排序方式: 共有22条查询结果,搜索用时 31 毫秒
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Systemic Practice and Action Research - My reading of the six accounts of co-operative inquiry in this volume comes during a historic moment for action research in which the tensions of celebration... 相似文献
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M P Maguire 《Nature》1969,222(5194):691-692
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Shea J Agarwala V Philippakis AA Maguire J Banks E Depristo M Thomson B Guiducci C Onofrio RC Kathiresan S Gabriel S Burtt NP Daly MJ Groop L Altshuler D;Myocardial Infarction Genetics Consortium 《Nature genetics》2011,43(8):801-805
Noncoding variants at human chromosome 9p21 near CDKN2A and CDKN2B are associated with type 2 diabetes, myocardial infarction, aneurysm, vertical cup disc ratio and at least five cancers. Here we compare approaches to more comprehensively assess genetic variation in the region. We carried out targeted sequencing at high coverage in 47 individuals and compared the results to pilot data from the 1000 Genomes Project. We imputed variants into type 2 diabetes and myocardial infarction cohorts directly from targeted sequencing, from a genotyped reference panel derived from sequencing and from 1000 Genomes Project low-coverage data. Polymorphisms with frequency >5% were captured well by all strategies. Imputation of intermediate-frequency polymorphisms required a higher density of tag SNPs in disease samples than is available on first-generation genome-wide association study (GWAS) arrays. Our association analyses identified more comprehensive sets of variants showing equivalent statistical association with type 2 diabetes or myocardial infarction, but did not identify stronger associations than the original GWAS signals. 相似文献
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Prodigiosin condensing enzyme (PCE) activities were present in Serratia marcescens wild type 08, mutants OF, WF and 9-3-3. Their specific activities exhibited different maxima and at different times during the late log phase or the early stationary phase of cell growth. The levels of prodigiosin and its precursors also showed a significant increase at this period. The results support that prodigiosin and/or its precursors are secondary metabolites. The ubiquity of the PCE activity in mutants deficient in prodigiosin biosynthesis suggest that this particular enzyme may also be present in non-pigmented clinical isolates. 相似文献
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Zusammenfassung Cyclophosphamid (aber nicht 6-Mercaptopurin oder Vincaleukoblastin) verhindert die primäre Antikörperbildung beim Meerschweinchen. Auch bei fortgesetzter Stimulation mit dem spezifischen Antigen bleiben die Tiere relativ refraktär. Dieser Hemmeffekt wird weitgehend aufgehoben, wenn das Antigen mit Freund's Adjuvans injiziert wird.
Aided by a grant from the American Cancer Society. 相似文献
Aided by a grant from the American Cancer Society. 相似文献
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Has the Earth's sixth mass extinction already arrived? 总被引:1,自引:0,他引:1
Barnosky AD Matzke N Tomiya S Wogan GO Swartz B Quental TB Marshall C McGuire JL Lindsey EL Maguire KC Mersey B Ferrer EA 《Nature》2011,471(7336):51-57
Palaeontologists characterize mass extinctions as times when the Earth loses more than three-quarters of its species in a geologically short interval, as has happened only five times in the past 540?million years or so. Biologists now suggest that a sixth mass extinction may be under way, given the known species losses over the past few centuries and millennia. Here we review how differences between fossil and modern data and the addition of recently available palaeontological information influence our understanding of the current extinction crisis. Our results confirm that current extinction rates are higher than would be expected from the fossil record, highlighting the need for effective conservation measures. 相似文献
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Li W Bloom JS Podsiadlowski P Miller AA Cenko SB Jha SW Sullivan M Howell DA Nugent PE Butler NR Ofek EO Kasliwal MM Richards JW Stockton A Shih HY Bildsten L Shara MM Bibby J Filippenko AV Ganeshalingam M Silverman JM Kulkarni SR Law NM Poznanski D Quimby RM McCully C Patel B Maguire K Shen KJ 《Nature》2011,480(7377):348-350
Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. There are two classes of models: double-degenerate (involving two white dwarfs in a close binary system) and single-degenerate models. In the latter, the primary white dwarf accretes material from a secondary companion until conditions are such that carbon ignites, at a mass of 1.38 times the mass of the Sun. The type Ia supernova SN 2011fe was recently detected in a nearby galaxy. Here we report an analysis of archival images of the location of SN 2011fe. The luminosity of the progenitor system (especially the companion star) is 10-100 times fainter than previous limits on other type Ia supernova progenitor systems, allowing us to rule out luminous red giants and almost all helium stars as the mass-donating companion to the exploding white dwarf. 相似文献
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Neale BM Kou Y Liu L Ma'ayan A Samocha KE Sabo A Lin CF Stevens C Wang LS Makarov V Polak P Yoon S Maguire J Crawford EL Campbell NG Geller ET Valladares O Schafer C Liu H Zhao T Cai G Lihm J Dannenfelser R Jabado O Peralta Z Nagaswamy U Muzny D Reid JG Newsham I Wu Y Lewis L Han Y Voight BF Lim E Rossin E Kirby A Flannick J Fromer M Shakir K Fennell T Garimella K Banks E Poplin R Gabriel S DePristo M Wimbish JR Boone BE Levy SE Betancur C Sunyaev S Boerwinkle E Buxbaum JD Cook EH Devlin B 《Nature》2012,485(7397):242-245
Autism spectrum disorders (ASD) are believed to have genetic and environmental origins, yet in only a modest fraction of individuals can specific causes be identified. To identify further genetic risk factors, here we assess the role of de novo mutations in ASD by sequencing the exomes of ASD cases and their parents (n = 175 trios). Fewer than half of the cases (46.3%) carry a missense or nonsense de novo variant, and the overall rate of mutation is only modestly higher than the expected rate. In contrast, the proteins encoded by genes that harboured de novo missense or nonsense mutations showed a higher degree of connectivity among themselves and to previous ASD genes as indexed by protein-protein interaction screens. The small increase in the rate of de novo events, when taken together with the protein interaction results, are consistent with an important but limited role for de novo point mutations in ASD, similar to that documented for de novo copy number variants. Genetic models incorporating these data indicate that most of the observed de novo events are unconnected to ASD; those that do confer risk are distributed across many genes and are incompletely penetrant (that is, not necessarily sufficient for disease). Our results support polygenic models in which spontaneous coding mutations in any of a large number of genes increases risk by 5- to 20-fold. Despite the challenge posed by such models, results from de novo events and a large parallel case-control study provide strong evidence in favour of CHD8 and KATNAL2 as genuine autism risk factors. 相似文献