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31.
Abundance and diversity of microbial life in ocean crust 总被引:2,自引:0,他引:2
Santelli CM Orcutt BN Banning E Bach W Moyer CL Sogin ML Staudigel H Edwards KJ 《Nature》2008,453(7195):653-656
Oceanic lithosphere exposed at the sea floor undergoes seawater-rock alteration reactions involving the oxidation and hydration of glassy basalt. Basalt alteration reactions are theoretically capable of supplying sufficient energy for chemolithoautotrophic growth. Such reactions have been shown to generate microbial biomass in the laboratory, but field-based support for the existence of microbes that are supported by basalt alteration is lacking. Here, using quantitative polymerase chain reaction, in situ hybridization and microscopy, we demonstrate that prokaryotic cell abundances on seafloor-exposed basalts are 3-4 orders of magnitude greater than in overlying deep sea water. Phylogenetic analyses of basaltic lavas from the East Pacific Rise (9 degrees N) and around Hawaii reveal that the basalt-hosted biosphere harbours high bacterial community richness and that community membership is shared between these sites. We hypothesize that alteration reactions fuel chemolithoautotrophic microorganisms, which constitute a trophic base of the basalt habitat, with important implications for deep-sea carbon cycling and chemical exchange between basalt and sea water. 相似文献
32.
Warne T Serrano-Vega MJ Baker JG Moukhametzianov R Edwards PC Henderson R Leslie AG Tate CG Schertler GF 《Nature》2008,454(7203):486-491
G-protein-coupled receptors have a major role in transmembrane signalling in most eukaryotes and many are important drug targets. Here we report the 2.7 A resolution crystal structure of a beta(1)-adrenergic receptor in complex with the high-affinity antagonist cyanopindolol. The modified turkey (Meleagris gallopavo) receptor was selected to be in its antagonist conformation and its thermostability improved by earlier limited mutagenesis. The ligand-binding pocket comprises 15 side chains from amino acid residues in 4 transmembrane alpha-helices and extracellular loop 2. This loop defines the entrance of the ligand-binding pocket and is stabilized by two disulphide bonds and a sodium ion. Binding of cyanopindolol to the beta(1)-adrenergic receptor and binding of carazolol to the beta(2)-adrenergic receptor involve similar interactions. A short well-defined helix in cytoplasmic loop 2, not observed in either rhodopsin or the beta(2)-adrenergic receptor, directly interacts by means of a tyrosine with the highly conserved DRY motif at the end of helix 3 that is essential for receptor activation. 相似文献
33.
The assimilation and mineralization of dissolved organic carbon (DOC) by marine bacterioplankton is a major process in the ocean carbon cycle. However, little information exists on the specific metabolic functions of participating bacteria and on whether individual taxa specialize on particular components of the marine DOC pool. Here we use experimental metagenomics to show that coastal communities are populated by taxa capable of metabolizing a wide variety of organic carbon compounds. Genomic DNA captured from bacterial community subsets metabolizing a single model component of the DOC pool (either dimethylsulphoniopropionate or vanillate) showed substantial overlap in gene composition as well as a diversity of carbon-processing capabilities beyond the selected phenotypes. Our direct measure of niche breadth for bacterial functional assemblages indicates that, in accordance with ecological theory, heterogeneity in the composition and supply of organic carbon to coastal oceans may favour generalist bacteria. In the important interplay between microbial community structure and biogeochemical cycling, coastal heterotrophic communities may be controlled less by transient changes in the carbon reservoir that they process and more by factors such as trophic interactions and physical conditions. 相似文献
34.
Simon Bell Francesca Benatti Neil R. Edwards Robin Laney David R. Morse Lara Piccolo Oliver Zanetti 《Systemic Practice and Action Research》2018,31(1):27-53
The research described in this paper is undertaken under the banner of the smart city, a concept that captures the way urban spaces are re-made by the incursion of new technology. Much of smart is centred on converting everyday activities into data, and using this data to generate knowledge mediated by technology. Ordinary citizens, those that may have their lives impacted by the technology, usually are not properly involved in the ‘smartification’ process. Their perceptions, concerns and expectations should inform the conception and development of smart technologies at the same extent. How to engage general public with smart cities research is the central challenge for the Making Metrics Meaningful (MMM) project. Applying a rapid participatory method, ‘Imagine’ over a five-month period (March – July) the research sought to gain insights from the general public into novel forms of information system innovation. This brief paper describes the nature of the accelerated research undertaken and explores some of the themes which emerged in the analysis. Generic themes, beyond the remit of an explicit transport focus, are developed and pointers towards further research directions are discussed. Participatory methods, including engaging with self-selected transport users actively through both picture creation and programmatically specific musical ‘signatures’ as well as group discussion, were found to be effective in eliciting users’ own concerns, needs and ideas for novel information systems. 相似文献
35.
FengPing Wang ShuLin Lu Beth N. Orcutt Wei Xie Ying Chen Xiang Xiao Katrina J. Edwards 《科学通报(英文版)》2013,58(4-5):456-467
The discovery of the marine “deep biosphere”—microorganisms living deep below the seafloor—is one of the most significant and exciting discoveries since the ocean drilling program began more than 40 years ago. Study of the deep biosphere has become a research frontier and a hot spot both for geological and biological sciences. Here, we introduce the history of the discovery of the deep biosphere, and then we describe the types of environments for life below the seafloor, the energy sources for the living creatures, the diversity of organisms within the deep biosphere, and the new tools and technologies used in this research field. We will highlight several recently completed Integrated Ocean Drilling Program Expeditions, which targeted the subseafloor deep biosphere within the crust and sediments. Finally, future research directions and challenges of deep biosphere investigation towards uncovering the roles of subsurface microorganisms will be briefly addressed. 相似文献
36.
Evolution of microRNA genes by inverted duplication of target gene sequences in Arabidopsis thaliana 总被引:8,自引:0,他引:8
Allen E Xie Z Gustafson AM Sung GH Spatafora JW Carrington JC 《Nature genetics》2004,36(12):1282-1290
37.
Regulation of neutrophil apoptosis via death receptors 总被引:4,自引:0,他引:4
38.
El Niño/Southern Oscillation and tropical Pacific climate during the last millennium 总被引:1,自引:0,他引:1
Any assessment of future climate change requires knowledge of the full range of natural variability in the El Ni?o/Southern Oscillation (ENSO) phenomenon. Here we splice together fossil-coral oxygen isotopic records from Palmyra Island in the tropical Pacific Ocean to provide 30-150-year windows of tropical Pacific climate variability within the last 1,100 years. The records indicate mean climate conditions in the central tropical Pacific ranging from relatively cool and dry during the tenth century to increasingly warmer and wetter climate in the twentieth century. But the corals also document a broad range of ENSO behaviour that correlates poorly with these estimates of mean climate. The most intense ENSO activity within the reconstruction occurred during the mid-seventeenth century. Taken together, the coral data imply that the majority of ENSO variability over the last millennium may have arisen from dynamics internal to the ENSO system itself. 相似文献
39.
Allen M Heinzmann A Noguchi E Abecasis G Broxholme J Ponting CP Bhattacharyya S Tinsley J Zhang Y Holt R Jones EY Lench N Carey A Jones H Dickens NJ Dimon C Nicholls R Baker C Xue L Townsend E Kabesch M Weiland SK Carr D von Mutius E Adcock IM Barnes PJ Lathrop GM Edwards M Moffatt MF Cookson WO 《Nature genetics》2003,35(3):258-263
Asthma is a common disease in children and young adults. Four separate reports have linked asthma and related phenotypes to an ill-defined interval between 2q14 and 2q32 (refs. 1-4), and two mouse genome screens have linked bronchial hyper-responsiveness to the region homologous to 2q14 (refs. 5,6). We found and replicated association between asthma and the D2S308 microsatellite, 800 kb distal to the IL1 cluster on 2q14. We sequenced the surrounding region and constructed a comprehensive, high-density, single-nucleotide polymorphism (SNP) linkage disequilibrium (LD) map. SNP association was limited to the initial exons of a solitary gene of 3.6 kb (DPP10), which extends over 1 Mb of genomic DNA. DPP10 encodes a homolog of dipeptidyl peptidases (DPPs) that cleave terminal dipeptides from cytokines and chemokines, and it presents a potential new target for asthma therapy. 相似文献
40.
人类乙型肝炎病毒的核衣壳由核心蛋白的二聚体所组成.但是,核心蛋白亚单位与亚单位之间相互作用的机制至今尚不清楚.研究发现,在人类乙型肝炎样病毒──土拨鼠肝炎病毒(WHV)核心蛋白的氨基端,存在着4个保守的疏水氨基酸残基(氨基酸位置101~102).它们分别是亮氨酸101,亮氨酸108,缬氨酸115和苯丙氨酸122.这4个疏水氨基酸残基以每隔6个氨基酸残基而重复出现1次.它们被称为“第7位疏水性氨基酸重复肽段(hhr)”.由于蛋白质中的疏水键往往在蛋白质的相互作用中起重要作用,因此就在培养细胞系统中研究WHV核心蛋白的hhr区域在… 相似文献