鱼腥藻PCC7120细胞液泡的初步研究

从保存３个月以上的老化培养物中直接检查到游离液泡。液泡为标准圆球状，完全透明，大小相差极为悬殊，多数大型液泡吞噬了数个衰老藻细胞。采用低渗酶解，渗透冲击，低渗酶解和渗透冲击相结合，从培养３个月以上，２个月，１个月，１８ｄ，１０ｄ及３ｄ的藻丝细胞都分离到液泡。液泡略大于细胞，泡内无吞噬物。培养３ｄ的藻丝有１５％的细胞分离到液泡。其他多种蓝藻也分离到同样的液泡。

细菌性败血症引起鲫凝血障碍的研究

以嗜水气单胞菌感染体重为70g左右的鲫并检测了感染鱼和对照鱼的血液学及播散性血管内凝血判定指标等参数。结果表明细菌性败血症病鱼严重贫血，存在明显的凝血障碍，在疾病发展过程中存在播散性血管内凝血现象，这一现象导致了病鱼全身性出血，并在疾病的病理生理过程中起了重要的作用。

密度和温度对萼花臂尾轮虫产卵量和混交雌体的影响

用小球藻(Chlorella sp.)为食培养萼花臂尾轮虫(Brachionus calyciflorus),食物浓度约1×10~6cells/mL,温度25℃,光照强度约40001x,昼长比LD=18:6。在1.0mL、0.5mL和0.25mL培养液中同时进行单个体和群体培养。结果发现:1)单个体培养时每个母体平均产卵量分别为12.0,13.8和7.8个;后代个体中混交雌体的百分比分别是46.38％,53.49％和55.83％。2)群体培养时,每个母体平均产卵量分别为8.7、3.1和2.65个,随密度增

多变鱼腥藻半稳定状态连续培养的若干特征

分别使用恒化装置和全玻璃发酵罐连续培养多变鱼腥藻。在稳定条件下加以周期性的光照(L∶D=12∶12),经5—6d得到半稳定状态连续培养物。在光照阶段,培养物的生物量增长速度约等于稀释速度D的两倍,叶绿素的增长速度略小于D的两倍,糖原的累积速度几乎高出D~5的一个数量级。细胞内糖原和蛋白质含量变化的时间过程反映出培养物在光-暗条件下的碳氮物质合成与消耗相互联系的代谢特点。半稳定状态连续培养受培养物内在的生理活性支配,生长参数的变化符合方程X=X_(oe)~((μ-D)~t),但不同于恒浊培养和恒化培养。外界

蓝藻分子遗传学十年研究进展

<正> 蓝藻遗传学研究始于60年代,其间经历了大约20年的徘徊,随着分子生物学、分子遗传学研究的进展,特别是重组DNA技术的广泛应用,为蓝藻遗传学研究提供了转机和新的洞察力,绕过应用经典遗传学技术方法所遇到的困难,另辟新径,直接分离基因,加速了研究工作的步伐。随着蓝藻本身一些重要而独特的生理特性逐渐为人们所认识,研究者日增,最近十年,蓝藻分子遗传学研究进展迅速,不仅在藻类学研究中处

新型浮选剂MPA对鱼类毒性效应的研究

MPA是一种新型浮选剂,主要由29种醇类化合物组成。测得它的96h的LC_(50)值:草鱼胚胎为100—200mg/L;草鱼苗为75.86mg/L;草鱼种为122.77mg/L。引起草鱼胚胎弯体畸形的EC_(50)值为48.98mg/L。弯体不严重的鱼苗在清水中饲养,能恢复成正常的鱼苗。对鱼苗生长没有影响的浓度是6.65mg/L。浓度为100mg/L的MPA在水环境中一周能去除一半,20天后未检出,在该浓度内放入的草鱼种,对其生长没有明显的影响。

寄生虫种群生态研究的综述

<正> 自从70年代以来,寄生虫生态学的不断发展吸引了愈来愈多的寄生虫学和生态学工作者。同时,寄生虫生态学也得到了极大的发展,成为一门颇具吸引力的学科。研究寄生虫生态学不仅具有理论上的意义,而且具有极大的实际意义。显而易见,寄生虫种群的研究以及宿主-寄生虫相互作用的研究有着极现实的经济价值。限于篇幅,本文将只介绍寄生虫种群生态学的一些主要的研究领域以及理论和实际意义较大的研究成果。

瓦氏雅罗鱼染色体组型研究

<正> 瓦氏雅罗鱼(Leuciscus waleckii)是一种适应高寒盐碱化水体生活的主要经济鱼类。用瓦氏雅罗鱼精液和鲮鱼精液混精授精所得的鲮鱼耐寒力有所提高。而对于这类喜冷鱼类细胞培养和染色体核型,迄今国内尚未见报道。为了进一步探讨和利用瓦氏雅罗鱼的耐寒性能,作者先就该鱼的染色体核型进行了分析研究。材料和方法材料取自内蒙古凉城县的岱海。染色体标本的制备采用体外短期培养肾细胞的常规方法。火焰干燥制片,吉姆萨染色法。共分析8个比较清晰的中期分裂相。有关染色体的测量、统计、以

Product intelligence in warehouse management: A case study

The need for more flexible, adaptable and customer-oriented warehouse operations has been increasingly identified as an important issue by today's warehouse companies due to the rapidly changing preferences of the customers that use their services. Motivated by manufacturing and other logistics operations, in this paper we argue on the potential application of product intelligence in warehouse operations as an approach that can help warehouse companies address these issues. We discuss the opportunities of such an approach using a real example of a third-party-logistics warehouse company and we present the benefits it can bring in their warehouse management systems. © 2013 Springer-Verlag.

黑龙江流域鳊鱼的种内变异及其生活习性

<正> 鳊鱼是很名贵的经济鱼类,亦称(鱼边)角,东北地区称鳊花。在我国的江河中分布很广,长江及松花江流域中最为丰盛。这种鱼最初的记载是在1844年,学名为Leuciscus bramula,是Cuvier和Valencienes两氏订立的。后来在1846及1855年中,Richardson和Basilewsky两氏又先后记述了这种鱼类;并分别订为Abramis bramula和Abramis pekinensis。到1865年,Bleeker氏才确定这种鱼的属名为Parabramis,借以和只有一行咽喉齿

Temporal Coherence of Chlorophyll a during a Spring Phytoplankton Bloom in Xiangxi Bay of Three-Gorges Reservoir, China

Algal bloom phenomenon was defined as "the rapid growth of one or more phytoplankton species which leads to a rapid increase in the biomass of phytoplankton", yet most estimates of temporal coherence are based on yearly or monthly sampling frequencies and little is known of how synchrony varies among phytoplankton or of the causes of temporal coherence during spring algal bloom. In this study, data of chlorophyll a and related environmental parameters were weekly gathered at 15 sampling sites in Xiangxi Bay of Three-Gorges Reservoir (TGR, China) to evaluate patterns of temporal coherence for phytoplankton during spring bloom and test if spatial heterogeneity of nutrient and inorganic suspended particles within a single ecosystem influences synchrony of spring phytoplankton dynamics. There is a clear spatial and temporal variation in chlorophyll a across Xiangxi Bay. The degree of temporal coherence for chlorophyll a between pairs of sites located in Xiangxi Bay ranged from -0.367 to 0.952 with mean and median values of 0.349 and 0.321, respectively. Low levels of temporal coherence were often detected among the three stretches of the bay (Down reach, middle reach and upper reach), while high levels of temporal coherence were often found within the same reach of the bay. The relative difference of DIN between pair sites was the strong predictor of temporal coherence for chlorophyll a in down and middle reach of the bay, while the relative difference in Anorganic Suspended Solids was the important factor regulating temporal coherence in middle and upper reach. Contrary to many studies, these results illustrate that, in a small geographic area (a single reservoir bay of approximately 25 km), spatial heterogeneity influence synchrony of phytoplankton dynamics during spring bloom and local processes may override the effects of regional processes or dispersal.

Expression pattern, cellular localization and promoter activity analysis of ovarian aromatase (Cyp19a1a) in protogynous hermaphrodite red-spotted grouper

Aromatase plays a key role in sex differentiation of gonads. In this study, we cloned the full-length cDNA of ovarian aromatase from protogynous hermaphrodite red-spotted grouper (Epinephelus akaara), and prepared the corresponding anti-EaCyp19a1a antiserum. Western blot and immunofluorescence studies revealed ovary-specific expression pattern of EaCyp19a1a in adults and its dynamic expression change during artificial sex reversal. EaCyp19a1a was expressed by follicular cells of follicular layer around oocytes because strong EaCyp19a1a immunofluorescence was observed in the cells of ovaries. During artificial sex reversal, EaCyp19a1a expression dropped significantly from female to male, and almost no any positive EaCyp19a1a signal was observed in testicular tissues. Then, we cloned and sequenced a total of 1967 bp T-flanking sequence of EaCyp19a1a promoter, and showed a number of potential binding sites for some transcriptional factors, such as SOX5, GATA gene family, CREB, AP1, FOXL1, C/EBP, ARE and SF-1. Moreover, we prepared a series of 5' deletion promoter constructs and performed in vitro luciferase assays of EaCyp19a1a promoter activities. The data indicated that the CREB regulation region from -1010 to -898 might be a major cis-acting element to EaCyp19a1a promoter, whereas the elements GATA and SOX5 in the region from -1216 to -1010 might be suppression elements. Significantly, we found a common conserved sequence region in the fish ovary-type aromatase promoters with identities from 93% to 34%. And, the motifs of TATA box, SF-1, SOX5, and CREB existed in the region and were conserved among the most of fish species. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Construction of habitat suitability models (HSMs) for benthic macroinvertebrate and their applications to instream environmental flows: A case study in Xiangxi River of Three Gorges Reservior region, China

Based on a long-term ecological monitoring, the present study chose the most dominant benthic macroinvertebrate (Baetis spp.) as target organisms in Xiangxi River, built the habitat suitability models (HSMs) for water depth, current velocity and substrate, respectively, which is the first aquatic organisms model for habitat suitability in the Chinese Mainland with a long-term consecutive in situ measurement. In order to protect the biointegrity and function of the river ecosystem, the theory system of instream environmental flow should be categorized into three hierarchies, namely minimum required instream flow (hydrological level), minimum instream environmental flow (biospecies level), and optimum instream environmental flow (ecosystem level). These three hierarchies of instream environmental flow models were then constructed with the hydrological and weighted usable area (WUA) method. The results show that the minimum required instream flow of Xiangxi River calculated by the Tennant method (10% of the mean annual flow) was 0.615 m(3) s(-1); the minimum instream environmental flow accounted for 19.22% of the mean annual flow (namely 1.182 m(3) s(-1)), which was the damaged river channel. ow in the dry season; and 42.91% of the mean annual flow (namely 2.639 m(3) s(-1)) should be viewed as the optimum instream environmental flow in order to protect the health of the river ecosystem, maintain the instream biodiversity, and reduce the impact of small hydropower stations nearby the Xiangxi River. We recommend that the hydrological and biological methods can help establish better instream environmental. ow models and design best management practices for use in the small hydropower station project. (C) 2008 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

Sequential ultrastructural and biochemical changes induced in vivo by the hepatotoxic microcystins in liver of the phytoplanktivorous silver carp Hypophthalmichthys molitrix

Up to now, in vivo studies on the toxic effects of microcystins (MCs) on the ultrastructures of fish liver have been very limited. The phytoplanktivorous silver carp was injected i.p. with extracted hepatotoxic microcystins (mainly MC-RR and -LR) at a dose of 1000 mu g MC-LReq. kg(-1) body weight, showing a time-dependent ultrastructural change in liver as well as significant increases in enzyme activity of plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH). We observed for the first time the occurrence of a large amount of activated secondary lysosomes, which might be an adaptive mechanism to eliminate or lessen cell damage caused by MCs through lysosome activation. Quantitative and qualitative determinations of MCs in the liver were conducted by HPLC and LC-MS2, respectively. MCs concentration in the liver reached the maximum (114.20 mu g g(-1) dry weight) after 3 h post-injection, and then rapidly dropped to 7.57 mu g g(-1) dry weight at 48 h, indicating a deputation of 99% accumulated MC-LReq. On the other hand, a decrease trend in glutathione (GSH) concentration was observed in the liver of silver carp while the activity of glutathione S-transferase (GST) increased significantly after injection. The high tolerance of silver carp to MCs might be due to the high basic GSH level in their liver, and/or an increased GSH synthesis. (C) 2007 Elsevier Inc. All rights reserved.