726 research outputs found

    Factors associated with first return to work and sick leave durations in workers with common mental disorders

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    Background: Associations are examined between socio-demographic, medical, work-related and organizational factors and the moment of first return to work (RTW) (within or after 6 weeks of sick leave) and total sick leave duration in sick leave spells due to common mental disorders. Methods: Data are derived from a Dutch database, build to provide reference data for sick leave duration for various medical conditions. The cases in this study were entered in 2004 and 2005 by specially trained occupational health physicians, based on the physician's assessment of medical and other factors. Odds ratios for first RTW and sick leave durations are calculated in logistic regression models. Results: Burnout, depression and anxiety disorder are associated with longer sick leave duration. Similar, but weaker associations were found for female sex, being a teacher, small company size and moderate or high psychosocial hazard. Distress is associated with shorter sick leave duration. Medical factors, psychosocial hazard and company size are also and analogously associated with first RTW. Part-time work is associated with delayed first RTW. The strength of the associations varies for various factors and for different sick leave durations. Conclusion: The medical diagnosis has a strong relation with the moment of first RTW and the duration of sick leave spells in mental disorders, but the influence of demographic and work-related factors should not be neglected

    Widespread cryptic variation in genetic architecture between the sexes

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    This is the final version. Available from Wiley via the DOI in this record.ā€ÆNo new data were collected for this study. All raw phenotype data are available from the International Mouse Phenotyping Consortium (https://www.mousephenotype.org/). The gene expression profiles of male and female gonadal tissue are available from the ArrayExpress database under accession number E-GEOD-1148. All estimates used in downstream analyses are available in the Supporting Information.The majority of the genome is shared between the sexes, and it is expected that the genetic architecture of most traits is shared as well. This common architecture has been viewed as a major source of constraint on the evolution of sexual dimorphism (SD). SD is nonetheless common in nature, leading to assumptions that it results from differential regulation of shared genetic architecture. Here, we study the effect of thousands of gene knockout mutations on 202 mouse phenotypes to explore how regulatory variation affects SD. We show that many traits are dimorphic to some extent, and that a surprising proportion of knockouts have sex-specific phenotypic effects. Many traits, regardless whether they are monomorphic or dimorphic, harbor cryptic differences in genetic architecture between the sexes, resulting in sexually discordant phenotypic effects from sexually concordant regulatory changes. This provides an alternative route to dimorphism through sex-specific genetic architecture, rather than differential regulation of shared architecture.European Research Council (ERC)Canada 150 Research Chair Progra

    Female brain size affects the assessment of male attractiveness during mate choice

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    Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice

    Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model

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    Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural selection could reduce expression of elaborated traits in females, as proposed by Wallace. Darwin and Wallace debated the origins of dichromatism in birds and butterflies, and although evidence in birds is roughly equal, if not in favor of Wallace's model, butterflies lack a similar scale of study. Here, we present a large-scale comparative phylogenetic analysis of the evolution of butterfly coloration, using all European non-hesperiid butterfly species (n = 369). We modeled evolutionary changes in coloration for each species and sex along their phylogeny, thereby estimating the rate and direction of evolution in three-dimensional color space using a novel implementation of phylogenetic ridge regression. We show that male coloration evolved faster than female coloration, especially in strongly dichromatic clades, with male contribution to changes in dichromatism roughly twice that of females. These patterns are consistent with a classic Darwinian model of dichromatism via sexual selection on male coloration, suggesting this model was the dominant driver of dichromatism in European butterflies

    Talking quiescence: a rigorous theory that supports parallel composition, action hiding and determinisation

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    The notion of quiescence - the absence of outputs - is vital in both behavioural modelling and testing theory. Although the need for quiescence was already recognised in the 90s, it has only been treated as a second-class citizen thus far. This paper moves quiescence into the foreground and introduces the notion of quiescent transition systems (QTSs): an extension of regular input-output transition systems (IOTSs) in which quiescence is represented explicitly, via quiescent transitions. Four carefully crafted rules on the use of quiescent transitions ensure that our QTSs naturally capture quiescent behaviour. We present the building blocks for a comprehensive theory on QTSs supporting parallel composition, action hiding and determinisation. In particular, we prove that these operations preserve all the aforementioned rules. Additionally, we provide a way to transform existing IOTSs into QTSs, allowing even IOTSs as input that already contain some quiescent transitions. As an important application, we show how our QTS framework simplifies the fundamental model-based testing theory formalised around ioco.Comment: In Proceedings MBT 2012, arXiv:1202.582

    The physics of water and wax in the pores of a working Gas-to-Liquids catalyst

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    The so-called Fischer-Tropsch catalysis allows to convert natural gas into liquid products and is the underlying mechanism of commercially used "Gas-to-Liquids" plants. The actual reaction takes place in millimetre sized porous pellets in which active metallic particles are dispersed as catalysts. Due to the reaction the pores of the pellets will become filled with the reaction products ("wax" and water), but it is uncertain if the fluid in the pores can be understood as a single liquid phase, a liquid-gas mixture, or multiple continuous phases. The answer to this question is important for a thorough understanding of the transport processes inside the reactor and can be utilized to improve its eciency. In this project, a theoretical analysis of the behaviour inside the pores is performed. It is concluded that a liquid water phase might well exist next to the wax phase. However, the analysis is based on very limited experimental data of unknown quality. Therefore, we propose a number of possible experiments to validate the theoretical concepts

    Patient journey during and after a pre-eclampsia-complicated pregnancy:a cross-sectional patient registry study

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    OBJECTIVES: To gain insight into the patient journey through a pre-eclampsia-complicated pregnancy. DESIGN: Cross-sectional patient registry study. SETTING: Online patient registry initiated by the Preeclampsia Foundation. PARTICIPANTS: Women with a history of pre-eclampsia enrolled in The Preeclampsia Registry (TPR). PRIMARY AND SECONDARY OUTCOME MEASURES: Retrospective patient-reported experience measures concerning awareness of pre-eclampsia, timing and type of information on pre-eclampsia received, involvement in decision making regarding medical care, mental/emotional impact of the pre-eclampsia-complicated pregnancy and impact on future pregnancy planning. RESULTS: Of 3618 TPR-participants invited to complete the Patient Journey questionnaire, data from 833 (23%) responders were available for analysis. Most responders were white (n=795, 95.4%) and lived in the USA (n=728, 87.4%). Before their pre-eclampsia diagnosis, 599 (73.9%) responders were aware of the term ā€˜pre-eclampsiaā€™, but only 348 (43.7%) were aware of its associated symptoms. Women with a lower level of education were less likely to have heard of pre-eclampsia (OR 0.36, 95%ā€‰CI 0.21 to 0.62). Around the time of diagnosis, 29.2% of responders did not feel involved in the decision making, which was associated with reporting a serious mental/emotional impact of the pre-eclampsia experience (OR 2.46, 95%ā€‰CI 1.58 to 3.84). Over time, there was an increase in the proportion of women who were aware of the symptoms of pre-eclampsia (32.2% before 2011 to 52.5% after 2016; p<0.001) and in the proportion of responders stating they received counselling about the later-life health risks associated with pre-eclampsia (14.2% before 2011 to 25.6% after 2016; p=0.005). CONCLUSIONS: This study demonstrates that improved patient education regarding pre-eclampsia is needed, that shared decision making is of great importance to patients to enhance their healthcare experience, and that healthcare providers should make efforts to routinely incorporate counselling about the later-life health risks associated with pre-eclampsia. TRIAL REGISTRATION NUMBER: NCT02020174

    Spin Excitations and Sum Rules in the Heisenberg Antiferromagnet

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    Various bounds for the energy of collective excitations in the Heisenberg antiferromagnet are presented and discussed using the formalism of sum rules. We show that the Feynman approximation significantly overestimates (by about 30\% in the S=12S={1\over2} square lattice) the spin velocity due to the non negligible contribution of multi magnons to the energy weighted sum rule. We also discuss a different, Goldstone type bound depending explicitly on the order parameter (staggered magnetization). This bound is shown to be proportional to the dispersion of classical spin wave theory with a q-independent normalization factor. Rigorous bounds for the excitation energies in the anisotropic Heisenberg model are also presented.Comment: 26 pages, Plain TeX including 1 PostScript figure, UTF-307-10/9

    Assessment of coronary artery calcium by using volumetric 320-row multi-detector computed tomography: comparison of 0.5Ā mm with 3.0Ā mm slice reconstructions

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    The purpose of this study was to assess the performance of 0.5 versus 3.0Ā mm slice reconstructions in depicting coronary calcium with special attention to patients having zero calcium scores at 3.0Ā mm reconstructions by using computed tomography (CT). Imaging was performed by volumetric 320-detector row CT. Scans of 100 patients with a negative and 100 patients with a positive Agatston score at 3.0Ā mm reconstructions were consecutively selected. Non-overlapping volume sets with 3.0 and 0.5Ā mm slice thickness were reconstructed from the same raw data and Agatston and volume scores were obtained. The Wilcoxon signed ranks test was used to determine statistical differences between 3.0 and 0.5Ā mm calcium scores. Agatston and volume scores obtained at 0.5Ā mm were significantly higher than at 3.0Ā mm reconstructions (mean Agatston score: 266Ā Ā±Ā 495 vs. 231Ā Ā±Ā 461. Mean volume score: 223Ā Ā±Ā 399 vs. 206Ā Ā±Ā 385, both PĀ <Ā 0.01). In 21% of patients with zero 3.0Ā mm Agatston scores, a positive Agatston and/or volume score was found at 0.5Ā mm reconstructions. With volumetric 320-detector row CT, prospective ECG-triggered calcium scoring at 0.5Ā mm compared to 3.0Ā mm reconstructions leads to an increase in Agatston and volume scores and small amounts of coronary calcium are earlier depicted. This may be of special interest in patients with zero calcium scores with traditional 3.0Ā mm measures, where 0.5Ā mm reconstructions may help in superior depicting or ruling out coronary artery disease
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