154 research outputs found
EDGE: A new approach to suppressing numerical diffusion in adaptive mesh simulations of galaxy formation
We introduce a new method to mitigate numerical diffusion in adaptive mesh refinement (AMR) simulations of cosmological
galaxy formation, and study its impact on a simulated dwarf galaxy as part of the ‘EDGE’ project. The target galaxy has a
maximum circular velocity of 21 km s−1 but evolves in a region that is moving at up to 90 km s−1 relative to the hydrodynamic
grid. In the absence of any mitigation, diffusion softens the filaments feeding our galaxy. As a result, gas is unphysically held
in the circumgalactic medium around the galaxy for 320 Myr, delaying the onset of star formation until cooling and collapse
eventually triggers an initial starburst at z = 9. Using genetic modification, we produce ‘velocity-zeroed’ initial conditions in
which the grid-relative streaming is strongly suppressed; by design, the change does not significantly modify the large-scale
structure or dark matter accretion history. The resulting simulation recovers a more physical, gradual onset of star formation
starting at z = 17. While the final stellar masses are nearly consistent (4.8 × 106 M and 4.4 × 106 M for unmodified and
velocity-zeroed, respectively), the dynamical and morphological structure of the z = 0 dwarf galaxies are markedly different due
to the contrasting histories. Our approach to diffusion suppression is suitable for any AMR zoom cosmological galaxy formation
simulations, and is especially recommended for those of small galaxies at high redshif
Molecular evidence for gender differences in the migratory behaviour of a small seabird
Molecular sexing revealed an unexpectedly strong female bias in the sex ratio of pre-breeding European Storm Petrels (Hydrobates pelagicus), attracted to playback of conspecific calls during their northwards migration past SW Europe. This bias was consistent across seven years, ranging from 80.8% to 89.7% female (mean annual sex ratio ± SD = 85.5% female ±4.1%). The sex ratio did not differ significantly from unity (i.e., 50% female) among (i) Storm Petrel chicks at a breeding colony in NW France, (ii) adults found dead on beaches in Southern Portugal, (iii) breeding birds attending nest burrows in the UK, captured by hand, and (iv) adults captured near a breeding colony in the UK using copies of the same sound recordings as used in Southern Europe, indicating that females are not inherently more strongly attracted to playback calls than males. A morphological discriminant function analysis failed to provide a good separation of the sexes, showing the importance of molecular sexing for this species. We found no sex difference in the seasonal or nocturnal timing of migration past Southern Europe, but there was a significant tendency for birds to be caught in sex-specific aggregations. The preponderance of females captured in Southern Europe suggests that the sexes may differ in migration route or in their colony-prospecting behaviour during migration, at sites far away from their natal colonies. Such differences in migration behaviour between males and females are poorly understood but have implications for the vulnerability of seabirds to pollution and environmental change at sea during the non-breeding season
Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand
This article presents the syntheses, crystal structures, topological features and magnetic properties of two NiII/NaI coordination clusters (CCs) formulated [NiII3Na(L1)3(HL1 (MeOH)2] (1) and [NiII6Na(L1)5(CO3)(MeO (MeOH)3(H2O)3]·4(MeOH) 2(H2O) [2 4(MeOH) 2(H2O)] where H2L1 is the semi rigid Schiff base ligand (E)-2-(2-hydroxy-3 methoxybenzylideneamino)-phenol). Compound 1 possesses a rare NiII3NaI cubane (3M4-1) topology and compound 2 is the first example in polynuclear Ni/Na chemistry that exhibits a 2,3,4M7-1 topology
The early-life exposome and epigenetic age acceleration in children
The early-life exposome influences future health and accelerated biological aging has been proposed as one of the underlying biological mechanisms. We investigated the association between more than 100 exposures assessed during pregnancy and in childhood (including indoor and outdoor air pollutants, built environment, green environments, tobacco smoking, lifestyle exposures, and biomarkers of chemical pollutants), and epigenetic age acceleration in 1,173 children aged 7 years old from the Human Early-Life Exposome project. Age acceleration was calculated based on Horvath’s Skin and Blood clock using child blood DNA methylation measured by Infinium HumanMethylation450 BeadChips. We performed an exposure-wide association study between prenatal and childhood exposome and age acceleration. Maternal tobacco smoking during pregnancy was nominally associated with increased age acceleration. For childhood exposures, indoor particulate matter absorbance (PMabs) and parental smoking were nominally associated with an increase in age acceleration. Exposure to the organic pesticide dimethyl dithiophosphate and the persistent pollutant polychlorinated biphenyl-138 (inversely associated with child body mass index) were protective for age acceleration. None of the associations remained significant after multiple-testing correction. Pregnancy and childhood exposure to tobacco smoke and childhood exposure to indoor PMabs may accelerate epigenetic aging from an early ageThe study received funding from the European Community’s Seventh Framework Programme (FP7/2007-206) (grant agreement no 308333) (HELIX project), the H2020-EU.3.1.2. - Preventing Disease Programme (grant agreement no 874583) (ATHLETE project), and from the European Union’s Horizon 2020 research and innovation programme (grant Agreement number: 733206) (Early Life stressors and Lifecycle Health (LIFECYCLE)). BiB received funding from the Welcome Trust (WT101597MA), from the UK Medical Research Council (MRC) and Economic and Social Science Research Council (ESRC) (MR/N024397/1). INMA was supported by grants from the Instituto de Salud Carlos III, CIBERESP, and the Generalitat de Catalunya-CIRIT. KANC was funded by the grant of the Lithuanian Agency for Science Innovation and Technology (6-04-2014_31V-66). The Norwegian Mother, Father and Child Cohort Study is supported by the Norwegian Ministry of Health and Care Services and the Ministry of Education and Research. The Rhea project was financially supported by European projects (EU FP6-2003-Food-3-NewGeneris, EU FP6. STREP Hiwate, EU FP7 ENV.2007.1.2.2.2. Project No 211250 Escape, EU FP7-2008-ENV-1.2.1.4 Envirogenomarkers, EU FP7-HEALTH-2009- single stage CHICOS, EU FP7 ENV.2008.1.2.1.6. Proposal No 226285 ENRIECO, EU- FP7- HEALTH-2012 Proposal No 308333 HELIX), and the Greek Ministry of Health (Program of Prevention of obesity and neurodevelopmental disorders in preschool children, in Heraklion district, Crete, Greece: 2011-2014; “Rhea Plus”: Primary Prevention Program of Environmental Risk Factors for Reproductive Health, and Child Health: 2012-15). We acknowledge support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. OR was funded by a UKRI Future Leaders Fellowship (MR/S03532X/1). MV-U and CR-A were supported by a FI fellowship from the Catalan Government (FI-DGR 2015 and #016FI_B 00272). MC received funding from Instituto Carlos III (Ministry of Economy and Competitiveness) (CD12/00563 and MS16/00128)S
Progress Report on Target Development
The present document is the D08 deliverable report of work package 1 (Target Development) from the MEGAPIE TEST project of the 5th European Framework Program. Deliverable D08 is the progress report on the activities performed within WP 1. The due date of this deliverable was the 5th month after the start of the EU project. This coincided with a technical status meeting of the MEGAPIE Initiative, that was held in March 2002 in Bologna (Italy). The content of the present document reflects the status of the MEGAPIE target development at that stage. It gives an overview of the Target Design, the related Design Support activities and the progress of the work done for the safety assessment and licensing of the target
Multi-omics signatures of the human early life exposome
Environmental exposures during early life play a critical role in life-course health, yet the molecular phenotypes underlying environmental effects on health are poorly understood. In the Human Early Life Exposome (HELIX) project, a multi-centre cohort of 1301 mother-child pairs, we associate individual exposomes consisting of >100 chemical, outdoor, social and lifestyle exposures assessed in pregnancy and childhood, with multi-omics profiles (methylome, transcriptome, proteins and metabolites) in childhood. We identify 1170 associations, 249 in pregnancy and 921 in childhood, which reveal potential biological responses and sources of exposure. Pregnancy exposures, including maternal smoking, cadmium and molybdenum, are predominantly associated with child DNA methylation changes. In contrast, childhood exposures are associated with features across all omics layers, most frequently the serum metabolome, revealing signatures for diet, toxic chemical compounds, essential trace elements, and weather conditions, among others. Our comprehensive and unique resource of all associations (https://helixomics.isglobal.org/) will serve to guide future investigation into the biological imprints of the early life exposome
Nociceptors: a phylogenetic view
The ability to react to environmental change is crucial for the survival of an organism and an essential prerequisite is the capacity to detect and respond to aversive stimuli. The importance of having an inbuilt “detect and protect” system is illustrated by the fact that most animals have dedicated sensory afferents which respond to noxious stimuli called nociceptors. Should injury occur there is often sensitization, whereby increased nociceptor sensitivity and/or plasticity of nociceptor-related neural circuits acts as a protection mechanism for the afflicted body part. Studying nociception and nociceptors in different model organisms has demonstrated that there are similarities from invertebrates right through to humans. The development of technology to genetically manipulate organisms, especially mice, has led to an understanding of some of the key molecular players in nociceptor function. This review will focus on what is known about nociceptors throughout the Animalia kingdom and what similarities exist across phyla; especially at the molecular level of ion channels
A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience
PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern
European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good
Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary
approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge
gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal
areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also
independently performed. The comparison between meta-analysis results and IAs shows similarities
for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food
web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification
of additional research themes targeting research topics that are requested to the achievement of GES.
2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe
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