鱼类血栓细胞免疫功能的研究现状     

高迎莉  韩高尚  姚海静  陈香凝  周谦青 《海洋科学》2021,45(1):120-128

血细胞研究是鱼类基础研究的重中之重。鱼类血细胞的前期研究主要聚焦于淋巴细胞、巨噬细胞和嗜中性粒细胞等细胞的功能特性,而忽略了血栓细胞。血栓细胞是低等脊椎动物具有的类似于哺乳动物血小板的一类细胞,该细胞的经典功能是参与凝血和血栓形成。近年来的研究表明,血栓细胞是一类特殊的免疫细胞,在鱼体免疫应答中发挥重要作用。作者将对鱼类血栓细胞免疫功能相关的形态学、免疫学功能和研究前景等内容进行综述,为鱼类血栓细胞功能的多样性提供基础资料。  相似文献   

海南省4种江蓠属(红藻门)海藻的形态分类学研究     

李永梅  刘瑞  杨楠  丁兰平  黄冰心  王艺晓  陈彦伟 《热带海洋学报》2018,37(4):29-37

利用形态学和解剖学方法, 对采自海南省东南和西南沿海的大型海洋红藻江蓠属(Gracilaria)进行了分类学研究。经鉴定, 共发现4个物种, 即凤尾菜G. eucheumoides、芋根江蓠G. blodgettii、缢江蓠G. salicornia和刺边江蓠G. spinulosa。文章对此4种江蓠的内、外部形态特征进行了较详细描述与介绍。结合生物冷冻切片技术, 获得了各个物种的比较清晰的解剖学特征图片。其中, 缢江蓠藻体表面瘤状突出物, 与其他文献报道的同体蓠生藻Gracilariophila deformans Weber-van Bosse相一致。  相似文献   

Advances in the Effects of Wind on Plants     

Zhang Linlin  Zhao Xiaoying  Yuan Hui 《地球科学进展》2013,28(12):1349-1353

Wind is a important factor. It can strongly affect development, growth and reproduction of terrestrial plants. The plant in wind environment can adapt to wind by special mechanism to decrease damage. This paper reviews the effects of wind on plant in phenotype, anatomy and root archetecture. Some plant species show a resistance strategy, but other species show an avoidance strategy. After the analysis of the restriction of current research in this area, the authors suggest that studies in the area should be extended to taking the whole plant as an integrated system rather than focusing on specific tissue level. Furthermore to understand the general mechanism across species, it is required to study different species from different environmental conditions. Advances in bioinformatics, molecular and physiological research will facilitate cross disciplinary studies to understand the complicated responses of plants to wind.  相似文献   

Alien cyanobacteria Anabaena bergii var. limnetica Couté et Preisig from Lithuania: Some aspects of taxonomy, ecology and distribution     

Judita Koreivien?  Jūrat? Kasperovi?ien? 《Limnologica》2011,41(4):325-333

The anthropogenic eutrophication of surface waters and the global climate warming promoted some bloom-forming tropical cyanobacteria, including Anabaena, distribution northwards. Anabaena bergii var. limnetica was for the first time recorded in Lithuania from the hypertrophic Lake Gineitišk?s in 2008. It developed when the water temperature reached its annual maximum (July–August); its highest biomass (0.26 mg L⁻¹) was reached at the end of July. Akinetes formation started in the middle of August. The morphological variability of A. bergii var. limnetica morphospecies is presented. The morphological, ecological differences and distribution of A. bergii var. limnetica and the related morphospecies A. bergii, A. bergii f. minor, Anabaena minderi are discussed.  相似文献   

粤东地区江蓠属Gracilaria(江蓠科,红藻门)的形态分类学   总被引：1，自引：0，他引：1       下载免费PDF全文

丁兰平  谭华强  孙国栋  梁冰冰  黄冰心 《热带海洋学报》2014,33(4):33-39

在2011~2013年间对粤东地区进行了20余次野外大型海藻资源调查,采集了大量标本。利用形态特征,对部分标本进行了分类学研究。经鉴定,标本中包含江蓠属5个种及变种,即芋根江蓠Gracilaria blodgettii Harvey、异枝江蓠G.bailinae Chang et Xia、细基江蓠G.tenuistipitata Chang et Xia、细基江蓠繁枝变种G.tenuistipitata var.liui Zhang et Xia、长喙江蓠G.longirostris Zhang et Wang。它们的主要鉴定特征分别为:芋根江蓠的分枝基部明显缢缩;异枝江蓠的藻体暗绿色,初级分枝围绕主轴互生、偏生或叉分;细基江蓠的藻体主轴基部纤细,分枝简单;细基江蓠繁枝变种的藻体纤细,分枝繁多;长喙江蓠的囊果具有明显的长喙状突起。其中,芋根江蓠和异枝江蓠在粤东地区属首次报道,文章对其进行了较详细的介绍。该研究结果丰富了粤东江蓠属的物种多样性,为粤东地区江蓠属物种资源的保护和利用提供了分类学依据。  相似文献   

Platyceratid gastropod infestations of Neoplatycrinus Wanner (Crinoidea) from the Permian of West Timor: speculations on thecal modifications     

Stephen K. Donovan  Gary D. Webster 《Proceedings of the Geologists' Association. Geologists' Association》2013

Distinctive trace fossils, indicating the infestation of the monobathrid camerate crinoid Neoplatycrinus Wanner by coprophagous platyceratid gastropods, are recognised for the first time from the Permian of West Timor. Platyceratid shells from West Timor have previously been reported preserved on or about the crinoid tegmen, that is, apically; in contrast, the trace fossils described herein occur in the CD interray (=posteriorly), mainly on the radials. There are two patterns of infestation in the CD interray. Circular grooves in this position, situated below the periproct, are referred to Lacrimichnus isp. Thecal modifications include the CD interray sloping towards the base, and incomplete curved ridges developed outside the circular groove and confined to the radials. A different morphology is shown by other specimens that have a broad, flattened CD interray, curving down to and extending onto the basals; this interray also slopes towards the base. These unusual CD interray modifications are interpreted as a product of snail/crinoid associations. We speculate that the major modifications to the theca may have permitted the platyceratid shell to mimic an uninfested CD interray and thus maintain the hydrodynamic integrity of the crown. This would have been to the advantage of both gastropod and crinoid. The camerates did not survive the P/Tr extinction; their demise ended an association that had persisted over 200 million years, although the platyceratids persisted into the Mesozoic.  相似文献   

不同降维策略下的高光谱影像多特征分类     

杨帆  余旭初  杨其淼  谭熊 《测绘与空间地理信息》2021,44(1):38-42

由于物体表面的空间分布通常是富有规律且局部连续的,在高光谱影像分类中应充分利用其光谱和空间信息。本文在对高光谱影像立方体进行降维处理的基础上,提出了一种联合空域和谱域信息的高光谱影像高效分类方法。首先,分别选用主成分分析(Principal Component Analysis,PCA)和正交投影波段选择(Orthogonal Projection Band Selection,OPBS)两种方法对原始高光谱数据进行预处理,获取降维后的影像数据。然后在其基础上提取扩展形态学特征(Extended Morphology Profiles,EMP)和地物表面纹理特征,组成联合光谱和纹理、形状结构特征。最后,采用支持向量机(Support Vector Machine,SVM)分类器对联合特征进行分类。针对不同真实高光谱数据集的实验结果表明,本文提出的方法运算效率高且具有令人满意的分类性能。  相似文献   

盐度胁迫下点带石斑鱼(Epinephelus malabaricus) 胚胎及卵黄囊仔鱼的形态变化   总被引：4，自引：0，他引：4       下载免费PDF全文

施兆鸿  陈波  彭士明  陈超  王建钢  傅荣兵  柳敏海 《海洋与湖沼》2008,39(3):222-227

将点带石斑鱼的受精卵置于不同盐度的水体中,观察受盐度胁迫下点带石斑鱼胚胎的沉浮 情况、卵径、油球径、孵化率、畸形率,以及卵黄囊仔鱼的形态变化和营养物质的消耗状况.结果 表明,点带石斑鱼受精卵在盐度25(含25)以下的水体中为沉性,在盐度35(含35)以上的海水中全部 漂浮于水表层,在盐度30和对照组31的水体中大部分胚胎浮在水上层.受精卵卵径随孵化盐度降低而减小.在水温26-28℃的条件下,点带石斑鱼受精卵经21-26h可孵化成仔鱼,盐度对孵化时间影响不显著(P>0.05).盐度在15-50范围内都能孵出仔鱼,但孵化率和畸形率因盐度不同而有显著差异.综合分析表明点带石斑鱼受精卵孵化的适合盐度范围为26.7-41.1.最适孵化盐度范围在30.5-32.5之间.盐度对卵黄囊仔鱼可量性状的影响主要表现在卵黄囊容积和全长的变化,高盐度(≥45)下胚后仔鱼卵黄囊容积、全长和体高显著减小(P<0.05),油球径不因盐度不同而改变.  相似文献   

南极长城站冬季地磁S_q变化特征          下载免费PDF全文

刘长发  张平  焦承民 《极地研究》1990,2(3):46-52

本文利用南极长城站1987年4月至9月的地磁资料,分析了长城站地区冬季地磁S_q变化特征。分析结果表明:(1)南极长城站在初冬(4月)与冬末(9月)月份的S_q变化形态与北半球中纬度的北京地磁台的S_q变化形态基本相似,这可能是由中纬度电离层中的发电机电流所控制的。在仲冬月份(6月与7月),由于太阳紫外辐射效应减少,高纬度的地磁扰动占主导地位,反映出S_q变幅很小和以8小时以下的较短周期谐波起主要作用,(2)在初冬与冬末月份的S_q等效电流矢量,白天比黑夜大约5倍;其矢量方向在白天(08—15时)为顺时针,黑夜为反时针。在仲冬月由于电离层中电流的影响相对减弱,S_q等效电流矢量很小,白天与黑夜基本一样;其矢量分布方向与初冬和冬末的矢量方向不同,这可能是极区的电离层电流或场向电流的影响造成的。  相似文献   

Morphological evolution of the Dee Estuary, Eastern Irish Sea, UK: A tidal asymmetry approach     

Rowena D. Moore  Judith Wolf  Alejandro J. Souza  Stephen S. Flint 《Geomorphology》2009,103(4):588-596

Asymmetry in the tide (unequal ebb and flood duration) is a dominant factor in causing residual sediment transport and morphological changes in estuaries. The evolution of estuarine morphology is a process of dynamic equilibrium in the short-term, while these features are ephemeral in the long-term. In this study we investigate the spatial distribution of tidal distortion and asymmetry in the Dee estuary, UK, by 3-dimensional numerical modelling methods. High resolution LIDAR surveys are used to underpin and explain our numerical modelling results in terms of basin hypsometry and areas of recent erosion and deposition. Harmonic analysis of the numerical modelling results showed that the shallower intertidal areas (sand and mud banks) were the most tidally asymmetric, showing flood dominance. The main navigation channels showed some ebb dominance but the tides here were relatively undistorted. This overall flood dominance is likely to induce net sediment import to the Dee, which explains known historical morphological changes (large scale accretion over the last two centuries) and also recent morphological changes as seen from the LIDAR surveys (which show predominantly net accretion between 2003 and 2006). Hypsometrical analysis suggests the Dee may be approaching equilibrium, and that the flood dominance and sedimentation rate may therefore decrease in the future. In an infilling estuary, an increase in the area and elevation of tidal flats can eventually shift an estuary towards ebb dominance, as shown by previous research and by ‘idealised estuary’ modelling results presented in this study. The large tidal amplitude to hydraulic depth ratio of the Dee, however, suggests that the tidal flats would have to be very extensive indeed for this to occur.  相似文献