Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four mach...Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four machine learning algorithms,namely,decision tree(DT),random forest(RF),XGBoost(XGB),and LightGBM(LGBM),were implemented for the lithostratigraphic classification and lithostratigraphic prediction of a quaternary coverage area based on stream sediment geochemical sampling data in the Chahanwusu River of Dulan County,Qinghai Province,China.The local Moran’s I to represent the features of spatial autocorrelations,and terrain factors to represent the features of surface geological processes,were calculated as additional features.The accuracy,precision,recall,and F1 scores were chosen as the evaluation indices and Voronoi diagrams were applied for visualization.The results indicate that XGB and LGBM models both performed well.They not only obtained relatively satisfactory classification performance but also predicted lithostratigraphic types of the Quaternary coverage area that are essentially consistent with their neighborhoods which have the known types.It is feasible to classify the lithostratigraphic types through the concentrations of geochemical elements in the sediments,and the XGB and LGBM algorithms are recommended for lithostratigraphic classification.展开更多
Information on the center of genetic diversity of soybean（Glycine max） will be helpful not only for designing efficient strategies for breeding programs, but also for understanding the domestication and origin of th...Information on the center of genetic diversity of soybean（Glycine max） will be helpful not only for designing efficient strategies for breeding programs, but also for understanding the domestication and origin of this species. Here, we describe an analysis of genetic diversity based on simple-sequence repeat（SSR） variations within a core collection of 2 111 accessions of Chinese soybean landraces. Prior to the diversity assessment, the geographic origin of each accession was mapped. The map was then divided into grids each 2.5° in latitude and 5° in longitude. We found two regions that had higher number of alleles（NA） and greater polymorphic information content（PIC） values than the others. These regions are adjacently located within grid position of 30°–35°N×105°–110°E, which includes the valley of the middle and lower reaches of the Wei River, and the valley of the upper reaches of the Hanjiang River. It was also observed that in many regions, genetic diversity decreased with the increase in distance from the center. Another region, in northern Hebei Province（115°–120°E×40°–42.5°N）, was observed having higher diversity than any surrounding regions, indicating that this is a sub-center of soybean diversity. Based on the presented results, the domestication and origin of soybean are also discussed.展开更多
2018年3月8?9日,中国临床肿瘤学会(Chinese Society of Clinical Oncology,CSCO)和中国抗癌协会肺癌专业委员会联合主办了第15届“中国肺癌高峰论坛”。本次论坛的主题为“聚焦中枢神经系统转移:精确诊断,精准治疗”。晚期肺癌患者往往...2018年3月8?9日,中国临床肿瘤学会(Chinese Society of Clinical Oncology,CSCO)和中国抗癌协会肺癌专业委员会联合主办了第15届“中国肺癌高峰论坛”。本次论坛的主题为“聚焦中枢神经系统转移:精确诊断,精准治疗”。晚期肺癌患者往往合并脑转移,在1 000多例的肺癌尸检结果中,肺癌脑转移发生率23%~36%,是脑转移性肿瘤中最常见的类型,且通常预后较差[1]。目前肺癌脑(膜)转移的综合治疗管理和治疗结果,仍不令人满意,治疗效果不佳,中位总生存时间16个月,其中脑膜转移的患者则仅为4.5个月左右[2?5]。近10年肺癌的治疗出现了革命性的改变,但肺癌脑转移的诊断和治疗成了提高肺癌长期生存率的瓶颈。临床医师及科研工作者,应如何对脑转移进行准确及时的诊断?在众多的分型分类体系中,又该如何参考应用?如何全面地对脑转移患者的颅内/颅外病灶进行合理评估?对于伴有驱动基因敏感突变的脑转移患者群体,应怎样对待酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)治疗的定位和应用时机?随着血管生成抑制剂和免疫检查点Checkpoint抑制剂的应用发展,新的治疗选择在肺癌脑转移治疗应用中又该如何管理?以上都是肺癌脑转移综合管理中的疑点和难点,急需解答和形成共识以指导临床实践。本次肺癌高峰论坛,综合近年来发表的前瞻性及回顾性重要研究结果、结合我国肺癌脑转移治疗管理的实际情况,与会专家们就肺癌脑转移的综合管理进行了详细的讨论和各抒己见的争辩,最后达成了以下四点共识。展开更多
基金Projects(41772348,42072326)supported by the National Natural Science Foundation of ChinaProject(2017YFC0601503)supported by the National Key Research and Development Program,China。
文摘Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four machine learning algorithms,namely,decision tree(DT),random forest(RF),XGBoost(XGB),and LightGBM(LGBM),were implemented for the lithostratigraphic classification and lithostratigraphic prediction of a quaternary coverage area based on stream sediment geochemical sampling data in the Chahanwusu River of Dulan County,Qinghai Province,China.The local Moran’s I to represent the features of spatial autocorrelations,and terrain factors to represent the features of surface geological processes,were calculated as additional features.The accuracy,precision,recall,and F1 scores were chosen as the evaluation indices and Voronoi diagrams were applied for visualization.The results indicate that XGB and LGBM models both performed well.They not only obtained relatively satisfactory classification performance but also predicted lithostratigraphic types of the Quaternary coverage area that are essentially consistent with their neighborhoods which have the known types.It is feasible to classify the lithostratigraphic types through the concentrations of geochemical elements in the sediments,and the XGB and LGBM algorithms are recommended for lithostratigraphic classification.
基金supported by the National Basic Research Program of China(973,G1998010203 and 2004CB117203)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences
文摘Information on the center of genetic diversity of soybean（Glycine max） will be helpful not only for designing efficient strategies for breeding programs, but also for understanding the domestication and origin of this species. Here, we describe an analysis of genetic diversity based on simple-sequence repeat（SSR） variations within a core collection of 2 111 accessions of Chinese soybean landraces. Prior to the diversity assessment, the geographic origin of each accession was mapped. The map was then divided into grids each 2.5° in latitude and 5° in longitude. We found two regions that had higher number of alleles（NA） and greater polymorphic information content（PIC） values than the others. These regions are adjacently located within grid position of 30°–35°N×105°–110°E, which includes the valley of the middle and lower reaches of the Wei River, and the valley of the upper reaches of the Hanjiang River. It was also observed that in many regions, genetic diversity decreased with the increase in distance from the center. Another region, in northern Hebei Province（115°–120°E×40°–42.5°N）, was observed having higher diversity than any surrounding regions, indicating that this is a sub-center of soybean diversity. Based on the presented results, the domestication and origin of soybean are also discussed.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.42072326,41772348)the National Key Research and Development Program,China(No.2019YFC1805905).
文摘2018年3月8?9日,中国临床肿瘤学会(Chinese Society of Clinical Oncology,CSCO)和中国抗癌协会肺癌专业委员会联合主办了第15届“中国肺癌高峰论坛”。本次论坛的主题为“聚焦中枢神经系统转移:精确诊断,精准治疗”。晚期肺癌患者往往合并脑转移,在1 000多例的肺癌尸检结果中,肺癌脑转移发生率23%~36%,是脑转移性肿瘤中最常见的类型,且通常预后较差[1]。目前肺癌脑(膜)转移的综合治疗管理和治疗结果,仍不令人满意,治疗效果不佳,中位总生存时间16个月,其中脑膜转移的患者则仅为4.5个月左右[2?5]。近10年肺癌的治疗出现了革命性的改变,但肺癌脑转移的诊断和治疗成了提高肺癌长期生存率的瓶颈。临床医师及科研工作者,应如何对脑转移进行准确及时的诊断?在众多的分型分类体系中,又该如何参考应用?如何全面地对脑转移患者的颅内/颅外病灶进行合理评估?对于伴有驱动基因敏感突变的脑转移患者群体,应怎样对待酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)治疗的定位和应用时机?随着血管生成抑制剂和免疫检查点Checkpoint抑制剂的应用发展,新的治疗选择在肺癌脑转移治疗应用中又该如何管理?以上都是肺癌脑转移综合管理中的疑点和难点,急需解答和形成共识以指导临床实践。本次肺癌高峰论坛,综合近年来发表的前瞻性及回顾性重要研究结果、结合我国肺癌脑转移治疗管理的实际情况,与会专家们就肺癌脑转移的综合管理进行了详细的讨论和各抒己见的争辩,最后达成了以下四点共识。
