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Biodiversity conservation in a dynamic world may lead to inefficiencies due to lock-in effects and path dependence 期刊论文
ECOLOGICAL ECONOMICS, 2020, 173
作者:  Drechsler, Martin;  Waetzold, Frank
收藏  |  浏览/下载:8/0  |  提交时间:2020/08/18
Dynamic optimisation  Ecological-economic model  Ecological benefit  Economic cost  Efficiency  Resource allocation  
Lineage dynamics of the endosymbiotic cell type in the soft coralXenia 期刊论文
NATURE, 2020
作者:  Lewnard, Joseph A.;  Lo, Nathan C.;  Arinaminpathy, Nimalan;  Frost, Isabel;  Laxminarayan, Ramanan
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/03

Many corals harbour symbiotic dinoflagellate algae. The algae live inside coral cells in a specialized membrane compartment known as the symbiosome, which shares the photosynthetically fixed carbon with coral host cells while host cells provide inorganic carbon to the algae for photosynthesis(1). This endosymbiosis-which is critical for the maintenance of coral reef ecosystems-is increasingly threatened by environmental stressors that lead to coral bleaching (that is, the disruption of endosymbiosis), which in turn leads to coral death and the degradation of marine ecosystems(2). The molecular pathways that orchestrate the recognition, uptake and maintenance of algae in coral cells remain poorly understood. Here we report the chromosome-level genome assembly of aXeniaspecies of fast-growing soft coral(3), and use this species as a model to investigate coral-alga endosymbiosis. Single-cell RNA sequencing identified 16 cell clusters, including gastrodermal cells and cnidocytes, inXeniasp. We identified the endosymbiotic cell type, which expresses a distinct set of genes that are implicated in the recognition, phagocytosis and/or endocytosis, and maintenance of algae, as well as in the immune modulation of host coral cells. By couplingXeniasp. regeneration and single-cell RNA sequencing, we observed a dynamic lineage progression of the endosymbiotic cells. The conserved genes associated with endosymbiosis that are reported here may help to reveal common principles by which different corals take up or lose their endosymbionts.


  
Video-based AI for beat-to-beat assessment of cardiac function 期刊论文
NATURE, 2020, 580 (7802) : 252-+
作者:  Pleguezuelos-Manzano, Cayetano;  Puschhof, Jens;  Huber, Axel Rosendahl;  van Hoeck, Arne;  Wood, Henry M.;  Nomburg, Jason;  Gurjao, Carino;  Manders, Freek;  Dalmasso, Guillaume;  Stege, Paul B.;  Paganelli, Fernanda L.;  Geurts, Maarten H.;  Beumer, Joep;  Mizutani, Tomohiro;  Miao, Yi;  van der Linden, Reinier;  van der Elst, Stefan;  Garcia, K. Christopher;  Top, Janetta;  Willems, Rob J. L.;  Giannakis, Marios;  Bonnet, Richard;  Quirke, Phil;  Meyerson, Matthew;  Cuppen, Edwin;  van Boxtel, Ruben;  Clevers, Hans
收藏  |  浏览/下载:116/0  |  提交时间:2020/07/03

A video-based deep learning algorithm-EchoNet-Dynamic-accurately identifies subtle changes in ejection fraction and classifies heart failure with reduced ejection fraction using information from multiple cardiac cycles.


Accurate assessment of cardiac function is crucial for the diagnosis of cardiovascular disease(1), screening for cardiotoxicity(2) and decisions regarding the clinical management of patients with a critical illness(3). However, human assessment of cardiac function focuses on a limited sampling of cardiac cycles and has considerable inter-observer variability despite years of training(4,5). Here, to overcome this challenge, we present a video-based deep learning algorithm-EchoNet-Dynamic-that surpasses the performance of human experts in the critical tasks of segmenting the left ventricle, estimating ejection fraction and assessing cardiomyopathy. Trained on echocardiogram videos, our model accurately segments the left ventricle with a Dice similarity coefficient of 0.92, predicts ejection fraction with a mean absolute error of 4.1% and reliably classifies heart failure with reduced ejection fraction (area under the curve of 0.97). In an external dataset from another healthcare system, EchoNet-Dynamic predicts the ejection fraction with a mean absolute error of 6.0% and classifies heart failure with reduced ejection fraction with an area under the curve of 0.96. Prospective evaluation with repeated human measurements confirms that the model has variance that is comparable to or less than that of human experts. By leveraging information across multiple cardiac cycles, our model can rapidly identify subtle changes in ejection fraction, is more reproducible than human evaluation and lays the foundation for precise diagnosis of cardiovascular disease in real time. As a resource to promote further innovation, we also make publicly available a large dataset of 10,030 annotated echocardiogram videos.


  
Mass-spectrometry-based draft of the Arabidopsis proteome 期刊论文
NATURE, 2020
作者:  Vasanthakumar, Ajithkumar;  Chisanga, David;  Blume, Jonas;  Gloury, Renee;  Britt, Kara;  Henstridge, Darren C.;  Zhan, Yifan;  Torres, Santiago Valle;  Liene, Sebastian;  Collins, Nicholas;  Cao, Enyuan;  Sidwell, Tom;  Li, Chaoran;  Spallanzani, Raul German;  Liao, Yang;  Beavis, Paul A.;  Gebhardt, Thomas;  Trevaskis, Natalie;  Nutt, Stephen L.;  Zajac, Jeffrey D.;  Davey, Rachel A.;  Febbraio, Mark A.;  Mathis, Diane;  Shi, Wei;  Kallies, Axel
收藏  |  浏览/下载:37/0  |  提交时间:2020/07/03

Plants are essential for life and are extremely diverse organisms with unique molecular capabilities(1). Here we present a quantitative atlas of the transcriptomes, proteomes and phosphoproteomes of 30 tissues of the model plant Arabidopsis thaliana. Our analysis provides initial answers to how many genes exist as proteins (more than 18,000), where they are expressed, in which approximate quantities (a dynamic range of more than six orders of magnitude) and to what extent they are phosphorylated (over 43,000 sites). We present examples of how the data may be used, such as to discover proteins that are translated from short open-reading frames, to uncover sequence motifs that are involved in the regulation of protein production, and to identify tissue-specific protein complexes or phosphorylation-mediated signalling events. Interactive access to this resource for the plant community is provided by the ProteomicsDB and ATHENA databases, which include powerful bioinformatics tools to explore and characterize Arabidopsis proteins, their modifications and interactions.


A quantitative atlas of the transcriptomes, proteomes and phosphoproteomes of 30 tissues of the model plant Arabidopsis thaliana provides a valuable resource for plant research.


  
Spatiotemporal changes of drought characteristics and their dynamic drivers in Canada 期刊论文
ATMOSPHERIC RESEARCH, 2020, 232
作者:  Yang, Yang;  Gan, Thian Yew;  Tan, Xuezhi
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/02
Drought characteristics  Standardized Precipitation Evapotranspiration  Index  Dynamic linear model  Large-scale climate drivers  Canada  
A simple dynamic model explains the diversity of island birds worldwide 期刊论文
NATURE, 2020
作者:  Li, Junxue;  Wilson, C. Blake;  Cheng, Ran;  Lohmann, Mark;  Kavand, Marzieh;  Yuan, Wei;  Aldosary, Mohammed;  Agladze, Nikolay;  Wei, Peng;  Sherwin, Mark S.;  Shi, Jing
收藏  |  浏览/下载:12/0  |  提交时间:2020/07/03

Colonization, speciation and extinction are dynamic processes that influence global patterns of species richness(1-6). Island biogeography theory predicts that the contribution of these processes to the accumulation of species diversity depends on the area and isolation of the island(7,8). Notably, there has been no robust global test of this prediction for islands where speciation cannot be ignored(9), because neither the appropriate data nor the analytical tools have been available. Here we address both deficiencies to reveal, for island birds, the empirical shape of the general relationships that determine how colonization, extinction and speciation rates co-vary with the area and isolation of islands. We compiled a global molecular phylogenetic dataset of birds on islands, based on the terrestrial avifaunas of 41 oceanic archipelagos worldwide (including 596 avian taxa), and applied a new analysis method to estimate the sensitivity of island-specific rates of colonization, speciation and extinction to island features (area and isolation). Our model predicts-with high explanatory power-several global relationships. We found a decline in colonization with isolation, a decline in extinction with area and an increase in speciation with area and isolation. Combining the theoretical foundations of island biogeography(7,8) with the temporal information contained in molecular phylogenies(10) proves a powerful approach to reveal the fundamental relationships that govern variation in biodiversity across the planet.


Using a global molecular phylogenetic dataset of birds on islands, the sensitivity of island-specific rates of colonization, speciation and extinction to island features (area and isolation) is estimated.


  
Long-term cyclic persistence in an experimental predator-prey system 期刊论文
NATURE, 2020, 577 (7789) : 226-+
作者:  Blasius, Bernd;  Rudolf, Lars;  Weithoff, Guntram;  Gaedke, Ursula;  Fussmann, Gregor F.
收藏  |  浏览/下载:8/0  |  提交时间:2020/04/16

Predator-prey cycles rank among the most fundamental concepts in ecology, are predicted by the simplest ecological models and enable, theoretically, the indefinite persistence of predator and prey(1-4). However, it remains an open question for how long cyclic dynamics can be self-sustained in real communities. Field observations have been restricted to a few cycle periods(5-8) and experimental studies indicate that oscillations may be short-lived without external stabilizing factors(9-19). Here we performed microcosm experiments with a planktonic predator-prey system and repeatedly observed oscillatory time series of unprecedented length that persisted for up to around 50 cycles or approximately 300 predator generations. The dominant type of dynamics was characterized by regular, coherent oscillations with a nearly constant predator-prey phase difference. Despite constant experimental conditions, we also observed shorter episodes of irregular, non-coherent oscillations without any significant phase relationship. However, the predator-prey system showed a strong tendency to return to the dominant dynamical regime with a defined phase relationship. A mathematical model suggests that stochasticity is probably responsible for the reversible shift from coherent to non-coherent oscillations, a notion that was supported by experiments with external forcing by pulsed nutrient supply. Our findings empirically demonstrate the potential for infinite persistence of predator and prey populations in a cyclic dynamic regime that shows resilience in the presence of stochastic events.


  
A Dynamic Rupture Source Model for Very Low-Frequency Earthquake Signal Without Detectable Nonvolcanic Tremors 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (21) : 11934-11943
作者:  Wu, Baoning;  Oglesby, David D.;  Ghosh, Abhijit;  Li, Bo
收藏  |  浏览/下载:8/0  |  提交时间:2020/02/17
very low-frequency earthquake  dynamic rupture model  slow earthquake  
Global Ten-Moment Multifluid Simulations of the Solar Wind Interaction with Mercury: From the Planetary Conducting Core to the Dynamic Magnetosphere 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019
作者:  Dong, Chuanfei;  Wang, Liang;  Hakim, Ammar;  Bhattacharjee, Amitava;  Slavin, James A.;  DiBraccio, Gina A.;  Germaschewski, Kai
收藏  |  浏览/下载:8/0  |  提交时间:2019/11/27
Mercury'  s dynamic magnetosphere  induction response from Mercury'  s conducting core  ten-moment multifluid model  collisionless magnetic reconnection and flux ropes  field-aligned current  magnetotail asymmetry  
Sensitivity analysis of the typhoon disturbance effect on forest dynamics and carbon balance in the future in a cool-temperate forest in northern Japan by using SEIB-DGVM 期刊论文
FOREST ECOLOGY AND MANAGEMENT, 2019, 451
作者:  Wu, Lan;  Kato, Tomomichi;  Sato, Hisashi;  Hirano, Takashi;  Yazaki, Tomotsugu
收藏  |  浏览/下载:8/0  |  提交时间:2019/11/27
Dynamic global vegetation model (DGVM)  Forest structure  Tomakomai forest  Typhoon frequency  Typhoon intensity