Half Smooth Tongue Sole(Cynoglossus semilaevis) Under Low Salinity Stress Can Change Hepatic igf2 Expression Through DNA Methylation     

LI Siping  HE Feng  WEN Haishen  SI Yufeng  LIU Mingyuan  HUANG Yajuan  WU Shuxian 《中国海洋大学学报(英文版)》2020,19(1):171-182

Salinity is a crucial environmental stress that severely affects fish growth and survival.Under environmental stress,DNA methylation plays an important role in gene expression and genome function.To better understand the epigenetic regulation mechanism of igf2 under low salinity stress,we analyzed the DNA methylation at 5’UTR,exon1,intron1,and exon2,and analyzed the relationship of DNA methylation with mRNA abundance as well as the special single CpG sites methylation patterns of igf2 in the liver of half smooth tongue sole under low salinity(15)for 0,7,and 60 d.When exposed to low salinity,DNA methylation at 5’UTR and exon2 remained stable,while it was up-regulated firstly and then down-regulated at exon1 and intron1.Some single CpG sites of igf2 associated with low salinity,and most of these sites with significantly changed methylation levels(P<0.05)are located in intron1 area.The discrepant variation of single CpG sites methylation levels and igf2 expression further revealed that females and males showed different response to low salinity.Remarkably,the 38-CpG site of intron1 servers as a sexual marker.Additionally,our integrative analysis demonstrated that regional DNA of igf2 methylation had highly complex interplay on gene expression.The single CpG sites in intron1 were indispensable epigenetic markers under external environmental stress.Above all,to resist the low salinity stress,half smooth tongue sole liver can regulate the expression of igf2 through methylation of CpG sites in intron1.  相似文献   

Numerical Study of Storm Surge Inundation in the Southwestern Hangzhou Bay Region During Typhoon Chan-Hom in 2015     

Wang  Kai  Hou  Yijun  Li  Shuiqing  Du  Mei  Li  Rui 《中国海洋大学学报(英文版)》2020,19(2):263-271

Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment.  相似文献   

基于遗传BP神经网络的海底沉积物声速预报   总被引：1，自引：0，他引：1  

陈文景  郭常升  王景强  侯正瑜 《海洋学报》2016,38(1):116-123

在海底沉积物声速预报中,针对传统经验公式存在预测精度差、适用范围窄、缺乏物理意义等问题,在已有BP神经网络预测的基础上,运用遗传算法优化其初始权值和阈值的方法,构建出基于含水量、孔隙度的声速预报模型。将南沙海域采集得到的海底沉积物样品分为两部分,抽取120组涵盖陆架、陆坡、海槽等地貌单元的样品作为训练数据,另外剩余6组作为测试数据。经试验对比后发现,在对本区域进行声速预报时,宜采用遗传算法优化的BP神经网络,其要优于传统的单参数、双参数回归拟合预报方法和国内外其他学者所得到的经验公式。此种预报方法具有一定的科学依据和广泛的应用前景,可在今后为建立明确、统一的声速预报模型提供参考。  相似文献   

地基微波辐射计反演水汽密度廓线精度分析   总被引：2，自引：0，他引：2  

侯叶叶  刘红燕  鲍艳松 《气象科技》2016,44(5):702-709

以探空水汽廓线为标准,对00:00UTC、12:00UTC北京南郊(39.93°E,116.28°N)观测站的微波辐射计水汽廓线与WRF(Weather ResearchForecasting Model)模拟的水汽廓线进行精度分析。结果表明,整体上WRF水汽密度接近探空,但在近地面处微波辐射计的更接近探空;水汽密度偏差在夏季较大冬季较小;微波辐射计的水汽密度在3km左右偏大,根据北京地区历史天气记录中有中云的天气较多的信息,推测可能是由于云对微波辐射计反演有影响。06:00UTC和18:00UTC以WRF水汽廓线为参考对微波辐射计的水汽廓线进行精度分析,得到的结果与00:00UTC和12:00UTC的类似。  相似文献   

A drift line bias estimator: ARMA-based filter or calibration method,and its application in BDS/GPS-based attitude determination     

Zhang Liang  Hou Yanqing  Wu Jie 《Journal of Geodesy》2016,90(12):1331-1343

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改进HOT法的Landsat 8 OLI遥感影像雾霾及薄云去除     

姜侯  吕宁  姚凌 《遥感学报》2016,20(4):620-631

针对Haze optimized transformation(HOT)方法存在的地物敏感性、过度矫正、红绿蓝波段RGB合成影像色彩失真等问题,提出了相应的改进方法。首先,采用归一化差分植被指数(NDVI)结合地物红蓝光谱差(RBSD)制作通用掩膜,并利用掩膜提取原始影像植被覆盖区对应的原始HOT图部分作为HOT值评估雾霾强度的有效像素集;然后从有效像素集出发推断非植被区的HOT值,得到有效HOT图;最后以有效HOT图为参考,实施暗目标减法。在暗目标减法过程中,首先利用直方图取百分位数的方法确定起始波段的改正值,然后根据散射模型计算其他波段的改正值。在红蓝光谱空间中,去雾后的影像表现出与原始无云区相似的特征,同时保持了不同地物间的差异。实验表明:改进的HOT方法能有效去除雾霾及薄云;有效解决了HOT对水体、裸地、人造地物等地表覆被类型的敏感性问题,避免了RGB合成影像的色彩失真;并且统一了不同波段的纠正尺度,解决了某一(或几个)波段的过度矫正问题,防止了块斑和光晕的产生。  相似文献   

Numerical investigation of the hydromechanical response of a natural fracture during fluid injection using an efficient sequential coupling model     

Lei Zhou  Xiaopeng Su  Zhengmeng Hou  Yiyu Lu  Yang Gou 《Environmental Earth Sciences》2016,75(18):1263

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Construction of a cDNA library for sea cucumber <Emphasis Type="Italic">Acaudina leucoprocta</Emphasis> and differential expression of ferritin peptide     

周君  侯付景  李晔  苏秀榕  李太武  金春华 《中国海洋湖沼学报》2016,34(4):719-729

Acaudina leucoprocta is an edible sea cucumber of economic interest that is widely distributed in China. Little information is available concerning the molecular genetics of this species although such knowledge would contribute to a better understanding of the optimal conditions for its aquaculture and its mechanisms of defense against disease. Therefore, we constructed a cDNA library and, based on bioinformatics analysis of the sequences, the functions of 75% of the cDNAs were identified, including those involved in cell structure, energy metabolism, mitochondrial function, and signal transduction pathways. Approximately 25% of genes in the library were unmatched. The gene for A. leucoprocta ferritin was also cloned. The predicted amino-acid sequence of ferritin displayed significant homology with other sea-cucumber counterparts but indicated that it was a new member of the ferritin family. Semiquantitative real-time RT-PCR indicated the highest levels of ferritin mRNA expression in the intestine. A polyclonal antibody of ferritin was also produced. These data provide a set of molecular tools essential for further studies of the functions of ferritin protein in A. leucoprocta.  相似文献   

Probabilistic modeling of disrupted infrastructures due to fallen trees subjected to extreme winds in urban community     

Hou  Guangyang  Chen  Suren 《Natural Hazards》2020,102(3):1323-1350

Natural Hazards - Tree failures due to strong winds in urban areas cause extensive direct and indirect economic and environmental loss, including disrupting adjacent infrastructures, such as...  相似文献   

Geochemical characteristics and origin of gases from the Upper,Lower Paleozoic and the Mesozoic reservoirs in the Ordos Basin,China     

AnPing Hu  Jian Li  WenZheng Zhang  ZhiSheng Li  Lu Hou  QuanYou Liu 《中国科学D辑(英文版)》2008,51(1):183-194

The Ordos Basin, the second largest sedimentary basin in China, contains the broad distribution of natural gas types. So far, several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin, each having over 1000×10⁸m³ of proven gas reserves, and several gas pools have also been discovered in the Mesozoic. This paper collected the data of natural gases and elucidated the geochemical characteristics of gases from different reservoirs, and then discussed their origin. For hydrocarbons preserved in the Upper Paleozoic, the elevated δ ¹³C values of methane, ethane and propane indicate that the gases would be mainly coal-formed gases; the singular reversal in the stable carbon isotopes of gaseous alkanes suggests the mixed gases from humic sources with different maturity. In the Lower Paleozoic, the δ ¹³C₁ values are mostly similar with those in the Upper Paleozoic, but the δ ¹³C₂ and δ ¹³C₃ values are slightly lighter, suggesting that the gases would be mixing of coal-type gases as a main member and oil-type gases. There are multiple reversals in carbon isotopes for gaseous alkanes, especially abnormal reversal for methane and ethane (i.e. δ ¹³C₁>δ ¹³C₂), inferring that gases would be mixed between high-mature coal-formed gases and oil-type gases. In the Mesozoic, the δ ¹³C values for gaseous alkanes are enriched in ¹²C, indicating that the gases are mainly derived from sapropelic sources; the carbon isotopic reversal for propane and butane in the Mesozoic is caused by microbial oxidation and mixing of gases from sapropelic sources with different maturity. In contrast to the Upper Paleozoic gases, the Mesozoic gases are characterized by heavier carbon isotopes of iso-butane than normal butane, which may be caused by gases generated from different kerogen types. Finally, according to δ ¹³C₁-R ₀ relationship and extremely low total organic carbon contents, the Low Paleozoic gases would not be generated from the Ordovician source as a main gas source, bycontrast, the Upper Paleozoic source as a main gas source is contributed to the Lower Paleozoic gases.  相似文献