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211.
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Petit R Aguinagalde I de Beaulieu JL Bittkau C Brewer S Cheddadi R Ennos R Fineschi S Grivet D Lascoux M Mohanty A Müller-Starck G Demesure-Musch B Palmé A Martín JP Rendell S Vendramin GG 《Science (New York, N.Y.)》2003,300(5625):1563-1565
Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse populations were not located in the south but at intermediate latitudes, a likely consequence of the admixture of divergent lineages colonizing the continent from separate refugia. 相似文献
214.
215.
Heath J Ayres E Possell M Bardgett RD Black HI Grant H Ineson P Kerstiens G 《Science (New York, N.Y.)》2005,309(5741):1711-1713
Forests have a key role as carbon sinks, which could potentially mitigate the continuing increase in atmospheric carbon dioxide concentration and associated climate change. We show that carbon dioxide enrichment, although causing short-term growth stimulation in a range of European tree species, also leads to an increase in soil microbial respiration and a marked decline in sequestration of root-derived carbon in the soil. These findings indicate that, should similar processes operate in forest ecosystems, the size of the annual terrestrial carbon sink may be substantially reduced, resulting in a positive feedback on the rate of increase in atmospheric carbon dioxide concentration. 相似文献
216.
Heldmaier G 《Science (New York, N.Y.)》2011,331(6019):866-867
217.
Brüggemann H Henne A Hoster F Liesegang H Wiezer A Strittmatter A Hujer S Dürre P Gottschalk G 《Science (New York, N.Y.)》2004,305(5684):671-673
Propionibacterium acnes is a major inhabitant of adult human skin, where it resides within sebaceous follicles, usually as a harmless commensal although it has been implicated in acne vulgaris formation. The entire genome sequence of this Gram-positive bacterium encodes 2333 putative genes and revealed numerous gene products involved in degrading host molecules, including sialidases, neuraminidases, endoglycoceramidases, lipases, and pore-forming factors. Surface-associated and other immunogenic factors have been identified, which might be involved in triggering acne inflammation and other P. acnes-associated diseases. 相似文献
218.
Aspholm-Hurtig M Dailide G Lahmann M Kalia A Ilver D Roche N Vikström S Sjöström R Lindén S Bäckström A Lundberg C Arnqvist A Mahdavi J Nilsson UJ Velapatiño B Gilman RH Gerhard M Alarcon T López-Brea M Nakazawa T Fox JG Correa P Dominguez-Bello MG Perez-Perez GI Blaser MJ Normark S Carlstedt I Oscarson S Teneberg S Berg DE Borén T 《Science (New York, N.Y.)》2004,305(5683):519-522
Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O-dominant human populations. 相似文献
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220.
Truong Xuan Vuong Felix Heitkamp Hermann F. Jungkunst Andreas Reimer Gerhard Gerold 《Journal of Soils and Sediments》2013,13(7):1133-1140