为评估从数值预报、客观方法到主观预报产品各环节对天气预报准确率的贡献,研发了天气预报全流程检验评估程序库(Meteorological Evaluation Program Library,简称为MetEva)。MetEva以检验算法的全流程覆盖和检验结果的可对比性为目标,...为评估从数值预报、客观方法到主观预报产品各环节对天气预报准确率的贡献,研发了天气预报全流程检验评估程序库(Meteorological Evaluation Program Library,简称为MetEva)。MetEva以检验算法的全流程覆盖和检验结果的可对比性为目标,采用包含基础层和功能层的分层架构,基于统一的数据结构,设计了模块化的检验计算流程。围绕数据读取、数据合并与匹配、样本选取、样本分组、检验计算和结果输出等6个主要步骤,MetEva提供了6类400项功能函数。MetEva集成了5类54种检验算法,涵盖了大部分世界气象组织推荐和国内业务规范要求的检验算法,并对其计算流程进行改进,同时采用矩阵计算方式和并行算法来提升检验程序的计算效率。以温度和降水预报的检验评估为例,简要说明了MetEva的功能和使用方法,展示了MetEva在精细化检验评估方面的应用价值。该程序库已开源发布,可有效支撑全国各级气象部门开展天气预报全流程检验评估工作。展开更多
利用自动气象站资料、FY-2G卫星TBB(black body temperature)产品、多普勒雷达组网资料和NCEP FNL分析资料对超强台风利奇马(1909)极端强降雨观测特征、热动力结构演变和水汽输送进行分析。结果表明:此次台风大暴雨覆盖华东大部,极端强...利用自动气象站资料、FY-2G卫星TBB(black body temperature)产品、多普勒雷达组网资料和NCEP FNL分析资料对超强台风利奇马(1909)极端强降雨观测特征、热动力结构演变和水汽输送进行分析。结果表明:此次台风大暴雨覆盖华东大部,极端强降雨区(过程雨量超过350 mm)位于浙江东部和山东中部,21个国家级气象站突破日雨量历史极值;副热带高压、台风和西风槽相互作用以及华东沿海强劲东南风急流为台风利奇马(1909)长时间维持与强降雨发生提供了有利的环境条件。浙江东部极端强降雨主要由发展极为强盛的台风本体产生,垂直深厚涡旋系统强烈的上升运动和台风眼墙区密实的深对流系统导致雨强大且降雨集中;而山东中部极端强降雨则与台风非对称结构演变和冷空气侵入密切相关。倒槽锋生、台风北侧3条螺旋雨带北移汇入及地形迎风坡处的列车效应导致山东中部远距离暴雨发生,随着500 hPa干冷空气从低层不断侵入,在台风西侧118°E附近形成向西倾斜的假相当位温锋区,暖湿气流爬升引发第2阶段稳定性降雨。展开更多
Nanog is a transcription factor identified by its ability to maintain the self-renewal of ES cells in the absence of leukemia inhibitory factor (LIF). Nanog protein contains an N-terminal domain (ND), a DNA-binding ho...Nanog is a transcription factor identified by its ability to maintain the self-renewal of ES cells in the absence of leukemia inhibitory factor (LIF). Nanog protein contains an N-terminal domain (ND), a DNA-binding homeobox domain (HD) and a C-terminal domain (CD). We previously reported that the CD in Nanog is a transcriptional activation domain essential for the in vivo function of Nanog. Here we demonstrated that the ND in Nanog is also functionally important. Deletion of the ND reduces the transcriptional activity of Nanog on either artificial reporters or native Nanog promoters. This truncated Nanog is also less effective in regulating the endogenous Nanog target genes. Furthermore, the ND truncation disrupted the ability of Nanog to maintain ES cell self-renewal as well. We found that the ND is not required for the nuclear localization of Nanog. These results suggest that the regulation of endogenous pluripotent genes such as oct3/4 and rex-1 is required for the in vivo function of Nanog.展开更多
文摘为评估从数值预报、客观方法到主观预报产品各环节对天气预报准确率的贡献,研发了天气预报全流程检验评估程序库(Meteorological Evaluation Program Library,简称为MetEva)。MetEva以检验算法的全流程覆盖和检验结果的可对比性为目标,采用包含基础层和功能层的分层架构,基于统一的数据结构,设计了模块化的检验计算流程。围绕数据读取、数据合并与匹配、样本选取、样本分组、检验计算和结果输出等6个主要步骤,MetEva提供了6类400项功能函数。MetEva集成了5类54种检验算法,涵盖了大部分世界气象组织推荐和国内业务规范要求的检验算法,并对其计算流程进行改进,同时采用矩阵计算方式和并行算法来提升检验程序的计算效率。以温度和降水预报的检验评估为例,简要说明了MetEva的功能和使用方法,展示了MetEva在精细化检验评估方面的应用价值。该程序库已开源发布,可有效支撑全国各级气象部门开展天气预报全流程检验评估工作。
基金Supported by the National Natural Science Foundation of China (Grant Nos. 30725012, 30630039 and 90813033)Knowledge Innovation Project of Chinese Academy of Sciences (Grant No. KSCX2-YW-R-48)+2 种基金Guangzhou Science and Technology Commission Foundation (Grant No. 2008A1-E4011)National Key Basic Research and Development Program of China (Grant Nos. 2006CB701504, 2006CB943600, 2007CB948002 and 2007CB947804)Beijing Forestry University Young Scientist Fund (Grant No. Blx2w8003)
文摘Nanog is a transcription factor identified by its ability to maintain the self-renewal of ES cells in the absence of leukemia inhibitory factor (LIF). Nanog protein contains an N-terminal domain (ND), a DNA-binding homeobox domain (HD) and a C-terminal domain (CD). We previously reported that the CD in Nanog is a transcriptional activation domain essential for the in vivo function of Nanog. Here we demonstrated that the ND in Nanog is also functionally important. Deletion of the ND reduces the transcriptional activity of Nanog on either artificial reporters or native Nanog promoters. This truncated Nanog is also less effective in regulating the endogenous Nanog target genes. Furthermore, the ND truncation disrupted the ability of Nanog to maintain ES cell self-renewal as well. We found that the ND is not required for the nuclear localization of Nanog. These results suggest that the regulation of endogenous pluripotent genes such as oct3/4 and rex-1 is required for the in vivo function of Nanog.
