瓦氏黄颡鱼(Pelteobagrus vachellii)Toll样受体2(TLR2)基因克隆及免疫功能

为探究Toll样受体2(Toll-like receptor 2,TLR2)及下游免疫分子对瓦氏黄颡鱼(Pelteobagrus vachellii)机体的保护作用,本研究采用RT-PCR及RACE法获得瓦氏黄颡鱼TLR2全长c DNA(2611bp),编码789个氨基酸残基,含有10个富含亮氨酸的重复序列(Leucine Rich Repeat,LRR)和Toll/IL-1R(Toll/IL-1 Receptor Domain,TIR)同源区结构域,属I型跨膜受体。序列同源性比对发现,瓦氏黄颡鱼TLR2 c DNA与斑点叉尾、鲤及虹鳟的同源性分别为78%、62%及49%。系统进化树分析表明,瓦氏黄颡鱼TLR2与斑点叉尾聚为一支。q RT-PCR分析表明,TLR2 m RNA在检测的组织中均有表达,且在头肾和脾脏中表达水平显著高于其他组织(P0.05)。嗜水气单胞菌感染能显著上调瓦氏黄颡鱼肝脏、头肾及脾脏中TLR2 m RNA表达(P0.05),分别在24h、48h及12h达到最大值。头肾中的TLR 2信号通路下游的髓样分化因子、半胱氨酸蛋白酶8、核转录因子kappa B、肿瘤坏死因子α、白细胞介素1βm RNA均显著上升(P0.05),分别在24h、12h、48h,48h和48h达到最大值。结果表明,嗜水气单胞菌感染激活了TLR2信号通路,通过上调表达,肿瘤坏死因子α,白细胞介素1β等。本研究表明,TLR2在瓦氏黄颡鱼抵御嗜水气单胞菌侵染的过程中发挥了重要的免疫作用。     

浙江朱家尖岛东沙海滩对热带风暴“娜基莉”的响应及风暴后的恢复

海滩对风暴的响应及风暴后海滩的恢复过程一直以来都是国内外海滩研究的热点。本文通过对浙江舟山市朱家尖岛东沙海滩地形地貌的现场调查,对比分析了热带风暴"娜基莉"影响下东沙海滩剖面的蚀积变化,探讨了海滩在热带风暴发生后的恢复情况。结果表明,在"娜基莉"影响期间,因风暴浪为向岸浪,东沙海滩几乎遭受全线侵蚀,12个剖面单宽侵蚀总量为73.46 m3/m,其中海滩直线段较两个遮蔽段侵蚀显著。由于海滩在风暴前进方向的左侧,且"娜基莉"距东沙较远,使得东沙海滩普遍侵蚀但强度较小。东沙海滩在热带风暴后的恢复过程中,不同部位的地貌调整和冲淤变化不同,下岬角遮蔽段基本趋于稳定,直线段和上岬角遮蔽段在恢复过程中因受海滩季节性调整的影响呈现持续侵蚀。     

青岛沿海24种鱼类耳石秤量特征与鱼体大小关系

研究中经常会用测量耳石称量特征推算饵料鱼类的形态参数,而青岛沿海鱼类相关的研究较少,因此作者根据2015年3、5、8月3个航次在青岛近海的拖网调查数据,分析了捕获的24种共1002尾鱼的耳石秤量特征(耳石长、耳石宽和耳石质量)和鱼体大小(体长、体质量)的关系。结果表明,渔获24种鱼类分属5个目、14个科、24种鱼类的体长体质量呈显著幂函数相关,相关系数R~2的范围为0.779～0.997,幂指数b的范围为2.376～3.591,平均值为3.048±0.327,其中黄鲫(Setipinna taty)等11种鱼类的b值均大于3(P0.05),为正异速生长,其余13种鱼类的b值小于3(P0.05),呈负异速增长。耳石宽-鱼体长的相关性比耳石长-鱼体长的相关性要好,仅有3种鱼(饰鳍斜棘鱼衔(Repomucenus ornatipinnis)、矛尾虾虎鱼(Chaeturichthys stigmatias)和焦氏舌鳎Cynoglossus lighti)未呈现显著相关关系。在耳石质量-鱼体质量的相关关系中,9种鱼(如皮氏叫姑(Johnius belengerii)、扁斜棘?(Repomucenus planus)、石鲽(Kareius bicoloratus)呈显著相关(只是列举了一部分), 5种鱼(锦鳚(Pholis nebulosus)、矛尾虾虎鱼(Chaeturichthys stigmatias)、斑尾刺虾虎鱼(Synechogobius ommaturus)、焦氏舌鳎(Cynoglossus lighti))在现有样品情况下未呈现显著相关关系。     

光裸方格星虫增养殖对滩涂底质的影响

基于2016年春、秋两个季节的现场实验数据, 研究光裸方格星虫(Sipunculus nudus Linnaeus)滩涂增养殖对滩涂底质的影响。实验对方格星虫单养区(S组)、方格星虫-贝类混养区(P组)和无星虫对照区(C组)进行了有机质、粒径组成、氧化还原电位(ORP)等指标测定, 结果表明: 1) 秋季S组20~30cm层次有机质含量和细沙比例均显著高于春季, 而C组仅表层物质有所增加, 表明方格星虫具有较强的表层物质迁移能力, 且其迁移深度为20~30cm。2) 秋季C组各层氧化还原电位值(ORP)均无明显降低趋势, 而S组仅10~20cm层次有一定程度降低, 表明方格星虫增养殖并不会明显降低滩涂底质状况。3) P组各层有机质以及细沙含量增加, 表明皱肋文蛤的过滤沉积作用可以提高滩涂颗粒物质的积累, 且方格星虫混养会加速颗粒物质的向下迁移; P组皱肋文蛤的栖息层次(0~3cm、3~10cm) ORP明显低于S组(p<0.05), 表明高密度的皱肋文蛤代谢活动会加剧0~10cm的底质恶化。4) 方格星虫与皱肋文蛤具有生态互补作用, 在同一区域进行增养殖可以提高滩涂物质利用率及碳汇功能; 方格星虫扰动引入富氧水可以缓解皱肋文蛤栖息层次的底质。     

Numerical study of sand scour with a modified Eulerian model based on incipient motion theory

Application of the standard Eulerian model to simulations of sand scour results in unrealistic phenomena. Therefore, the present work develops a modified Eulerian model based on sand incipient motion theory. The modified model is applied for simulating a two-dimensional single vertical jet and a moving planar jet. The simulation results generally demonstrate fairly good agreement with published results of scour profiles and the velocity contours of the water and sand phases. In addition, equations to describe self-similar scour profiles for the moving planar jet cases are given. The results demonstrate that the modified model efficiently and accurately simulates the two-dimensional sand scour produced by jets, particularly for the moving jet cases.     

绝对重力仪的自由落体凸轮驱动器设计与仿真

提出一种适合绝对重力仪的凸轮驱动器设计方法,研究了具体运动过程,基于自由落体运动得到凸轮驱动器的运动曲线,并采用SolidWorks进行仿真验证。结果表明,该设计方法可以解决绝对重力仪的自由落体凸轮驱动器设计实现问题。     

Effects of Anthropogenic Disturbance on Sediment Organic Carbon Mineralization Under Different Water Conditions in Coastal Wetland of a Subtropical Estuary

The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to investigate the effects of anthropogenic disturbance(aquaculture pond, pollutant discharge and agricultural activity) on soil organic C mineralization under different water conditions in the Minjiang River estuary wetland, Southeast China. The results showed that the organic C mineralization in the wetland soils was significantly affected by human disturbance and water conditions(P 0.001), and the interaction between human disturbance activities and water conditions was also significant(P 0.01). The C mineralization rate and the cumulative mineralized carbon dioxide-carbon(CO_2-C)(at the 49th day) ranked from highest to lowest as follows: Phragmites australis wetland soil aquaculture pond sediment soil near the discharge outlet rice paddy soil. This indicated that human disturbance inhibited the mineralization of C in soils of the Minjiang River estuary wetland, and the inhibition increased with the intensity of human disturbance. The data for cumulative mineralized CO_2-C showed a good fit(R~2 0.91) to the first-order kinetic model C_t = C_0(1 – exp(–kt)). The kinetic parameters C_0, k and C_0 k were significantly affected by human disturbance and water conditions. In addition, the total amount of mineralized C(in 49 d) was positively related to C_0, C_0 k and electrical conductivity of soils. These findings indicated that anthropogenic disturbance suppressed the organic C mineralization potential in subtropical coastal wetland soils, and changes of water pattern as affected by human activities in the future would have a strong influence on C cycling in the subtropical estuarine wetlands.     

Effects of feeding time on complement component C7 expression in Pelteobagrus vachellii subject to bacterial challenge

Journal of Oceanology and Limnology - Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may affect immune-related...     

Regional Characteristics and Causes of Haze Events in Northeast China

Northeast China experiences severe atmospheric pollution, with an increasing occurrence of heavy haze episodes. However, the underlying forces driving haze formation during different seasons are poorly understood. In this study, we explored the spatio-temporal characteristics and causes of haze events in Northeast China by combining a range of data sources(i.e., ground monitoring, satellite-based products, and meteorological products). It was found that the ‘Shenyang-Changchun-Harbin(SCH)'city belt was the most polluted area in the region on an annual scale. The spatial distribution of air quality index(AQI) values had a clear seasonality, with the worst pollution occurring in winter, an approximately oval-shaped polluted area around western Jilin Province in spring, and the best air quality occurring in summer and most of the autumn. The three periods that typically experienced intense haze events were Period I from mid-October to mid-November(i.e., late autumn and early winter), Period II from late-December to February(i.e., the coldest time in winter), and Period III from April to mid-May(i.e., spring). During Period I, strong PM_(2.5) emissions from seasonal crop residue burning and coal burning for winter heating were the dominant reasons for the occurrence of extreme haze events(AQI 300). Period II had frequent heavy haze events(200 AQI 300) in the coldest months of January and February, which were due to high PM_(2.5) emissions from coal burning and vehicle fuel consumption, a lower atmospheric boundary layer, and stagnant atmospheric conditions. Haze events in Period III, with high PM_(10) concentrations, were primarily caused by the regional transportation of windblown dust from degraded grassland in central Inner Mongolia and bare soil in western Jilin Province. Local agricultural tilling could also release PM_(10) and enhance the levels of windblown dust from tilled soil. Better control of coal burning, fuel consumption, and crop residue burning in winter and autumn is urgently needed to address the haze problem in Northeast China.