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James Ladyman Stuart Presnell Anthony J. Short 《Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics》2008,39(2):315-324
When considering controversial thermodynamic scenarios such as Maxwell's demon, it is often necessary to consider probabilistic mixtures of macrostates. This raises the question of how, if at all, to assign entropy to them. The information-theoretic entropy is often used in such cases; however, no general proof of the soundness of doing so has been given, and indeed some arguments against doing so have been presented. We offer a general proof of the applicability of the information-theoretic entropy to probabilistic mixtures of macrostates that is based upon a probabilistic generalisation of the Kelvin statement of the second law. We defend the latter and make clear the other assumptions on which our main result depends. We also briefly discuss the interpretation of our result. 相似文献
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Bryan L. Stuart Hannah E. Som Thy Neang Huy Duc Hoang Duong Thi Thuy Le Vinh Quang Dau 《Journal of Natural History》2020,54(1-4):225-255
ABSTRACT Species boundaries within the red-eyed Leptobrachium of southern Indochina have been uncertain. Leptobrachium pullum and L. mouhoti from upper and lower elevations, respectively, of the Langbian Plateau of southern Vietnam and eastern Cambodia differ in body size but have relatively low interspecific mitochondrial DNA divergence, leading to speculation that these might represent a single species with an elevational cline in body size. The recent discovery of an allopatric high-elevation population of red-eyed Leptobrachium on the Kon Tum Plateau (= Central Highlands) of north-eastern Cambodia and central Vietnam has been referred to both species, and to a putatively undescribed species. We examine variation in morphology of adults and tadpoles, mitochondrial DNA, 11 nuclear genes and advertisement calls, and show corroborating lines of evidence for the existence of three species of red-eyed Leptobrachium in southern Indochina. Although the three species are reciprocally monophyletic in mitochondrial DNA, their shallow mitochondrial DNA divergences are not mirrored by morphology, advertisement calls, or – in part – nuclear DNA, and probably reflect past mitochondrial introgression rather than recent speciation. The Central Highlands taxon is described herein as a new species. http://www.zoobank.org/urn:lsid:zoobank.org:pub:CE6650AF-D9FB-40F4-8A2E-9B4E23AAC205 相似文献
86.
从地方性艺术市场的角度对意大利佛罗伦萨的当代艺术体系进行分析,可以发现,佛罗伦萨的困境在于:既要充分利用其独一无二的艺术历史,又要保持活跃的当代艺术氛围。佛罗伦萨与颇具代表性的美国密苏里州圣路易斯市的地方性艺术市场截然不同。现今佛罗伦萨艺术体系中存在的问题可以从历史和以大众旅游为中心的现有生活方式中体现出来。 相似文献
87.
Leptothorax (Nesomyrmex) spininodis andL. (N.) echinatinodis workers lay pheromone trails when returning from food sources to their nests. Workers from within the nest begin following the trail almost immediately upon the successful forager's return and do not require a leader. The trail remains effective for about four minutes under our laboratory conditions but it is unclear whether the trail alone is sufficient to induce recruitment or whether additional signals, perhaps emitted within the nest, are involved. Pheromone trails of this type have not previously been documented for leptothoracine ants. 相似文献
88.
Exome sequencing identifies frequent mutation of the SWI/SNF complex gene PBRM1 in renal carcinoma 总被引:1,自引:0,他引:1
Varela I Tarpey P Raine K Huang D Ong CK Stephens P Davies H Jones D Lin ML Teague J Bignell G Butler A Cho J Dalgliesh GL Galappaththige D Greenman C Hardy C Jia M Latimer C Lau KW Marshall J McLaren S Menzies A Mudie L Stebbings L Largaespada DA Wessels LF Richard S Kahnoski RJ Anema J Tuveson DA Perez-Mancera PA Mustonen V Fischer A Adams DJ Rust A Chan-on W Subimerb C Dykema K Furge K Campbell PJ Teh BT Stratton MR Futreal PA 《Nature》2011,469(7331):539-542
89.
Yokoyama S Woods SL Boyle GM Aoude LG MacGregor S Zismann V Gartside M Cust AE Haq R Harland M Taylor JC Duffy DL Holohan K Dutton-Regester K Palmer JM Bonazzi V Stark MS Symmons J Law MH Schmidt C Lanagan C O'Connor L Holland EA Schmid H Maskiell JA Jetann J Ferguson M Jenkins MA Kefford RF Giles GG Armstrong BK Aitken JF Hopper JL Whiteman DC Pharoah PD Easton DF Dunning AM Newton-Bishop JA Montgomery GW Martin NG Mann GJ Bishop DT Tsao H Trent JM Fisher DE Hayward NK Brown KM 《Nature》2011,480(7375):99-103
90.
Campbell PJ Yachida S Mudie LJ Stephens PJ Pleasance ED Stebbings LA Morsberger LA Latimer C McLaren S Lin ML McBride DJ Varela I Nik-Zainal SA Leroy C Jia M Menzies A Butler AP Teague JW Griffin CA Burton J Swerdlow H Quail MA Stratton MR Iacobuzio-Donahue C Futreal PA 《Nature》2010,467(7319):1109-1113
Pancreatic cancer is an aggressive malignancy with a five-year mortality of 97-98%, usually due to widespread metastatic disease. Previous studies indicate that this disease has a complex genomic landscape, with frequent copy number changes and point mutations, but genomic rearrangements have not been characterized in detail. Despite the clinical importance of metastasis, there remain fundamental questions about the clonal structures of metastatic tumours, including phylogenetic relationships among metastases, the scale of ongoing parallel evolution in metastatic and primary sites, and how the tumour disseminates. Here we harness advances in DNA sequencing to annotate genomic rearrangements in 13 patients with pancreatic cancer and explore clonal relationships among metastases. We find that pancreatic cancer acquires rearrangements indicative of telomere dysfunction and abnormal cell-cycle control, namely dysregulated G1-to-S-phase transition with intact G2-M checkpoint. These initiate amplification of cancer genes and occur predominantly in early cancer development rather than the later stages of the disease. Genomic instability frequently persists after cancer dissemination, resulting in ongoing, parallel and even convergent evolution among different metastases. We find evidence that there is genetic heterogeneity among metastasis-initiating cells, that seeding metastasis may require driver mutations beyond those required for primary tumours, and that phylogenetic trees across metastases show organ-specific branches. These data attest to the richness of genetic variation in cancer, brought about by the tandem forces of genomic instability and evolutionary selection. 相似文献