The Stability of Self Assessed Health Status

The use of self assessed health status as a measure of health is common in empirical research. We analyse a unique Australian survey in which a random sub-sample of respondents answer a standard self assessed health question twice – before and after an additional set of health related questions. 28% of respondents change their reported health status. Response instability is related to age, income and occupation. We also compare the responses of these individuals to other respondents who are queried only once. The distributions of responses to both questions by the former group are statistically different from the distribution of responses by the latter group.Self assessed health status

The Stability of Self Assessed Health Status

The use of self assessed health status as a measure of health is common in empirical research. We analyse a unique Australian survey in which a random sub-sample of respondents answer a standard self assessed health question twice -- before and after an additional set of health related questions. 28% of respondents change their reported health status. Response instability is related to age, income and occupation. We also compare the responses of these individuals to other respondents who are queried only once. The distributions of responses to both questions by the former group are statistically different from the distribution of responses by the latter group.self-assessed health status

The stability of self assessed health status

The use of self assessed health status as a measure of health is common in empirical research. We analyse a unique Australian survey in which a random sub-sample of respondents answer a standard self assessed health question twice – before and after an additional set of health related questions. 28% of respondents change their reported health status. Response instability is related to age, income and occupation. We also compare the responses of these individuals to other respondents who are queried only once. The distribution of the responses to both questions by the former group are statistically different from the distribution of responses by the latter group

MOLECULAR ENGINEERING STRATEGIES FOR THE PRODUCTION OF FUELS FROM CONVENTIONAL AND RENEWABLE RESOURCES

The combination of Quantitative Structure Property Relationships (QSPR) with experimental studies using model compounds provides great promise for fuel upgrading. Through this approach, QSPR software is utilized to predict fuel properties of interest for model compounds as well as for any potential reaction products. Catalytic studies are performed in combination with QSPR, attempting to maximize selectivity to products with the optimal fuel properties of interest. QSPR provides the direction to which specific chemical bonds should be broken or formed to optimize fuel properties, while model compound studies relate the properties of the catalyst and reaction conditions to the selectivity towards specific products. The end result is a guided approach to catalyst design which maximizes knowledge gained, with a constant link to practical application through fuel property prediction. This methodology has a dual benefit. While practical advancement for fuel improvement is gained, fundamental knowledge is developed about relationships between specific molecules and catalysts.In this contribution, examples will be given for the development of important fuel properties, their prediction with QSPR, and further optimization through model compound studies. A further extension of QSPR will then be made in order to predict not only fuel properties, but primary product selectivities as well. Transitioning of these strategies to oxygenated hydrocarbons more representative of renewable fuel sources (e.g. biomass) will also be discussed. This methodology allows the development of not only novel catalytic strategies utilizing conventional reactors, but also a new catalytic system with enormous potential through the use of nano-hybrids at the oil-water interface

Effects of geodynamic setting on the redox state of fluids released by subducted mantle lithosphere

Magnetite breakdown during subduction of serpentinised ultramafic rocks may produce oxidised fluids that oxidise the deep Earth and/or the sub-arc mantle, either via direct transport of ferric iron, or via redox reactions between ferric iron and other elements, such as sulfur. However, so far, there is no consensus on the oxidation state of fluids released during subduction of ultramafic rocks, or the factors that control this oxidation state. Subducted samples from a magma-poor rifted margin and a supra-subduction zone geodynamic setting were compared to examine evidence of changes in opaque phase assemblage and ferric iron content as a consequence of subduction, and as a function of geodynamic setting. Thermodynamic calculations in the system Fe–Ni–O–H–S and Fe–Ni–O–S at the pressures and temperatures of interest were used to constrain oxygen activities and fluid compositions. Samples from New Caledonia, which exemplify supra-subduction zone mantle, contain awaruite (FeNi3) and equilibrated with hydrogen-bearing fluids at oxygen activity less than the FMQ (fayalite–magnetite–quartz) buffer. In contrast, samples from the Zermatt Saas Zone ophiolite, Western Alps, which are thought to represent mantle from a subducted magma-poor rifted margin, contain magnetite plus sulfur-rich phases such as pyrite (FeS2), and are inferred to have equilibrated with hydrogen-poor fluids at oxygen activity greater than FMQ. This major difference is independent of differences in subduction pressure–temperature conditions, variation in peridotite protolith composition, or the nature of adjacent units. We propose that the Zermatt Saas Zone samples would have undergone more complete serpentinisation prior to subduction than the supra-subduction zone (SSZ) New Caledonian samples. This difference explains the different fluid compositions, because incompletely serpentinised rocks containing olivine and brucite retain or evolve awaruite-bearing assemblages that buffer fluid compositions to high hydrogen activity (aH2). Ultramafic rocks are associated with two distinctly different fluid compositions during pre-subduction and subduction serpentinisation. Initially, while olivine is in equilibrium with infiltrating fluid, mineral assemblages that include awaruite in the rocks buffer fluids to H2-bearing, low aO2 compositions. Deserpentinisation of incompletely serpentinised rocks in which awaruite is present also produces H2-bearing fluids. Once awaruite is exhausted, H2-poor, high aO2 fluids co-exist with awaruite-absent assemblages, and deserpentinisation of such rocks would produce H2O-rich fluids. Thus, deserpentinisation of ultramafic rocks could produce either hydrogen-bearing fluids that could infiltrate and reduce the sub-arc mantle, or more oxidised fluids, which could transfer redox budget to other geochemical reservoirs such as the sub-arc mantle. Therefore, the redox contribution of subducted ultramafic rocks to the deep Earth and sub-arc mantle depends on the extent of protolith serpentinisation. Pre-subduction settings that promote extensive serpentinisation by oxidised fluids at high fluid:rock ratios in open systems, such as slow and ultraslow spreading ridges, transform faults, oceanic core complexes, and exhumed mantle at rifted continental margins, may produce more oxidised fluids than those associated with less pervasive serpentinisation and fluids that may be rock-buffered to a reduced state

Who rebounds most? Estimating direct and indirect rebound effects for different UK socioeconomic groups

This study estimates the combined direct and indirect rebound effects from various types of energy efficiency improvement and behavioural change by UK households and explores how these effects vary with total expenditure. The methodology is based upon estimates of the expenditure elasticity and GHG intensity of 16 categories of goods and services, and allows for the capital cost and embodied emissions of the energy efficiency measures themselves. The study finds that rebound effects, in GHG terms, are modest (0–32%) for measures affecting domestic energy use, larger (25–65%) for measures affecting vehicle fuel use and very large (66–106%) for measures that reduce food waste. Furthermore, measures undertaken by low income households are associated with the largest rebound effects, with direct emissions forming a larger proportion of the total rebound effect for those households. Measures that are subsidised or affect highly taxed energy commodities may be less effective in reducing aggregate emissions. These findings highlight the importance of allowing for rebound effects within policy appraisals, as well as reinforcing the case for economy-wide carbon pricing

Contesting the psychiatric framing of ME / CFS

ME/CFS is a medically contested illness and its understanding, framing and treatment has been the subject of heated debate. This paper examines why framing the condition as a psychiatric issue—what we refer to as ‘psychiatrisation’—has been so heavily contested by patients and activists. We argue that this contestation is not simply about stigmatising mental health conditions, as some have suggested, but relates to how people diagnosed with mental illness are treated in society, psychiatry and the law. We highlight the potentially harmful consequences of psychiatrisation which can lead to people’s experiential knowledge being discredited. This stems, in part, from a psychiatric-specific form of ‘epistemic injustice’ which can result in unhelpful, unwanted and forced treatments. This understanding helps explain why the psychiatrisation of ME/CFS has become the focus of such bitter debate and why psychiatry itself has become such a significant field of contention, for both ME/CFS patients and mental health service users/survivors. Notwithstanding important differences, both reject the way psychiatry denies patient explanations and understandings, and therefore share a collective struggle for justice and legitimation. Reasons why this shared struggle has not resulted in alliances between ME and mental health activists are noted

HAPPi Kneecaps! Protocol for a participant- and assessor-blinded, randomised, parallel group feasibility trial of foot orthoses for adolescents with patellofemoral pain

BACKGROUND: Patellofemoral pain (PFP) is a common cause of knee pain in adolescents, but there are limited evidence-based treatment options for this population. Foot orthoses can improve pain and function in adults with PFP, and may be effective for adolescents. The primary aim of th

Genetic randomization reveals functional relationships among morphologic and tissue-quality traits that contribute to bone strength and fragility

We examined femora from adult AXB/BXA recombinant inbred (RI) mouse strains to identify skeletal traits that are functionally related and to determine how functional interactions among these traits contribute to genetic variability in whole-bone stiffness, strength, and toughness. Randomization of A/J and C57BL/6J genomic regions resulted in each adult male and female RI strain building mechanically functional femora by assembling unique sets of morphologic and tissue-quality traits. A correlation analysis was conducted using the mean trait values for each RI strain. A third of the 66 correlations examined were significant, indicating that many bone traits covaried or were functionally related. Path analysis revealed important functional interactions among bone slenderness, cortical thickness, and tissue mineral density. The path coefficients describing these functional relations were similar for both sexes. The causal relationship among these three traits suggested that cellular processes during growth simultaneously regulate bone slenderness, cortical thickness, and tissue mineral density so that the combination of traits is sufficiently stiff and strong to satisfy daily loading demands. A disadvantage of these functional interactions was that increases in tissue mineral density also deleteriously affected tissue ductility. Consequently, slender bones with high mineral density may be stiff and strong but they are also brittle. Thus, genetically randomized mouse strains revealed a basic biological paradigm that allows for flexibility in building bones that are functional for daily activities but that creates preferred sets of traits under extreme loading conditions. Genetic or environmental perturbations that alter these functional interactions during growth would be expected to lead to loss of function and suboptimal adult bone quality