| 1 | Multi-scale phylogenetic structure in coastal dune plant communities across the globe显示文摘Aims Studies integrating phylogenetic history and large-scale community assembly are few,and many questions remain unanswered.Here,we use a global coastal dune plant data set to uncover the important factors in community assembly across scales from the local filtering processes to the global long-term diversification and dispersal dynamics.Coastal dune plant communities occur worldwide under a wide range of climatic and geologic conditions as well as in all biogeographic regions.However,global patterns in the phylogenetic composition of coastal dune plant communities have not previously been studied.Methods The data set comprised vegetation data from 18463 plots in New Zealand,South Africa,South America,North America and Europe.The phylogenetic tree comprised 2241 plant species from 149 families.We calculated phylogenetic clustering(Net Relatedness Index,NRI,and Nearest Taxon Index,NTI)of regional dune floras to estimate the amount of in situ diversification relative to the global dune species pool and evaluated the relative importance of land and climate barriers for these diversification patterns by geographic analyses of phylogenetic similarity.We then tested whether dune plant communities exhibit similar patterns of phylogenetic structure within regions.Finally,we calculated NRI for local communities relative to the regional species pool and tested for an association with functional traits(plant height and seed mass)thought to vary along sea–inland gradients.Important Findings Regional species pools were phylogenetically clustered relative to the global pool,indicating regional diversification.NTI showed stronger clustering than NRI pointing to the importance of especially recent diversifications within regions.The species pools grouped phylogenetically into two clusters on either side of the tropics suggesting greater dispersal rates within hemispheres than between hemispheres.Local NRI plot values confirmed that most communities were also phylogenetically clustered within regions.NRI values decreased with increasing plant height and seed mass,indicating greater phylogenetic clustering in communities with short maximum height and good dispersers prone to wind and tidal disturbance as well as salt spray,consistent with environmental filtering along sea–inland gradients.Height and seed mass both showed significant phylogenetic signal,and NRI tended to correlate negatively with both at the plot level.Low NRI plots tended to represent coastal scrub and forest,whereas high NRI plots tended to represent herb-dominated vegetation.We conclude that regional diversification processes play a role in dune plant community assembly,with convergence in local phylogenetic community structure and local variation in community structure probably reflecting consistent coastal-inland gradients.Our study contributes to a better understanding of the globally distributed dynamic coastal ecosystems and the structuring factors working on dune plant communities across spatial scales and regions. | Ane Kirstine Brunbjerg Jeannine Cavender-Bares Wolf L.Eiserhardt Rasmus Ejrnæs Lonnie W.Aarssen Hannah L.Buckley Estelle Forey Florian Jansen Jens Kattge Cynthia Lane Roy A.Lubke Angela T.Moles Ana Laura Monserrat Robert K.Peet Julissa Roncal Louise Wootton Jens-Christian Svenning | 2014 | Journal of Plant Ecology2014，7，2： | 9 |
| 9 | Environmental tobacco smoke exposure and lung cancer:A systematic review显示文摘AIM:To review evidence relating passive smoking to lung cancer risk in never smokers,considering various major sources of bias.METHODS:Epidemiological prospective or case-control studies were identified which provide estimates of relative risk(RR) and 95% CI for never smokers for one or more of seven different indices of exposure to environmental tobacco smoke(ETS):The spouse; household; workplace; childhood; travel; social and other; and total.A wide range of study details were entered into a database,and the RRs for each study,including descriptions of the comparisons made,were entered into a linked database.RRs were derived where necessary.Results were entered,where available,for all lung cancer,and for squamous cell cancer and adenocarcinoma.'Most adjusted' results were entered based on results available,adjusted for the greatest number of potential confounding variables.'Least adjusted' results were also entered,with a preference for results adjusted at least for age for prospective studies.A pre-planned series of fixed-effects and random-effects meta-analyses were conducted.Overall analyses and analyses by continent were run for each exposure index,with results for spousal smoking given by sex,and results for childhood exposure given by source of ETS exposure.For spousal exposure,more extensive analyses provide results by various aspects of study design and definition of the RR.For smoking by the husband(or nearest equivalent),additional analyses were carried out both for overall risk,and for risk per 10 cigarettes per day smoked by the husband.These adjusted for uncontrolled confounding by four factors(fruit,vegetable and dietary fat consumption,and education),and corrected for misclassification of smoking status of the wife.For the confounding adjustment,estimates for never smoking women were derived from publications on the relationship of the four factors to both lung cancer risk and at home ETS exposure,and on the correlations between the factors.The bias due to misclassification was calculated on the basis that the proportion of ever smokers denying smoking is 10% in Asian studies and 2.5% elsewhere,and that those who deny smoking have the same risk as those who admit it.This approach,justified in previous work,balances higher true denial rates and lower risk in deniers compared to non-deniers.RESULTS:One hundred and two studies were identified for inclusion,published in 1981 onwards,45 in Asia,31 in North America,21 in Europe,and five elsewhere.Eightyfive were of case-control design and 17 were prospective.Significant(P < 0.05) associations were noted,with random-effects of(RR=1.22,95%CI:1.14-1.31,n=93) for smoking by the husband(RR=1.14,95%CI:1.01-1.29,n=45) for smoking by the wife(RR=1.22,95%CI:1.15-1.30,n=47) for workplace exposure(RR=1.15,95%CI:1.02-1.29,n=41) for childhood exposure,and(RR=1.31,95%CI:1.19-1.45,n=48) for total exposure.No significant association was seen for ETS exposure in travel(RR=1.34,95%CI:0.94-1.93,n=8) or in social situations(RR=1.01,95%CI:0.82-1.24,n=15).A significant negative association(RR=0.78,95%CI:0.64-0.94,n=8) was seen for ETS exposure in childhood,specifically from the parents.Significant associations were also seen for spousal smoking for both squamous cell carcinoma(RR=1.44,95%CI:1.15-1.80,n=24) and adenocarcinoma(RR=1.33,95%CI:1.17-1.51,n=30).Results generally showed marked heterogeneity between studies.For smoking by either the husband or wife,where 119 RR estimates gave an overall estimate of(RR=1.21,95%CI:1.14-1.29),the heterogeneity was highly significant(P < 0.001),with evidence that the largest RRs were seen in studies published in 1981-89,in small studies(1-49 cases),and for estimates unadjusted by age.For smoking by the husband,the additional analyses showed that adjustment for the four factors reduced the overall(RR=1.22,95%CI:1.14-1.31) based on 93 estimates to(RR=1.14,95%CI:1.06-1.22),implying bias due to uncontrolled confounding of 7%.Further correction for misclassification reduced the estimate to a marginally non-significant(RR=1.08,95%CI:0.999-1.16).In the fully adjusted and corrected analyses,there was evidence of an increase in Asia(RR=1.18,95%CI:1.07-1.30,n=44),but not in other regions(RR=0.96,95%CI:0.86-1.07,n=49).Studies published in the 1980's,studies providing dose-response data,and studies only providing results unadjusted for age showed elevated RRs,but later published studies,studies not providing dose-response data,and studies adjusting for age did not.The pattern of results for RRs per 10 cigs/d was similar,with no significant association in the adjusted and corrected results(RR=1.03,95%CI:0.994-1.07).CONCLUSION:Most,if not all,of the ETS/lung cancer association can be explained by confounding adjustment and misclassification correction.Any causal relationship is not convincingly demonstrated. | Peter N Lee John S Fry Barbara A Forey Jan S Hamling Alison J Thornton | 2016 | World Journal of Meta-Analysis2016，4，2： | 1 |
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