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721篇 您的检索式:作者名="Legendre"
    题名 作者 年代 出处 被引量
1β-多样性的研究:应用多元回归和典范分析研究生态方差的分解显示文摘β-多样性刻画了地理区域中不同地点物种组成的变化,是理解生态系统功能、生物多样性保护和生态系统管理的一个重要概念。该文介绍了如何从群落组成,相关环境和空间数据角度去分析β-多样性。β-多样性可以通过计算每个地点的多样性指数,进而对可能解释点之间差异的因子所作的假设进行检验来研究。也可以将涵盖所有点的群落组成数据表看作是一系列环境和空间变量的函数,进行直接分析。这种分析应用统计方法将多样性指数或群落组成数据表的方差进行关于环境和空间变量的分解。该文对方差分解进行阐述。方差分解是利用环境和空间变量来解释β-多样性的一种方法。β-多样性是生态学家用来比较不同地点或同一地点不同生态群落的一种手段。方差分解就是将群落组成数据表的总方差无偏分解成由各个解释变量所决定的子方差。调整的决定系数提供了针对多元回归和典范冗余分析的无偏估计。方差分解后,可以对感兴趣的方差解释部分进行显著性检验,同时绘出基于这部分方差解释的预测图。Pierre Legendre 2007植物生态学报2007,31,5:23
2Studying beta diversity: ecological variation partitioning by multiple regression and canonical analysis显示文摘Aims Beta diversity is the variation in species composition among sites in a geographic region.Beta diversity is a key concept for understanding the functioning of ecosystems,for the conservation of biodiversity and for ecosystem management.The present report describes how to analyse beta diversity from community composition and associated environmental and spatial data tables.Methods Beta diversity can be studied by computing diversity indices for each site and testing hypotheses about the factors that may explain the variation among sites.Alternatively,one can carry out a direct analysis of the community composition data table over the study sites,as a function of sets of environmental and spatial variables.These analyses are carried out by the statistical method of partitioning the variation of the diversity indices or the community composition data table with respect to environmental and spatial variables.Variation partitioning is briefly described herein.Important findings Variation partitioning is a method of choice for the interpretation of beta diversity using tables of environmental and spatial variables.Beta diversity is an interesting‘currency’for ecologists to compare either different sampling areas or different ecological communities cooccurring in an area.Partitioning must be based upon unbiased estimates of the variation of the community composition data table that is explained by the various tables of explanatory variables.The adjusted coefficient of determination provides such an unbiased estimate in both multiple regression and canonical redundancy analysis.After partitioning,one can test the significance of the fractions of interest and plot maps of the fitted values corresponding to these fractions.Pierre Legendre 2008Journal of Plant Ecology2008,1,1:19
3Evolving paradigms in biological carbon cycling in the ocean显示文摘Carbon is a keystone element in global biogeochemical cycles.It plays a fundamental role in biotic andabiotic processes in the ocean,which intertwine to mediate the chemistry and redox status of carbon in the ocean and the atmosphere.The interactions between abiotic and biogenic carbon(e.g.CO_2,Ca CO_3,organic matter)in the ocean are complex,and there is a half-century-old enigma about the existence of a huge reservoir of recalcitrant dissolved organic carbon(RDOC)that equates to the magnitude of the pool of atmospheric CO_2.The concepts of the biological carbon pump(BCP)and the microbial loop(ML)shaped our understanding of the marine carbon cycle.The more recent concept of the microbial carbon pump(MCP),which is closely connected to those of the BCP and the ML,explicitly considers thesignificance of the ocean’s RDOC reservoir and provides a mechanistic framework for the exploration of its formation and persistence.Understanding of the MCP has benefited from advanced‘omics’and novel research in biological oceanography and microbial biogeochemistry.The need to predict the ocean’sresponse to climate change makes an integrative understanding of the BCP,ML and MCP a high priority.In this review,we summarize and discuss progress since the proposal of the MCP in 2010 and formulate research questions for the future.Chuanlun Zhang Hongyue Dang Farooq Azam Ronald Benner Louis Legendre Uta Passow Luca Polimene Carol Robinson Curtis A.Suttle Nianzhi Jiao 2018National Science Review2018,5,4:12
4The Treatment of Peritoneal Carcinomatosis of Colorectal Cancer with Complete Cytoreductive Surgery and Hyperthermic Intraperitoneal Peroperative Chemotherapy (HIPEC) with Oxaliplatin: A Belgian Multicentre Prospective Phase II Clinical Study显示文摘Daphne Hompes André D’Hoore Eric Cutsem Steffen Fieuws Wim Ceelen Marc Peeters Kurt Speeten Claude Bertrand Hugues Legendre Joseph Kerger 2012Annals of Surgical Oncology2012,,7:3
5Spatial and temporal analysis of beta diversity in the Barro Colorado Island forest dynamics plot, Panama显示文摘Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(BCI), Panama,divided into 1250(20 m × 20 m) quadrats.Methods, spatial analysis: Total beta diversity was measured as the total variance of the Hellinger-transformed community data throughout the BCI plot. Total beta was partitioned into contributions of individual sites(LCBD indices), which were tested for significance and mapped.Results, spatial analysis: LCBD indices indicated the sites with exceptional community composition. In 1985,they were mostly found in the swamp habitat. In the 2015 survey, none of the swamp quadrats had significant LCBDs.What happened to the tree community in the interval?Methods, temporal analysis: The dissimilarity in community composition in each quadrat was measured between time 1(1985) and time 2(2015). Temporal Beta Indices(TBI) were computed from abundance and presence-absence data and tested for significance. TBI indices can be decomposed into B = species(or abundances-per-species) losses and C = species(or abundances-per-species) gains. B-C plots were produced; they display visually the relative importance of the loss and gain components, through time, across the sites.Results, temporal analysis: In BCI, quadrats with significant TBI indices were found in the swamp area, which is shrinking in importance due to changes to the local climate. A published habitat classification divided the BCI forest plot into six habitat zones. Graphs of the B and C components were produced for each habitat group. Group 4(the swamp) was dominated by species(and abundances-per-species) gains whereas the five other habitat groups were dominated by losses, some groups more than others.Conclusions: We identified the species that had changed the most in abundances in the swamp between T1 and T2.This analysis supported the hypothesis that the swamp is drying out and is invaded by species from the surrounding area. Analysis of the B and C components of temporal beta diversity bring us to the heart of the mechanisms of community change through time: losses(B) and gains(C) of species, losses and gains of individuals of various species. TBI analysis is especially interesting in species-rich communities where we cannot examine the changes in every species individually.Pierre Legendre Richard Condit 2019Forest Ecosystems2019,6,1:2
6胚胎巨噬细胞和小胶质细胞消融调控小鼠胚胎背根神经节感觉神经元的发育显示文摘众所周知,小胶质细胞可以调节中枢神经系统发育的一些方面。在第11.5天的小鼠胚胎中的小胶质细胞定殖脊髓时,它们与背根神经节感觉神经元(SN)的生长中心轴突相互作用,这表明它们可能在SN发育中发挥一定功能。为了解决这个问题,我们使用缺乏胚胎巨噬细胞(PU.1敲除小鼠)和免疫细胞消融的小鼠胚胎分析胚胎巨噬细胞消融对SNs早期发育的影响。我们发现,除小胶质细胞外,胚胎巨噬细胞还与来自第11.5天的小鼠胚胎的原肌球蛋白受体激酶(Trk)C+感觉神经元,TrkB+感觉神经元和TrkA+感觉神经元外周神经突产生交联。免疫细胞剥夺会导致第11.5天的小鼠胚胎的TrkC+感觉神经元和TrkB+感觉神经元初始数量的减少,这与其发育细胞死亡(DCD)的改变有关联的可能性较小,因为其后在第12.5天的胚胎中的数量有短暂增加。在分析的发育期(第11.5~15.5天),它也导致TrkA+感觉神经元数量减少,尽管我们没有观察到他们的DCD有任何变化。与神经元祖细胞可能存在一致性的脑脂肪酸结合蛋白(BFABP-)阴性细胞的增殖在第11.5天的胚胎中增加,而它们的增殖在第12.5天的胚胎减少,这可部分解释从11.5 d观察到的SN亚型产生的改变。此外,我们观察到在缺乏胚胎巨噬细胞的情况下神经胶质细胞祖细胞(BFABP+细胞)增殖的改变。我们的数据表明,胚胎巨噬细胞和小胶质细胞消融调控SN的发育。Angelim MKSC Maia LMSS Mouffle C Ginhoux F Low D Amancio-Dos-Santos A Makhoul J Le Corronc H Mangin JM Legendre P 聂昊(编译) 2018神经损伤与功能重建2018,13,9:2
7用于油基泥浆的新型高分辨率双物理学随钻测井成像仪显示文摘斯伦贝谢公司在2018年的SPWLA年会上推出了一种旨在获取随钻测井(LWD)环境中高分辨率图像的新仪器,通过使用独立的电阻率和超声成像传感器的双物理学原理来最大化地获取数据。新仪器克服了LWD成像在油基泥浆中所面临的挑战。唐宇 王小宁 Maeso C J Legendre E 2018测井技术2018,42,3:2
8Peroxisome proliferator-activated receptor alpha-isoform deficient leads to progressive dyslipidemia with sexuallly dimorphic obesity and steatosis显示文摘COSTET P LEGENDRE C MORE J 1998J Biol Chem1998,273,29:2
9A note on the lift force on a spherical bubble or drop in a low-Reynolds-number shear flow 显示文摘Legendre D Magnaudet J 1997Physics of Fluids1997,9,11:1
10Terminal regions of the NS-1 protein of the parvovirus minute virus of mice are involved in cytotoxicity and promoter trans inhibition显示文摘LEGENDRE D ROMMELAERE J 1992J Virol1992,66,10:1
11yon Willebrand factor C1C2 domain is involved in platelet adhesion to polymerized fibrin at high shear rate显示文摘Keuren JF Baruch D Legendre P 2004Blood2004,103,5:1
12Reducing antibiotic usage is a necessity 显示文摘Legendre N Barsky E 2011Soins Pediatr Puer/c2011,262,:1
13Distribution patterns of tree species in a Malaysian tropical rain forest显示文摘He F Legendre P La Frankie J V 1997Journal of Vegetation Science1997,8,:1
14Identification of lipoxygenase linoleate decomposition products by direct gas chromatography-mass spectrometry显示文摘Angelo A J Legendre M G Dupuy H P 1980Lipids1980,15,:1
15Multiscale source of variation in ecological variable: modeling spatial disperson, elaborating sampling designs显示文摘Bellehumeur G Legendre P 1998Landscape Ecology1998,13,:1
16yon Willebrand factor C1 C2 domain is involved in platelet adhesion to polymerized fibrin at high shear rate显示文摘KEUREN J F BARUCH D LEGENDRE P 2004Blood2004,103,5:1
17Terminal complementinhibitor eculizumab in atypical hemolytic-uremicsyndrome显示文摘Legendre CM Licht C Muus P 2013N Engl J Med2013,368,23:1
18Instrumental analysis of volatiles from rice and corn produets 显示文摘Legendre M G Dupuy H P Mcllrath W V J 1978Ae Food Chem1978,26,:1
19Spatial modeling : a comprehensive framework for principal coordinate analysis of neighbor matrices ( PC- NM) 显示文摘Dray S Legendre P Peres - Neto P R 2006Ecological Modelling2006,196,:1
20Export of biogenic carbon to fish and to the deep ocean: the role of large planktonic mirophages显示文摘FORTIER L LE FeVRE J LEGENDRE L 1994JournalofPlanktonResearch1994,16,:1
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