324 research outputs found
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
Background Over 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). Methods 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). Results 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 (Rgâ=â0.23; Pâ=â9âĂâ10â6). 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 âneurodevelopmental hubâ on chromosome 8p11.23.
Conclusions 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
Facile Synthesis of High Quality Graphene Nanoribbons
Graphene nanoribbons have attracted attention for their novel electronic and
spin transport properties1-6, and because nanoribbons less than 10 nm wide have
a band gap that can be used to make field effect transistors. However,
producing nanoribbons of very high quality, or in high volumes, remains a
challenge. Here, we show that pristine few-layer nanoribbons can be produced by
unzipping mildly gas-phase oxidized multiwalled carbon nanotube using
mechanical sonication in an organic solvent. The nanoribbons exhibit very high
quality, with smooth edges (as seen by high-resolution transmission electron
microscopy), low ratios of disorder to graphitic Raman bands, and the highest
electrical conductance and mobility reported to date (up to 5e2/h and 1500
cm2/Vs for ribbons 10-20 nm in width). Further, at low temperature, the
nanoribbons exhibit phase coherent transport and Fabry-Perot interference,
suggesting minimal defects and edge roughness. The yield of nanoribbons was ~2%
of the starting raw nanotube soot material, which was significantly higher than
previous methods capable of producing high quality narrow nanoribbons1. The
relatively high yield synthesis of pristine graphene nanoribbons will make
these materials easily accessible for a wide range of fundamental and practical
applications.Comment: Nature Nanotechnology in pres
Co3O4 Nanocrystals on Graphene as a Synergistic Catalyst for Oxygen Reduction Reaction
Catalysts for oxygen reduction and evolution reactions are at the heart of
key renewable energy technologies including fuel cells and water splitting.
Despite tremendous efforts, developing oxygen electrode catalysts with high
activity at low costs remains a grand challenge. Here, we report a hybrid
material of Co3O4 nanocrystals grown on reduced graphene oxide (GO) as a
high-performance bi-functional catalyst for oxygen reduction reaction (ORR) and
oxygen evolution reaction (OER). While Co3O4 or graphene oxide alone has little
catalytic activity, their hybrid exhibits an unexpected, surprisingly high ORR
activity that is further enhanced by nitrogen-doping of graphene. The
Co3O4/N-doped graphene hybrid exhibits similar catalytic activity but superior
stability to Pt in alkaline solutions. The same hybrid is also highly active
for OER, making it a high performance non-precious metal based bi-catalyst for
both ORR and OER. The unusual catalytic activity arises from synergetic
chemical coupling effects between Co3O4 and graphene.Comment: published in Nature Material
Influenza D Virus Infection in Feral Swine Populations, United States
Influenza D virus (IDV) has been identified in domestic cattle, swine, camelid, and small ruminant populations across North America, Europe, Asia, South America, and Africa. Our study investigated seroprevalence and transmissibility of IDV in feral swine. During 2012â2013, we evaluated feral swine populations in 4 US states; of 256 swine tested, 57 (19.1%) were IDV seropositive. Among 96 archived influenza A virusâseropositive feral swine samples collected from 16 US states during 2010â2013, 41 (42.7%) were IDV seropositive. Infection studies demonstrated that IDV-inoculated feral swine shed virus 3â5 days postinoculation and seroconverted at 21 days postinoculation; 50% of in-contact naive feral swine shed virus, seroconverted, or both. Immunohistochemical staining showed viral antigen within epithelial cells of the respiratory tract, including trachea, soft palate, and lungs. Our findings suggest that feral swine might serve an important role in the ecology of IDV
Tissue tropisms opt for transmissible reassortants during avian and swine influenza A virus co-infection in swine
Genetic reassortment between influenza A viruses (IAVs) facilitate emergence of pandemic strains, and swine are proposed as a âmixing vesselâ for generating reassortants of avian and mammalian IAVs that could be of risk to mammals, including humans. However, how a transmissible reassortant emerges in swine are not well understood. Genomic analyses of 571 isolates recovered from nasal wash samples and respiratory tract tissues of a group of co-housed pigs (influenza-seronegative, avian H1N1 IAVâinfected, and swine H3N2 IAVâ infected pigs) identified 30 distinct genotypes of reassortants. Viruses recovered from lower respiratory tract tissues had the largest genomic diversity, and those recovered from turbinates and nasal wash fluids had the least. Reassortants from lower respiratory tracts had the largest variations in growth kinetics in respiratory tract epithelial cells, and the cold temperature in swine nasal cells seemed to select the type of reassortant viruses shed by the pigs. One reassortant in nasal wash samples was consistently identified in upper, middle, and lower respiratory tract tissues, and it was confirmed to be transmitted efficiently between pigs. Study findings suggest that, during mixed infections of avian and swine IAVs, genetic reassortments are likely to occur in the lower respiratory track, and tissue tropism is an important factor selecting for a transmissible reassortant
Code-based Syndromic Surveillance for Influenzalike Illness by International Classification of Diseases, Ninth Revision
ICD-9 codes collected automatically in a syndromic system are sensitive and specific in detecting outbreaks caused by respiratory viruses
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain âŒ8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
Graphene-Wrapped Sulfur Particles as a Rechargeable Lithium-Sulfur-Battery Cathode Material with High Capacity and Cycling Stability
We report the synthesis of a graphene-sulfur composite material by wrapping
polyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidized
graphene oxide sheets decorated by carbon black nanoparticles. The PEG and
graphene coating layers are important to accommodating volume expansion of the
coated sulfur particles during discharge, trapping soluble polysulfide
intermediates and rendering the sulfur particles electrically conducting. The
resulting graphene-sulfur composite showed high and stable specific capacities
up to ~600mAh/g over more than 100 cycles, representing a promising cathode
material for rechargeable lithium batteries with high energy density.Comment: published in Nano Letter
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High-density mapping of the MHC identifies a shared role for HLA-DRB1*01:03 in inflammatory bowel diseases and heterozygous advantage in ulcerative colitis.
This is the author accepted manuscript. The final version is available from NPG at http://www.nature.com/ng/journal/v47/n2/full/ng.3176.html#acknowledgmentsGenome-wide association studies of the related chronic inflammatory bowel diseases (IBD) known as Crohn's disease and ulcerative colitis have shown strong evidence of association to the major histocompatibility complex (MHC). This region encodes a large number of immunological candidates, including the antigen-presenting classical human leukocyte antigen (HLA) molecules. Studies in IBD have indicated that multiple independent associations exist at HLA and non-HLA genes, but they have lacked the statistical power to define the architecture of association and causal alleles. To address this, we performed high-density SNP typing of the MHC in >32,000 individuals with IBD, implicating multiple HLA alleles, with a primary role for HLA-DRB1*01:03 in both Crohn's disease and ulcerative colitis. Noteworthy differences were observed between these diseases, including a predominant role for class II HLA variants and heterozygous advantage observed in ulcerative colitis, suggesting an important role of the adaptive immune response in the colonic environment in the pathogenesis of IBD.We would like to thank the International PSC study group (http://www.ipscsg.org/) for sharing data. We are grateful to B.A. Lie and K. Holm for helpful discussions. J.D.R. holds a Canada Research Chair, and this work was supported by a US National Institute of Diabetes and Digestive and Kidney Diseases grant (NIDDK; R01 DK064869 and U01 DK062432). The laboratory of A.F. is supported by the German Ministry of Education and Research (BMBF) grant program e:Med (sysINFLAME). A.F. receives infrastructure support from the Deutsche Forschungsgemeinschaft (DFG) Cluster of Excellence 'Inflammation at Interfaces' and holds an endowment professorship (Peter Hans Hofschneider Professorship) of the Foundation for Experimental Biomedicine (Zurich, Switzerland). Grant support for T.H.K. and A.F. was received from the European Union Seventh Framework Programme (FP7/2007-2013, grant number 262055, ESGI). M.N.C. is supported by the Intramural Research Program of the US National Institutes of Health (NIH), Frederick National Laboratory, Center for Cancer Research. This project has been funded in whole or in part with federal funds from the Frederick National Laboratory for Cancer Research, under contract HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the US Department of Health and Human Services, nor does mention of trade names, commercial products or organizations imply endorsement by the US government. J.C.B. was supported by a Wellcome Trust grant (WT098051). D.M. and V.K. are supported by the NIHR Cambridge Biomedical Research Centre. L.P.S. is supported by an NIDDK grant (U01 DK062429-14). J.A.T. is supported by the UK Medical Research Council. D.P.B.M. is supported by the Leona M. and Harry B. Helmsley Charitable Trust, the European Union (305479) and by grants from the NIDDK (U01 DK062413, P01 DK046763-19, U54 DE023789-01), the National Institute of Allergy and Infectious Diseases (NIAID; U01 AI067068) and the Agency for Healthcare Research and Quality (AHRQ; HS021747). R.H.D. holds the Inflammatory Bowel Disease Genetic Research endowed chair at the University of Pittsburgh and was supported by an NIDDK grant (U01 DK062420) and a US National Cancer Institute grant (CA141743). S.L.H. and J.R.O. would like to also acknowledge the support of the US NIH (R01 NS049477 and 1U19 A1067152) and the National Multiple Sclerosis Society (RG 2899-D11). S.L. wishes to acknowledge support from the Australian National Health and Medical Research Council (R.D. Wright Career Development Fellowship, APP1053756)
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