Chronotype, daily affect and social contact:An ecological momentary assessment study

Eveningness is associated with lower daily positive affect (PA). The relationship between negative affect (NA) and chronotype, however, is less consistent in the literature. Eveningness may be further characterized by increased social isolation, which could explain the associations between chronotype and PA/NA. In the present longitudinal study, we used ecological momentary assessment (EMA) to investigate the associations of chronotype with daily PA, NA, and social contact in individuals with current and remitted major depressive disorder (MDD) and healthy controls. As part of the Netherlands Study of Depression and Anxiety (NESDA), 279 participants (n = 49 depressed, n = 172 remitted, n = 58 controls) monitored daily PA, NA, and social contact (i.e., being alone vs. with others) for two weeks, five times per day. Overall, eveningness was associated with less social contact. This effect became nonsignificant, however, after accounting for sociodemographics (gender, age, education, living situation). Chronotype was not related to PA or NA. Less social contact was associated with lower PA and higher NA independent of chronotype. In conclusion, we could not replicate the finding of lower PA among evening types, but found social contact to associate with both daily PA and NA

Chronotype changes with age; seven-year follow-up from the Netherlands study of depression and anxiety cohort

Background: Chronotype reflects an individual's optimal daily timing of sleep, activity, and cognitive performance. Previous, cross-sectional, studies have suggested an age effect on chronotype with later chronotypes in adolescents and earlier chronotypes in children and elderly. Additionally, later chronotypes have been associated with more depressive symptoms. Few studies have been able to study longitudinal associations between chronotype and age, while adjusting for depressive symptoms. Methods: Chronotype was assessed twice with the Munich Chronotype Questionnaire 7 years apart in the Netherlands Study of Depression and Anxiety (T1: N = 1842, mean age (SD): 42.63 years (12.66)) and T2: N = 1829, mean age (SD) 50.67 (13.11)). The longitudinal association between change in age and change in chronotype was tested using a generalized estimated equation analysis adjusted for covariates (including level of depressive symptoms). Using age-bins of 5 years (age at T2), change in chronotype between T1 and T2 was analyzed with Linear Mixed Models. Results: We found a change towards an earlier chronotype with higher age (B (95% CI): -0.011 (-0.014-0.008), p < 0.001). For the age-bins, the difference in chronotype was significant for the 25-29 years age-bin. Limitations: The sample did not include individuals younger than 19 years or older than 68 years. Conclusions: In the whole sample chronotype changed towards becoming more morning-type over a period of 7 years, but this change was only significant for those aged 25-29 years. The study was performed in a large naturalistic cohort study with a wide age-range, including patients with a diagnosis of depressive and anxiety disorder and healthy controls.Stress and Psychopatholog

Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015–2016

This is the final version. Available from European Geosciences Union via the DOI in this record.The stratospheric circulation determines the transport and lifetime of key trace gases in a changing climate, including water vapor and ozone, which radiatively impact surface climate. The unusually warm El Niño–Southern Oscillation (ENSO) event aligned with a disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation to this circulation in 2015–2016. Here, we quantify the impact of the alignment of these two phenomena in 2015–2016 on lower stratospheric water vapor and ozone from satellite observations. We show that the warm ENSO event substantially increased water vapor and decreased ozone in the tropical lower stratosphere. The QBO disruption significantly decreased global lower stratospheric water vapor and tropical ozone from early spring to late autumn. Thus, this QBO disruption reversed the lower stratosphere moistening triggered by the alignment of the warm ENSO event with westerly QBO in early boreal winter. Our results suggest that the interplay of ENSO events and QBO phases will be crucial for the distributions of radiatively active trace gases in a changing future climate, when increasing El Niño-like conditions and a decreasing lower stratospheric QBO amplitude are expected.European CommissionEuropean CommissionNatural Environment Research Council (NERC)Helmholtz Associatio

Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015–2016

The stratospheric circulation determines the transport and lifetime of key trace gases in a changing climate, including water vapor and ozone, which radiatively impact surface climate. The unusually warm El Niño–Southern Oscillation (ENSO) event aligned with a disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation to this circulation in 2015–2016. Here, we quantify the impact of the alignment of these two phenomena in 2015–2016 on lower stratospheric water vapor and ozone from satellite observations. We show that the warm ENSO event substantially increased water vapor and decreased ozone in the tropical lower stratosphere. The QBO disruption significantly decreased global lower stratospheric water vapor and tropical ozone from early spring to late autumn. Thus, this QBO disruption reversed the lower stratosphere moistening triggered by the alignment of the warm ENSO event with westerly QBO in early boreal winter. Our results suggest that the interplay of ENSO events and QBO phases will be crucial for the distributions of radiatively active trace gases in a changing future climate, when increasing El Niño-like conditions and a decreasing lower stratospheric QBO amplitude are expected

3-D tomographic observations of Rossby wave breaking over the North Atlantic during the WISE aircraft campaign in 2017

This paper presents measurements of ozone, water vapour and nitric acid (HNO3) in the upper troposphere/lower stratosphere (UTLS) over North Atlantic and Europe. The measurements were acquired with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) during the Wave Driven Isentropic Exchange (WISE) campaign in October 2017. GLORIA is an airborne limb imager capable of acquiring both 2-D data sets (curtains along the flight path) and, when the carrier aircraft is flying around the observed air mass, spatially highly resolved 3-D tomographic data. Here, we present a case study of a Rossby wave (RW) breaking event observed during two subsequent flights 2 d apart. RW breaking is known to steepen tracer gradients and facilitate stratosphere–troposphere exchange (STE). Our measurements reveal complex spatial structures in stratospheric tracers (ozone and nitric acid) with multiple vertically stacked filaments. Backward-trajectory analysis is used to demonstrate that these features are related to several previous Rossby wave breaking events and that the small-scale structure of the UTLS in the Rossby wave breaking region, which is otherwise very hard to observe, can be understood as stirring and mixing of air masses of tropospheric and stratospheric origin. It is also shown that a strong nitric acid enhancement observed just above the tropopause is likely a result of NOx production by lightning activity. The measurements showed signatures of enhanced mixing between stratospheric and tropospheric air near the polar jet with some transport of water vapour into the stratosphere. Some of the air masses seen in 3-D data were encountered again 2 d later, stretched to very thin filament (horizontal thickness down to 30 km at some altitudes) rich in stratospheric tracers. This repeated measurement allowed us to directly observe and analyse the progress of mixing processes in a thin filament over 2 d. Our results provide direct insight into small-scale dynamics of the UTLS in the Rossby wave breaking region, which is of great importance to understanding STE and poleward transport in the UTLS

Coherent X-ray Scattering from Manganite Charge and Orbital Domains

We report coherent x-ray scattering studies of charge and orbital domains in manganite systems. The experiments were carried out on LaMnO_3 and Pr_{0.6}Ca_{0.4}MnO_3, with the incident photon energy tuned near the Mn K edge. At room temperature, the orbital speckle pattern of LaMnO_3 was observed to be constant over a timescale of at least minutes, which is indicative of static orbital domains on this timescale. For Pr_{0.6}Ca_{0.4}MnO_3, both charge and orbital speckle patterns were observed. The observation of the latter rules out the presence of fast orbital fluctuations, while long time series data-- on the order of several minutes-- were suggestive of slow dynamic behavior. In contrast, the charge order speckle patterns were static.Comment: 6 pages, 4 figure

Bivariate genetic modelling of the response to an oral glucose tolerance challenge: A gene x environment interaction approach

AIMS/HYPOTHESIS: Twin and family studies have shown the importance of genetic factors influencing fasting and 2 h glucose and insulin levels. However, the genetics of the physiological response to a glucose load has not been thoroughly investigated. METHODS: We studied 580 monozygotic and 1,937 dizygotic British female twins from the Twins UK Registry. The effects of genetic and environmental factors on fasting and 2 h glucose and insulin levels were estimated using univariate genetic modelling. Bivariate model fitting was used to investigate the glucose and insulin responses to a glucose load, i.e. an OGTT. RESULTS: The genetic effect on fasting and 2 h glucose and insulin levels ranged between 40% and 56% after adjustment for age and BMI. Exposure to a glucose load resulted in the emergence of novel genetic effects on 2 h glucose independent of the fasting level, accounting for about 55% of its heritability. For 2 h insulin, the effect of the same genes that already influenced fasting insulin was amplified by about 30%. CONCLUSIONS/INTERPRETATION: Exposure to a glucose challenge uncovers new genetic variance for glucose and amplifies the effects of genes that already influence the fasting insulin level. Finding the genes acting on 2 h glucose independently of fasting glucose may offer new aetiological insight into the risk of cardiovascular events and death from all causes

Long-range transport pathways of tropospheric source gases originating in Asia into the northern lower stratosphere during the Asian monsoon season 2012

Global simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) using artificial tracers of air mass origin are used to analyze transport mechanisms from the Asian monsoon region into the lower stratosphere. In a case study, the transport of air masses from the Asian monsoon anticyclone originating in India/China by an eastward-migrating anticyclone which broke off from the main anticyclone on 20 September 2012 and filaments separated at the northeastern flank of the anticyclone are analyzed. Enhanced contributions of young air masses (younger than 5 months) are found within the separated anticyclone confined at the top by the thermal tropopause. Further, these air masses are confined by the anticyclonic circulation and, on the polar side, by the subtropical jet such that the vertical structure resembles a bubble within the upper troposphere. Subsequently, these air masses are transported eastwards along the subtropical jet and enter the lower stratosphere by quasi-horizontal transport in a region of double tropopauses most likely associated with Rossby wave breaking events. As a result, thin filaments with enhanced signatures of tropospheric trace gases were measured in the lower stratosphere over Europe during the TACTS/ESMVal campaign in September 2012 in very good agreement with CLaMS simulations. Our simulations demonstrate that source regions in Asia and in the Pacific Ocean have a significant impact on the chemical composition of the lower stratosphere of the Northern Hemisphere. Young, moist air masses, in particular at the end of the monsoon season in September/October 2012, flooded the extratropical lower stratosphere in the Northern Hemisphere with contributions of up to ≈30% at 380K (with the remaining fraction being aged air). In contrast, the contribution of young air masses to the Southern Hemisphere is much lower. At the end of October 2012, approximately 1.5 ppmv H$_{2}$O is found in the lower Northern Hemisphere stratosphere (at 380 K) from source regions both in Asia and in the tropical Pacific compared to a mean water vapor content of ≈5 ppmv. In addition to this main transport pathway from the Asian monsoon anticyclone to the east along the subtropical jet and subsequent transport into the northern lower stratosphere, a second horizontal transport pathway out of the anticyclone to the west into the tropics (TTL) is found in agreement with MIPAS HCFC-22 measurements