116 research outputs found
An international laboratory comparison of dissolved organic matter composition by high resolution mass spectrometry: Are we getting the same answer?
High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The instruments identified ~1000 common ions in both negative- and positive-ion modes over a wide range of m/z values and chemical space, as determined by van Krevelen diagrams. Calculated metrics of abundance-weighted average indices (H/C, O/C, aromaticity, and m/z) of the commonly detected ions showed that hydrogen saturation and aromaticity were consistent for each reference sample across the instruments, while average mass and oxygenation were more affected by differences in instrument type and settings. In this paper we present 32 metric values for future benchmarking. The metric values were obtained for the four different parameters from four samples in two ionization modes and can be used in future work to evaluate the performance of HRMS instruments
Two randomized trials of effect of live attenuated influenza vaccine on pneumococcal colonization
The human nasopharynx is frequently colonized by Streptococcus pneumoniae (the pneumococcus), serving as the reservoir for transmission, a state which necessarily precedes invasive pneumococcal infection. Influenza infection increases pneumococcal colonization density and dysregulates host immune responses, increasing the risk of secondary bacterial pneumonia and death
The Compton Spectrometer and Imager
The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer (SMEX)
satellite mission in development with a planned launch in 2027. COSI is a
wide-field gamma-ray telescope designed to survey the entire sky at 0.2-5 MeV.
It provides imaging, spectroscopy, and polarimetry of astrophysical sources,
and its germanium detectors provide excellent energy resolution for emission
line measurements. Science goals for COSI include studies of 0.511 MeV emission
from antimatter annihilation in the Galaxy, mapping radioactive elements from
nucleosynthesis, determining emission mechanisms and source geometries with
polarization measurements, and detecting and localizing multimessenger sources.
The instantaneous field of view for the germanium detectors is >25% of the sky,
and they are surrounded on the sides and bottom by active shields, providing
background rejection as well as allowing for detection of gamma-ray bursts and
other gamma-ray flares over most of the sky. In the following, we provide an
overview of the COSI mission, including the science, the technical design, and
the project status.Comment: 8 page
The cosipy library: COSI's high-level analysis software
The Compton Spectrometer and Imager (COSI) is a selected Small Explorer
(SMEX) mission launching in 2027. It consists of a large field-of-view Compton
telescope that will probe with increased sensitivity the under-explored MeV
gamma-ray sky (0.2-5 MeV). We will present the current status of cosipy, a
Python library that will perform spectral and polarization fits, image
deconvolution, and all high-level analysis tasks required by COSI's broad
science goals: uncovering the origin of the Galactic positrons, mapping the
sites of Galactic nucleosynthesis, improving our models of the jet and emission
mechanism of gamma-ray bursts (GRBs) and active galactic nuclei (AGNs), and
detecting and localizing gravitational wave and neutrino sources. The cosipy
library builds on the experience gained during the COSI balloon campaigns and
will bring the analysis of data in the Compton regime to a modern open-source
likelihood-based code, capable of performing coherent joint fits with other
instruments using the Multi-Mission Maximum Likelihood framework (3ML). In this
contribution, we will also discuss our plans to receive feedback from the
community by having yearly software releases accompanied by publicly-available
data challenges
Epigenome-wide meta-analysis of blood DNA methylation and its association with subcortical volumes:findings from the ENIGMA Epigenetics Working Group
DNA methylation, which is modulated by both genetic factors and environmental exposures, may offer a unique opportunity to discover novel biomarkers of disease-related brain phenotypes, even when measured in other tissues than brain, such as blood. A few studies of small sample sizes have revealed associations between blood DNA methylation and neuropsychopathology, however, large-scale epigenome-wide association studies (EWAS) are needed to investigate the utility of DNA methylation profiling as a peripheral marker for the brain. Here, in an analysis of eleven international cohorts, totalling 3337 individuals, we report epigenome-wide meta-analyses of blood DNA methylation with volumes of the hippocampus, thalamus and nucleus accumbens (NAcc)-three subcortical regions selected for their associations with disease and heritability and volumetric variability. Analyses of individual CpGs revealed genome-wide significant associations with hippocampal volume at two loci. No significant associations were found for analyses of thalamus and nucleus accumbens volumes. Cluster-based analyses revealed additional differentially methylated regions (DMRs) associated with hippocampal volume. DNA methylation at these loci affected expression of proximal genes involved in learning and memory, stem cell maintenance and differentiation, fatty acid metabolism and type-2 diabetes. These DNA methylation marks, their interaction with genetic variants and their impact on gene expression offer new insights into the relationship between epigenetic variation and brain structure and may provide the basis for biomarker discovery in neurodegeneration and neuropsychiatric conditions
Pharmacogenetic meta-analysis of genome-wide association studies of LDL cholesterol response to statins
Statins effectively lower LDL cholesterol levels in large studies and the observed interindividual response variability may be partially explained by genetic variation. Here we perform a pharmacogenetic meta-analysis of genome-wide association studies (GWAS) in studies addressing the LDL cholesterol response to statins, including up to 18,596 statin-treated subjects. We validate the most promising signals in a further 22,318 statin recipients and identify two loci, SORT1/CELSR2/PSRC1 and SLCO1B1, not previously identified in GWAS. Moreover, we confirm the previously described associations with APOE and LPA. Our findings advance the understanding of the pharmacogenetic architecture of statin response
The Human Brain Is Best Described as Being on a Female/Male Continuum: Evidence from a Neuroimaging Connectivity Study
Psychological androgyny has long been associated with greater cognitive flexibility, adaptive behavior, and better mental health, but whether a similar concept can be defined using neural features remains unknown. Using the neuroimaging data from 9620 participants, we found that global functional connectivity was stronger in the male brain before middle age but became weaker after that, when compared with the female brain, after systematic testing of potentially confounding effects. We defined a brain gender continuum by estimating the likelihood of an observed functional connectivity matrix to represent a male brain. We found that participants mapped at the center of this continuum had fewer internalizing symptoms compared with those at the 2 extreme ends. These findings suggest a novel hypothesis proposing that there exists a neuroimaging concept of androgyny using the brain gender continuum, which may be associated with better mental health in a similar way to psychological androgyny
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Association between childhood trauma and risk for obesity: a putative neurocognitive developmental pathway
Funder: Zhangjiang LabFunder: the Shanghai AI Platform for Diagnosis and Treatment of Brain DiseasesFunder: the Project of Zhangjiang Hi-Tech District Management CommitteeFunder: Shanghai (grant 2016-17)Funder: BRIDGET (JPND: BRain Imaging, cognition Dementia and next generation GEnomics); Grant(s): MR/N027558/1Funder: Associazione Emma e Ernesto Rulfo per la Genetica Medica (IT)Funder: the Swedish Research Council FORMASFunder: the Medical Research CouncilFunder: the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College LondonFunder: the Human Brain Project (HBP SGA 2)Funder: the Fondation de France, the Fondation pour la Recherche MédicaleFunder: the Assistance-Publique-Hôpitaux-de-Paris and INSERM (interface grant)Funder: Paris Sud University IDEX 2012Funder: cross-NIH alliance that funds Big Data to Knowledge Centres of ExcellenceAbstract: Background: Childhood trauma increases the risk for adult obesity through multiple complex pathways, and the neural substrates are yet to be determined. Methods: Participants from three population-based neuroimaging cohorts, including the IMAGEN cohort, the UK Biobank (UKB), and the Human Connectome Project (HCP), were recruited. Voxel-based morphometry analysis of both childhood trauma and body mass index (BMI) was performed in the longitudinal IMAGEN cohort; validation of the findings was performed in the UKB. White-matter connectivity analysis was conducted to study the structural connectivity between the identified brain region and subdivisions of the hypothalamus in the HCP. Results: In IMAGEN, a smaller frontopolar cortex (FPC) was associated with both childhood abuse (CA) (β = − .568, 95%CI − .942 to − .194; p = .003) and higher BMI (β = − .086, 95%CI − .128 to − .043; p < .001) in male participants, and these findings were validated in UKB. Across seven data collection sites, a stronger negative CA-FPC association was correlated with a higher positive CA-BMI association (β = − 1.033, 95%CI − 1.762 to − .305; p = .015). Using 7-T diffusion tensor imaging data (n = 156), we found that FPC was the third most connected cortical area with the hypothalamus, especially the lateral hypothalamus. A smaller FPC at age 14 contributed to higher BMI at age 19 in those male participants with a history of CA, and the CA-FPC interaction enabled a model at age 14 to account for some future weight gain during a 5-year follow-up (variance explained 5.8%). Conclusions: The findings highlight that a malfunctioning, top-down cognitive or behavioral control system, independent of genetic predisposition, putatively contributes to excessive weight gain in a particularly vulnerable population, and may inform treatment approaches
A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape
Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain >99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways
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