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排序方式: 共有706条查询结果,搜索用时 22 毫秒
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Thea Kristiansen Jens‐Christian Svenning Wolf L. Eiserhardt Dennis Pedersen Hans Brix Søren Munch Kristiansen Maria Knadel César Grández Henrik Balslev 《Journal of Biogeography》2012,39(7):1318-1332
Aim It is a central issue in ecology and biogeography to understand what governs community assembly and the maintenance of biodiversity in tropical rain forest ecosystems. A key question is the relative importance of environmental species sorting (niche assembly) and dispersal limitation (dispersal assembly), which we investigate using a large dataset from diverse palm communities. Location Lowland rain forest, western Amazon River Basin, Peru. Methods We inventoried palm communities, registering all palm individuals and recording environmental conditions in 149 transects of 5 m × 500 m. We used ordination, Mantel tests and indicator species analysis (ISA) to assess compositional patterns, species responses to geographical location and environmental factors. Mantel tests were used to assess the relative importance of geographical distance (as a proxy for dispersal limitation) and environmental differences as possible drivers of dissimilarity in palm species composition. We repeated the Mantel tests for subsets of species that differ in traits of likely importance for habitat specialization and dispersal (height and range size). Results We found a strong relationship between compositional dissimilarity and environmental distance and a weaker but also significant relationship between compositional dissimilarity and geographical distance. Consistent with expectations, relationships with environmental and geographical distance were stronger for understorey species than for canopy species. Geographical distance had a higher correlation with compositional dissimilarity for small‐ranged species compared with large‐ranged species, whereas the opposite was true for environmental distance. The main environmental correlates were inundation and soil nutrient levels. Main conclusions The assembly of palm communities in the western Amazon appears to be driven primarily by species sorting according to hydrology and soil, but with dispersal limitation also playing an important role. The importance of environmental characteristics and geographical distance varies depending on plant height and geographical range size in agreement with functional predictions, increasing our confidence in the inferred assembly mechanisms. 相似文献
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Scytosiphon complanatus from Greenland was grown under long-day conditions on a temperature-gradient device with a temperature range from 5.4°C to 31.8°C. Growth was optimal between 16.0°C and 20.9°C. In a four week experimental period at 5.4°C and 7.5°C growth was slow and not measurable. The inoculated germlings died at temperatures between 24.0°C and 27.5°C. Under all temperatures the prostrate systems, knot filaments or ralfsioid thalli, as well as the parenchymatous macrothalli remained sterile during the experimental period. Prolongation of the growth period showed that formation of swarmers was prevented at temperatures above 18.6°C. The geographic distribution is discussed in relation to these results. 相似文献
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Migration patterns and recapture rates of North-east Arctic and Norwegian coastal cod reared and released under similar conditions 总被引:1,自引:0,他引:1
A total of 5000 1-group cod of Northeast Arctic and Norwegian coastal origin were reared under similar conditions, anchor tagged and released at two sites in western Norway. There were significantly more recaptures from the coastal cod. No differences in migration patterns were detected, suggesting that mortality rates were higher in North-east Arctic cod. 相似文献
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Anne-Marie Lundsgaard Jacob B. Holm Kim A. Sjøberg Kirstine N. Bojsen-Møller Lene S. Myrmel Even Fjære Benjamin A.H. Jensen Trine S. Nicolaisen Janne R. Hingst Sine L. Hansen Sophia Doll Philip E. Geyer Atul S. Deshmukh Jens J. Holst Lise Madsen Karsten Kristiansen Jørgen F.P. Wojtaszewski Erik A. Richter Bente Kiens 《Cell metabolism》2019,29(1):50-63.e4
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Guangyi Fan Yaolei Zhang Xiaochuan Liu Jiahao Wang Zeguo Sun Shuai Sun He Zhang Jianwei Chen Meiqi Lv Kai Han Xiaoxuan Tan Jie Hu Rui Guan Yuanyuan Fu Shanshan Liu Xi Chen Qiwu Xu Yating Qin Longqi Liu Jie Bai Ou Wang Jingbo Tang Haorong Lu Zhouchun Shang Bo Wang Guohai Hu Xia Zhao Yan Zou Ao Chen Meihua Gong Wenwei Zhang Simon M.‐Y. Lee Songhai Li Junnian Liu Zhen Li Yishan Lu Jamal S. M. Sabir Mumdooh J. Sabir Muhummadh Khan Nahid H. Hajrah Ye Yin Karsten Kristiansen Huanming Yang Jian Wang Xun Xu Xin Liu 《Molecular ecology resources》2019,19(4):944-956
Marine mammals are important models for studying convergent evolution and aquatic adaption, and thus reference genomes of marine mammals can provide evolutionary insights. Here, we present the first chromosome‐level marine mammal genome assembly based on the data generated by the BGISEQ‐500 platform, for a stranded female sperm whale (Physeter macrocephalus). Using this reference genome, we performed chromosome evolution analysis of the sperm whale, including constructing ancestral chromosomes, identifying chromosome rearrangement events and comparing with cattle chromosomes, which provides a resource for exploring marine mammal adaptation and speciation. We detected a high proportion of long interspersed nuclear elements and expanded gene families, and contraction of major histocompatibility complex region genes which were specific to sperm whale. Using comparisons with sheep and cattle, we analysed positively selected genes to identify gene pathways that may be related to adaptation to the marine environment. Further, we identified possible convergent evolution in aquatic mammals by testing for positively selected genes across three orders of marine mammals. In addition, we used publicly available resequencing data to confirm a rapid decline in global population size in the Pliocene to Pleistocene transition. This study sheds light on the chromosome evolution and genetic mechanisms underpinning sperm whale adaptations, providing valuable resources for future comparative genomics. 相似文献
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Systems‐wide analysis of BCR signalosomes and downstream phosphorylation and ubiquitylation 下载免费PDF全文
Petra Beli Rajat Gupta Trine A Kristiansen Dessislava Malinova Chiara Francavilla Pavel Tolar Gail A Bishop Bruce S Hostager Chunaram Choudhary 《Molecular systems biology》2015,11(6)
B‐cell receptor (BCR) signaling is essential for the development and function of B cells; however, the spectrum of proteins involved in BCR signaling is not fully known. Here we used quantitative mass spectrometry‐based proteomics to monitor the dynamics of BCR signaling complexes (signalosomes) and to investigate the dynamics of downstream phosphorylation and ubiquitylation signaling. We identify most of the previously known components of BCR signaling, as well as many proteins that have not yet been implicated in this system. BCR activation leads to rapid tyrosine phosphorylation and ubiquitylation of the receptor‐proximal signaling components, many of which are co‐regulated by both the modifications. We illustrate the power of multilayered proteomic analyses for discovering novel BCR signaling components by demonstrating that BCR‐induced phosphorylation of RAB7A at S72 prevents its association with effector proteins and with endo‐lysosomal compartments. In addition, we show that BCL10 is modified by LUBAC‐mediated linear ubiquitylation, and demonstrate an important function of LUBAC in BCR‐induced NF‐κB signaling. Our results offer a global and integrated view of BCR signaling, and the provided datasets can serve as a valuable resource for further understanding BCR signaling networks. 相似文献
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