175 research outputs found
The magnetic phase diagram of underdoped YBa2Cu3Oy inferred from torque magnetization and thermal conductivity
Strong evidence for charge-density correlation in the underdoped phase of the
cuprate YBa2Cu3Oy was obtained by nuclear magnetic resonance (NMR) and resonant
x-ray scatter- ing. The fluctuations were found to be enhanced in strong
magnetic fields. Recently, 3D (three dimensional) charge-density wave (CDW)
formation with long-range order (LRO) was observed by x-ray diffraction in H
>15 T. To elucidate how the CDW transition impacts the pair condensate, we have
used torque magnetization to 45 T and thermal conductivity to
construct the magnetic phase diagram in untwinned crystals with hole density p
= 0.11. We show that the 3D CDW transitions appear as sharp features in the
susceptibility and at the fields HK and Hp, which define phase
boundaries in agreement with spectroscopic techniques. From measurements of the
melting field Hm(T) of the vortex solid, we obtain evidence for two vortex
solid states below 8 K. At 0.5 K, the pair condensate appears to adjust to the
3D CDW by a sharp transition at 24 T between two vortex solids with very
different shear moduli. At even higher H (42 T) the second vortex solid melts
to a vortex liquid which survives to fields well above 45 T. de Haas-van Alphen
oscillations appear at fields 24-28 T, below the lower bound for the upper
critical field Hc2.Comment: 7 pages, 8 figures; New version of previous posting, reporting torque
measurements to 45 Tesla and final magnetic phase diagra
Host-linked soil viral ecology along a permafrost thaw gradient
Climate change threatens to release abundant carbon that is sequestered at high latitudes, but the constraints on microbial metabolisms that mediate the release of methane and carbon dioxide are poorly understood1,2,3,4,5,6,7. The role of viruses, which are known to affect microbial dynamics, metabolism and biogeochemistry in the oceans8,9,10, remains largely unexplored in soil. Here, we aimed to investigate how viruses influence microbial ecology and carbon metabolism in peatland soils along a permafrost thaw gradient in Sweden. We recovered 1,907 viral populations (genomes and large genome fragments) from 197 bulk soil and size-fractionated metagenomes, 58% of which were detected in metatranscriptomes and presumed to be active. In silico predictions linked 35% of the viruses to microbial host populations, highlighting likely viral predators of key carbon-cycling microorganisms, including methanogens and methanotrophs. Lineage-specific virus/host ratios varied, suggesting that viral infection dynamics may differentially impact microbial responses to a changing climate. Virus-encoded glycoside hydrolases, including an endomannanase with confirmed functional activity, indicated that viruses influence complex carbon degradation and that viral abundances were significant predictors of methane dynamics. These findings suggest that viruses may impact ecosystem function in climate-critical, terrestrial habitats and identify multiple potential viral contributions to soil carbon cycling
New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.
Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
Viral Etiology of Influenza-Like Illnesses in Antananarivo, Madagascar, July 2008 to June 2009
In Madagascar, despite an influenza surveillance established since 1978, little is known about the etiology and prevalence of viruses other than influenza causing influenza-like illnesses (ILIs).From July 2008 to June 2009, we collected respiratory specimens from patients who presented ILIs symptoms in public and private clinics in Antananarivo (the capital city of Madagascar). ILIs were defined as body temperature ≥38°C and cough and at least two of the following symptoms: sore throat, rhinorrhea, headache and muscular pain, for a maximum duration of 3 days. We screened these specimens using five multiplex real time Reverse Transcription and/or Polymerase Chain Reaction assays for detection of 14 respiratory viruses. We detected respiratory viruses in 235/313 (75.1%) samples. Overall influenza virus A (27.3%) was the most common virus followed by rhinovirus (24.8%), RSV (21.2%), adenovirus (6.1%), coronavirus OC43 (6.1%), influenza virus B (3.9%), parainfluenza virus-3 (2.9%), and parainfluenza virus-1 (2.3%). Co-infections occurred in 29.4% (69/235) of infected patients and rhinovirus was the most detected virus (27.5%). Children under 5 years were more likely to have one or more detectable virus associated with their ILI. In this age group, compared to those ≥5 years, the risk of detecting more than one virus was higher (OR = 1.9), as was the risk of detecting of RSV (OR = 10.1) and adenovirus (OR = 4.7). While rhinovirus and adenovirus infections occurred year round, RSV, influenza virus A and coronavirus OC43 had defined period of circulation.In our study, we found that respiratory viruses play an important role in ILIs in the Malagasy community, particularly in children under 5 years old. These data provide a better understanding of the viral etiology of outpatients with ILI and describe for the first time importance of these viruses in different age group and their period of circulation
GWAS of longevity in CHARGE consortium confirms APOE and FOXO3 candidacy.
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 Files.
This article is open access.The genetic contribution to longevity in humans has been estimated to range from 15% to 25%. Only two genes, APOE and FOXO3, have shown association with longevity in multiple independent studies.We conducted a meta-analysis of genome-wide association studies including 6,036 longevity cases, age ≥90 years, and 3,757 controls that died between ages 55 and 80 years. We additionally attempted to replicate earlier identified single nucleotide polymorphism (SNP) associations with longevity.In our meta-analysis, we found suggestive evidence for the association of SNPs near CADM2 (odds ratio [OR] = 0.81; p value = 9.66 × 10(-7)) and GRIK2 (odds ratio = 1.24; p value = 5.09 × 10(-8)) with longevity. When attempting to replicate findings earlier identified in genome-wide association studies, only the APOE locus consistently replicated. In an additional look-up of the candidate gene FOXO3, we found that an earlier identified variant shows a highly significant association with longevity when including published data with our meta-analysis (odds ratio = 1.17; p value = 1.85×10(-10)).We did not identify new genome-wide significant associations with longevity and did not replicate earlier findings except for APOE and FOXO3. Our inability to find new associations with survival to ages ≥90 years because longevity represents multiple complex traits with heterogeneous genetic underpinnings, or alternatively, that longevity may be regulated by rare variants that are not captured by standard genome-wide genotyping and imputation of common variants.Netherlands Organisation of Scientific Research NWO Investments
175.010.2005.011
911-03-012
Research Institute for Diseases in the Elderly
014-93-015
RIDE2
Netherlands Genomics Initiative (NGI)/Netherlands Organisation for Scientific Research (NWO)
050-060-810
Erasmus Medical Center
Erasmus University, Rotterdam
Netherlands Organization for the Health Research and Development (ZonMw)
Research Institute for Diseases in the Elderly (RIDE)
Ministry of Education, Culture and Science
Ministry for Health, Welfare and Sports
European Commission (DG XII)
Municipality of Rotterdam
National Institutes of Health
National Institute on Aging (NIA)
R01 AG005407
R01 AR35582
R01 AR35583
R01 AR35584
R01 AG005394
R01 AG027574
R01 AG027576
AG023629
R01AG29451
U01AG009740
RC2 AG036495
RC4 AG039029
P30AG10161
R01AG17917
R01AG15819
R01AG30146
U01-AG023755
U19-AG023122
NHLBI
HHSN 268201200036C
HHSN268200800007C
N01HC55222
N01HC85079
N01HC85080
N01HC85081
N01HC85082
N01HC85083
N01HC 85086
HL080295
HL087652
HL105756
National Institute of Neurological Disorders and Stroke (NINDS)
National Center for Advancing Translational Sciences, CTSI
UL1TR000124
National Institute of Diabetes and Digestive and Kidney Disease Diabetes Research Center (DRC)
DK063491
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
National Center for Research Resources (NCRR)
NIH Roadmap for Medical Research
U01 AR45580
U01 AR45614
U01 AR45632
U01 AR45647
U01 AR45654
U01 AR45583
U01 AG18197
U01-AG027810
UL1 RR024140
NIAMS
R01-AR051124
RC2ARO58973
National Heart, Lung and Blood Institute's Framingham Heart Study
N01-HC-25195
Affymetrix, Inc
N02-HL-6-4278
Robert Dawson Evans Endowment of the Department of Medicine at Boston University School of Medicine
Boston Medical Center
National Institute of Arthritis, Musculoskeletal and Skin Diseases
NIA
R01 AR/AG 41398
NIH
N01-AG-12100
NIA Intramural Research Program
Hjartavernd (the Icelandic Heart Association)
Althingi (the Icelandic Parliament)
Illinois Department of Public Health
Translational Genomics Research Institute
Italian Ministry of Health
ICS110.1/RF97.71
U.S. National Institute on Aging
263 MD 9164
263 MD 821336
Intramural Research Program of the NIH, National Institute on Aging
1R01AG028321
1R01HL09257
A Meta-Analysis and Genome-Wide Association Study of Platelet Count and Mean Platelet Volume in African Americans
Several genetic variants associated with platelet count and mean platelet volume
(MPV) were recently reported in people of European ancestry. In this
meta-analysis of 7 genome-wide association studies (GWAS) enrolling African
Americans, our aim was to identify novel genetic variants associated with
platelet count and MPV. For all cohorts, GWAS analysis was performed using
additive models after adjusting for age, sex, and population stratification. For
both platelet phenotypes, meta-analyses were conducted using inverse-variance
weighted fixed-effect models. Platelet aggregation assays in whole blood were
performed in the participants of the GeneSTAR cohort. Genetic variants in ten
independent regions were associated with platelet count
(N = 16,388) with p<5×10−8 of
which 5 have not been associated with platelet count in previous GWAS. The novel
genetic variants associated with platelet count were in the following regions
(the most significant SNP, closest gene, and p-value): 6p22 (rs12526480,
LRRC16A, p = 9.1×10−9), 7q11
(rs13236689, CD36, p = 2.8×10−9),
10q21 (rs7896518, JMJD1C,
p = 2.3×10−12), 11q13 (rs477895,
BAD, p = 4.9×10−8), and 20q13
(rs151361, SLMO2, p = 9.4×10−9).
Three of these loci (10q21, 11q13, and 20q13) were replicated in European
Americans (N = 14,909) and one (11q13) in Hispanic
Americans (N = 3,462). For MPV
(N = 4,531), genetic variants in 3 regions were significant
at p<5×10−8, two of which were also associated with
platelet count. Previously reported regions that were also significant in this
study were 6p21, 6q23, 7q22, 12q24, and 19p13 for platelet count and 7q22,
17q11, and 19p13 for MPV. The most significant SNP in 1 region was also
associated with ADP-induced maximal platelet aggregation in whole blood (12q24).
Thus through a meta-analysis of GWAS enrolling African Americans, we have
identified 5 novel regions associated with platelet count of which 3 were
replicated in other ethnic groups. In addition, we also found one region
associated with platelet aggregation that may play a potential role in
atherothrombosis
Cell Specific eQTL Analysis without Sorting Cells
The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-environment interaction (GxE) meta-analysis on data from 5,683 samples to infer the cell type specificity of whole blood cis-eQTLs. We demonstrate that this method is able to predict neutrophil and lymphocyte specific cis-eQTLs and replicate these predictions in independent cell-type specific datasets. Finally, we show that SNPs associated with Crohn’s disease preferentially affect gene expression within neutrophils, including the archetypal NOD2 locus
Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons. A cross-ancestry genome-wide association meta-analysis of amyotrophic lateral sclerosis (ALS) including 29,612 patients with ALS and 122,656 controls identifies 15 risk loci with distinct genetic architectures and neuron-specific biology
Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure.
Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP
Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons. A cross-ancestry genome-wide association meta-analysis of amyotrophic lateral sclerosis (ALS) including 29,612 patients with ALS and 122,656 controls identifies 15 risk loci with distinct genetic architectures and neuron-specific biology
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