The effects of rheological layering on post-seismic deformation

We examine the effects of rheological layering on post-seismic deformation using models of an elastic layer over a viscoelastic layer and a viscoelastic half-space. We extend a general linear viscoelastic theory we have previously proposed to models with two layers over a half-space, although we only consider univiscous Maxwell and biviscous Burgers rheologies. In layered viscoelastic models, there are multiple mechanical timescales of post-seismic deformation; however, not all of these timescales arise as distinct phases of post-seismic relaxation observed at the surface. The surface displacements in layered models with only univiscous, Maxwell viscoelastic rheologies always exhibit one exponential-like phase of relaxation. Layered models containing biviscous rheologies may produce multiple phases of relaxation, where the distinctness of the phases depends on the geometry and the contrast in strengths between the layers. Post-seismic displacements in models with biviscous rheologies can often be described by logarithmic functions

Interseismic strain accumulation: Spin-up, cycle invariance, and irregular rupture sequences

Using models of infinite length strike-slip faults in an elastic layer above linear viscoelastic regions, we investigate interseismic deformation. In the models we investigate, interseismic strain accumulation on mature faults is the result of the cumulative effects of all previous ruptures and is independent of the fault loading conditions. The time for a fault to spin-up to a mature state depends on the rheologies and the fault loading conditions. After the model has spun-up, the temporal variation of shear stresses is determined by the fault slip rate and model rheologies. The change in stress during spin-up depends on the slip rate, rheologies, and fault loading conditions but is independent of the magnitude of the initial stress. Over enough cycles such that the cumulative deformation is block-like, the average mature interseismic velocities are equal to the interseismic velocities of an elastic model with the same geometry and distribution of shear moduli. In a model that has spun-up with the fault rupturing periodically, the cumulative deformation is block-like at the end of each seismic cycle, and the interseismic deformation is cycle-invariant (i.e., the same in all cycles). When the fault ruptures nonperiodically, the fault spins up to a mature state that is the same as if the fault had ruptured periodically with the mean slip rate. When the fault slip rate within each cycle varies, the interseismic deformation evolves toward the cycle-invariant deformation determined by the most recent fault slip rate. Around a fault whose slip rate has been faster (slower) than average, interseismic velocities are larger (smaller) than the cycle-invariant velocities and increase (decrease) from cycle to cycle

Job crafting and playful work design: Links with performance during busy and quiet days

This study uses proactive work behavior and job demands–resources (JD-R) theories to propose that employees can use two proactive behavioral strategies to improve the internal organizational environment, namely job crafting and playful work design (PWD). Whereas job crafting concerns the proactive adjustment of the job, PWD refers to the active creation of conditions at work that foster play. We hypothesize that individuals perform better on the days they seek job resources and challenges, or design their work to be playful. In addition, we propose that seeking job resources and reducing job demands are most effective when work pressure is high, and that seeking challenges and PWD are most effective when work pressure is low. A total of 77 Norwegian naval cadets completed a diary questionnaire for 30 consecutive days (total N = 2310). Results of multilevel modeling showed that daily seeking job resources, seeking challenges, and playful work design were each positively related to colleague-ratings of job performance. Reducing job demands was negatively related to performance. Furthermore, as hypothesized, seeking challenges and PWD were most effective when the work pressure was low. These findings contribute to the proactive work motivation and JD-R literatures by showing which work strategies are positively related to job performance, and under which conditions.acceptedVersio

Cytokine release from alveolar macrophages exposed to ambient particulate matter: Heterogeneity in relation to size, city and season

BACKGROUND: Several studies have demonstrated an association between exposure to ambient particulate matter (PM) and respiratory and cardiovascular diseases. Inflammation seems to play an important role in the observed health effects. However, the predominant particle component(s) that drives the inflammation is still not fully clarified. In this study representative coarse (2.5–10 μm) and fine (0.1–2.5 μm) particulate samples from a western, an eastern, a northern and a southern European city (Amsterdam, Lodz, Oslo and Rome) were collected during three seasons (spring, summer and winter). All fractions were investigated with respect to cytokine-inducing potential in primary macrophages isolated from rat lung. The results were related to the physical and chemical parameters of the samples in order to disclose possible connections between inflammatory potential and specific characteristics of the particles. RESULTS: Compared on a gram-by gram basis, both site-specific and seasonal variations in the PM-induced cytokine responses were demonstrated. The samples collected in the eastern (Lodz) and southern (Rome) cities appeared to be the most potent. Seasonal variation was most obvious with the samples from Lodz, with the highest responses induced by the spring and summer samples. The site-specific or seasonal variation in cytokine release could not be attributed to variations in any of the chemical parameters. Coarse fractions from all cities were more potent to induce the inflammatory cytokines interleukin-6 and tumour necrosis factor-α than the corresponding fine fractions. Higher levels of specific elements such as iron and copper, some polycyclic aromatic hydrocarbons (PAHs) and endotoxin/lipopolysaccaride seemed to be prevalent in the coarse fractions. However, variations in the content of these components did not reflect the variation in cytokine release induced by the different coarse fractions. Addition of polymyxin B did not affect the particle-induced cytokine release, indicating that the variations in potency among the coarse fractions are not explained by endootoxin. CONCLUSION: The inflammatory potential of ambient PM demonstrated heterogeneity in relation to city and season. The coarse particle fractions were consistently more potent than the respective fine fractions. Though a higher level of some elements, PAH and endotoxin was found in the coarse fractions, the presence of specific components was not sufficient to explain all variations in PM-induced cytokine release

Measurement and calculation of levitation forces between magnets and granular superconductors

Recent developments indicate that exploitation of the phenomenon of magnetic levitation may become one of the most important near-term applications of high-T(sub c) superconductivity. Because of this, the interaction between a strong permanent magnet(PM) and bulk high-T(sub c) superconductor (HTSC) is currently a subject of much interest. We have studied central features of the mechanics of PM-HTSC systems of simple geometries. Here we report experimental results for the components of the levitation force, their associated stiffness and mechanical ac-loss. To analyze the observed behavior a theoretical framework based on critical-state considerations is developed. It will be shown that all the mechanical properties can be explained consistently at a quantitative level wing a minimum of model parameters

New Radar Interferometric Time Series Analysis Toolbox Released

Interferometric synthetic aperture radar (InSAR) has become an important geodetic tool for measuring deformation of Earth’s surface due to various geophysical phenomena, including slip on earthquake faults, subsurface migration of magma, slow‐moving landslides, movement of shallow crustal fluids (e.g., water and oil), and glacier flow. Airborne and spaceborne synthetic aperture radar (SAR) instruments transmit microwaves toward Earth’s surface and detect the returning reflected waves. The phase of the returned wave depends on the distance between the satellite and the surface, but it is also altered by atmospheric and other effects. InSAR provides measurements of surface deformation by combining amplitude and phase information from two SAR images of the same location taken at different times to create an interferogram. Several existing open‐source analysis tools [Rosen et al., 2004; Rosen et al., 2011; Kampes et al., 2003 ; Sandwell et al., 2011] enable scientists to exploit observations from radar satellites acquired at two different epochs to produce a surface displacement map

The frequency of anti-infliximab antibodies in patients with rheumatoid arthritis treated in routine care and the associations with adverse drug reactions and treatment failure

Objectives. To investigate the frequency of anti-infliximab antibodies in patients with RA and the associations with adverse drug reactions and treatment failure. Methods. Based on the DANBIO registry, patients with RA who initiated treatment with infliximab at Hvidovre Hospital between 2000 and 2008 and had available serum samples were identified. The patients were followed for 52 weeks. Anti-infliximab antibodies were determined prior to infusion at baseline and during follow-up (weeks 2, 6, 14 and 52 or at withdrawal) using the IMPACT indirect assay (Roche Diagnostics) and merged with clinical data prospectively registered in the DANBIO registry. Results. A total of 218 patients with RA were included (80% females, median age 56 years, disease duration 10 years, 65% RF positive, median DAS28 = 5.0). During the 52-week follow-up, 28 patients (13%) withdrew due to adverse events and 50 (23%) due to treatment failure. Antibodies were detected in 118 patients (54%) during follow-up. Patients with detectable anti-infliximab antibodies after 6 weeks had an increased risk of adverse drug reactions [hazard ratio (HR) = 5.06, 95% CI 2.36, 10.84; P < 0.0001] compared with patients without anti-infliximab antibodies. Similar results were observed in patients with anti-infliximab antibodies after 14 weeks (HR = 3.30, 95% CI 1.56, 6.99; P = 0.0009). Patients with detectable anti-infliximab antibodies during the 52-week follow-up were less likely to achieve sustained minimal disease activity and remission. Conclusion. Early anti-infliximab antibody formation increased the risk of adverse drug reactions, including infusion reactions. Anti-infliximab antibody formation during the 52-week follow-up decreased the likelihood of minimal disease activity and remission in patients with RA treated in routine car

Daily interpersonal conflicts and daily exposure to bullying behaviors at work: The moderating roles of trait anger and trait anxiety

Building on the three-way model of workplace bullying and its underlying theories, this study investigates the role of trait anger and trait anxiety in the link between daily interpersonal conflicts and daily exposure to bullying behaviors. Using a quantitative diary study design, we approached 57 military naval cadets participating in a tall-ship voyage across the Atlantic, from Europe to North America, in 2017. They responded to a questionnaire on a daily basis over a period of 30 days—yielding 1428 measurement points. Prior to the voyage, participants also responded to a general questionnaire including measures of trait anger and trait anxiety. As hypothesized, multilevel analyses showed positive main effects of daily interpersonal conflicts on interpersonal conflicts the next day and exposure to bullying behaviors the same day. However, daily involvement in interpersonal conflicts did not predict exposure to bullying behaviors the next day. Moreover, and in support of the hypothesized moderating effects, trait anger (but not trait anxiety) interacted positively with daily interpersonal conflicts in the prediction of interpersonal conflicts the next day as well as exposure to bullying behaviors the same day. The study suggests that interpersonal conflicts persist and have an immediate effect on exposure to bullying behaviors and that this is particularly the case for individuals high (vs. low) on trait anger. We discuss how these findings contribute to the three-way model of workplace bullying, as well as possible practical implications.publishedVersionpublishedVersio

Daily interpersonal conflicts and daily exposure to bullying behaviors at work: The moderating roles of trait anger and trait anxiety

Building on the three-way model of workplace bullying and its underlying theories, this study investigates the role of trait anger and trait anxiety in the link between daily interpersonal conflicts and daily exposure to bullying behaviors. Using a quantitative diary study design, we approached 57 military naval cadets participating in a tall-ship voyage across the Atlantic, from Europe to North America, in 2017. They responded to a questionnaire on a daily basis over a period of 30 days—yielding 1428 measurement points. Prior to the voyage, participants also responded to a general questionnaire including measures of trait anger and trait anxiety. As hypothesized, multilevel analyses showed positive main effects of daily interpersonal conflicts on interpersonal conflicts the next day and exposure to bullying behaviors the same day. However, daily involvement in interpersonal conflicts did not predict exposure to bullying behaviors the next day. Moreover, and in support of the hypothesized moderating effects, trait anger (but not trait anxiety) interacted positively with daily interpersonal conflicts in the prediction of interpersonal conflicts the next day as well as exposure to bullying behaviors the same day. The study suggests that interpersonal conflicts persist and have an immediate effect on exposure to bullying behaviors and that this is particularly the case for individuals high (vs. low) on trait anger. We discuss how these findings contribute to the three-way model of workplace bullying, as well as possible practical implications.publishedVersio