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71.
Characterization of acetylcholinesterase and its molecular forms in organs of five freshwater teleosts 总被引:1,自引:0,他引:1
J. Ferenczy T. Szegletes T. Bálint M. Ábrahám J. Nemcsók 《Fish physiology and biochemistry》1997,16(6):515-529
The activity and molecular forms of acetylcholinesterase (AChE, EC 3.1.1.7) were characterized in the brain, heart, white skeletal muscle and liver of the Siberian sturgeon (Acipenser baeri), European eel (Anguilla anguilla), wels (Silurus glanis), common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix), belonging in four families. The brain had the highest (between 183.2±10.6 and 1361.2±189.7 mU mg-1 protein and between 4.7±0.4 and 23.5±2.7 U g-1 wet tissue) and the liver the lowest (between 25.3±1.9 and 126.5±22.7 mU mg-1 protein and between 1.0±0.1 and 4.5±0.5 U g-1 wet tissue) activity in all these fish, with the exception of the wels, where the heart contained the smallest amount of AChE (26.2±7.5 mU mg-1 protein and 1.2±0.3 U g-1 wet tissue). The highest tissue AChE activity was found in the carp and lowest in the sturgeon. The solubility properties and molecular forms of AChE in the four tissues were studied by extraction in high-salt medium (1.0 M NaCl) with and without the detergent Triton X-100 (0.5%, v/v). The proportions of detergent-soluble (DS) and salt-soluble (SS) forms of AChE varied considerably from one species to another, but a general tendency could be observed: the proportion of DS AChE was generally higher in the brain (between 70.4±4.1 and 82.5±1.2%) and lower in the heart (between 12.0±2.0 and 51.3±2.3%) and skeletal muscle (between 16.0±2.0 and 64.4±0.7%). Velocity sedimentation centrifugation revealed that most tissues contained the G4 or A4 form. Three tissues (brain, heart, and liver) of the Siberian sturgeon contained a relatively high proportion of the G1 form (between 24.3±2.4 and 28.6±4.9%), while the skeletal muscle of the wels contained only the most complex type of AChE, i.e., A12. Amongst the tissues studied, the brain and liver mostly contained amphiphilic globular forms of the G4 type, while the heart and skeletal muscle were rich in asymmetric forms (A4 and A12). It was concluded that the differences revealed in the activities of AChE and in the distribution of its molecular forms may be connected with the variation in behavioral habits (feeding and swimming patterns), and the developmental stage of the nervous system. 相似文献
72.
Abstract Artificially hatched and reared juvenile European grayling, Thymallus thymallus (L.), from three natural populations were released into an experimental stream. Two of the populations were from lakes and the third population was from a river. Post-stocking dispersal was studied by recapturing fish in traps and by electric fishing after each of the stocking exercises. On all three occasions the first fish to be recaptured were caught in a trap about 400 m downstream from the release site, within 5–12 min of release. Proportions of stocked grayling juveniles recaptured by electric fishing in the fast-flowing section of the experimental stream (the rapids) were 9.9%, 46.7% and 16.6% after the first, second and third stocking, respectively. No significant population-specific difference was found between fish caught in the downstream trap and fish recaptured in the rapids. The uppermost part of the rapids (stretch 1) and the catch in the upstream trap was dominated by fish of riverine origin. Post-stocking migration was influenced by sex but not by body size. Females showed a greater propensity to stay in the rapids compared with males. Implications of the results for stocking grayling in natural streams and regulated rivers are discussed. 相似文献
73.
网络流行文化视域下“90后”大学生价值观教育探析 总被引:1,自引:1,他引:0
张海霞 《信阳农业高等专科学校学报》2014,(4):25-29
随着信息时代的来临和智能手机的普及,网络流行文化在丰富了"90后"大学生文化生活的同时,也导致了其价值观的模糊化、扭曲化、功利化和世俗化。针对网络流行文化对价值观的影响,我们应该大力弘扬"中国梦"和社会主义核心价值观,坚持思想引领,积极构建"五位一体"大学生价值观教育机制,并借鉴网络流行文化的优势和特点,创新"90后"大学生价值观教育的内容、方法和途径。 相似文献
74.
75.
王光应 《安徽农业大学学报》2014,(3):113-117
大学生马克思主义信仰教育是大学生思想政治教育的根本任务和崇高使命,为了检验大学生马克思主义信仰教育的效果,思想政治教育工作者对大学生马克思主义信仰状况开展调查和研究。“危机论”是众多思想政治教育工作者对当前大学生马克思主义信仰状况的基本观点,但是多数大学生的现实表现并不符合“危机论”。对产生“危机论”的原因进行分析和批判、重新对大学生马克思主义信仰状况进行科学判断可以深化对大学生马克思主义信仰的认识,弄清楚大学生马克思主义信仰状况,推进大学生马克思主义信仰教育与时俱进。 相似文献
76.
Effect of different methods for the induction of spermiation on semen quality in European eel 总被引:2,自引:0,他引:2
Juan F Asturiano Luz Pérez Daniel L Garzón David S Peñaranda Francisco Marco-Jiménez Silvia Martínez-Llorens Ana Tomás & Miguel Jover 《Aquaculture Research》2005,36(15):1480-1487
Five hormonal treatments with human chorionic gonadotropin (hCG) were tested for the induction of maturation and spermiation in male farmed eels. The main aim was to optimize previously used hormonal treatments to achieve shorter induction treatments, longer spermiation periods and/or higher sperm quality. Fish treated for just 3 weeks (treatment E) or until the onset of spermiation (treatment C) showed the worst results, while the treatment consisting of weekly administration of 1.5 IU hCG g?1 fish (treatment A) induced the highest percentage of spermiating males, the highest number of sperm samples and sperm volumes and densities similar to the rest of the treatments (B: half hormone dosage, or D: biweekly administration). Evaluation of the sperm quality was performed by computer‐assisted sperm analysis (CASA), considering the percentage of total motile spermatozoa, the percentage of fast and medium‐velocity spermatozoa, as well as different motility parameters. Sperm samples from A‐D groups showed between 44% and 54% motile spermatozoa, and between 10% and 15% fast spermatozoa, while samples from E‐treated males showed 0% motile cells. No significant differences were found in the spermatozoa straight line velocity (VSL), curvilinear velocity (VCL) or the angular velocity (VAP), neither spermatozoa beating cross frequency (BCF) between A–D groups. 相似文献
77.
Eggs of European hake (Merluccius merluccius L.) were stripped from fish caught at sea. Larvae were kept under semi‐intensive conditions at around 12°C. In addition, eggs were incubated in single wells at 9.2, 12.7 and 14.5°C, where hatching, development and survival were closely examined. During the larval stage, a total of 299 larvae were sampled to follow development and growth. In addition a small number of juveniles were sampled. Larvae hatched approximately 4 days after fertilization, and were 2.9 mm in total length (TL). At 6‐day post hatching (dph), the larvae were 4.1 mm (TL), the jaw apparatus was developed, and the larvae had started to feed. Most of the growth during the early larval period is restricted to the head, and there is almost no increase in length for the first 3–4 weeks post hatching. Teeth and pelvic fins appear at 25 dph. Development of unpaired fins at approximately 30 dph marks the start of the larval–juvenile transition. Weaning to formulated feed was accomplished 50 dph, when external morphology was similar to that of adult hake. 相似文献
78.
Linna Danne Lisa Horn Anita Feldhaus Daniel Fey Sebastian Emde Heike Schütze Mikolaj Adamek John Hellmann 《Journal of fish diseases》2022,45(1):69-76
Viral infections have been suggested to play a role in the decline of the panmictic population of the European eel (Anguilla anguilla). However, despite the importance of knowledge about pathogenic eel viruses, little is known about their spread in the wild European eel population and only a few eel pathogenic viruses have been described so far. In this study, we aimed to investigate the health status of the A. anguilla stock in North Rhine Westphalia (NRW) State of Germany. For this purpose, we examined tissue samples of 16 elvers, 100 yellow eels and 6 silver eels, sampled from the rivers Rhine, Lippe and Ems. Virus detection was performed via a combination of cell culture and PCR. Next to the detection of frequently encountered pathogenic eel viruses (anguillid herpesvirus 1 and eel virus European X (EVEX)), we isolated the eel picornavirus 1 (EPV-1) from tissue of yellow eels and elvers and demonstrate the distribution of EPV-1 in wild eel population in NRW. 相似文献
79.
基于Sujit模型,通过在支付清算系统内构建嵌入投资银行的危机传导模型,同时考虑中央银行的两种政策对防范少数银行危机蔓延至系统危机的作用,结果发现,少数银行引发系统危机的主要原因在于危机银行影响了与其有着支付清算关系的债权银行的收益和它们的预期信心,中央银行政策对控制危机传导是有效的。 相似文献
80.
周俊 《信阳农业高等专科学校学报》2010,20(3):47-48
面对日益发展的金融证券及保险业我国银行监管仍显不足。应抓紧完善银行监管法律制度和非现场监管机制,建立监管信息平台,提高现场检查效率。 相似文献