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81.
THOMAS A. WHITE JEREMY B. SEARLE 《Biological journal of the Linnean Society. Linnean Society of London》2008,94(4):797-808
In this paper we apply molecular methods to study the colonization of islands off the west coast of Scotland by the common shrew ( Sorex araneus L.), and current gene flow. We collected 497 individuals from 13 islands of the Inner Hebrides and Clyde Island groups and six mainland regions. Individuals were genotyped at eight microsatellite loci, and the mitochondrial cytochrome b sequence (1140 base pairs) was obtained for five individuals from each island/mainland region. Based on these molecular data, island colonization apparently proceeded directly from the mainland, except for Islay, for which Jura was the most likely source population. Raasay may also have been colonized by island hopping. Most island populations are genetically very distinct from the mainland populations, suggesting long periods of isolation. Two exceptions to this are the islands of Skye and Seil, which are geographically and genetically close to the mainland, suggesting in each case that there has been long-term gene flow between these islands and the mainland. We consider possible methods of island colonization, including human-mediated movement, swimming, and land and ice bridges. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 797–808. 相似文献
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Risk-sensitive behavior is the phenomenon of animals exhibitingpreferences when offered choices whose outcomes differ in theirdegree of variance. It is now well demonstrated that many animalsare sensitive to differences in the magnitude of variance inrewards. A considerable body of literature on risk sensitivityhas been generated in recent years, encompassing theoreticaland empirical work, from both functional and mechanistic approaches.Nevertheless, it is less than clear how animal preferences forvariability are determined. It is therefore timely to look broadlyat what has been accomplished, and to identify the most promisingsynthetic approaches for future work. 相似文献
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Dunlop, J., Knighton, M. V. and White, D. W. R. 1988. Ion transportand the effects of acetic acid in white clover. II. Potassiumabsorption.J. exp. Bot. 39: 8996. Acetic acid stimulated K+ influx into cells of white cloverin suspension culture and net K+ influx by roots of intact whiteclover plants. At concentrations of acetic acid up to 2·0mol m3 the stimulation continued unabated for at least2 h. However, at higher concentrations the rate of absorptiondeclined to near zero values after 2 h. When acetic acid wasremoved from the solution there was a net efflux of K+. Thestimulation was pH dependent with a maximum at pH 5·0.There was maximum stimulation at an acetic acid concentrationof 2·0 mol m3 Net H+ efflux was reduced by 1·0 mol m3 aceticacid. When Rb+ uptake and H+ efflux were measured at a rangeof RbCl concentrations Rb+ uptake increased with concentrationwhereas H+ efflux was maximum in the absence of Rb+ (and K+)and decreased as RbCl concentration was increased Acetic acid caused a hyperpolarization of the membrane electricalpotential difference (E) of about 25 mV. In 1·0 mol m3acetic acid the hyperpolarization persisted for at least 2 hwhereas at 10 mol m3 d E subsequently depolarized tovalues around 80 mV. With a slight lag, the time courseof the stimulation of the rate of K+ absorption followed thepolarization and depolarization of E. These results imply thatthe linkage between K+ and H+ movements is probably throughE. Key words: Proton efflux, membrane electrical potential difference, Trifolium repens 相似文献
85.
GUTHRIE S. ZIMMERMAN TIMOTHY J. MOSER WILLIAM L. KENDALL PAUL F. DOHERTY JR. GARY C. WHITE DALE F. CASWELL 《The Journal of wildlife management》2009,73(5):710-719
ABSTRACT We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US$10, $20, $30, $50, or $100) and control ($0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95% CI = 0.69–0.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities. 相似文献
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An omnibus test of normality for moderate and large size samples 总被引:4,自引:0,他引:4
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Mechanisms of action of abscisic acid at the cellular level 总被引:9,自引:2,他引:9