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Insights into variation in meiosis from 31,228 human sperm genomes 期刊论文
NATURE, 2020, 583 (7815) : 259-+
作者:  Sakai, Akito;  Minami, Susumu;  Koretsune, Takashi;  Chen, Taishi;  Higo, Tomoya;  Wang, Yangming;  Nomoto, Takuya;  Hirayama, Motoaki;  Miwa, Shinji;  Nishio-Hamane, Daisuke;  Ishii, Fumiyuki;  Arita, Ryotaro;  Nakatsuji, Satoru
收藏  |  浏览/下载:30/0  |  提交时间:2020/07/03

Meiosis, although essential for reproduction, is also variable and error-prone: rates of chromosome crossover vary among gametes, between the sexes, and among humans of the same sex, and chromosome missegregation leads to abnormal chromosome numbers (aneuploidy)(1-8). To study diverse meiotic outcomes and how they covary across chromosomes, gametes and humans, we developed Sperm-seq, a way of simultaneously analysing the genomes of thousands of individual sperm. Here we analyse the genomes of 31,228 human gametes from 20 sperm donors, identifying 813,122 crossovers and 787 aneuploid chromosomes. Sperm donors had aneuploidy rates ranging from 0.01 to 0.05 aneuploidies per gamete  crossovers partially protected chromosomes from nondisjunction at the meiosis I cell division. Some chromosomes and donors underwent more-frequent nondisjunction during meiosis I, and others showed more meiosis II segregation failures. Sperm genomes also manifested manygenomic anomalies that could not be explained by simple nondisjunction. Diverse recombination phenotypes-from crossover rates to crossover location and separation, a measure of crossover interference-covaried strongly across individuals and cells. Our results can be incorporated with earlier observations into a unified model in which a core mechanism, the variable physical compaction of meiotic chromosomes, generates interindividual and cell-to-cell variation in diverse meiotic phenotypes.


  
Evaluating satellite-based and reanalysis precipitation datasets with gauge-observed data and hydrological modeling in the Xihe River Basin, China 期刊论文
ATMOSPHERIC RESEARCH, 2020, 234
作者:  Wang, Ning;  Liu, Wenbin;  Sun, Fubao;  Yao, Zhihong;  Wang, Hong;  Liu, Wanqing
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/02
Satellite-based precipitation  Reanalysis-based precipitation  Error correction  Hydrological model  Xihe River Basin  
A distributional code for value in dopamine-based reinforcement learning 期刊论文
NATURE, 2020, 577 (7792) : 671-+
作者:  House, Robert A.;  Maitra, Urmimala;  Perez-Osorio, Miguel A.;  Lozano, Juan G.;  Jin, Liyu;  Somerville, James W.;  Duda, Laurent C.;  Nag, Abhishek;  Walters, Andrew;  Zhou, Ke-Jin;  Roberts, Matthew R.;  Bruce, Peter G.
收藏  |  浏览/下载:75/0  |  提交时间:2020/07/03

Since its introduction, the reward prediction error theory of dopamine has explained a wealth of empirical phenomena, providing a unifying framework for understanding the representation of reward and value in the brain(1-3). According to the now canonical theory, reward predictions are represented as a single scalar quantity, which supports learning about the expectation, or mean, of stochastic outcomes. Here we propose an account of dopamine-based reinforcement learning inspired by recent artificial intelligence research on distributional reinforcement learning(4-6). We hypothesized that the brain represents possible future rewards not as a single mean, but instead as a probability distribution, effectively representing multiple future outcomes simultaneously and in parallel. This idea implies a set of empirical predictions, which we tested using single-unit recordings from mouse ventral tegmental area. Our findings provide strong evidence for a neural realization of distributional reinforcement learning.


Analyses of single-cell recordings from mouse ventral tegmental area are consistent with a model of reinforcement learning in which the brain represents possible future rewards not as a single mean of stochastic outcomes, as in the canonical model, but instead as a probability distribution.


  
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:136/0  |  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.


  
Reply to "Comments on 'What Is the Predictability Limit of Midlatitude Weather?'" 期刊论文
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2020, 77 (2) : 787-793
作者:  Sun, Y. Qiang;  Zhang, Fuqing;  Magnusson, Linus;  Buizza, Roberto;  Chen, Jan-Huey;  Emanuel, Kerry
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/02
Error analysis  Forecasting  Numerical weather prediction  forecasting  Operational forecasting  Ensembles  Model errors  
Benefits of Explicit Treatment of Zero Flows in Probabilistic Hydrological Modeling of Ephemeral Catchments 期刊论文
WATER RESOURCES RESEARCH, 2019, 55 (12) : 11035-11060
作者:  McInerney, David;  Kavetski, Dmitri;  Thyer, Mark;  Lerat, Julien;  Kuczera, George
收藏  |  浏览/下载:19/0  |  提交时间:2020/02/16
probabilistic streamflow prediction  ephemeral catchments  residual error model  zero flow  censoring approach  Box-Cox transformation  
Regime switching effect of financial development on energy intensity: Evidence from Markov-switching vector error correction model 期刊论文
ENERGY POLICY, 2019, 135
作者:  Pan, Xiongfeng;  Uddin, Md. Kamal;  Saima, Umme;  Guo, Shucen;  Guo, Ranran
收藏  |  浏览/下载:24/0  |  提交时间:2020/02/17
Financial development  Energy intensity  Markov-switching  Vector error correction model  Regime switching  Bangladesh  
On the Use of Adaptive Ensemble Kalman Filtering to Mitigate Error Misspecifications in GRACE Data Assimilation 期刊论文
WATER RESOURCES RESEARCH, 2019, 55 (9) : 7622-7637
作者:  Shokri, Ashkan;  Walker, Jeffrey P.;  van Dijk, Albert I. J. M.;  Pauwels, Valentijn R. N.
收藏  |  浏览/下载:15/0  |  提交时间:2019/11/27
adaptive EnKF  GRACE  data assimilation  model error misspecification  error correction  
Effect of excessive equatorial Pacific cold tongue bias on the El Nino-Northwest Pacific summer monsoon relationship in CMIP5 multi-model ensemble 期刊论文
CLIMATE DYNAMICS, 2019, 52: 6195-6212
作者:  Li, Gen;  Jian, Yuntao;  Yang, Song;  Du, Yan;  Wang, Ziqian;  Li, Zhenning;  Zhuang, Wei;  Jiang, Wenping;  Huang, Gang
收藏  |  浏览/下载:28/0  |  提交时间:2019/11/26
Equatorial Pacific cold tongue  Model error  El Nino  Tropical Northwest Pacific anticyclone  Asian summer monsoons  Matsuno-Gill dynamics  
Reply to "Comment on "Ensemble Averaging and the Curse of Dimensionality'" 期刊论文
JOURNAL OF CLIMATE, 2018, 31 (21) : 9017-9019
作者:  Christiansen, Bo
收藏  |  浏览/下载:12/0  |  提交时间:2019/04/09
Error analysis  Climate models  Ensembles  Model evaluation  performance