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Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation 总被引:1,自引:0,他引:1
Kirkby J Curtius J Almeida J Dunne E Duplissy J Ehrhart S Franchin A Gagné S Ickes L Kürten A Kupc A Metzger A Riccobono F Rondo L Schobesberger S Tsagkogeorgas G Wimmer D Amorim A Bianchi F Breitenlechner M David A Dommen J Downard A Ehn M Flagan RC Haider S Hansel A Hauser D Jud W Junninen H Kreissl F Kvashin A Laaksonen A Lehtipalo K Lima J Lovejoy ER Makhmutov V Mathot S Mikkilä J Minginette P Mogo S Nieminen T Onnela A Pereira P Petäjä T Schnitzhofer R Seinfeld JH Sipilä M Stozhkov Y 《Nature》2011,476(7361):429-433
Atmospheric aerosols exert an important influence on climate through their effects on stratiform cloud albedo and lifetime and the invigoration of convective storms. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia. Here we present the first results from the CLOUD experiment at CERN. We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100-1,000-fold. Time-resolved molecular measurements reveal that nucleation proceeds by a base-stabilization mechanism involving the stepwise accretion of ammonia molecules. Ions increase the nucleation rate by an additional factor of between two and more than ten at ground-level galactic-cosmic-ray intensities, provided that the nucleation rate lies below the limiting ion-pair production rate. We find that ion-induced binary nucleation of H(2)SO(4)-H(2)O can occur in the mid-troposphere but is negligible in the boundary layer. However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary-layer nucleation. 相似文献
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Valdar W Solberg LC Gauguier D Burnett S Klenerman P Cookson WO Taylor MS Rawlins JN Mott R Flint J 《Nature genetics》2006,38(8):879-887
Difficulties in fine-mapping quantitative trait loci (QTLs) are a major impediment to progress in the molecular dissection of complex traits in mice. Here we show that genome-wide high-resolution mapping of multiple phenotypes can be achieved using a stock of genetically heterogeneous mice. We developed a conservative and robust bootstrap analysis to map 843 QTLs with an average 95% confidence interval of 2.8 Mb. The QTLs contribute to variation in 97 traits, including models of human disease (asthma, type 2 diabetes mellitus, obesity and anxiety) as well as immunological, biochemical and hematological phenotypes. The genetic architecture of almost all phenotypes was complex, with many loci each contributing a small proportion to the total variance. Our data set, freely available at http://gscan.well.ox.ac.uk, provides an entry point to the functional characterization of genes involved in many complex traits. 相似文献
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Balasubramanian S Sureshkumar S Agrawal M Michael TP Wessinger C Maloof JN Clark R Warthmann N Chory J Weigel D 《Nature genetics》2006,38(6):711-715
Light has an important role in modulating seedling growth and flowering time. We show that allelic variation at the PHYTOCHROME C (PHYC) photoreceptor locus affects both traits in natural populations of A. thaliana. Two functionally distinct PHYC haplotype groups are distributed in a latitudinal cline dependent on FRIGIDA, a locus that together with FLOWERING LOCUS C explains a large portion of the variation in A. thaliana flowering time. In a genome-wide scan for association of 65 loci with latitude, there was an excess of significant P values, indicative of population structure. Nevertheless, PHYC was the most strongly associated locus across 163 strains, suggesting that PHYC alleles are under diversifying selection in A. thaliana. Our work, together with previous findings, suggests that photoreceptor genes are major agents of natural variation in plant flowering and growth response. 相似文献
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Scott RH Douglas J Baskcomb L Huxter N Barker K Hanks S Craft A Gerrard M Kohler JA Levitt GA Picton S Pizer B Ronghe MD Williams D;Factors Associated with Childhood Tumours 《Nature genetics》2008,40(11):1329-1334
Constitutional abnormalities at the imprinted 11p15 growth regulatory region cause syndromes characterized by disordered growth, some of which include a risk of Wilms tumor. We explored their possible contribution to nonsyndromic Wilms tumor and identified constitutional 11p15 abnormalities in genomic lymphocyte DNA from 13 of 437 individuals (3%) with sporadic Wilms tumor without features of growth disorders, including 12% of bilateral cases (P = 0.001) and in one familial Wilms tumor pedigree. No abnormality was detected in 220 controls (P = 0.006). Abnormalities identified included H19 DMR epimutations, uniparental disomy 11p15 and H19 DMR imprinting center mutations (one microinsertion and one microdeletion), thus identifying microinsertion as a new class of imprinting center mutation. Our data identify constitutional 11p15 defects as one of the most common known causes of Wilms tumor, provide mechanistic insights into imprinting disruption and reveal clinically important epigenotype-phenotype associations. The impact on clinical management dictates that constitutional 11p15 analysis should be considered in all individuals with Wilms tumor. 相似文献
38.
The Pristionchus pacificus genome provides a unique perspective on nematode lifestyle and parasitism
Dieterich C Clifton SW Schuster LN Chinwalla A Delehaunty K Dinkelacker I Fulton L Fulton R Godfrey J Minx P Mitreva M Roeseler W Tian H Witte H Yang SP Wilson RK Sommer RJ 《Nature genetics》2008,40(10):1193-1198
Here we present a draft genome sequence of the nematode Pristionchus pacificus, a species that is associated with beetles and is used as a model system in evolutionary biology. With 169 Mb and 23,500 predicted protein-coding genes, the P. pacificus genome is larger than those of Caenorhabditis elegans and the human parasite Brugia malayi. Compared to C. elegans, the P. pacificus genome has more genes encoding cytochrome P450 enzymes, glucosyltransferases, sulfotransferases and ABC transporters, many of which were experimentally validated. The P. pacificus genome contains genes encoding cellulase and diapausin, and cellulase activity is found in P. pacificus secretions, indicating that cellulases can be found in nematodes beyond plant parasites. The relatively higher number of detoxification and degradation enzymes in P. pacificus is consistent with its necromenic lifestyle and might represent a preadaptation for parasitism. Thus, comparative genomics analysis of three ecologically distinct nematodes offers a unique opportunity to investigate the association between genome structure and lifestyle. 相似文献
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Twigger SN Pruitt KD Fernández-Suárez XM Karolchik D Worley KC Maglott DR Brown G Weinstock G Gibbs RA Kent J Birney E Jacob HJ 《Nature genetics》2008,40(5):523-527
It has been four years since the original publication of the draft sequence of the rat genome. Five groups are now working together to assemble, annotate and release an updated version of the rat genome. As the prevailing model for physiology, complex disease and pharmacological studies, there is an acute need for the rat's genomic resources to keep pace with the rat's prominence in the laboratory. In this commentary, we describe the current status of the rat genome sequence and the plans for its impending 'upgrade'. We then cover the key online resources providing access to the rat genome, including the new SNP views at Ensembl, the RefSeq and Genes databases at the US National Center for Biotechnology Information, Genome Browser at the University of California Santa Cruz and the disease portals for cardiovascular disease and obesity at the Rat Genome Database. 相似文献