香鱼(Plecoglossus altivelis)脾脏酪氨酸激酶SYK的鉴定及其介导的MAPK信号通路研究     

孙娇  聂力  苗亮  陈炯 《海洋与湖沼》2020,51(5):1182-1193

脾脏酪氨酸激酶(SYK)是一种非受体型酪氨酸激酶(non-receptor tyrosine kinase, NRTK)。在哺乳动物中,SYK是重要的细胞信号通路接头分子,其在免疫细胞活化,胞外刺激的信号转导和病原体识别等多种生命过程中扮演重要角色,然而在鱼类中却鲜有报道。本研究以香鱼(Plecoglossus altivelis)为研究对象,探讨了其SYK(PaSYK)在应对病原微生物感染及在活化免疫信号通路中的作用。我们克隆获得了香鱼SYK的cDNA序列,并利用多重序列比对、构建进化树等生物信息学方法分析PaSYK的进化地位;采用实时荧光定量PCR(RT-qPCR)方法分析PaSYK在健康组织及鳗弧菌(Vibrio anguillarum)感染后的表达变化;亚细胞定位检测PaSYK在HEK293T细胞的分布情况;在香鱼头肾单核/巨噬细胞(Monocyte/macrophage,MO/MΦ)中过表达PaSYK,研究其对炎症细胞因子表达的调控作用并在HEK293T细胞及香鱼头肾MO/MΦ中研究PaSYK对MAPK信号通路的活化作用。多重序列比对结果显示,SYK的蛋白质序列和结构域在进化过程中是高度保守的。系统进化树结果表明, PaSYK与河鳟的亲缘关系密切。RT-qPCR结果表明, SYK基因mRNA在检测的所有组织中均有表达,鳗弧菌感染后免疫相关组织中PaSYK表达量均上调。此外,PaSYK能显著诱导香鱼头肾MO/MΦ中促炎因子TNF-α和IL-1β的表达,但对抑炎因子TGF-β和IL-10的表达起到略微的抑制作用。Western blot结果证明PaSYK可以激活MAPK信号通路。综上所述, SYK分子在进化上高度保守,香鱼SYK与其哺乳动物中的同源物具有保守的功能,均能活化MAPK信号通路并在炎症反应中发挥作用。  相似文献   

中国沿海小黄鱼种群动力学及其空间异质性研究     

麻秋云  焦燕  任一平  薛莹 《海洋学报(英文版)》2020,39(10):107-119

小黄鱼是我国近海四种最重要的经济鱼类之一，在过去的几十年中小黄鱼种群及其两个地理亚种群经历了巨大的变化。小黄鱼的种群动力学研究，对于维持这一重要渔业的可持续管理是至关重要的。目前仅有的两个小黄鱼种群动力学模型只涵盖了较短的时间，且没有关注其空间差异。本文研究了1968年至2015年间黄渤海和东海小黄鱼的种群动力学模型，包含和不包含空间分层结构的两种贝叶斯模型被用于分析其种群动力学的大尺度空间异质性。本文分析了不同的假设，来研究小黄鱼种群动力学潜在的变化趋势。研究结果表明小黄鱼种群动力学特征具有明显的时间和空间变化。种群的增长速度从20世纪八十年代开始增加，而可捕系数从1981年到2015年增加了两倍多。与黄渤海亚种群相比，东海的小黄鱼亚种群生长速度更快，遭受的捕捞压力也更大。基于最大可持续产量MSY的参考点表明，无论是整个小黄鱼种群还是两个亚种群，近年来都有非常高的过度捕捞风险。因此我国小黄鱼的渔业管理急需更加保守的管理策略，同时考虑其地域差异。本文所用的方法可以应用于其他种类的资源评估和渔业管理，尤其是具有空间异质性和数据有限的种类。  相似文献   

A two‐dimensional coupled hydromechanical discontinuum model for simulating rock hydraulic fracturing          下载免费PDF全文

Yu‐Yong Jiao  Huan‐Qiang Zhang  Xiu‐Li Zhang  Hai‐Bo Li  Qing‐Hui Jiang 《国际地质力学数值与分析法杂志》2015,39(5):457-481

Within the framework of our discontinuous deformation analysis for rock failure algorithm, this paper presents a two‐dimensional coupled hydromechanical discontinuum model for simulating the rock hydraulic fracturing process. In the proposed approach, based on the generated joint network, the calculation of fluid mechanics is performed first to obtain the seepage pressure near the tips of existing cracks, and then the fluid pressure is treated as linearly distributed loads on corresponding block boundaries. The contribution of the hydraulic pressure to the initiation/propagation of the cracks is considered by adding the components of these blocks into the force matrix of the global equilibrium equation. Finally, failure criteria are applied at the crack tips to determine the occurrence of cracking events. Several verification examples are simulated, and the results show that this newly proposed numerical model can simulate the hydraulic fracturing process correctly and effectively. Although the numerical and experimental verifications focus on one unique preexisting crack, because of the capability of discontinuous deformation analysis in simulating block‐like structures, the proposed approach is capable of modeling rock hydraulic fracturing processes. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Simulation of site-scale water fluxes in desert and natural oasis ecosystems of the arid region in Northwest China     

Mingjuan Xie  Geping Luo  Olaf Hellwich  Amaury Frankl  Wenqiang Zhang  Chunbo Chen  Chen Zhang  Philippe De Maeyer 《水文研究》2021,35(12):e14444

The study of water fluxes is important to better understand hydrological cycles in arid regions. Data-driven machine learning models have been recently applied to water flux simulation. Previous studies have built site-scale simulation models of water fluxes for individual sites separately, requiring a large amount of data from each site and significant computation time. For arid areas, there is no consensus as to the optimal model and variable selection method to simulate water fluxes. Using data from seven flux observation sites in the arid region of Northwest China, this study compared the performance of random forest (RF), support vector machine (SVM), back propagation neural network (BPNN), and multiple linear regression (MLR) models in simulating water fluxes. Additionally, the study investigated inter-annual and seasonal variation in water fluxes and the dominant drivers of this variation at different sites. A universal simulation model for water flux was built using the RF approach and key variables as determined by MLR, incorporating data from all sites. Model performance of the SVM algorithm (R² = 0.25–0.90) was slightly worse than that of the RF algorithm (R² = 0.41–0.91); the BPNN algorithm performed poorly in most cases (R² = 0.15–0.88). Similarly, the MLR results were limited and unreliable (R² = 0.00–0.66). Using the universal RF model, annual water fluxes were found to be much higher than the precipitation received at each site, and natural oases showed higher fluxes than desert ecosystems. Water fluxes were highest during the growing season (May–September) and lowest during the non-growing season (October–April). Furthermore, the dominant drivers of water flux variation were various among different sites, but the normalized difference vegetation index (NDVI), soil moisture and soil temperature were important at most sites. This study provides useful insights for simulating water fluxes in desert and oasis ecosystems, understanding patterns of variation and the underlying mechanisms. Besides, these results can make a contribution as the decision-making basis to the water management in desert and oasis ecosystems.  相似文献   

渝东南下古生界页岩构造裂缝形成及分布控制因素          下载免费PDF全文

岳锋  程礼军  焦伟伟  王飞 《地质科学》2016,(4):1090-1100

天然裂缝对页岩气储集和渗流有重要影响,但目前对页岩构造裂缝研究不够深入。本文通过露头、岩心裂缝观察和分析,探讨了渝东南下古生界页岩构造裂缝类型、形成机理及分布控制因素。基于裂缝特征及力学成因,将剪切裂缝分为高角度剪切裂缝、倾斜滑脱裂缝和水平滑脱裂缝。倾斜滑脱裂缝是在上覆岩层重力和水平构造应力共同作用下沿应力集中的软弱面发生剪切滑动形成,水平滑脱裂缝是在构造挤压应力作用条件下主要沿页理面方向的剪切或层间滑动形成;页理发育程度及岩层曲率是控制水平滑脱裂缝形成的关键因素,岩石矿物组成、构造作用及岩层厚度是控制其它类型构造裂缝形成和分布的主要因素,页岩岩石力学层的划分需要根据裂缝特征、岩性变化特征、岩石力学参数及沉积界面等综合确定,岩层厚度与层间构造裂缝密度呈负相关关系。  相似文献   

利用尺度空间及多角度地形断面提取山谷山脊线     

林铁  张翰超  金姣 《测绘通报》2016,(2):97-99

从数字高程模型中自动提取山脊线和山谷线,在测绘领域有着重要的意义。地形断面高程极值法是其中一种常用的方法,但此方法在提取过程中容易产生遗漏。针对此缺点,本文提出了基于尺度空间及多角度判断的地形断面高程极值法,主要步骤是构建影像金字塔,然后从上到下逐级提取并加密。试验验证了该方法的有效性,提取得到的山谷线或山脊线较为完整,并与实际地形相符合。  相似文献   

多元时间序列分析的滑坡演化阶段划分          下载免费PDF全文

罗文强  李飞翱  刘小珊  黄丽 《地球科学》2016,41(4):711-717

滑坡的时间-位移曲线一般具有3个阶段特征,即初始变形阶段、等速变形阶段和加速变形阶段,不同演化阶段加速度具有不同的变化特点.目前往往是依据对加速度曲线特征的分析来人为划分演化阶段,缺少相应的理论支持和定量计算.针对上述问题,选取月降雨量、月库水位高程变化量对滑坡的累计位移建立多因素的时间序列预测模型.然后利用Chow分割点检验理论,以所建模型中F和LR统计量最大值点作为分割点对滑坡演化阶段进行划分.以新滩滑坡和三峡库区白水河滑坡为例,利用累计位移、降雨及库水位变化数据进行计算验证.结果表明,对多元时间序列模型进行Chow分割点检验可对滑坡的演化阶段进行准确划分,为滑坡的临滑预警预报提供重要判据.   相似文献   

云南建水腊里河超基性岩地质特征及其构造意义          下载免费PDF全文

刘娇  周洋  郭宏杰  熊昕  李德威 《贵州地质》2016,33(3):178-186

川滇黔等地在二叠世晚期发生峨眉山玄武岩短期内大规模溢流喷发。滇西地区发育的镁铁—超镁铁质岩均被认为是峨眉山大火成岩省的产物,但在滇东地区却一直缺少该类岩石组合的报道。本文在滇东建水地区首次发现了腊里河超基性岩体,通过LA-ICP-MS锆石UPb定年分析表明该超基性岩先期形成年龄为(246±5.2)Ma,为晚二叠-早三叠世的产物,后期中侏罗世晚期(169.6±2.0)Ma(MSWD=3.5)发生岩浆活化。该超基性岩Mg#值平均为78.73,稀土元素表现出略微右倾的平坦型特征,Rb、Sr、Ba、Pb等大离子亲石元素相对富集,高场强元素Zr、Hf相对亏损,Ta异常富集。其地化特征表现出富集型地幔源区特征,与峨眉山玄武岩成因关系密切。晚二叠世建水地区由于地幔柱活动形成地表溢流玄武岩,在深部岩浆房由玄武质岩浆结晶分异作用形成超基性侵入岩,到中侏罗世晚期,伴随着华南地区发生多期次构造运动,先前存在于岩浆房中的超镁铁质岩经过后期热液改造活化,沿着断层裂隙侵入地表。  相似文献   

云南建水煌斑岩年代学和地球化学及其构造意义          下载免费PDF全文

刘娇  周洋  谢德根  纪星星  李德威 《中国地质》2016,(6):1977-1991

华南大陆内部燕山期的岩浆事件可分为2期:燕山早期180~150 Ma,燕山晚期140~80 Ma。而处于扬子板块西南缘的滇黔贵等地,仅见有第二期晚白垩世中酸性侵入岩与相关成矿作用,缺乏第一期岩浆活动的时间记录。本文在滇东建水地区首次发现了麦地村煌斑岩,对其进行高精度LA-ICP-MS锆石U-Pb定年和主微量元素测试分析。结果显示煌斑岩的锆石U-Pb年龄为(158.4±2.4)Ma(MSWD=4.2),为晚侏罗世的产物,补充了该区较为空白的第一期岩浆热事件。麦地村煌斑岩不相容元素明显高于原始地幔,表现出不同程度的富集,大离子亲石元素Rb、Ba、Ce等富集程度不明显,高场强元素中U、Ta、Pb等表现出一定程度富集,LREE相对富集,HREE相对亏损,不具有Nb-Ta-Ti负异常的俯冲型配分曲线特征,具有明显的OIB型洋岛玄武岩稀土元素配分特征,为板内伸展环境下的产物。滇东地区发育中生代时期的NNE构造,早期NNE向褶皱叠加有后期同方向正断层。早期褶皱表现为SEE-NWW挤压应力作用下的构造特征,后期断层表现出同方向张应力作用下的特征。煌斑岩正是由于该区发生挤压之后伴随着一期应力松弛调整,伸展减压作用诱发地幔物质部分融熔,来自于深处的软流圈地幔流体与岩石圈地幔发生交代作用,形成富集型地幔,交代富集的岩石圈地幔局部受热、部分熔融,发生上升侵位。煌斑岩的侵位时间即是滇东地区中生代从挤压向伸展转换的起始时间。  相似文献   

Paratacamite from Gypsum Veins in Sandstones of the Kuqa Basin,Xinjiang, China: Implications for a New Epigenetic Cu Enrichment Mechanism          下载免费PDF全文

Yangtong Cao  Chenglin Liu  Pengcheng Jiao  Chunlian Wang 《Resource Geology》2016,66(2):114-126

The Kuqa Basin filled with Paleogene evaporite series is located in the northeast of the Tarim Basin, Xinjiang, China. It is famous for sandstone‐hosted Cu deposits formed by synsedimentary processes. However, our recent studies reveal that there has been another Cu mineralization mechanism in this basin. Field investigations show that there is a close relationship among faults, salt domes, and brine. Cu deposits are mainly located in two east–west‐trending anticlinal belts in the basin, adjacent to salt domes in the belts. Cu minerals in gypsum veins of the Jidike and Kangcun formations have been investigated by SEM, EDS, and X‐ray diffraction methods. The occurrence of paratacamite in gypsum veins has been reported to coexist with glauberite and halite in the joint planes of sandstones. In addition, it occurs accompanying residual crystal salt encrustation in limestone fractures, or in sandstones in dendritic form. These features indicate that the surface‐Cu enrichment in the Kuqa Basin might have originated from Cu‐bearing brine in the underlying evaporite units, which migrated upward along fractures. In addition, the presence of H₂S in the east–west fault belt in the Kuqa Basin, and the discovery of surface sulfur, calcium carbonate, and covellite, suggest thermochemical sulfate reduction near salt domes in the deeper parts of the rock units. This process resulted in the generation of reduced brine and provided a favorable environment for Cu enrichment. Therefore, the surface‐Cu mineralization near salt domes is interpreted to be the result of Cu‐bearing brine migrating upward to the surface along faults (or joints) following the intrusion of deep salt domes. The geological evidence indicates the presence of reducing brine and Cu‐bearing brine near the salt dome in the deeper rocks of the Kuqa Basin, thus making the intrusive contact zone of the salt dome a favorable site for the epigenetic enrichment of Cu. Our study demonstrates that Cu enrichment in the Kuqa Basin resulted not only from synsedimentary deposition but also through epigenetic enrichment associated with salt dome intrusion and brine‐rich fluids.  相似文献