina, and some categories of hospital admissions probably resulted from the tendency of participants reporting higher stress to also report more symptoms. The lack of a corresponding relation with objective indices of heart disease suggests that these symptoms did not reflect physical disease. The data suggest that associations between psychosocial measures and disease outcomes reported from some other studies may be spurious

    Limitations of adjustment for reporting tendency in observational studies of stress and self reported coronary heart disease

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    Recently, observational evidence has been suggested to show a causal association between various "psychosocial" exposures, including psychological stress, and heart disease. Much of this evidence derives from studies in which a self reported psychosocial exposure is related to an outcome dependent on the subjective experience of coronary heart disease (CHD) symptoms. Such outcomes may be measured using standard symptom questionnaires (like the Rose angina schedule). Alternatively they may use diagnoses of disease from medical records, which depend on an individual perceiving symptoms and reporting them to a health worker. In these situations, reporting bias may generate spurious exposure-outcome associations. For example if people who perceive and report their life as most stressful also over-report symptoms of cardiovascular disease then an artefactual association between stress and heart disease will result

    Solar Coronal Structures and Stray Light in TRACE

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    Using the 2004 Venus transit of the Sun to constrain a semi-empirical point-spread function for the TRACE EUV solar telescope, we have measured the effect of stray light in that telescope. We find that 43% of 171A EUV light that enters TRACE is scattered, either through diffraction off the entrance filter grid or through other nonspecular effects. We carry this result forward, via known-PSF deconvolution of TRACE images, to identify its effect on analysis of TRACE data. Known-PSF deconvolution by this derived PSF greatly reduces the effect of visible haze in the TRACE 171A images, enhances bright features, and reveals that the smooth background component of the corona is considerably less bright (and hence much more rarefied) than commonly supposed. Deconvolution reveals that some prior conlclusions about the Sun appear to have been based on stray light in the images. In particular, the diffuse background "quiet corona" becomes consistent with hydrostatic support of the coronal plasma; feature contrast is greatly increased, possibly affecting derived parameters such as the form of the coronal heating function; and essentially all existing differential emission measure studies of small features appear to be affected by contamination from nearby features. We speculate on further implications of stray light for interpretation of EUV images from TRACE and similar instruments, and advocate deconvolution as a standard tool for image analysis with future instruments such as SDO/AIA.Comment: Accepted by APJ; v2 reformatted to single-column format for online readabilit

    Cause-specific hospital admission and mortality among working men: association with socioeconomic circumstances in childhood and adult life, and the mediating role of daily stress

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    BACKGROUND: The aim of this study was to investigate the association of childhood and adulthood social class with the occurrence of specific diseases, including those not associated with a high mortality rate, and to investigate daily stress as the mechanism for that part of any association which cannot be accounted for by established risk factors. METHODS: This was a prospective cohort study with 25 years of follow-up for cause-specific morbidity and mortality. A total of 5577 Scottish men were recruited from 27 workplaces in the West of Scotland. Childhood social class was determined from the occupation held by the individual's father, and adulthood social class from the individual's occupation at enrolment. Daily stress was measured at enrolment using the Reeder Stress Inventory. RESULTS: Health differentials were found for cardiovascular diseases, lung cancer, peptic ulcer, asthma, accidents and violence, alcohol-related diseases, and perhaps psychiatric illness. Adulthood circumstances were associated with the incidence of most diseases in adulthood, the exception being stroke, which was strongly associated with less privileged circumstances in childhood. Both childhood and adulthood circumstances contributed to the incidence of coronary heart disease. Daily stress did not underlie any of these associations once the influence of established risk factors had been taken into account. CONCLUSIONS: Socioeconomic circumstances in childhood and adulthood both contribute to health differentials in adulthood, the relative contributions depending upon the particular disease. Where known risk factors explained only part of the excess of a disease among individuals raised or living in less-privileged circumstances, there was no evidence to suggest that daily stress was the reason for the unexplained excess

    Extension in the western Ross Sea region-links between Adare Basin and Victoria Land Basin

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    Spreading in the Adare Basin off north-western Ross Sea (43–26 Ma) and extension in the Victoria Land Basin (VLB, > 36 Ma) are used to constrain the pole of rotation for the Adare Basin, providing a rifting model for the region for the past 45 Ma. The offset from Northern Basin to VLB at about 74°S coincides with the linear Polar-3 magnetic anomaly, inferred to be caused by a major 48 - 34 Ma igneous intrusion. The style of extension apparently changed at about 34 Ma, with the end of intrusion at the Polar-3 anomaly, a change from highly asymmetric extension in Adare Basin, and the onset of major subsidence on the flanks of VLB. Ductile lower crustal and lithospheric flow is proposed as the cause of the inferred thick crust underlying southern Adare Basin, and a result of the constraining of extension to the adjacent contiguous Northern Basin

    Are "EIT Waves" Fast-Mode MHD Waves?

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    We examine the nature of large-scale, coronal, propagating wave fronts (``EIT waves'') and find they are incongruous with solutions using fast-mode MHD plane-wave theory. Specifically, we consider the following properties: non-dispersive single pulse manifestions, observed velocities below the local Alfven speed, and different pulses which travel at any number of constant velocities, rather than at the ``predicted'' fast-mode speed. We discuss the possibility of a soliton-like explanation for these phenomena, and show how it is consistent with the above-mentioned aspects.Comment: to be published in the Astrophysical Journa

    Statistical mechanical aspects of joint source-channel coding

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    An MN-Gallager Code over Galois fields, qq, based on the Dynamical Block Posterior probabilities (DBP) for messages with a given set of autocorrelations is presented with the following main results: (a) for a binary symmetric channel the threshold, fcf_c, is extrapolated for infinite messages using the scaling relation for the median convergence time, tmed∝1/(fc−f)t_{med} \propto 1/(f_c-f); (b) a degradation in the threshold is observed as the correlations are enhanced; (c) for a given set of autocorrelations the performance is enhanced as qq is increased; (d) the efficiency of the DBP joint source-channel coding is slightly better than the standard gzip compression method; (e) for a given entropy, the performance of the DBP algorithm is a function of the decay of the correlation function over large distances.Comment: 6 page

    A study of packaging and shipping procedures for small electroexplosive devices Final report, May 1, 1966 - Aug. 1, 1967

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    Packaging, shipping, and shielding procedures for electroexplosive device
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