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1.
对海洋数据进行挖掘能够有效地预测海洋灾害事件。海洋监测数据具有时序长、间隔短、多要素间强关联的特点，对长时间序列进行直接分析挖掘速度慢、效率低，现有方法大多采用符号化时间序列方法，但可能导致部分信息丢失且破坏
要素间的关联性。本文定义了时间序列 motif，用于发现时间序列中重复出现的，先前未知的局部信息，解决了符号化导致的信息丢失的问题，实现了时间序列 motif 的精确快速提取。通过构建 motif 规则树，实现了海洋多要素时间序列间强关联规则的挖掘。最后，给出关联规则评价参数，同随机游走数据对比后，证明了本文方法的有效性。 相似文献
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为探究长牡蛎在繁殖期间的糖原含量与类胰岛素基因(cgMIP123、cgMIP4、cgMILP7、cgILP)和相关转录调控因子(cgPdx)相对表达量的相关性,自2020年5月至2020年10月采集了山东胶南养殖海区的长牡蛎,测定了血糖含量、糖原含量、条件指数、类胰岛素基因相对表达量及环境因子(酸度、温度、盐度)等数据,采用多元统计方法对数据进行分析。logistic回归分析结果显示,长牡蛎配子排放前后血糖含量和内脏团糖原含量具有显著差异。构建的回归模型可以通过血糖含量和内脏团糖原含量准确判断配子是否已经排放,区分度C-index为0.903,Hosmer-Lemeshow拟合优度检验χ2值为9.06,P>0.05,验证结果显示该模型可靠。多元线性回归分析结果显示:条件指数与cgMIP123和cgMIP4基因的相对表达量具有相关性,R2为0.91,P值为0.0076,极显著相关;内脏团和唇瓣组织的糖原含量与ILPs和cgPdx相对表达量具有一定的相关性,其中cgMILP7的相对表达量与内脏团和唇瓣组织的糖原含量呈负相关,cgPdx相对表达量与唇瓣组织的糖原含量呈负相关,cgMIP4和cgILP的相对表达量与糖原含量呈正相关。 相似文献
3.
利用简并引物扩增及RACE全长克隆技术, 克隆得到绿鳍马面鲀(Navodon septentrionalis)CYP19a基因cDNA全长序列。通过多序列比对, 发现具有芳香化酶特定保守序列, 包括一个I-螺旋区, 一个Ozol肽区, 一个亚铁血红素结合区域以及一个芳香化酶特异性结合区域。通过RT-PCR技术检测了其在绿鳍马面鲀成鱼各组织表达的情况, 发现其CYP19a基因只在卵巢中有表达; 同时也分析了其在不同卵巢发育期的表达情况, 发现CYP19a在卵黄发生后期表达量达到最高值, 卵巢退化吸收期表达量达到最低值。 相似文献
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与其他钵水母相比,倒立水母具有独特行为：在生命周期的大部分时间里,它都在海底呈倒立附着、“睡眠”的状态。为探索与这一独特行为相关的遗传信息,本研究对安朵仙水母(Cassiopea andromeda)和同属于钵水母纲的海蜇(Rhopilema esculentum)、巴布亚硝水母(Mastigias papua)进行首次全基因组测序、拼接和注释,并重点分析了这3种钵水母与感觉功能、神经系统发育相关的重要转录调节因子Hox和POU基因家族的多样性与系统发育关系。遗传分析显示,刺胞动物门中Hox和POU基因家族具有明显的物种间差异性。对Hox基因的分析首次发现钵水母及水螅(Hydra vulgaris)的“前段Hox基因”产生了部分缺失,并进一步印证了刺胞动物不存在“中段Hox基因”的假说。安朵仙水母和海蜇具有相对全面的ParaHox基因种类,即GSX和XLOX/CDX基因,而巴布亚硝水母只有GSX基因。在POU基因多样性方面,安朵仙水母、海蜇、星状海葵(Nematostella vectensis)的基因组具有全部4类POU,而巴布亚硝水母、海月水母(Aurelia aurita)、水螅只有2类POU。在本研究分析的刺胞动物中,安朵仙水母的POU-1,-6亚型的核苷酸多态性最高;安朵仙水母与指形鹿角珊瑚(Acropora digitifera)、星状海葵的POU-2/3/5亚型的序列多样性较其他钵水母更高。另外,3种钵水母与水螅粘附蛋白的比较结果表明,安朵仙水母具有巴布亚硝水母和海蜇所不具有的粘附相关鼠李糖结合凝集素和一类抗氧化活性物质铁螯合物还原酶。综上所述,安朵仙水母具有更多POU编码基因和复杂POU亚型,以及具有粘附相关凝集素和还原酶的编码基因,可能是与安朵仙水母倒立附着生活方式相关的关键遗传信息。 相似文献
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为比较中国不同海域口虾蛄(Oratosqilla oratoria)群体的遗传特性, 作者对采自皮口、绥中、青岛和广州4 个海域的口虾蛄群体的线粒体COI基因序列进行扩增和测序, 比较并分析了其遗传多样性和系统进化关系。获得585bp 的口虾蛄线粒体COI基因序列, 发现变异位点54 个, 占总位点数的9.2%。COI基因序列A+T 含量(64.8%)显著高于G+T 含量(35.2%), 符合节肢动物线粒体DNA 碱基组成的特点。转换与颠换的平均比值是7.84, 碱基替换未达到饱和。100 个样本的线粒体COI基因序列共定义35 个单倍型, 单倍型多样性(Hd)为0.9162, 平均核苷酸多样性(π)为0.0203。4 个群体均具有高的单倍型多样性和低的核苷酸多样性的特点, 说明4 个海域口虾蛄的遗传多样性均处于中等水平, 但广州海域的遗传多样性水平最高。AMOVA 分析表明, 来自于群体间的遗传差异(84.53%)明显高于来自群体内的差异(15.47%)。遗传分化系数(Fst)表明皮口、绥中、青岛3 个海域间几乎没有发生分化(Fst<0), 而广州海域口虾蛄遗传分化较大。从GenBank 上下载了19 条粤东海域口虾蛄的同源序列与本实验获得序列共同构建NJ 系统发育树, 结果显示皮口、绥中、青岛聚为一支, 广州和粤东(深圳和汕尾)聚为另一支。单倍型系统发育树和单倍型进化网络关系图均显示出广州海域口虾蛄群体较大的遗传分化。 相似文献
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为了阐明南中国海裸胸鳝属(Gymnothorax)鱼类系统进化情况,利用聚合酶链式反应扩增目的产物,将其连接到T载体后,并对其序列进行测定,共得到9种裸胸鳝属鱼类线粒体16S ribosomalDNA(16S rDNA)基因的部分序列,采用多个生物软件对序列变异和碱基组成进行分析,计算了Kimura2-parameter遗传距离,转换/颠换比等遗传信息指数,下载基因库中16SrDNA基因的同源序列,以鳗鲡属(Anguilla)的花鳗鲡(Anguilla marmorata)为外群构建NJ(Neighbore-Joining)、MP(MaximumParsimony)和ME(Minimum Evolution)系统进化树。根据所得分子数据并结合形态学特征推论如下:(1)在所研究的10种裸胸鳝鱼中共有516个位点、其中143个核苷酸位点存在变异(27.7%);(2)序列变异的转换/颠换比值的平均值为3.441;相对遗传距离数据表明斑颈裸胸鳝(G. margaritophorus)和网纹裸胸鳝(G. reticularis)差异最大(0.177),褐祼胸鳝(G. hepaticus)与布雷顿氏裸胸鳝(G. breedeni)差异最小(0.022);(3)NJ树、ME树表明裸胸鳝属内部存在3个平行进化的姐妹分支,分支内部的种类组成与地理分布无关。 相似文献
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郑华 朱小华 Nakamura Hirohiko Park Jae-Hun Jeon Chanhyung 赵瑞祥 Nishina Ayako 张传正 Na Hann 朱泽南 Min Hong-Sik 《海洋学报(英文版)》2020,39(7):91-106
在2015年6月至2017年6月期间，跨越庆良间水道的由2台加载压力传感器的倒置式回声仪（PIES）和5台加载压力传感器和海流计的倒置式回声仪（CPIES）组成的观测断面获得了近2年的海底压力时间序列。该时间序列中存在着显著的21天周期的振荡（Pbot21），该信号在2016年7月至10月期间尤为强烈。Pbot21与东海陆架上的风应力旋度存在较显著的3天延迟相关，其相关系数达到0.65。本文采用正压海洋模式解释了这一信号的产生、传播以及耗散过程，模式结果显示东海陆架上的风应力旋度驱动产生Pbot21并向琉球岛链传播，而深海上的风应力旋度不能驱动产生这一信号。在陆架上，Pbot21伴随21天周期的风应力旋度由海岸向东南方向传播，但由于摩擦作用，信号在离开风场后几天内即耗散。断面能否观测到Pbot21与陆架上21天周期风应力旋度场的分布相关，长江口东南方向风应力旋度驱动的Pbot21能被观测到，而长江口东北方向产生的Pbot21不能被观测到。 相似文献
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超氧化物歧化酶(SOD)是植物细胞应对氧化胁迫的第一道,也是最重要的防线。本研究以坛紫菜转录组数据库中的unigene序列为基础,通过RACE扩增技术克隆得到了3条坛紫菜SOD基因的全长序列,分别命名为PhMSD,PhCSD1和PhCSD2。序列分析结果表明,PhMSD序列全长973 bp,可编码包含224个氨基酸,等电点为5.75的多肽序列;PhCSD1序列全长1029 bp,可编码包含134个氨基酸,等电点为4.65的多肽序列;PhCSD2序列全长954 bp,可编码包含216个氨基酸,等电点为10.74的多肽序列。根据保守序列和系统进化树分析,可以将三条PhSODs分成两个亚型:其中PhMSD属于锰超氧化物歧化酶,PhCSD1和PhCSD2属于铜锌超氧化物歧化酶。采用实时荧光定量PCR技术(qPCR)测定了3条PhSOD基因在坛紫菜不同世代,高温胁迫不同时间水平以及不同失水胁迫梯度下的表达水平变化,结果表明:3条PhSOD基因在叶状体世代中的表达水平均显著高于丝状体世代;在不同水平的高温和失水胁迫下,PhCSD1和PhCSD2的表达水平显著上调,而PhMSD则表现出不同的表达模式,高温胁迫下被显著抑制,失水胁迫下没有发生显著变化。 相似文献
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为了解调水调沙期间黄河口及邻近海域鱼卵、仔稚鱼群落结构的动态变化,作者分别于2011年和2018年黄河调水调沙期间（6月—7月）,利用大型浮游生物网对该海域的鱼卵、仔稚鱼进行表层水平拖网调查。结果表明：2011年3个航次共采集鱼卵1 280粒,仔稚鱼5 973尾,隶属于7目11科13属;2018年3个航次共采集鱼卵4 104粒,仔稚鱼237尾,隶属于7目11科13属。优势种以斑鰶（Konosirus punctatus）、鳀（Engraulis japonicus）和赤鼻棱鳀（Thryssa kammalensis）等短生命周期、低营养层级的小型中上层鱼类为主。靠近黄河入海口处站位的鱼卵、仔稚鱼密度相对较高,鱼卵、仔稚鱼分布范围向黄河入海口门处集中。鱼卵、仔稚鱼的多样性指数在调水调沙过程中出现波动,过后又恢复至调水调沙前水平。环境因子Pearson相关性分析表明,鱼卵数量与环境因子间无显著相关性（P0.05）,仔稚鱼数量与叶绿素a的含量呈极显著正相关（R=0.870,P<0.01）。两个年度调查结果对比发现,总体来说调查期间黄河口及邻近海域鱼卵、仔稚鱼种类数变化不大,在适温类型组成上均以暖温种为主;2018年鱼卵、仔稚鱼采集数量均小于2011年,但是鱼卵、仔稚鱼的均匀度指数（J’）和多样性指数（H’）均大于2011年,除6月上旬航次外,其他两个航次丰富度指数（D）也均大于2011年。本研究补充了黄河口及邻近海域鱼类早期补充资源的基础数据,旨为黄河口邻近海域及渤海的渔业资源评估和养护提供依据。 相似文献
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热带气旋资料长度对风暴潮危险性评估结果的影响 总被引：1，自引：1，他引：0
热带气旋历史样本数不足一直困扰着风暴潮风险评估研究,本文基于西北太平洋62 a(1949-2010年)历史观测热带气旋事件集资料和用随机模拟方法构造的1000 a模拟热带气旋随机事件集,以福建省连江县为例,开展了资料长度对风暴潮灾害危险性评估结果的影响分析。文中用ADCIRC模型模拟了两种数据集强迫下的风暴潮增水,采用极值Ⅰ型分布法得到了典型重现期的风暴潮增水,经过对计算结果分析发现典型重现期的风暴潮增水计算结果与所用数据资料长度有着密切相关性,数据资料越长,结果越稳定。对于1000 a一遇的风暴潮增水值,使用500 a长度的资料已经趋于稳定,并接近用1000 a资料计算得到的结果。在进行风暴潮危险性评估时,相比用几十年尺度的热带气旋历史数据集,1000 a的热带气旋模拟数据集的计算结果更具实际意义。 相似文献
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The main characteristics of spatial and temporal variability of the precipitation regime in Sweden were studied by using the long‐term monthly precipitation amount (1890‐1990) at 33 stations. The data were filtered by using Empirical Orthogonal Function (EOF) analysis, which provides principal modes of both spatial variability and time coefficient series describing the dominant temporal variability. Canonical correlation analysis (CCA) was used to reveal association between the atmospheric circulation and the characteristics of the climate variability. Statistically significant upward shifts in the mean precipitation have been found during cold months (March, September, November and December) and only a downward shift (less significant) for August. Simultaneous changes in the time series associated to the optimally correlated circulation patterns were found, indicating an important role of the circulation. The circulation patterns are given by the North Atlantic Oscillation (NAO) in March and December and a cyclonic structure centred over southern Scandinavia in September and November. These changes may have induced changes in the mean precipitation seasonality reflected by a shift of the maximum precipitation from August to July (after 1931 for western part and after 1961 for the southeastern coast) and after 1961 to September, October or November for other regions. Combining rotated EOF analysis with cluster analysis, 4 regions with similar climate variability were objectively identified. For these regions the standardised monthly precipitation anomalies were computed. The frequency of the extreme events (very dry/wet and dry/wet months) over 5‐year consecutive intervals was analysed. It has been concluded that extreme wet months were more frequent than extreme dry months over the entire country, especially in the northern and southeastern part. 相似文献
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A non-traditional fuzzy quantification method is presented in the modeling of an extreme significant wave height. First, a set of parametric models are selected to fit time series data for the significant wave height and the extrapolation for extremes are obtained based on high quantile estimations. The quality of these results is compared and discussed. Then, the proposed fuzzy model, which combines Poisson process and generalized Pareto distribution(GPD) model, is applied to characterizing the wave extremes in the time series data. The estimations for a long-term return value are considered as time-varying as a threshold is regarded as non-stationary. The estimated intervals coupled with the fuzzy theory are then introduced to construct the probability bounds for the return values. This nontraditional model is analyzed in comparison with the traditional model in the degree of conservatism for the long-term estimate. The impact on the fuzzy bounds of extreme estimations from the non stationary effect in the proposed model is also investigated. 相似文献
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Statistical analysis of the extreme values of the Baltic Sea level has been performed for a series of observations for 15–125 years at 13 tide gauge stations. It is shown that the empirical relation between value of extreme sea level rises or ebbs (caused by storm events) and its return period in the Baltic Sea can be well approximated by the Gumbel probability distribution. The maximum values of extreme floods/ebbs of the 100-year recurrence were observed in the Gulf of Finland and the Gulf of Riga. The two longest data series, observed in Stockholm and Vyborg over 125 years, have shown a significant deviation from the Gumbel distribution for the rarest events. Statistical analysis of the hourly sea level data series reveals some asymmetry in the variability of the Baltic Sea level. The probability of rises proved higher than that of ebbs. As for the magnitude of the 100-year recurrence surge, it considerably exceeded the magnitude of ebbs almost everywhere. This asymmetry effect can be attributed to the influence of low atmospheric pressure during storms. A statistical study of extreme values has also been applied to sea level series for Narva over the period of 1994–2000, which were simulated by the ROMS numerical model. Comparisons of the “simulated” and “observed” extreme sea level distributions show that the model reproduces quite satisfactorily extreme floods of “moderate” magnitude; however, it underestimates sea level changes for the most powerful storm surges. 相似文献
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Human presence, coastal erosion, and tourism activities are increasing the attention to coastal flooding risk. To perform risk assessments, long time series of observed or hindcast wave parameters and tide levels are then necessary. In some cases, only a few years of observation are available, so that observed extreme data are not always representative and reliable. A hindcast system aimed to reconstruct long time series of total tide levels may be of great help to perform robust extreme events analysis and then to protect human life, activities as well as to counteract coastal erosion by means of risk assessments. This work aims to propose a simplified method to hindcast storm surge levels time series in semi-enclosed basins with low computational costs. The method is an extension of a previous work of some of the authors and consists of a mixed approach in which the estimation of storm surge obtained by using the theory of linear dynamic system is corrected by using a statistical method. Both steps are characterized by low computational costs. Nevertheless, the results may be considered reliable enough also in view of the simplicity of the approach. The proposed method has been applied to the Manfredonia case study, a small village located in the Southern Adriatic Italian coast and often prone to coastal flooding events. The comparison of extreme events estimated on the basis of hindcast levels time series is satisfactorily similar to those estimated on the basis of observed tide series. 相似文献
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《Applied Ocean Research》2004,26(1-2):35-48
We present a statistical analysis of some of the largest waves occurring during 793 h of surface elevation measurements collected during 14 severe storms in the North Sea. This data contains 104 freak waves. It is found that the probability of occurrence of freak waves is only weekly dependent on the significant wave height, significant wave steepness and spectral bandwidth. The probability does show a slightly stronger dependency on the skew and kurtosis of the surface elevation data, but on removing the contribution to these measures from the presence of the freakwaves themselves, this dependency largely disappears.Distributions of extreme waves are modelled by fitting Generalised Pareto distributions, and extreme value distributions and return periods are given for freak waves in terms of the empirical fitted parameters. It is shown by comparison with these fits that both the Rayleigh distribution and the fit of Nerzic and Prevosto severely under-predict the probability of occurrence of extreme waves. For the most extreme freak wave in our data, the Rayleigh distribution over-predicts the return period by about 300 times when compared to the fitted model. 相似文献
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Slamming pressures are predicted using a nonlinear ship motion program whose input is an ensemble of short wave trains tailored to produce a large, linear pitch response. These short wave trains are calculated via a design methodology that first creates short time series containing a specified, large ship response and then back-calculates the incident wave trains using linear systems theory. The background simulations and theory used to create these short time series are presented here. Monte Carlo simulation of moderately rare events of a random process indicate the random Fourier component phase PDFs are non-uniform, non-identically distributed, and dependent on the rarity of the target event. These PDFs are modeled using a single parameter, Modified Gaussian distribution and used to generate design time series with a given expected value at a specific time. To predict rare events without resorting to Monte Carlo simulation, the parameters of the Modified Gaussian distributions are calculated via characteristic function comparison. The characteristic functions compare a target PDF calculated from extreme value theory to a PDF based on a discrete Fourier representation of the stochastic process with non-uniform component phases. The comparison to extreme value theory helps to quantify the risk associated with rare events. 相似文献
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基于辽东东探区1966—2007年出现的76次温带气旋减水过程,对10个工程地点抽取了10个统计样本。考虑每年温带气旋出现频次的影响,使用泊松最大熵分布对其进行减水的长期统计分析。得到100年一遇和50年一遇最大幅度的减水重现值分别为304和286cm。由于受地形的影响,北部海域的减水幅度大于南部区域。 相似文献
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文章以山东省警戒潮位核定为基础,对其沿岸验潮站的实测数据情况进行分类;根据不同类别,分别采用相关分析、数值模拟等方法补充实测数据,获得年极值水位序列,并采用极值Ⅰ型方法计算重现期高潮位。在警戒潮位核定中建立年极值水位序列所使用方法的顺序是,有实测数据优先采用实测数据、没有实测数据利用相关关系、没有相关关系再使用数值模拟和调和分析的方法进行。值得注意的是,在使用相关关系建立年极值水位序列中,计算重现期高潮位时一定要满足潮汐性质相同、所受风暴潮过程相似等条件;在使用数值模拟建立年极值水位序列中,须与其全年天文潮最大值进行对比。 相似文献