青蛤(Cyclina sinensis) TRAF6基因克隆及其在Poly I:C胁迫下的免疫应答     

高玮玮  潘宝平  闫春财 《海洋与湖沼》2016,47(5):1040-1046

对青蛤(Cyclina sinensis)转录组文库筛选并克隆得到青蛤TRAF6(Cs TRAF6)基因的c DNA序列,其开放阅读框为2337bp,编码778个氨基酸,分子量为86.59k Da。Cs TRAF6蛋白包含RING型锌指结构,两个TRAF型锌指结构,coiled-coil结构域以及MATH结构域。经生物信息学及分子系统学分析表明Cs TRAF6属于TRAF6家族的一员。利用实时荧光定量PCR方法检测了Cs TRAF6基因在青蛤各个组织以及在Poly I:C侵染下在血淋巴中的时序性表达情况。结果表明,Cs TRAF6基因在青蛤血淋巴、闭壳肌、鳃、性腺、外套膜和肝脏中普遍表达,其中在血淋巴中的表达水平最高。在Poly I:C刺激后的3h,青蛤血淋巴中Cs TRAF6的表达量迅速升高,在6h达到最大值,说明青蛤的Cs TRAF6基因参与了病毒类似物侵染下的免疫应答反应。  相似文献   

基于相干特征的岩石薄片序列图像边缘提取及颗粒分割     

周恒  张春雷  张欣  陈庆轩  张艳  仲诚诚 《吉林大学学报(地球科学版)》2021,51(6):1897-1907

针对岩石颗粒边缘模糊、结构复杂的特点,为了更有效地识别颗粒边缘,在基于特征值的C3相干算法的基础上,融合多尺度和多角度的特征表达,提出了一种改进的C3相干算法。该算法综合考虑岩石薄片图像角度域光学特征、空间尺度信息和各向异性信息,能更有效地表征颗粒边缘特征,表现出对复杂矿物结构的适应能力。在采集的岩石薄片正交偏光图像上验证提出的算法,实验结果表明,与原生C3相干算法相比,改进后的C3相干算法在全局图像上的方差和灰度差分乘积分别提升了68.41%和22.91%,信息熵下降了21.61%。  相似文献   

Landslide susceptibility zonation method based on C5.0 decision tree and K-means cluster algorithms to improve the efficiency of risk management   总被引：1，自引：0，他引：1  

Zizheng Guo  Yu Shi  Faming Huang  Xuanmei Fan  Jinsong Huang 《地学前缘(英文版)》2021,12(6):243-261

Machine learning algorithms are an important measure with which to perform landslide susceptibility assessments,but most studies use GIS-based classification methods to conduct susceptibility zonation.This study presents a machine learning approach based on the C5.0 decision tree(DT)model and the K-means cluster algorithm to produce a regional landslide susceptibility map.Yanchang County,a typical landslide-prone area located in northwestern China,was taken as the area of interest to introduce the proposed application procedure.A landslide inventory containing 82 landslides was prepared and subse-quently randomly partitioned into two subsets:training data(70％landslide pixels)and validation data(30％landslide pixels).Fourteen landslide influencing factors were considered in the input dataset and were used to calculate the landslide occurrence probability based on the C5.0 decision tree model.Susceptibility zonation was implemented according to the cut-off values calculated by the K-means clus-ter algorithm.The validation results of the model performance analysis showed that the AUC(area under the receiver operating characteristic(ROC)curve)of the proposed model was the highest,reaching 0.88,compared with traditional models(support vector machine(SVM)=0.85,Bayesian network(BN)=0.81,frequency ratio(FR)=0.75,weight of evidence(WOE)=0.76).The landslide frequency ratio and fre-quency density of the high susceptibility zones were 6.76/km2 and 0.88/km2,respectively,which were much higher than those of the low susceptibility zones.The top 20％interval of landslide occurrence probability contained 89％of the historical landslides but only accounted for 10.3％of the total area.Our results indicate that the distribution of high susceptibility zones was more focused without contain-ing more"stable"pixels.Therefore,the obtained susceptibility map is suitable for application to landslide risk management practices.  相似文献   

北京市城近郊区地下水的环境同位素研究   总被引：3，自引：1，他引：2  

王新娟  谢振华  李世君  崔亚莉  邵景力 《地学前缘》2006,13(1):205-210

应用环境同位素方法,研究北京城近郊区地下水演化规律。沿北京市永定河冲洪积扇地下水流动方向取样15组(D、18O、T、14C及全分析),对所取水样进行D、18O、T、14C分析,并确定地下水同位素年龄。运用地下水14C和T含量在垂向和水平方向变化的结果,验证了地下水的流向并计算了地下水的流速变化范围为5·02~62·63m/a,从山前至平原浅层地下水径流速度逐渐变小,反映了地下水水平径流强度逐渐减弱,地下水交替逐渐变差;浅层孔隙水以垂向交替为主,深层孔隙水以水平径流为主。对地下水D、18O之间的关系进行分析,从而判断地下水的补给来源等。  相似文献   

用化学地层学研究新元古代地层划分和对比   总被引：3，自引：0，他引：3  

王自强  尹崇玉  高林志  柳永清  唐烽  张传恒 《地学前缘》2006,13(6):268-279

随着传统地层学向多学科相互渗透的综合地层学方向的发展,笔者开展了湖北峡东地区新元古界震旦系和南华系的化学地层学研究。分别介绍了碳酸盐岩地层的稳定同位素和碎屑岩化学蚀变指数的研究方法和成果并依此提出新元古界划分和对比方案。震旦系碳酸盐岩中所获得的δ13C变化曲线和87Sr/86Sr比值与世界诸多剖面的变化曲线基本一致。南华系碎屑岩的化学蚀变指数(CIA)的特征是莲沱组下部CIA值为55~65(代表寒冷环境的CIA值),莲沱组上部CIA值则增至65~75(代表温湿环境),而莲沱组顶部两个样品的CIA值再次降为寒冷指数60~65;南沱组CIA值均为60~65,除了顶部(接近震旦系)的两个样品分别为69·4和70·9。上述CIA值的变化表明南华系以寒冷气侯为主,并且经历过“寒冷—温湿—寒冷”气候的演变条件下的沉积物。沉积相的多样性说明即使在“冰期”期间古构造、古地理环境对沉积物特征的影响依然存在。  相似文献   

Sedimentary facies and paleoenvironmental interpretation of a Holocene marsh in the Gironde Estuary in France     

WANG Jianhu  MASSE Laurent  TASTET Jean-Pierre 《海洋学报(英文版)》2006,25(6):52-62

1Introduction Since the last glacial maximum, the Holocenehas been marked by a rapid rise in sea level. After6 000 a BP, the present-day level was reached andthe rate of sea-level rise (SLR) decreased rapidly(Morzadec -Kerfourn, 1974; Kidson, 1986 ).These…  相似文献   

基于GPU加速的Boussinesq类波浪传播变形数值模型     

孙家文  朱桐  房克照  刘忠波 《海洋工程》2020,38(2):111-119

Boussinesq波浪模型是一类相位解析模型,在时域内求解需要较高的空间和时间分辨率以保证计算精度。为提高计算效率,有必要针对该类模型开展并行算法的研究。与传统的中央处理器(CPU)相比,图形处理器(GPU)有大量的运算器,可显著提高计算效率。基于统一计算设备架构CUDA C语言和图形处理器,实现了Boussinesq模型的并行运算。将本模型的计算结果同CPU数值模拟结果和解析解相比较,发现得到的结果基本一致。同时也比较了CPU端与GPU端的计算效率,结果表明,GPU数值模型的计算效率有明显提升,并且伴随数值网格的增多,提升效果更为明显。  相似文献   

FY-3C/VIRR中红外图像太阳光污染订正     

朱吉彪  胡秀清  杨磊库  徐寒列  徐娜  张鹏 《遥感学报》2021,25(3):803-815

风云三号C星(FY-3C)上搭载的可见光红外扫描辐射计VIRR (Visible and Infra-Red Radiometer)是继承风云一号卫星光学成像仪器,它在高纬度昼夜交替区域附近由于地平线附近太阳光照射,导致仪器扫描镜和其他部件产生杂散光,导致对地观测图像被污染,尤其VIRR中红外第3通道(3.7 μm)图...  相似文献   

Mid-late Holocene anthropogenic and natural variations in geochemistry and sedimentation in the Yazoo Basin: Clark Lake,Sharkey County,Mississippi     

Stan Galicki  Maria Bujenovic  Theresa Woehnker  Jeb Galtney  Trevor Galicki 《自然地理学》2019,40(3):209-226

A 4000-yr history at Clark Lake reveals natural variations in sediment geochemistry and nutrient levels and anthropogenic influence on twentieth century sedimentation rates. Sediment texture and ridge and swale topography indicate that the channel system creating Clark Lake is now occupied by the Yazoo River. Between 1.24 and 0.60 m (2522–865 cal yr BP), total carbon percentages and the C/N ratio average 42% and 17, respectively. The base of the 1650-yr interval and onset of high organic activity in the lake coincides with the abandonment of the Yazoo Meander Belt. The top of the interval is marked by a drop in C/N ratio to 11 and a geochemical transition zone. No change in the rate of sediment accumulation or clay mineralogy was observed despite increased cumulative percentages of Al, Fe, K, Mg, Mn, Ca, and Na. The decrease in organic activity at 865 cal yr BP is attributed to unfavorable growth conditions related to the entrenchment of the Yazoo River and changes in the hydroperiod of the area. Significant floodplain alteration was completed in 1978, but the only major effect was increased sedimentation in the late twentieth century due to the completion of the Whittington Auxiliary Channel.  相似文献   

"资源一号"02C卫星影像土地利用变化检测能力分析     

周亦  吕从  王慧敏 《测绘通报》2019,(1):97-100

“资源一号”02C卫星自成功发射以来,被广泛应用于土地资源、矿产资源、地质环境调查,以及国土资源、地质灾害应急监测等应用领域。“资源一号”02C卫星是一颗填补我国高分辨率遥感数据空白的卫星,是根据国土资源主体业务需求定制的第一颗国产高分辨率业务卫星。本文以吉林省和浙江省某试验区“资源一号”02C卫星数据为例,对“资源一号”02C卫星数据融合影像进行了土地利用遥感监测变化信息检测能力的方法试验。根据试验区数据变化信息提取试验结果,对“资源一号”02C卫星影像在土地利用动态遥感监测中的变化检测能力和适用性开展了试验、分析和评价工作。  相似文献