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411.
Two event-related potential (ERP) experiments were performed to compare the time course of graphic, semantic and phonological activation of high and low frequency Chinese characters. In Experiment 1, for high frequency materials, graphic priming produced smaller P200 and N400, while semantic priming produced smaller N400 only, but there were no homophonic priming compared to unrelated pairs. In Experiment 2, for low frequency materials, graphic priming produced a smaller P200 and N400, homophonic priming produced an increased P200 and smaller N400 and semantic priming produced a moderately reduced N400 compared to unrelated pairs. The results suggest that there are some differences of activating lexical information of high and low frequency Chinese characters. Graphic activation emerges first, regardless of frequency. For high frequency characters, semantic activation was found, but there is no phonological activation. Whereas for low frequency characters, phonological activation emerges before semantic activation.  相似文献   
412.
Animals, ranging from basal metazoans to primates, are host to complex microbial ecosystems; engaged in a symbiotic relationship that is essential for host physiology and homeostasis. Epithelial surfaces vary in the composition of colonizing microbiota as one compares anatomic sites, developmental stages and species origin. Alterations of microbial composition likely contribute to susceptibility to several distinct diseases. The forces that shape the colonizing microbial composition are the focus of much current investigation, and it is evident that there are pressures exerted both by the host and the external environment to mold these ecosystems. The focus of this review is to discuss recent studies that demonstrate the critical importance of host factors in selecting for its microbiome. Greater insight into host–microbiome interactions will be essential for understanding homeostasis at mucosal surfaces, and developing useful interventions when homeostasis is disrupted.  相似文献   
413.
Goddard MR  Godfray HC  Burt A 《Nature》2005,434(7033):636-640
Why sex evolved and persists is a problem for evolutionary biology, because sex disrupts favourable gene combinations and requires an expenditure of time and energy. Further, in organisms with unequal-sized gametes, the female transmits her genes at only half the rate of an asexual equivalent (the twofold cost of sex). Many modern theories that provide an explanation for the advantage of sex incorporate an idea originally proposed by Weismann more than 100 years ago: sex allows natural selection to proceed more effectively because it increases genetic variation. Here we test this hypothesis, which still lacks robust empirical support, with the use of experiments on yeast populations. Capitalizing on recent advances in the molecular biology of recombination in yeast, we produced by genetic manipulation strains that differed only in their capacity for sexual reproduction. We show that, as predicted by the theory, sex increases the rate of adaptation to a new harsh environment but has no measurable effect on fitness in a new benign environment where there is little selection.  相似文献   
414.
Detection of large-scale variation in the human genome   总被引:26,自引:0,他引:26  
We identified 255 loci across the human genome that contain genomic imbalances among unrelated individuals. Twenty-four variants are present in > 10% of the individuals that we examined. Half of these regions overlap with genes, and many coincide with segmental duplications or gaps in the human genome assembly. This previously unappreciated heterogeneity may underlie certain human phenotypic variation and susceptibility to disease and argues for a more dynamic human genome structure.  相似文献   
415.
416.
The history of the Hawaiian hotspot is of enduring interest in studies of plate motion and mantle flow,and has been investigated by many researchers using the d...  相似文献   
417.
With scale relativity theory, Laurent Nottale has provided a powerful conceptual and mathematical framework with numerous validated predictions that has fundamental implications and applications for all sciences. We discuss how this extended framework reviewed in Nottale (Found Sci 152 (3):101–152, 2010a) may help facilitating integration across multiple size and time frames in systems biology, and the development of a scale relative biology with increased explanatory power.  相似文献   
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