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利用综合建模框架以评估灌溉在区域尺度上的影响 快报文章
资源环境快报,2022年第19期
作者:  吴秀平
Microsoft Word(16Kb)  |  收藏  |  浏览/下载:727/1  |  提交时间:2022/10/14
integrated modeling framework  surface and ground water resources  assess  
International evaluation of an AI system for breast cancer screening 期刊论文
NATURE, 2020, 577 (7788) : 89-+
作者:  McKinney, Scott Mayer;  Sieniek, Marcin;  Godbole, Varun;  Godwin, Jonathan;  Antropova, Natasha;  Ashrafian, Hutan;  Back, Trevor;  Chesus, Mary;  Corrado, Greg C.;  Darzi, Ara;  Etemadi, Mozziyar;  Garcia-Vicente, Florencia;  Gilbert, Fiona J.;  Halling-Brown, Mark;  Hassabis, Demis;  Jansen, Sunny;  Karthikesalingam, Alan;  Kelly, Christopher J.;  King, Dominic;  Ledsam, Joseph R.;  Melnick, David;  Mostofi, Hormuz;  Peng, Lily;  Reicher, Joshua Jay;  Romera-Paredes, Bernardino;  Sidebottom, Richard;  Suleyman, Mustafa;  Tse, Daniel;  Young, Kenneth C.;  De Fauw, Jeffrey;  Shetty, Shravya
收藏  |  浏览/下载:63/0  |  提交时间:2020/07/03

Screening mammography aims to identify breast cancer at earlier stages of the disease, when treatment can be more successful(1). Despite the existence of screening programmes worldwide, the interpretation of mammograms is affected by high rates of false positives and false negatives(2). Here we present an artificial intelligence (AI) system that is capable of surpassing human experts in breast cancer prediction. To assess its performance in the clinical setting, we curated a large representative dataset from the UK and a large enriched dataset from the USA. We show an absolute reduction of 5.7% and 1.2% (USA and UK) in false positives and 9.4% and 2.7% in false negatives. We provide evidence of the ability of the system to generalize from the UK to the USA. In an independent study of six radiologists, the AI system outperformed all of the human readers: the area under the receiver operating characteristic curve (AUC-ROC) for the AI system was greater than the AUC-ROC for the average radiologist by an absolute margin of 11.5%. We ran a simulation in which the AI system participated in the double-reading process that is used in the UK, and found that the AI system maintained non-inferior performance and reduced the workload of the second reader by 88%. This robust assessment of the AI system paves the way for clinical trials to improve the accuracy and efficiency of breast cancer screening.


  
AI tracks a beating heart's function over time 期刊论文
NATURE, 2020, 580 (7802)
作者:  Ball, Philip
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/03

Clinicians use ultrasound videos of heartbeats to assess subtle changes in the heart'  s pumping function. A method that uses artificial intelligence might simplify these complex assessments when heartbeats are out of rhythm.


  
Hepatic NADH reductive stress underlies common variation in metabolic traits 期刊论文
NATURE, 2020, 583 (7814) : 122-+
作者:  Skov, Laurits;  Coll Macia, Moises;  Sveinbjoernsson, Gardar;  Mafessoni, Fabrizio;  Lucotte, Elise A.;  Einarsdottir, Margret S.;  Jonsson, Hakon;  Halldorsson, Bjarni;  Gudbjartsson, Daniel F.;  Helgason, Agnar;  Schierup, Mikkel Heide;  Stefansson, Kari
收藏  |  浏览/下载:42/0  |  提交时间:2020/07/03

The cellular NADH/NAD(+) ratio is fundamental to biochemistry, but the extent to which it reflects versus drives metabolic physiology in vivo is poorly understood. Here we report the in vivo application of Lactobacillus brevis (Lb)NOX1, a bacterial water-forming NADH oxidase, to assess the metabolic consequences of directly lowering the hepatic cytosolic NADH/NAD(+) ratio in mice. By combining this genetic tool with metabolomics, we identify circulating alpha-hydroxybutyrate levels as a robust marker of an elevated hepatic cytosolic NADH/NAD(+) ratio, also known as reductive stress. In humans, elevations in circulating alpha-hydroxybutyrate levels have previously been associated with impaired glucose tolerance(2), insulin resistance(3) and mitochondrial disease(4), and are associated with a common genetic variant in GCKR(5), which has previously been associated with many seemingly disparate metabolic traits. Using LbNOX, we demonstrate that NADH reductive stress mediates the effects of GCKR variation on many metabolic traits, including circulating triglyceride levels, glucose tolerance and FGF21 levels. Our work identifies an elevated hepatic NADH/NAD(+) ratio as a latent metabolic parameter that is shaped by human genetic variation and contributes causally to key metabolic traits and diseases. Moreover, it underscores the utility of genetic tools such as LbNOX to empower studies of '  causal metabolism'  .


The authors identify an increased hepatic NADH/NAD(+) ratio as an underlying metabolic parameter that is shaped by human genetic variation and contributes causally to key metabolic traits and diseases.


  
Variability in the analysis of a single neuroimaging dataset by many teams 期刊论文
NATURE, 2020
作者:  Liu, Jifeng;  Soria, Roberto;  Zheng, Zheng;  Zhang, Haotong;  Lu, Youjun;  Wang, Song;  Yuan, Hailong
收藏  |  浏览/下载:38/0  |  提交时间:2020/07/03

Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed.


The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.


  
Asynchronous carbon sink saturation in African and Amazonian tropical forests 期刊论文
NATURE, 2020, 579 (7797) : 80-+
作者:  Wannes Hubau;  Simon L. Lewis;  Oliver L. Phillips;  Kofi Affum-Baffoe;  Hans Beeckman;  Aida Cuní;  -Sanchez;  Armandu K. Daniels;  Corneille E. N. Ewango;  Sophie Fauset;  Jacques M. Mukinzi;  Douglas Sheil;  Bonaventure Sonké;  Martin J. P. Sullivan;  Terry C. H. Sunderland;  Hermann Taedoumg;  Sean C. Thomas;  Lee J. T. White;  Katharine A. Abernethy;  Stephen Adu-Bredu;  Christian A. Amani;  Timothy R. Baker;  Lindsay F. Banin;  Fidè;  le Baya;  Serge K. Begne;  Amy C. Bennett;  Fabrice Benedet;  Robert Bitariho;  Yannick E. Bocko;  Pascal Boeckx;  Patrick Boundja;  Roel J. W. Brienen;  Terry Brncic;  Eric Chezeaux;  George B. Chuyong;  Connie J. Clark;  Murray Collins;  James A. Comiskey;  David A. Coomes;  Greta C. Dargie;  Thales de Haulleville;  Marie Noel Djuikouo Kamdem;  Jean-Louis Doucet;  Adriane Esquivel-Muelbert;  Ted R. Feldpausch;  Alusine Fofanah;  Ernest G. Foli;  Martin Gilpin;  Emanuel Gloor;  Christelle Gonmadje;  Sylvie Gourlet-Fleury;  Jefferson S. Hall;  Alan C. Hamilton;  David J. Harris;  Terese B. Hart;  Mireille B. N. Hockemba;  Annette Hladik;  Suspense A. Ifo;  Kathryn J. Jeffery;  Tommaso Jucker;  Emmanuel Kasongo Yakusu;  Elizabeth Kearsley;  David Kenfack;  Alexander Koch;  Miguel E. Leal;  Aurora Levesley;  Jeremy A. Lindsell;  Janvier Lisingo;  Gabriela Lopez-Gonzalez;  Jon C. Lovett;  Jean-Remy Makana;  Yadvinder Malhi;  Andrew R. Marshall;  Jim Martin;  Emanuel H. Martin;  Faustin M. Mbayu;  Vincent P. Medjibe;  Vianet Mihindou;  Edward T. A. Mitchard;  Sam Moore;  Pantaleo K. T. Munishi;  Natacha Nssi Bengone;  Lucas Ojo;  Fidè;  le Evouna Ondo;  Kelvin S.-H. Peh;  Georgia C. Pickavance;  Axel Dalberg Poulsen;  John R. Poulsen;  Lan Qie;  Jan Reitsma;  Francesco Rovero;  Michael D. Swaine;  Joey Talbot;  James Taplin;  David M. Taylor;  Duncan W. Thomas;  Benjamin Toirambe;  John Tshibamba Mukendi;  Darlington Tuagben;  Peter M. Umunay;  Geertje M. F. van der Heijden;  Hans Verbeeck;  Jason Vleminckx;  Simon Willcock;  Hannsjö;  rg Wö;  ll;  John T. Woods;  Lise Zemagho
收藏  |  浏览/下载:71/0  |  提交时间:2020/05/13

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions(1-3). Climate-driven vegetation models typically predict that this tropical forest '  carbon sink'  will continue for decades(4,5). Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests(6). Therefore the carbon sink responses of Earth'  s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature(7-9). Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth'  s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass(10) reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth'  s climate.


  
Tracking of marine predators to protect Southern Ocean ecosystems 期刊论文
NATURE, 2020
作者:  Kim, Eugene;  Kerssemakers, Jacob;  Shaltiel, Indra A.;  Haering, Christian H.;  Dekker, Cees
收藏  |  浏览/下载:36/0  |  提交时间:2020/07/03

Tracking data from 17 marine predator species in the Southern Ocean are used to identify Areas of Ecological Significance, the protection of which could help to mitigate increasing pressures on Southern Ocean ecosystems.


Southern Ocean ecosystems are under pressure from resource exploitation and climate change(1,2). Mitigation requires the identification and protection of Areas of Ecological Significance (AESs), which have so far not been determined at the ocean-basin scale. Here, using assemblage-level tracking of marine predators, we identify AESs for this globally important region and assess current threats and protection levels. Integration of more than 4,000 tracks from 17 bird and mammal species reveals AESs around sub-Antarctic islands in the Atlantic and Indian Oceans and over the Antarctic continental shelf. Fishing pressure is disproportionately concentrated inside AESs, and climate change over the next century is predicted to impose pressure on these areas, particularly around the Antarctic continent. At present, 7.1% of the ocean south of 40 degrees S is under formal protection, including 29% of the total AESs. The establishment and regular revision of networks of protection that encompass AESs are needed to provide long-term mitigation of growing pressures on Southern Ocean ecosystems.


  
Premature mortality related to United States cross-state air pollution 期刊论文
NATURE, 2020, 578 (7794) : 261-+
作者:  Helmink, Beth A.;  Reddy, Sangeetha M.;  Gao, Jianjun;  Zhang, Shaojun;  Basar, Rafet;  Thakur, Rohit;  Yizhak, Keren;  Sade-Feldman, Moshe;  Blando, Jorge;  Han, Guangchun;  Gopalakrishnan, Vancheswaran;  Xi, Yuanxin;  Zhao, Hao;  Amaria, Rodabe N.;  Tawbi, Hussein A.;  Cogdill, Alex P.;  Liu, Wenbin;  LeBleu, Valerie S.;  Kugeratski, Fernanda G.;  Patel, Sapna;  Davies, Michael A.;  Hwu, Patrick;  Lee, Jeffrey E.;  Gershenwald, Jeffrey E.;  Lucci, Anthony;  Arora, Reetakshi;  Woodman, Scott;  Keung, Emily Z.;  Gaudreau, Pierre-Olivier;  Reuben, Alexandre;  Spencer, Christine N.;  Burton, Elizabeth M.;  Haydu, Lauren E.;  Lazar, Alexander J.;  Zapassodi, Roberta;  Hudgens, Courtney W.;  Ledesma, Deborah A.;  Ong, SuFey;  Bailey, Michael;  Warren, Sarah;  Rao, Disha;  Krijgsman, Oscar;  Rozeman, Elisa A.;  Peeper, Daniel;  Blank, Christian U.;  Schumacher, Ton N.;  Butterfield, Lisa H.;  Zelazowska, Monika A.;  McBride, Kevin M.;  Kalluri, Raghu;  Allison, James;  Petitprez, Florent;  Fridman, Wolf Herman;  Sautes-Fridman, Catherine;  Hacohen, Nir;  Rezvani, Katayoun;  Sharma, Padmanee;  Tetzlaff, Michael T.;  Wang, Linghua;  Wargo, Jennifer A.
收藏  |  浏览/下载:67/0  |  提交时间:2020/05/13

Outdoor air pollution adversely affects human health and is estimated to be responsible for five to ten per cent of the total annual premature mortality in the contiguous United States(1-3). Combustion emissions from a variety of sources, such as power generation or road traffic, make a large contribution to harmful air pollutants such as ozone and fine particulate matter (PM2.5)(4). Efforts to mitigate air pollution have focused mainly on the relationship between local emission sources and local air quality(2). Air quality can also be affected by distant emission sources, however, including emissions from neighbouring federal states(5,6). This cross-state exchange of pollution poses additional regulatory challenges. Here we quantify the exchange of air pollution among the contiguous United States, and assess its impact on premature mortality that is linked to increased human exposure to PM2.5 and ozone from seven emission sectors for 2005 to 2018. On average, we find that 41 to 53 per cent of air-quality-related premature mortality resulting from a state'  s emissions occurs outside that state. We also find variations in the cross-state contributions of different emission sectors and chemical species to premature mortality, and changes in these variations over time. Emissions from electric power generation have the greatest cross-state impacts as a fraction of their total impacts, whereas commercial/residential emissions have the smallest. However, reductions in emissions from electric power generation since 2005 have meant that, by 2018, cross-state premature mortality associated with the commercial/residential sector was twice that associated with power generation. In terms of the chemical species emitted, nitrogen oxides and sulfur dioxide emissions caused the most cross-state premature deaths in 2005, but by 2018 primary PM2.5 emissions led to cross-state premature deaths equal to three times those associated with sulfur dioxide emissions. These reported shifts in emission sectors and emission species that contribute to premature mortality may help to guide improvements to air quality in the contiguous United States.


  
The emergence of transcriptional identity in somatosensory neurons 期刊论文
NATURE, 2020, 577 (7790) : 392-+
作者:  Sharma, Nikhil;  Flaherty, Kali;  Lezgiyeva, Karina;  Wagner, Daniel E.;  Klein, Allon M.;  Ginty, David D.
收藏  |  浏览/下载:18/0  |  提交时间:2020/07/03

More than twelve morphologically and physiologically distinct subtypes of primary somatosensory neuron report salient features of our internal and external environments(1-4). It is unclear how specialized gene expression programs emerge during development to endow these subtypes with their unique properties. To assess the developmental progression of transcriptional maturation of each subtype of principal somatosensory neuron, we generated a transcriptomic atlas of cells traversing the primary somatosensory neuron lineage in mice. Here we show that somatosensory neurogenesis gives rise to neurons in a transcriptionally unspecialized state, characterized by co-expression of transcription factors that become restricted to select subtypes as development proceeds. Single-cell transcriptomic analyses of sensory neurons from mutant mice lacking transcription factors suggest that these broad-to-restricted transcription factors coordinate subtype-specific gene expression programs in subtypes in which their expression is maintained. We also show that neuronal targets are involved in this process  disruption of the prototypic target-derived neurotrophic factor NGF leads to aberrant subtype-restricted patterns of transcription factor expression. Our findings support a model in which cues that emanate from intermediate and final target fields promote neuronal diversification in part by transitioning cells from a transcriptionally unspecialized state to transcriptionally distinct subtypes by modulating the selection of subtype-restricted transcription factors.


  
Importance and vulnerability of the world's water towers 期刊论文
NATURE, 2020, 577 (7790) : 364-+
作者:  Krebs, John R.;  Hassell, Michael
收藏  |  浏览/下载:62/0  |  提交时间:2020/04/16

Mountains are the water towers of the world, supplying a substantial part of both natural and anthropogenic water demands(1,2). They are highly sensitive and prone to climate change(3,4), yet their importance and vulnerability have not been quantified at the global scale. Here we present a global water tower index (WTI), which ranks all water towers in terms of their water-supplying role and the downstream dependence of ecosystems and society. For each water tower, we assess its vulnerability related to water stress, governance, hydropolitical tension and future climatic and socioeconomic changes. We conclude that the most important (highest WTI) water towers are also among the most vulnerable, and that climatic and socio-economic changes will affect them profoundly. This could negatively impact 1.9 billion people living in (0.3 billion) or directly downstream of (1.6 billion) mountainous areas. Immediate action is required to safeguard the future of the world'  s most important and vulnerable water towers.