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The conservation of land snails has become an urgent issue because of the current global decline of this group. Detailed knowledge of population dynamics is needed to develop an appropriate strategy for conservation. We investigated the population dynamics of two threatened European land snail species: Vertigo angustior and Vertigo moulinsiana. Although the species may be found at the same site, V. moulinsiana is more tolerant of wetter conditions than is V. angustior. Abundance data for the two species were collected at two sites (one drier and one wetter) in western Poland biweekly during the spring and summer months in 2008 and 2009. In the drier year, snail abundance was similar between the drier and wetter sites. In the wetter year, snail abundances were generally higher than in the dry year, except that the inundation-intolerant V. angustior became less abundant at the wetter site. We conclude that weather affects different species differently and therefore should be considered along with the habitat features in interpreting survey results for land snails.  相似文献   
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Résumé Chez le rat, un traitement à l'acide acétylsalicilique, au salicilate sodique et au phénylbutazone fait remonter le taux de protrombine abaissé par la bishydrocoumarine.  相似文献   
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Arabidopsis boron transporter for xylem loading   总被引:21,自引:0,他引:21  
Boron deficiency hampers the productivity of 132 crops in more than 80 countries. Boron is essential in higher plants primarily for maintaining the integrity of cell walls and is also beneficial and might be essential in animals and in yeast. Understanding the molecular mechanism(s) of boron transport is crucial for alleviating boron deficiency. Here we describe the molecular identification of boron transporters in biological systems. The Arabidopsis thaliana mutant bor1-1 is sensitive to boron deficiency. Uptake studies indicated that xylem loading is the key step for boron accumulation in shoots with a low external boron supply and that the bor1-1 mutant is defective in this process. Positional cloning identified BOR1 as a membrane protein with homology to bicarbonate transporters in animals. Moreover, a fusion protein of BOR1 and green fluorescent protein (GFP) localized to the plasma membrane in transformed cells. The promoter of BOR1 drove GFP expression in root pericycle cells. When expressed in yeast, BOR1 decreased boron concentrations in cells. We show here that BOR1 is an efflux-type boron transporter for xylem loading and is essential for protecting shoots from boron deficiency.  相似文献   
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Summary Evidence is presented that the use of 2 different culture media, with or without methionine, can help to distinguish between normal and leukaemic methotrexate (MTX)-sensitive cells derived from chronic myeloid leukaemia patients. During the blast crisis MTX assays may help directly in the diagnostics of lymphoid involvement.This work was supported by the Polish Academy of Sciences within the project 09.7.4.1.4.Acknowledgments. We are indebted to Prof. Zofia Zieliska, Dept. of Cell Biochemistry, M. Nencki Institute of Experimental Biology PAN for providing the 5-methyltetrahydrofolate and for advice in these studies.  相似文献   
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Résumé On décrit le facteur protéique stimulant in vitro la transformation blastique des lymphocytes allogènes. La présence de ce facteur ne put être établie à l'intérieur des lysosomes des macrophages, des lymphocytes, des cellules hépatiques, ni dans les fractions des granulocytes polymorphonucléaires contenant le plasma cellulaire dépourvu d'autres structures à la suite d'une centrifugation. On discute le rôle présumé du facteur étudié in vivo.  相似文献   
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Summary Blockade of beta receptors inhibited thyroxine-induced increases in Tre, blood FFA and LA levels during exercise in dogs.  相似文献   
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