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Allan Chapman 《Annals of science》2013,70(5):431-463
When Thomas Hornsby commissioned John Bird to build a set of five major astronomical instruments for the new Radcliffe Observatory, Oxford, the order included an Equatorial Sector. This was an instrument of experimental design, intended to measure angles out of the meridian. Although in itself a transitional instrument, the Equatorial Sector's capacity for extra-meridional measurement, especially for the observation of comets, encouraged craftsmen to develop the design first into the Equatorial Circle, and then into the large equatorially mounted refracting telescope used in conjunction with micrometers. Although other Equatorial Sectors were made, Bird's instrument for Oxford is the only one that survives intact. The present study examines this unique artefact within the context of changing astronomical demands between the 1770s and the 1820s. 相似文献
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Complex gas hydrate from the Cascadia margin 总被引:3,自引:0,他引:3
Lu H Seo YT Lee JW Moudrakovski I Ripmeester JA Chapman NR Coffin RB Gardner G Pohlman J 《Nature》2007,445(7125):303-306
Natural gas hydrates are a potential source of energy and may play a role in climate change and geological hazards. Most natural gas hydrate appears to be in the form of 'structure I', with methane as the trapped guest molecule, although 'structure II' hydrate has also been identified, with guest molecules such as isobutane and propane, as well as lighter hydrocarbons. A third hydrate structure, 'structure H', which is capable of trapping larger guest molecules, has been produced in the laboratory, but it has not been confirmed that it occurs in the natural environment. Here we characterize the structure, gas content and composition, and distribution of guest molecules in a complex natural hydrate sample recovered from Barkley canyon, on the northern Cascadia margin. We show that the sample contains structure H hydrate, and thus provides direct evidence for the natural occurrence of this hydrate structure. The structure H hydrate is intimately associated with structure II hydrate, and the two structures contain more than 13 different hydrocarbon guest molecules. We also demonstrate that the stability field of the complex gas hydrate lies between those of structure II and structure H hydrates, indicating that this form of hydrate is more stable than structure I and may thus potentially be found in a wider pressure-temperature regime than can methane hydrate deposits. 相似文献
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Dawson MA Prinjha RK Dittmann A Giotopoulos G Bantscheff M Chan WI Robson SC Chung CW Hopf C Savitski MM Huthmacher C Gudgin E Lugo D Beinke S Chapman TD Roberts EJ Soden PE Auger KR Mirguet O Doehner K Delwel R Burnett AK Jeffrey P Drewes G Lee K Huntly BJ Kouzarides T 《Nature》2011,478(7370):529-533
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Stephens PJ Tarpey PS Davies H Van Loo P Greenman C Wedge DC Nik-Zainal S Martin S Varela I Bignell GR Yates LR Papaemmanuil E Beare D Butler A Cheverton A Gamble J Hinton J Jia M Jayakumar A Jones D Latimer C Lau KW McLaren S McBride DJ Menzies A Mudie L Raine K Rad R Chapman MS Teague J Easton D Langerød A;Oslo Breast Cancer Consortium 《Nature》2012,486(7403):400-404
All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease. 相似文献
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Deloukas P Earthrowl ME Grafham DV Rubenfield M French L Steward CA Sims SK Jones MC Searle S Scott C Howe K Hunt SE Andrews TD Gilbert JG Swarbreck D Ashurst JL Taylor A Battles J Bird CP Ainscough R Almeida JP Ashwell RI Ambrose KD Babbage AK Bagguley CL Bailey J Banerjee R Bates K Beasley H Bray-Allen S Brown AJ Brown JY Burford DC Burrill W Burton J Cahill P Camire D Carter NP Chapman JC Clark SY Clarke G Clee CM Clegg S Corby N Coulson A Dhami P Dutta I Dunn M Faulkner L Frankish A 《Nature》2004,429(6990):375-381