Subduction dynamics is strongly dependent on the geometry and rheology of the subducting slab and adjacent plates, as well as on the induced mantle flow driven by the evolution of tectonic ...configurations along subduction zones. However, these processes, and the associated plate tectonic driving forces, are difficult to study using time‐dependent 3‐dimensional computer simulations due to limitations in computing resources. We investigate these phenomena with a novel numerical approach, using BEM‐Earth, a Stokes flow solver based on the Boundary Element Method (BEM) with a Fast‐Multipole (FM) implementation. The initial BEM‐Earth model configurations self‐consistently determine the evolution of the entire lithosphere‐mantle system without imposing additional constraints in a whole‐Earth spherical setting. We find that models without an overriding plate overestimate trench retreat by 65% in a 20 m.y. model run. Also, higher viscosity overriding plates are associated with higher velocity subducting slabs, analogue to faster oceanic plates subducting beneath more rigid continental lithosphere. In our models poloidal flows dominate the coupling between the down‐going and overriding plates, with trench‐orthogonal length variations in overriding plates inducing flows at least ∼2× stronger than trench‐parallel width variations. However, deformation in the overriding plate is related to its length and width, with narrower and longer plates extending more than wider and shorter plates.
Key Points
Quantify the role an overriding plate has on subduction dynamics
Determine subduction zone geometry and rheology influence on plate velocities
Determine ratios of driving forces distributed in simplified subduction systems
Violence against women is increasingly recognised as an important issue in both research and social policy.
To assess the lifetime experience of physical and sexual violence among lone and partnered ...mothers and the association with psychiatric disorders.
Analysis of the Australian National Survey of Mental Health and Wellbeing. The representative sample included 2232 women with children who completed the Composite International Diagnostic Interview, a scale of psychological distress and sociodemographic measures.
Lone mothers were more likely to have psychiatric disorders (odds ratios between 2.4 and 3.4) and have experienced physical and sexual violence (odds ratios between 3.1 and 4.1) than partnered mothers. The measures of physical and sexual violence were better predictors of psychiatric disorders than either lone parent status or the sociodemographic measures.
Experience of physical and sexual violence accounted for much of the greater prevalence of psychiatric disorders among lone compared with partnered mothers.
Abstract Objective While it is clear that health behaviors are related to self-rated health (SRH), it is less clear if maintaining positive behaviors, or improving, can protect SRH over time. Method ...SRH trajectories were modeled in a large representative Australian sample (n = 7485 at baseline), of three age cohorts (20–24, 40–44 and 60–64 years at baseline; 1999, 2000 & 2001 respectively), over an 8 year period. Change in smoking, alcohol consumption and physical activity on SRH trajectories were examined, controlling for demographic, physical and mental health factors. Results SRH became poorer over time across the sample. Being a non-smoker was associated with more positive SRH levels across all groups. Maintaining or increasing moderate physical activity was associated with less decline in SRH. Conclusions Findings highlight the benefits of positive health behaviors, particularly performing regular physical activity over time, for reducing the risk of subjective health becoming poorer across the adult life course.
•Psychological distress has been linked to a higher risk of sickness absence (SA).•Most studies have failed to control for unmeasured time-invariant confounders.•A within-individual analysis takes ...time-invariant differences into account.•Within-individual associations were much smaller than those between-individuals.•Repeated measures for the same individuals may provide more reliable SA estimates.
Uncertainty remains whether associations for psychological distress and sickness absence (SA) observed between and within individuals differ, and whether age, gender and work-related factors moderate these associations.
We analyzed SA records of 41,184 participants of the Finnish Public Sector study with repeated survey data between 2000 and 2016 (119,024 observations). Psychological distress was measured by the General Health Questionnaire (GHQ-12), while data on SA days were from the employers’ registers. We used a hybrid regression estimation approach adjusting for time-variant confounders—age, marital status, occupational class, body mass index, job contract type, months worked in the follow-up year, job demand, job control, and workplace social capital—and time-invariant gender (for between-individual analysis).
Higher levels of psychological distress were consistently associated with SA, both within- and between-individuals. The within-individual association (incidence rate ratio (IRR) 1.68, 95% CI 1.61−1.75 for SA at high distress), however, was substantially smaller than the between-individual association (IRR 2.53, 95% CI 2.39−2.69). High levels of psychological distress had slightly stronger within-individual associations with SA among older (>45 years) than younger employees, lower than higher occupational class, and among men than women. None of the assessed work unit related factors (e.g. job demand, job control) were consistent moderators.
These findings may not be generalizable to other working sectors or cultures with different SA policies or study populations that are male dominated.
Focus on within-individual variation over time provides more accurate estimates of the contribution of mental health to subsequent sickness absence.
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•Psychosocial risks are well-recognised occupational health hazards.•No critical exposure levels exist for psychosocial risks to inform risk management.•We offer a method to estimate critical levels ...of exposure for psychosocial risks.•We identify critical levels of job control using the benchmark dose method.•Influence over many aspects of work is needed to reduce the risk of depression.
We present a novel approach to identify critical exposure levels or health-based benchmarks of job control using the benchmark dose (BMD) method. This method provides benchmarks for risk assessment of psychosocial risks, similar to benchmarks used for other occupational health hazards such as chemicals.
Two staged (bivariate and adjusted) BMD modelling was conducted using epidemiological data from an age-cohort study in south-eastern Australia. The adjusted BMD model incorporated age, gender, education, personality traits and mental health status at baseline.
Depression is a more sensitive (health compromising) outcome for job control compared to anxiety in both types of BMD modelling. For an excess risk of 5% for depression, the adjusted benchmark dose was 0.49 and the critical exposure level, being the lower one sided 95% confidence limit of the adjusted BMD, was 0.37. If workplace guidelines are based on this critical exposure level, workers need to have a minimum of ten out of 15 aspects of job control measured in this study to reduce the excess risk of depression.
The BMD approach can identify critical exposure levels for job control. This suggests a similar approach can be used for other psychosocial risks for which no critical exposure levels are currently available. Critical exposure levels can provide guidance needed to assess risk and address psychosocial risks, similar to other health hazards. Benchmarks or critical exposure levels of psychosocial risks can assist the inspectorate and employers to conduct risk assessment of workplaces and identify areas for intervention.
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