法氏囊（Bursa of fabricius,BF）是禽类特有的中枢体液免疫器官,相当于哺乳动物的骨髓。B淋巴细胞在此发育分化成熟并且参与机体体液免疫应答。三肽囊素（Bursin,BS）是从BF组织中分离的第一个活性肽。作为BF的重要活性组成成分,不仅...法氏囊（Bursa of fabricius,BF）是禽类特有的中枢体液免疫器官,相当于哺乳动物的骨髓。B淋巴细胞在此发育分化成熟并且参与机体体液免疫应答。三肽囊素（Bursin,BS）是从BF组织中分离的第一个活性肽。作为BF的重要活性组成成分,不仅可以提高禽类免疫功能,展开更多
A 700-year record （1.0-1.5 a resolution） of the East Asian winter monsoon （EAWM）, based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea （ECS）, was com...A 700-year record （1.0-1.5 a resolution） of the East Asian winter monsoon （EAWM）, based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea （ECS）, was compared with the Dongge stalagmite 8180 record during the mid-Holocene. The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang （Yangtze） River mouth since 7.3 ka BP. High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate （1 324-1 986 crn/ka） between 5.9-5.2 ka BP. The EAWM strengthened when the Asian summer monsoon weakened, especially around 5 500 a BE which corresponded to a worldwide cold event. The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a. The 5 500 a BP cold event might be resulted from orbital forcing and changes in solar activity.展开更多
Background: DNA methylation will influence the gene expression pattern and cause the changes of the genetic functions. Computational analysis of the methylation status for nucleotides can help to explore the underlyin...Background: DNA methylation will influence the gene expression pattern and cause the changes of the genetic functions. Computational analysis of the methylation status for nucleotides can help to explore the underlying reasons for developing methylations. Results: We present a DNA sequence based method to analyze the methylation status of CpG dinucleotides using 5bp (5-mer) DNA fragments – named as the word composition encoding method. The prediction accuracy is 75.16% when all 5bp word compositions are used (totally 45 = 1024). Furthermore, 5-bp DNA fragments/words having the most impact on the methylation status are identified by mRMR (Maximum-Relevant-Minimum-Redundancy) feature selection method. As a result, 58 words are selected, and they are used to build a compact predictor, which achieves 77.45% prediction accuracy. When the word composition encoding method and the feature selection strategy are coupled together, the meaning of these words can be analyzed through their contribution towards the prediction. The biological evidence in the literature supports that the surrounding DNA sequence of the CpG dinucleotides will affect the methylation of the CpG dinucleotides. Conclusions: The main contribution of this paper is to find out and analyze the key DNA words taken from the neighbor-hood of the CpG dinucleotides that are inducing the DNA methylation.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 40576032 and 40776030)Doctor Foundation of China University of Petroleum
文摘A 700-year record （1.0-1.5 a resolution） of the East Asian winter monsoon （EAWM）, based on grain-size analysis and AMSI4C dating of Core EC2005 from the inner-shelf mud wedge of the East China Sea （ECS）, was compared with the Dongge stalagmite 8180 record during the mid-Holocene. The upper muddy section of Core EC2005 has been formed mainly by suspended sediments derived from the Changjiang （Yangtze） River mouth since 7.3 ka BP. High precipitation and a strengthened EAWM might have played key roles in the high sedimentation rate （1 324-1 986 crn/ka） between 5.9-5.2 ka BP. The EAWM strengthened when the Asian summer monsoon weakened, especially around 5 500 a BE which corresponded to a worldwide cold event. The EAWM during the mid-Holocene shows statistically significant solar periodicities at 62 and 11 a. The 5 500 a BP cold event might be resulted from orbital forcing and changes in solar activity.
文摘Background: DNA methylation will influence the gene expression pattern and cause the changes of the genetic functions. Computational analysis of the methylation status for nucleotides can help to explore the underlying reasons for developing methylations. Results: We present a DNA sequence based method to analyze the methylation status of CpG dinucleotides using 5bp (5-mer) DNA fragments – named as the word composition encoding method. The prediction accuracy is 75.16% when all 5bp word compositions are used (totally 45 = 1024). Furthermore, 5-bp DNA fragments/words having the most impact on the methylation status are identified by mRMR (Maximum-Relevant-Minimum-Redundancy) feature selection method. As a result, 58 words are selected, and they are used to build a compact predictor, which achieves 77.45% prediction accuracy. When the word composition encoding method and the feature selection strategy are coupled together, the meaning of these words can be analyzed through their contribution towards the prediction. The biological evidence in the literature supports that the surrounding DNA sequence of the CpG dinucleotides will affect the methylation of the CpG dinucleotides. Conclusions: The main contribution of this paper is to find out and analyze the key DNA words taken from the neighbor-hood of the CpG dinucleotides that are inducing the DNA methylation.
