591 research outputs found
Semantic diversity:A measure of contextual variation in word meaning based on latent semantic analysis
Semantic ambiguity is typically measured by summing the number of senses or dictionary definitions that a word has. Such measures are somewhat subjective and may not adequately capture the full extent of variation in word meaning, particularly for polysemous words that can be used in many different ways, with subtle shifts in meaning. Here, we describe an alternative, computationally derived measure of ambiguity based on the proposal that the meanings of words vary continuously as a function of their contexts. On this view, words that appear in a wide range of contexts on diverse topics are more variable in meaning than those that appear in a restricted set of similar contexts. To quantify this variation, we performed latent semantic analysis on a large text corpus to estimate the semantic similarities of different linguistic contexts. From these estimates, we calculated the degree to which the different contexts associated with a given word vary in their meanings. We term this quantity a word's semantic diversity (SemD). We suggest that this approach provides an objective way of quantifying the subtle, context-dependent variations in word meaning that are often present in language. We demonstrate that SemD is correlated with other measures of ambiguity and contextual variability, as well as with frequency and imageability. We also show that SemD is a strong predictor of performance in semantic judgments in healthy individuals and in patients with semantic deficits, accounting for unique variance beyond that of other predictors. SemD values for over 30,000 English words are provided as supplementary materials. © 2012 Psychonomic Society, Inc
Genome-wide association study of knee pain identifies associations with GDF5 and COL27A1 in UK Biobank
Knee pain is one of the most common musculoskeletal complaints that brings people to medical attention. Approximately 50% of individuals over the age of 50 report an experience of knee pain within the past 12 months. We sought to identify the genetic variants associated with knee pain in 171,516 subjects from the UK Biobank cohort and seek supporting evidence in cohorts from 23andMe, the Osteoarthritis Initiative, and the Johnston County Osteoarthritis Project. We identified two loci that reached genome-wide significance in the UK Biobank: rs143384, located in GDF5 (P = 1.32 × 10−12), a gene previously implicated in osteoarthritis; and rs2808772, located near COL27A1 (P = 1.49 × 10−8). These findings were supported in cohorts with self-reported osteoarthritis/radiographic knee osteoarthritis without pain information. In this report on genome-wide association of knee pain, we identified two loci in or near GDF5 and COL27A1 that are associated with knee pain
Chromatin loop anchors are associated with genome instability in cancer and recombination hotspots in the germline
Abstract Background Chromatin loops form a basic unit of interphase nuclear organization, with chromatin loop anchor points providing contacts between regulatory regions and promoters. However, the mutational landscape at these anchor points remains under-studied. Here, we describe the unusual patterns of somatic mutations and germline variation associated with loop anchor points and explore the underlying features influencing these patterns. Results Analyses of whole genome sequencing datasets reveal that anchor points are strongly depleted for single nucleotide variants (SNVs) in tumours. Despite low SNV rates in their genomic neighbourhood, anchor points emerge as sites of evolutionary innovation, showing enrichment for structural variant (SV) breakpoints and a peak of SNVs at focal CTCF sites within the anchor points. Both CTCF-bound and non-CTCF anchor points harbour an excess of SV breakpoints in multiple tumour types and are prone to double-strand breaks in cell lines. Common fragile sites, which are hotspots for genome instability, also show elevated numbers of intersecting loop anchor points. Recurrently disrupted anchor points are enriched for genes with functions in cell cycle transitions and regions associated with predisposition to cancer. We also discover a novel class of CTCF-bound anchor points which overlap meiotic recombination hotspots and are enriched for the core PRDM9 binding motif, suggesting that the anchor points have been foci for diversity generated during recent human evolution. Conclusions We suggest that the unusual chromatin environment at loop anchor points underlies the elevated rates of variation observed, marking them as sites of regulatory importance but also genomic fragility
Population genomics of marine zooplankton
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Bucklin, Ann et al. "Population Genomics of Marine Zooplankton." Population Genomics: Marine Organisms. Ed. Om P. Rajora and Marjorie Oleksiak. Springer, 2018. doi:10.1007/13836_2017_9.The exceptionally large population size and cosmopolitan biogeographic distribution that
distinguish many – but not all – marine zooplankton species generate similarly exceptional patterns of
population genetic and genomic diversity and structure. The phylogenetic diversity of zooplankton has
slowed the application of population genomic approaches, due to lack of genomic resources for closelyrelated
species and diversity of genomic architecture, including highly-replicated genomes of many
crustaceans. Use of numerous genomic markers, especially single nucleotide polymorphisms (SNPs), is
transforming our ability to analyze population genetics and connectivity of marine zooplankton, and
providing new understanding and different answers than earlier analyses, which typically used
mitochondrial DNA and microsatellite markers. Population genomic approaches have confirmed that,
despite high dispersal potential, many zooplankton species exhibit genetic structuring among geographic
populations, especially at large ocean-basin scales, and have revealed patterns and pathways of population
connectivity that do not always track ocean circulation. Genomic and transcriptomic resources are
critically needed to allow further examination of micro-evolution and local adaptation, including
identification of genes that show evidence of selection. These new tools will also enable further
examination of the significance of small-scale genetic heterogeneity of marine zooplankton, to
discriminate genetic “noise” in large and patchy populations from local adaptation to environmental
conditions and change.Support was provided by the
US National Science Foundation to AB and RJO (PLR-1044982) and to RJO (MCB-1613856); support to
IS and MC was provided by Nord University (Norway)
Meta-analysis of GWAS of over 16,000 individuals with autism spectrum disorder highlights a novel locus at 10q24.32 and a significant overlap with schizophrenia.
To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesOver the past decade genome-wide association studies (GWAS) have been applied to aid in the understanding of the biology of traits. The success of this approach is governed by the underlying effect sizes carried by the true risk variants and the corresponding statistical power to observe such effects given the study design and sample size under investigation. Previous ASD GWAS have identified genome-wide significant (GWS) risk loci; however, these studies were of only of low statistical power to identify GWS loci at the lower effect sizes (odds ratio (OR) <1.15).We conducted a large-scale coordinated international collaboration to combine independent genotyping data to improve the statistical power and aid in robust discovery of GWS loci. This study uses genome-wide genotyping data from a discovery sample (7387 ASD cases and 8567 controls) followed by meta-analysis of summary statistics from two replication sets (7783 ASD cases and 11359 controls; and 1369 ASD cases and 137308 controls).We observe a GWS locus at 10q24.32 that overlaps several genes including PITX3, which encodes a transcription factor identified as playing a role in neuronal differentiation and CUEDC2 previously reported to be associated with social skills in an independent population cohort. We also observe overlap with regions previously implicated in schizophrenia which was further supported by a strong genetic correlation between these disorders (Rg = 0.23; P = 9 × 10(-6)). We further combined these Psychiatric Genomics Consortium (PGC) ASD GWAS data with the recent PGC schizophrenia GWAS to identify additional regions which may be important in a common neurodevelopmental phenotype and identified 12 novel GWS loci. These include loci previously implicated in ASD such as FOXP1 at 3p13, ATP2B2 at 3p25.3, and a 'neurodevelopmental hub' on chromosome 8p11.23.This study is an important step in the ongoing endeavour to identify the loci which underpin the common variant signal in ASD. In addition to novel GWS loci, we have identified a significant genetic correlation with schizophrenia and association of ASD with several neurodevelopmental-related genes such as EXT1, ASTN2, MACROD2, and HDAC4.National Institutes of Mental Health (NIMH, USA)
ACE Network
Autism Genetic Resource Exchange (AGRE) is a program of Autism Speaks (USA)
The Autism Genome Project (AGP) from Autism Speaks (USA)
Canadian Institutes of Health Research (CIHR), Genome Canada
Health Research Board (Ireland)
Hilibrand Foundation (USA)
Medical Research Council (UK)
National Institutes of Health (USA)
Ontario Genomics Institute
University of Toronto McLaughlin Centre
Simons Foundation
Johns Hopkins
Autism Consortium of Boston
NLM Family foundation
National Institute of Health grants
National Health Medical Research Council
Scottish Rite
Spunk Fund, Inc.
Rebecca and Solomon Baker Fund
APEX Foundation
National Alliance for Research in Schizophrenia and Affective Disorders (NARSAD)
endowment fund of the Nancy Pritzker Laboratory (Stanford)
Autism Society of America
Janet M. Grace Pervasive Developmental Disorders Fund
The Lundbeck Foundation
universities and university hospitals of Aarhus and Copenhagen
Stanley Foundation
Centers for Disease Control and Prevention (CDC)
Netherlands Scientific Organization
Dutch Brain Foundation
VU University Amsterdam
Trinity Centre for High Performance Computing through Science Foundation Ireland
Autism Genome Project (AGP) from Autism Speak
Twelve type 2 diabetes susceptibility loci identified through large-scale association analysis (vol 42, pg 579, 2010)
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Genomics and proteomics of vertebrate cholesterol ester lipase (LIPA) and cholesterol 25-hydroxylase (CH25H)
Cholesterol ester lipase (LIPA; EC 3.1.1.13) and cholesterol 25-hydroxylase (CH25H; EC 1.14.99.48) play essential role in cholesterol metabolism in the body by hydrolysing cholesteryl esters and triglycerides within lysosomes (LIPA) and catalysing the formation of 25-hydroxycholesterol from cholesterol (CH25H) which acts to repress cholesterol biosynthesis. Bioinformatic methods were used to predict the amino acid sequences, structures and genomic features of several vertebrate LIPA and CH25H genes and proteins, and to examine the phylogeny of vertebrate LIPA. Amino acid sequence alignments and predicted subunit structures enabled the identification of key sequences previously reported for human LIPA and CH25H and transmembrane structures for vertebrate CH25H sequences. Vertebrate LIPA and CH25H genes were located in tandem on all vertebrate genomes examined and showed several predicted transcription factor binding sites and CpG islands located within the 5′ regions of the human genes. Vertebrate LIPA genes contained nine coding exons, while all vertebrate CH25H genes were without introns. Phylogenetic analysis demonstrated the distinct nature of the vertebrate LIPA gene and protein family in comparison with other vertebrate acid lipases and has apparently evolved from an ancestral LIPA gene which predated the appearance of vertebrates
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