草鱼出血病的电镜观察

草鱼出血病是由呼肠孤病毒感染所致的急性传染病，由于病鱼小血管受损引起全身性出血，并造成内脏器官和体壁肌肉组织局灶性病变。电镜观察表明病变细胞内各种细胞器的数量较正常细胞显著减少，形态结构也遭损坏。质膜的三层结构模糊不清，及至解体消失。与机体代谢密切相关的粗面内质网、滑面内质网、线粒体和高尔基复合体的数量减少及结构受损，使蛋白质、糖类和脂质合成及分解等一系列细胞代谢活动不能正常进行，加速了病鱼死亡。     

First account of a transient intersex in spotted scat,Scatophagus argus: a marine gonochoristic fish

Fish Physiology and Biochemistry - This study presents the first incidence of intersex associated with testis-ova in spotted scat (Scatophagus argus) reared in a controlled environment. The...     

Aquatic birnavirus induces apoptosis through activated caspase-8 and -3 in a zebrafish cell line

In this study, the possible influence of temperature on infectious pancreatic necrosis virus (IPNV)-induced apoptosis in a zebrafish liver epithelium (ZLE) cell line was investigated. At a lower temperature (18 degrees C), there was expression of viral proteins VP2 and VP3 at 4 h post-infection (p.i.). At this time no expression was found in the high temperature group at 28 degrees C. The cell survival ratio was 52 and 18% at 24 and 48 h p.i., respectively, during IPNV infection at 18 degrees C. In addition, we assayed for apoptosis in IPNV-infected cells with terminal deoxynucleotidyl transferase (TdT)-mediated end labelling (TUNEL) of DNA at different dosages of virus. We found a ratio of apoptotic cells of 8 and 25% at 12 and 18 h p.i., respectively, in the multiplicity of infection (MOI) 1 group. The MOI 10 group had 20 and 45% apoptotic cells at 12 and 18 h, respectively. Furthermore, at 18 degrees C IPNV activated the caspase-8 and 3 from 1.5 to 2 times at 12 and 18 h p.i., respectively. Taken together, these findings suggest that successful virus replication occurs at the low temperature (18 degrees C) compared with the non-permissive temperature of 28 degrees C. Thus, IPNV replication is capable of activating caspase-8 and -3 and inducing host apoptosis.     

The pathology of selenium deficiency in Cyprinus carpio L

Selenium is essential for the normal life processes, and all animals, including fish, need this inorganic element. In order to research the pathology of selenium deficiency in common carp, Cyprinus carpio L., 360 juvenile carp were allocated to three treatments. Each treatment containing 120 fish was randomly divided into four groups, fed with purified diets containing selenium at 0, 0.15, 0.30 and 0.45 mg kg^?1. The results indicated that the morbidity and mortality rates of the test groups were negatively correlated with the level of selenium in the diets. The morbidity and mortality rates were, respectively, 46.7%, 33.3%, 13.3%, 0 and 26.7% 16.7%, 6.7%, 0. The affected fish exhibited pathological changes, such as ‘thin back disease’ and lordosis. Histologically, there was no abnormality observed in muscles, liver and pancreas. Ultrastructurally, there was swelling of the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells, with disintegration and lysis of the cristae of the mitochondria which vesiculated. Serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels were increased and the activity of the serum glutathione peroxidase and the serum superoxide dismutase was decreased; in contrast, the serum malonaldehyde concentration was increased.     

LPG 发动机微机控制点火与数据采集系统的研究

国内 LPG 发动机多由汽油机改装而成,第二代电控 LPG 系统的开发和应用水平不高。介绍了一种小功率单缸汽油机的普通电子点火改装成 LPG 发动机微机控制点火与数据采集系统的实验研究。     

五味子的研究概况及其开发前景

通过对五味子的研究作简要概述,并试对我国五味子的资源培育、野生驯化、人工栽培、产业开发进行初步探讨。     

冰雪灾害后南岭常绿阔叶林受损优势种萌条特性

在南岭冰雪灾害受损常绿阔叶林建立4块样地,分析样地内受损树木的受损类型、径级、树种组成等因子与灾后萌条关系,结果表明:1)灾害后受损优势木72.00%以上均有萌条出现,乔木层优势木萌条率高于灌木层,为南岭地区冰雪灾害后受损森林生态系统快速恢复与重建提供保障;2)不同受损优势木萌条率存在差异,萌条率随着受损程度的增加呈增加的趋势,其中倒伏类型萌条率最高(100%),其他受损类型中灌木层金缕梅科萌条率最低,乔木层樟科萌条率最低;3)冰雪灾害后萌条特性表现出与采伐、刀耕火种后不同的规律,应做为1个特例进行研究;4)建议在我国亚热带地区森林自然干扰频发区,在人工促进恢复时多选用格药柃、小红栲和交让木等,有利于各层次结构与组成的保持.     

北斗导航系统在新疆安全生产过程中的应用研究

针对新疆通信盲区多、移动信号覆盖差，安全事故信息不能及时上报，应急救援指挥严重滞后的现状，提出了建设针对长途客货营运车辆、危险品运输车辆、应急运输车辆、野外工程车的基于我国自主建设、独立运行的北斗卫星导航系统的安全生产运输车辆监控管理系统，提供面向各行业需重点监控各型车辆及其主管调度部门的基于位置的综合信息服务。从而实现生产事故应急救援指挥，有序开展野外事故设备、人员的搜寻，有效提高安全生产信息化水平。     

Effects of Culture Area,Stocking Density,and Shrimp and Fish Polyculture on the Cost Efficiency of Hard Clam,Meretrix meretrix,Culture: A Case Study of Hard Clam Farms in Yunlin,Taiwan

Using the hard clam farms in Yunlin, Taiwan as examples, this study analyzes the effects of culture area, stocking density, and shrimp and fish polyculture on the cost efficiency (CE) of hard clam farming. A data envelopment analysis (DEA) is used to estimate the farms' technical efficiency (TE), allocative efficiency (AE), and CE values. The findings show that the mean TE, AE, and CE values of hard clam farms are 0.74, 0.57, and 0.43, respectively. The TE value is higher than the AE value, which indicates that cost inefficiency is mainly attributable to poor AE. Tobit regression results suggest that there are positive relationships between CE and both culture area and operator experience. Hard clam stocking density and age of the operators have negative effects on CE. Hard clam culture areas larger than 2 ha and a stocking density of 1.1–1.2 million hard clams per hectare have higher CEs than smaller culture areas and smaller or larger stocking densities. The use of sand shrimp, white shrimp, kuruma shrimp, and grass shrimp for polyculture and the use of milkfish and silver sea bream for polyculture are both associated with high CEs.     

Effect of Hybrid Abalone,Haliotis discus hannai × Haliotis discus discus,Cultivation on the Carbon Cycle: Carbon Source/Sink

Respiration, calcification, and bio‐deposition of hybrid abalone, Haliotis discus hannai × Haliotis discus discus, fed on different foodstuffs have been measured to evaluate the effect of hybrid abalone culture on carbon source/sink in coastal areas. Fed with Laminaria japonica, Undaria pinnatifida, Gracilaria lemaneiformis, U. pinnatifida, and Ulva pertusa, alternated mutually, the carbon bio‐deposition rate of hybrid abalone was 24.29 ± 6.39, 65.40 ± 10.55, 21.48 ± 5.99, and 29.28 ± 6.47 µg/g/h, respectively. Hybrid abalone fed on U. pinnatifida had a higher carbon bio‐deposition rate compared to that fed on other foodstuff (P < 5%). Rate of CO₂ released by respiration of hybrid abalone fed on the experimental foodstuff was 24.53 ± 8.57, 32.73 ± 7.99, 29.31 ± 6.39, and 33.67 ± 12.37 µg/g/h, respectively. Results indicated that calcification presented less relationship with body weight type of the foodstuff. The rate of CO₂ released by calcification into seawater and atmosphere was 2.77 ± 1.89 and 6.53 ± 3.36 µg/g/h, respectively. The total rate of CO₂ released because of bio‐deposition, respiration, and calcification processes was 16.19 ± 4.67 µg/g/h, while the total rate of carbon sequestered in shells and tissues was 8.94 ± 2.07 µg/g/h. The study revealed that hybrid abalone culture is a source of CO₂.