快速测定海藻中碘含量样品前处理方法研究

海带及海藻中含有大量的碘，其中碘的测定，目前主要以溴水氧化法为主，样品前处理是制约测定效率的主要因素。本文以海带为研究对象，对测定中样品前处理的方法进行了研究，简化了操作步骤，缩短检测时间3h以上，大大提高了检测效率。经试验验证，测定精密度(RSD)小于2％，与经典方法比较，相对偏差≤1．5％。方法具有简单、快速、准确、适用的特点。     

尼罗罗非鱼行为习性及其捕捞渔具的设计

尼罗罗非鱼(OreochromisniloticaL.)属热带性鱼类,为我国1978年从国外引进的优良海淡水养殖对象,具有食性杂、生长速度快、肉质鲜美、经济价值高等优点[1]。目前已在我国数个省、市开展养殖。尼罗罗非鱼性喜群游,其最适生长水温为24～32℃,水温降至14℃时,活动迟缓,停止摄食,水温降至12℃以下时便逐渐死亡[2]。因此,在我国北方地区养殖的尼罗罗非鱼,一般在严冬前开始进行捕捞。水温达到20℃以上时,雄鱼会在池边或者池底挖洞,当遇到外界刺激或拉网捕捞受惊后,便潜入洞中或软泥中。尼罗罗非鱼的这一行为习性给捕捞造成很大困难,因此各地一般…     

真鲷消化道的组织学和形态学研究

采用扫描电镜和光镜技术对真鲷的消化道进行了组织学和形态学研究。具发达颌齿的口咽腔之后，真鲷消化道由分化明显的食道、胃、小肠和直肠构成。口咽腔粘膜表面为复层上皮，其中含有怀状细胞和味蕾，表层细胞具微褶（脊）；食道粘膜也衬着复层上皮，由表层具微褶（脊）的扁平细胞、中层的怀状细胞及底部的基底细胞组成，食道粘部分区域 衬着单层柱状上皮；胃Ｖ形，粘膜表层为单层柱状上皮，贲门部和盲囊部上皮下有一厚层胃腺组织；     

换水换气式充氧密封鱼苗运输装置及其应用的研究

换水换气式充氧密封鱼苗运输装置是直接在塑料袋运输活鱼基础上改装而成,它能在不松开塑料袋的条件下,轻松快速地进行换水换气。通过以鳙鱼苗为试验对象,选用换水量、换气量、换水间隔期和换气间隔期四因素模拟运输进行了该装置的九组正交试验,得出了四因素最经济可行的组合是换水量为60％,换水间隔期为16小时,换气量为50％,换气间隔期为8小时。正交试验中存活时间最长为55小时（空白试验为26小时）,换水量是最主要的影响因素,只换水比只换气更利于延长活鱼运输时间。     

The significance of the structural characteristics of the agent for the problems of immunization against blue tongue]

Bluetongue virus (BTV), an arthropod-borne virus, is transmitted primarily by biting midges of the genus Culicoides. Some insect species, which might serve as a potential vector, are prevalent in Central Europe. In sheep, bluetongue is acute and mortality is high, whereas in cattle, goats and most wild ruminants the infection is usually clinically inapparent. Viremia is of short duration in sheep, but cattle experience a prolonged viremia and provide a reservoir for the dissemination of BTV. At least 24 different BTV serotypes have been identified. Antigenic variations occur in the polypeptides of the outer viral capsid and the segmented nature of the viral genome provides the potential for evolution of the virus by a mechanism of reassortment. This renders the use of polyvalent vaccines inefficient and emphasizes the significance of import/export restrictions on ruminants from BTV endemic areas.     

Evaluation of the advantage of marine protected areas over the reduction of the fishing mortality coefficient

ABSTRACT:   In the present study, we compared the advantage of marine protected areas (MPA) to the reduction of the fishing mortality coefficient ( F ). We accomplished this by comparing the yield per recruitment (YPR) and spawner biomass per recruitment (SPR) under two controls. This was accomplished using a mathematical model. We used the following five measures as comparisons: (i) the condition of the fishery where the increase in YPR is possible; (ii) the increase in YPR or SPR obtained by allocating half the fishing ground as an MPA and by reducing F by half; (iii) the maximum YPR obtainable when the fishing mortality coefficient or the proportion of MPA in the fishing ground is completely controlled; (iv) the proportion of the MPA and the reduction ratio of F required for attaining 30% SPR; and (v) the YPR obtainable while maintaining 30% SPR. Our results show that the MPA has a minor disadvantage in terms of the first measure. The MPA is advantageous in increasing SPR in the second measure, with a low migration rate of fish. The MPA is also advantageous in increasing YPR in the second measure, with some intermediate migration. The MPA is disadvantageous in the third measure. The MPA is advantageous in the fourth measure, with a low migration rate. The MPA is disadvantageous in the fifth measure.     

On the temporal variability of the physical environment over the south-eastern Bering Sea

During 1997 and 1998, unusual physical conditions occurred in the Bering Sea: strong May storms and calm conditions in July; record high sea surface temperature; a shallow wind mixed layer; a fresher-than-normal water column; and abnormal cross-shelf currents. Accompanying these conditions were changes in the dominant phytoplankton, a die-off of seabirds, increased sightings of large whales and diminished returns of salmon. Changes to the physical environment during 1997 and 1998 are placed in context of historical meteorological and oceanographic data sets. Although 1997 had the warmest sea surface temperature ever observed on the south-east Bering Sea shelf, the heat content of the water column was cooler than average. In contrast, during 1998, the sea surface temperature was cooler than in 1997 but the water column had significantly higher heat content. During recent years, the water column has freshened over the middle shelf because of increased sea ice and reduction of on-shelf transport of the saline, high-nutrient water from the slope. The timing of the spring bloom is directly related to the presence of ice. When ice is advected over the south-east shelf during March/April an early, sharp phytoplankton bloom occurs. The absence of ice during this critical time is associated with a May/June bloom.     

日本沼虾蜕皮过程中头胸甲外骨骼超微结构的改变

采用HE染色及石蜡切片的扫描电镜观察方法,描述了日本沼虾(Macrobrachium nipponense)蜕皮间期(C期,intermolt stage)及新旧表皮更替变化剧烈的蜕皮前晚期(D4期,late premolt stage)和蜕皮后期(postmolt stage)A-B期头胸甲外骨骼的形态结构变化特点。结果显示,日本沼虾外骨骼分为上表皮、外表皮、内表皮三层,D4期出现新的上表皮和外表皮,B期出现新内表皮,外表皮强嗜碱性而内表皮弱嗜酸性。扫描电镜观察发现,C期头胸甲内、外表皮均为几丁质-蛋白质纤维构成的平行板层结构且板层内有发达的孔道系统(pore canals,pc),但内外表皮板层间排列紧密程度不同,外表皮板层切面边缘较整齐,结构致密,板层内pc大小均一、近似圆形,内表皮板层切面边缘粗糙,结构较疏松,板层内pc大小不等、多为梭形。在蜕皮前后,新外表皮结构变化显著,与C期相比,D4期新外表皮超微结构与旧内表皮结构相似,而在A期,外表皮超微结构由疏松变为致密,这可能与蜕皮后表皮的钙化相关。本研究旨为阐明沼虾的蜕皮机制提供基础资料。     

对虾虾头、虾壳副产品综合利用的研究概况

对虾在加工过程中会产生大量的虾头及虾壳等副产品,其副产品中含有丰富的营养物质.近年来,随着对虾产量的递增,其副产品的产量也越来越多,但产生的副产品大多被低值化利用或直接被废弃.既浪费资源又对环境造成了污染.为解决这一问题,本文就虾副产品在食品、化工、医学等方面的综合利用作简要概述,以期为对虾食品加工企业提高虾的综合利用...     

河纯毒素的起源及检测技术研究进展

分析了不同学者对河纯毒素起源的几种解释,从遗传学角度解释河纯毒素是河纯在长期进化过程中自然选择的结果的解释较为合理。本文对河豚毒素的检测方法进行了综述。河豚毒素是钠离子通道阻断剂,是一种强海洋神经毒剂,结合国内外研究现状介绍了河鲍毒素的控毒手段以及河纯毒素作为一种工具药在临床上的应用前景。     

1999年2月黄海声学调查鳀鱼种群群体结构评估

IntroductionEstimation of the size structure of a fish population is often one of the primary objectives of an acoustic/trawl survey (Gunderson 1993;Honkalehto and Williamson 1996 ) .The size structure contains much informa-tion enabling a quick estimate of the fishable size of a stock in a regulated fishery or the recruitment status ofa stock.It is also a common practice to use the number at length of a population together with the age/lengthkey to produce the age structure of the fish popul…     

添加小麦蛋白对马面鲀鱼糜凝胶强度影响的研究

<正> 自从60年代初日本的西谷等人开发冷冻鱼糜制造技术以来,鱼糜制品在日本得到了很大的发展。目前日本冷冻鱼糜年产量100万吨左右,鱼肉香肠、鱼肉火腿年产量10万吨左右。近年来,鱼糜制品技术日益引起世界各国的重视,美国、欧洲和亚洲的泰国、南朝鲜,我国台湾等都在研究开发鱼糜制品。鱼肉火腿,鱼肉香肠作为鱼糜制品中的     

Diseases of the prostate in the dog

BPH (benign prostatic hyperplasia) is frequently observed in male dogs older than five years. Uncomplicated BPH is therefore regarded as a normal aging process. Only 1-2% of the males develop malign tumors, furthermore acute or chronic prostatitis, abscesses or cysts. The diagnosis of prostatic diseases requires special physical and laboratory examinations. For the treatment hormonal effective substances, antibiotics, antiphlogistics, analgesics and surgical procedures (prostatectomy, castration) are recommended. The author successfully uses a therapy in two phases starting with an intensive medication (Tardack plus antibiotics s.c./p.o. and local) for at least 10, up to 30 days, followed by surgery. Particularities in diagnosis and therapy are pointed out.     

Implications of the precautionary approach for the management of the European eel, Anguilla anguilla

The European eel, Anguilla anguilla (L.), has a complex life history and many aspects of the biology and population dynamics of this species remain unknown or, at best, poorly understood. Relatively little is also known about the status of the stocks and fisheries, but available data suggest that recruitment of glass eels has been falling for the last 20 years and is at historically low levels. Yellow and silver eel catches have also been falling in many parts of the species range over a similar time‐scale. Re‐examination of the principles applied to fisheries management over recent years has resulted in the adoption of a ‘precautionary approach’ to the conservation, management and exploitation of fish stocks, and in an explicit need to take account of uncertainties in management to reduce risks to stocks and their environment. Such an approach is highly relevant to the management of the European eel and requires that urgent consideration is given to harvest strategies and decision structures for the national and international management of stocks and fisheries. Provisional biological reference levels should be established to provide an equable assessment of the status of stocks in all parts of Europe and to evaluate the need for management measures in all fisheries. These will need to be reviewed as further information comes available. Monitoring and research on eel stocks should therefore be enhanced and co‐ordinated to improve our understanding of the status of stocks throughout Europe and the biology of the species.     

Assessing the inclusion of seafood in the sustainable diet literature

The literature on sustainable diets is broad in its scope, and application yet is consistently supportive of a move away from animal‐based diets towards more plant‐based diets. The positioning of seafood within the sustainable diet literature is less clear. A literature review was conducted to examine how the environmental impacts of seafood consumption are assessed and what conclusions are being drawn about the inclusion of seafood in a sustainable diet. Seafood is an essential part of the global food system but is not adequately addressed in most of the sustainable diet literature. Aquaculture, the world's fastest growing food sector, was considered by very few papers. Seafood consumption was commonly presented as a dilemma due to the perceived trade‐offs between positive health outcomes from eating seafood and concerns of overfishing. A number of studies included seafood as part of their sustainable diet scenario, or as part of a diet that had lower impacts than current consumption. Most of the indicators used were biophysical, with a strong focus on greenhouse gas emissions, and very few studies addressed biological or ecological impacts. The assessment of seafood was limited in many studies due to relevant data sets not being incorporated into the models used. Where they were used, data sources and methodological choices were often not stated thereby limiting the transparency of many studies. Both farmed and wild‐capture production methods need to be integrated into research on the impacts of diets and future food scenarios to better understand and promote the benefits of sustainable diets.     

基于马尔可夫过程的湖泊生态需水保障不确定性研究

湖泊生态需水对维持湖泊基本生态功能具有重要的作用,保障生态需水已成为湖泊生态保护的重要组成部分。目前湖泊生态需水的保障方法都是在同一时间尺度下维持一个确定的生态需水量;然而,湖泊水位是一个随机过程,湖泊生态状况与湖泊水位波动息息相关,仅保持湖泊在一个水位值不足以满足湖泊在不同时期的生态需水量;另一方面,生态系统的结果和功能在不断变化,导致湖泊的生态需水量也发生变化,只保障一个确定的生态需水量的方法不足以应对湖泊生态需水量未来可能存在的各种情况,也无法应对未来生态需水保障的不确定性。因此,亟需对湖泊生态需水进行不确定性研究,以保障不同时期的生态需水量。本研究以白洋淀为案例,将白洋淀水位划分成五个区间,代表五个水位时期,再将每个时期下的生态环境状况进行分析,得出每个时期有利于湖泊生物多样性的生态需水量。然后根据马尔可夫过程,利用改进加权马尔可夫链模型,计算出未来湖泊水位处于各个时期的概率,从而确定湖泊未来生态需水量的保障程度,对未来生态需水保障情况进行预测。     

Recent perceptions on the development, assembly and function of the immune system

The immune system developed through many stages during evolution. It is fascinating that none of the diverse defense mechanisms vanished in such a long period of nearly 3.5 billion years. They still function in the integrated immune system. The barrier system can be compared to the immune system. The immune system itself is subdivided in antigen-independent, paraspecific (primitive immune system) and antigen specific (specific immune system), restricted immune reactions. The role and use of the phylogenetically older, paraspecific mechanisms, that will react immediately after antigen exposure, are discussed in detail. The immune system is not autonomous. It is closely linked to the hormonal, circulatory, metabolic and nervous systems. Its function is comparable to a sensory organ. Psychoneuroimmunology as a new discipline is mentioned. Immunity and paramunity are not seen as opposing phenomena but are linked in their functions. The terminology of immunology is discussed.     

大宁河龙溪段鱼类早期资源研究

为了解十年禁渔背景下大宁河鱼类早期资源变化状况,2020和2021年5-7月在大宁河龙溪断面开展了鱼类早期资源现状的调查。结果表明,龙溪江段产浮性卵鱼类1种、漂流性卵鱼类4种、粘沉性卵鱼类19种;中华纹胸鮡（Glyptothorax sinensis）和大眼鳜（Siniperca kneri）的产卵规模相对较大,其卵占比分别达48%和30%以上;2020年的鱼类卵苗资源量和种类都少于2021年。RDA分析结果显示,中华纹胸鮡（Glyptothorax sinensis）、张氏?(Hemiculter tchangi)鱼卵漂流密度与水温变化呈现一定相关性,适宜水温促使中华纹胸鮡（Glyptothorax sinensis）、张氏?(Hemiculter tchangi)产卵;随着流速和流量增加,多鳞白甲鱼(Scaphesthes macrolepis)和云南盘鮈(Discogobio yunnanensis)卵漂流密度均相应增加;大眼鳜（Siniperca kneri）和峨眉后平鳅(Metahomaloptera omeiensis)产卵期间江水酸碱度相对较低。十年禁渔的实施对大宁河鱼类资源的恢复可能产生积极影响。     

The influence of ovarian fluid on the gamete physiology in the Salmonidae

The present study investigated the influence of ovarian fluid (OV) on the gamete physiology in the brown trout (Salmo trutta f. fario). In comparison to water OV prolongs the duration of sperm motility for >'5 min and the fertilizability of eggs for >'10 min independent from the quality of the egg batch from which the OV derived. These stabilizing effects are related to the inorganic composition of OV as similar results are obtained in buffered artificial saline solution (AFS). OV compensates also for sub-optimal environmental conditions as demonstrated in fertilization experiments with mixtures of OV and buffer solutions of different pH. At a dilution ratio of OV: water of 1:1 the stabilizing effect on gametes is significantly decreased and at a dilution ratio of 1:8 it is completely lost. Due to the described effects significantly higher fertilization rates are obtained in OV than in water. In OV the fertilization rates are also higher than in AFS but only at low sperm to egg ratios or when semen with low motility rates and swimming velocities is used. This is considered to be due to a semen dependent egg activation which is partly suppressed by a OV protein with a molecular weight between 20 and 62 kdaltons. The phenomen is discussed in detail.     

Preliminary study on the fishery resources of the River Niger in the Upper Niger National Park, Guinea

A survey of fishing activity, main fishing methods and fish species composition in the upper River Niger enabled current fishing effort, seasonal yield and its economic value to be assessed. Fishing is a traditional activity, supporting part of the regional economy, and an important animal protein source for local people. The catches, 63 fish species included in 20 different families, confirmed the high biological diversity present in the River Niger. Sixteen main fish species were identified as the most important by weight in the commercial captures. Fishing methods used are very selective. The catch is mainly large fishes, and only a low percentage of juvenile specimens is present in the catch, suggesting there is no overfishing of the exploited fish stocks.