排序方式: 共有6条查询结果,搜索用时 15 毫秒
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Nanometre-level analysis demonstrates that lipid flow does not drive membrane glycoprotein movements 总被引:30,自引:0,他引:30
Nanometre-level analyses of the movements of membrane glycoproteins tagged with gold particles demonstrate that diffusing particles are not under the influence of a lipid flow, although a subset of particles which appear attached to the cytoskeleton are moving rearward. 相似文献
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An SNP map of human chromosome 22 总被引:35,自引:0,他引:35
Mullikin JC Hunt SE Cole CG Mortimore BJ Rice CM Burton J Matthews LH Pavitt R Plumb RW Sims SK Ainscough RM Attwood J Bailey JM Barlow K Bruskiewich RM Butcher PN Carter NP Chen Y Clee CM Coggill PC Davies J Davies RM Dawson E Francis MD Joy AA Lamble RG Langford CF Macarthy J Mall V Moreland A Overton-Larty EK Ross MT Smith LC Steward CA Sulston JE Tinsley EJ Turney KJ Willey DL Wilson GD McMurray AA Dunham I Rogers J Bentley DR 《Nature》2000,407(6803):516-520
The human genome sequence will provide a reference for measuring DNA sequence variation in human populations. Sequence variants are responsible for the genetic component of individuality, including complex characteristics such as disease susceptibility and drug response. Most sequence variants are single nucleotide polymorphisms (SNPs), where two alternate bases occur at one position. Comparison of any two genomes reveals around 1 SNP per kilobase. A sufficiently dense map of SNPs would allow the detection of sequence variants responsible for particular characteristics on the basis that they are associated with a specific SNP allele. Here we have evaluated large-scale sequencing approaches to obtaining SNPs, and have constructed a map of 2,730 SNPs on human chromosome 22. Most of the SNPs are within 25 kilobases of a transcribed exon, and are valuable for association studies. We have scaled up the process, detecting over 65,000 SNPs in the genome as part of The SNP Consortium programme, which is on target to build a map of 1 SNP every 5 kilobases that is integrated with the human genome sequence and that is freely available in the public domain. 相似文献
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Morwood MJ Soejono RP Roberts RG Sutikna T Turney CS Westaway KE Rink WJ Zhao JX van den Bergh GD Due RA Hobbs DR Moore MW Bird MI Fifield LK 《Nature》2004,431(7012):1087-1091
Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominins, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis. The finds comprise the cranial and some post-cranial remains of one individual, as well as a premolar from another individual in older deposits. Here we describe their context, implications and the remaining archaeological uncertainties. Dating by radiocarbon (14C), luminescence, uranium-series and electron spin resonance (ESR) methods indicates that H. floresiensis existed from before 38,000 years ago (kyr) until at least 18 kyr. Associated deposits contain stone artefacts and animal remains, including Komodo dragon and an endemic, dwarfed species of Stegodon. H. floresiensis originated from an early dispersal of Homo erectus (including specimens referred to as Homo ergaster and Homo georgicus) that reached Flores, and then survived on this island refuge until relatively recently. It overlapped significantly in time with Homo sapiens in the region, but we do not know if or how the two species interacted. 相似文献
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The El Ni?o/Southern Oscillation (ENSO) phenomenon is believed to have operated continuously over the last glacial-interglacial cycle. ENSO variability has been suggested to be linked to millennial-scale oscillations in North Atlantic climate during that time, but the proposals disagree on whether increased frequency of El Ni?o events, the warm phase of ENSO, was linked to North Atlantic warm or cold periods. Here we present a high-resolution record of surface moisture, based on the degree of peat humification and the ratio of sedges to grass, from northern Queensland, Australia, covering the past 45,000 yr. We observe millennial-scale dry periods, indicating periods of frequent El Ni?o events (summer precipitation declines in El Ni?o years in northeastern Australia). We find that these dry periods are correlated to the Dansgaard-Oeschger events--millennial-scale warm events in the North Atlantic climate record--although no direct atmospheric connection from the North Atlantic to our site can be invoked. Additionally, we find climatic cycles at a semiprecessional timescale (approximately 11,900 yr). We suggest that climate variations in the tropical Pacific Ocean on millennial as well as orbital timescales, which determined precipitation in northeastern Australia, also exerted an influence on North Atlantic climate through atmospheric and oceanic teleconnections. 相似文献
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