Paleostress field reconstruction and revised tectonic history of the Donbas fold and thrust belt (Ukraine and Russia).

In the WNW-ESE Donbas fold belt (DF), inversion of 3500 microtectonic data collected at 135 sites, in Proterozoic, Devonian, Carboniferous, and Cretaceous competent rocks allowed reconstruction of 123 local stress states. Accordingly, four successive paleostress fields reveal the tectonic evolution of the DF. At the numerous sites that have been affected by polyphase tectonics, the chronology between local paleostress states (also paleostress fields) was established using classical criteria (crosscutting striae, pre- or post-folding stress states, stratigraphic control). The oldest event is an extensional stress field with NNE-SSW σ<inf>3</inf>. It corresponds to the rifting phases that generated the basin in Devonian times and its early Visean reactivation. Later, the DF was affected by a transtension, with NW-SE σ<inf>3</inf> characterizing Early Permian tectonism, including the development of the "Main Anticline" of the DF and the pronounced uplift of its southern margin and Ukrainian Shield. Two paleostress fields characterize the Cretaceous/Paleocene inversion of the DF, which was accompanied by folding and thrusting. Both are compressional in type but differ by the trend of σ<inf>1</inf>, which was first NW-SE and subsequently N-S. The discrete paleostress history of the DF allows a revised interpretation of its tectonic evolution with significant implications for understanding the geodynamic evolution of the southern margin of the East European Craton. Copyright 2003 by the American Geophysical Union

Scholar-activists in an expanding European food sovereignty movement

This article analyzes the roles, relations, and positions of scholar-activists in the European food sovereignty movement. In doing so, we document, make visible and question the political dimensions of researchers' participation in the movement. We argue that scholar-activists are part of the movement, but are distinct from the affected constituencies, put in place to ensure adequate representation of key movement actors. This is because scholar-activists lack a collective identity, have no processes to formulate collective demands, and no mechanisms for inter-researcher and researchers-movement communication. We reflect on whether and how scholar-activists could organize, and discuss possible pathways for a more cohesive and stronger researcher engagement in the movement.</p

Self-reported sleep disturbance and incidence of dementia in ageing men

Background Sleep disturbance is suggested to contribute to the development of dementia. However, prospective longitudinal data from middle-aged populations are scarce. Methods We investigated a population-based sample of 2386 men aged 42-62 years at baseline during 1984-1989. Participants having a history of mental illnesses, psychiatric medication, Parkinson's disease or dementia within 2 years after baseline (n=296) were excluded. Difficulty falling asleep or maintaining sleep, sleep duration and daytime tiredness were enquired. Dementia diagnoses (n=287) between 1984 and 2014 were obtained through linkage with hospital discharge, national death and special reimbursement registers. Cox proportional hazards analyses were performed for all dementias, and separately for Alzheimer's disease (n=234) and other phenotypes (n=53). Additional analyses were performed on a subsample of an apolipoprotein E (APOE) genotype-tested population (n=1199). Results The risk ratio for dementia was 1.58 (95% CI 1.10 to 2.27) in men with frequent sleep disturbance after adjustments for age, examination year, elevated depressive symptoms, physical activity, alcohol consumption, cumulative smoking history, systolic blood pressure, body mass index, low-density lipoprotein and high-density lipoprotein cholesterol, high-sensitivity C reactive protein, cardiovascular disease history, education years and living alone. Daytime tiredness and sleep duration were not associated with dementia in adjusted analysis. In the APOE subsample, both APOE epsilon 4 genotype and frequent sleep disturbance were associated with increased dementia risk, but in the interaction analysis they had no joint effect. Conclusions Self-reported frequent sleep disturbance in middle-aged men may relate to the development of dementia in later life. Having an APOE e4 genotype did not affect the relationship

All correlations must die: Assessing the significance of a stochastic gravitational-wave background in pulsar-timing arrays

We present two methods for determining the significance of a stochastic gravitational-wave background affecting a pulsar-timing array, where detection is based on recovering evidence for correlations between different pulsars, i.e. spatial correlations. Nulling these spatial correlations is crucial to understanding the response of our detection statistic under the null hypothesis so that we can properly assess the significance of plausible signals. The usual approach of creating many noise-only simulations is, albeit useful, undesirable since in that case detection significance is predicated on our (incomplete) understanding of all noise processes. Alternatively, destroying any possible correlations in our real datasets and using those (containing all actual noise features) is a much superior approach. In our first method, we perform random phase shifts in the signal-model basis functions, which has the effect of eliminating signal phase coherence between pulsars, while keeping the statistical properties of the pulsar timing residuals intact. We also explore a method to null correlations between pulsars by using a "scrambled" overlap-reduction function in the signal model for the array. This scrambled overlap-reduction function should be effectively orthogonal to what we expect of a real background signal. We demonstrate the efficacy of these methods in a set of simulated datasets that contain a stochastic gravitational wave background, using Bayesian model selection to compare models that do, or do not, account for the correlation between pulsars induced by this signal. Finally, we introduce an overarching formalism under which these two techniques can be seen as natural companions to each other. These methods are immediately applicable to all current pulsar-timing array datasets, and should become standard tools for future analyses

The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational wave searches

The sensitivity of Pulsar Timing Arrays to gravitational waves depends on the noise present in the individual pulsar timing data. Noise may be either intrinsic or extrinsic to the pulsar. Intrinsic sources of noise will include rotational instabilities, for example. Extrinsic sources of noise include contributions from physical processes which are not sufficiently well modelled, for example, dispersion and scattering effects, analysis errors and instrumental instabilities. We present the results from a noise analysis for 42 millisecond pulsars (MSPs) observed with the European Pulsar Timing Array. For characterising the low-frequency, stochastic and achromatic noise component, or "timing noise", we employ two methods, based on Bayesian and frequentist statistics. For 25 MSPs, we achieve statistically significant measurements of their timing noise parameters and find that the two methods give consistent results. For the remaining 17 MSPs, we place upper limits on the timing noise amplitude at the 95% confidence level. We additionally place an upper limit on the contribution to the pulsar noise budget from errors in the reference terrestrial time standards (below 1%), and we find evidence for a noise component which is present only in the data of one of the four used telescopes. Finally, we estimate that the timing noise of individual pulsars reduces the sensitivity of this data set to an isotropic, stochastic GW background by a factor of >9.1 and by a factor of >2.3 for continuous GWs from resolvable, inspiralling supermassive black-hole binaries with circular orbits.Comment: Accepted for publication by the Monthly Notices of the Royal Astronomical Societ

High-density genotyping reveals signatures of selection related to acclimation and economically important traits in 15 local sheep breeds from Russia

Domestication and centuries of selective breeding have changed genomes of sheep breeds to respond to environmental challenges and human needs. The genomes of local breeds, therefore, are valuable sources of genomic variants to be used to understand mechanisms of response to adaptation and artificial selection. As a step toward this we performed a high-density genotyping and comprehensive scans for signatures of selection in the genomes from 15 local sheep breeds reared across Russia

Genetical genomics: spotlight on QTL hotspots

No abstract available

A Bayesian Partition Method for Detecting Pleiotropic and Epistatic eQTL Modules

Studies of the relationship between DNA variation and gene expression variation, often referred to as “expression quantitative trait loci (eQTL) mapping”, have been conducted in many species and resulted in many significant findings. Because of the large number of genes and genetic markers in such analyses, it is extremely challenging to discover how a small number of eQTLs interact with each other to affect mRNA expression levels for a set of co-regulated genes. We present a Bayesian method to facilitate the task, in which co-expressed genes mapped to a common set of markers are treated as a module characterized by latent indicator variables. A Markov chain Monte Carlo algorithm is designed to search simultaneously for the module genes and their linked markers. We show by simulations that this method is more powerful for detecting true eQTLs and their target genes than traditional QTL mapping methods. We applied the procedure to a data set consisting of gene expression and genotypes for 112 segregants of S. cerevisiae. Our method identified modules containing genes mapped to previously reported eQTL hot spots, and dissected these large eQTL hot spots into several modules corresponding to possibly different biological functions or primary and secondary responses to regulatory perturbations. In addition, we identified nine modules associated with pairs of eQTLs, of which two have been previously reported. We demonstrated that one of the novel modules containing many daughter-cell expressed genes is regulated by AMN1 and BPH1. In conclusion, the Bayesian partition method which simultaneously considers all traits and all markers is more powerful for detecting both pleiotropic and epistatic effects based on both simulated and empirical data