共查询到20条相似文献,搜索用时 15 毫秒
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Why are proteins O-glycosylated? 总被引:35,自引:0,他引:35
N Jentoft 《Trends in biochemical sciences》1990,15(8):291-294
The O-linked oligosaccharides of glycoproteins are usually clustered within heavily glycosylated regions of the peptide chain. Steric interactions between carbohydrate and peptide within these clusters induce the peptide core to adopt a stiff and extended conformation and this conformational effect appears to represent a major function of O-glycosylation. 相似文献
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Richard T. Corlett 《Biotropica》2013,45(3):273-275
The tropics are clearly defined while ‘subtropics’ and ‘subtropical’ have been applied to a variety of zones, climates, and ecosystems. However, in the recent terrestrial biology literature, they have been used mainly for the zones between the tropics (±23.4o C) and ±30.0o. Adopting this standard would facilitate pan‐subtropical comparisons. 相似文献
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Teitelbaum S 《Plastic and reconstructive surgery》2011,127(2):1003-4; author reply 1004-5
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Decision trees have been applied to problems such as assigning protein function and predicting splice sites. How do these classifiers work, what types of problems can they solve and what are their advantages over alternatives? 相似文献
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Andrew Buskell 《Biology & philosophy》2017,32(3):377-394
Concepts from cultural attractor theory are now used in domains far from their original home in anthropology and cultural evolution. Yet these concepts have not been consistently characterised. I here distinguish four ways in which the cultural attractor concept has been used and identify three kinds of factors of attraction typically appealed to. Clarifying these explanatory concepts identifies problems and ambiguities in the work of cultural epidemiologists and commentators alike. 相似文献
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In the February 8th issue of Cell, Wang et al. report the surprising finding that vacuolar fusion occurs at the periphery of the contact area of the vacuoles and not by the expansion of a central fusion pore. During fusion, a disk of boundary membrane is excised and left behind within the fused vacuoles. 相似文献
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Yiannis Manetas 《Flora》2006,201(3):163-177
The adaptive significance of leaf reddening, as it occurs during specific developmental stages or after stress, has puzzled biologists for more than a century. Theoretically, the accumulation of a non-photosynthetic pigment competing with chlorophylls for photon capture would impose a photosynthetic cost, which should be paid off by the benefits afforded by anthocyanins under some circumstances. Hence, the proposed hypotheses presume protective functions against excess light, UV-B radiation, reactive oxygen species, water stress (osmoregulation) and herbivory. The existing arguments in favor of an anti-oxidant, anti-UV-B and osmoregulatory role are confounded by the co-occurrence in leaves of other compounds having the same properties, not absorbing visible light, attaining much higher concentrations and, in some cases, having a more appropriate location to fulfill the ascribed functions. Moreover, the excess light hypothesis should take into account that anthocyanins mainly absorb green photons, which are used photosynthetically in deeper cell layers needing less photoprotection. The more ecological, anti-herbivore hypotheses, consider red leaf color as a signal denoting high defensive commitment, as a camouflage obscuring the green reflectance indicative of a healthy leaf and/or as a device undermining the folivorous insects camouflage. The anti-herbivore hypotheses have not been thoroughly tested, yet they are compatible with the known optical preferences of insects and their underlying physiology. Overall, although a multiplicity of potential roles can be argued, the primary role may depend on the reference system, i.e. species, developmental stage or specific biotic and abiotic stressors. 相似文献
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Caulfield T 《Human genetics》2011,130(1):23-25
Direct-to-consumer genetic testing continues to receive significant attention from both the popular press and policymakers.
While the demand for these services has not, to date, been significant, it nevertheless seems likely that more and more individuals
will be accessing DTC services. As a result, commentators have suggested that the DTC industry requires more oversight. A
common rationale for policy action is that DTC services might cause undue anxiety. However, emerging evidence suggests that
this is not the case. Indeed, it appears that genetic risk information has little impact on individual behavior or anxiety
levels. Though more research is clearly needed, this type of research should inform the regulatory response to DTC services. 相似文献
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How Tough are Sclerophylls? 总被引:2,自引:0,他引:2
Fracture toughness was estimated for a 'least tough' path inthe leaves of woody species from three sclerophyllous plantcommunities. Most of the species from Mediterranean, tropicalheath forest and lowland tropical rain forest habitats had verytough leaves, with toughness generally 600-1300 J m-2, whichis two to four times higher than soft-leaved tropical pioneertrees. The toughest leaf (2032 J m-2), Parishia insignis, camefrom the canopy of the lowland rain forest. Leaves from theshaded understorey of the rain forest did not appear any lesstough than those from the canopy.Copyright 1993, 1999 AcademicPress Leaf fracture toughness, sclerophylly, Mediterranean vegetation, tropical forest 相似文献
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