Occurrence of gravel in the stomachs of two New Zealand stream‐dwelling fish (note)     

Philip L. Cadwallader 《新西兰海洋与淡水研究杂志》2013,47(1):101-103

Gravel occurred in. the stomachs of 17.8% of 924 Galaxias vulgaris and 2.8% of 430 Philypnodon breviceps taken from the Glentui River, Canterbury, between June 1970 and November 1971. It is suggested that differences in feeding habits and feeding locality are responsible for the difference in occurrence of gravel in the stomachs of the two fish species. Galaxias vulgaris feeds in the water column in riffles and, being a drift feeder, is more likely to ingest inedible material by accident than is P. breviceps, which feeds on the bottom in sheltered or quiet stretches of the river.  相似文献   

疑患EMS/AHPNS对虾中检出黄头病毒的一种新株型     

刘群  黄倢  杨昊霖  杨冰  刘笋  王海亮  王勤涛  刘飞  张庆利 《海洋与湖沼》2014,45(4):703-709

对2012—2013年从河北、福建和广东3个对虾养殖场采集的12份发生疑似早期死亡综合征/急性肝胰腺坏死综合征(EMS/AHPNS)的样品,采用组织病理学方法、套式RT-PCR检测方法以及快速灵敏检测试剂盒进行了检测。三地来源的养殖对虾样品症状均表现为肝胰腺颜色变淡,部分出现萎缩,空肠空胃,腹节肌肉略微白浊;组织病理切片结果表明,患病对虾肝胰腺血细胞浸润,肝胰腺盲管上皮细胞脱落,继发性细菌感染,淋巴器官和血淋巴细胞内存在核固缩、破裂和细胞质包涵体。按世界动物卫生组织(OIE)手册的套式RT-PCR方法检测,结果显示,黄头病毒(Yellow head virus,YHV)目的产物的阳性样品检出率为66.7%,该方法对这些样品的灵敏度可能很低。目的产物测序后经NCBI Blast,与已报道的YHV相似性为76.5%—89%;系统发育树显示这3个来源的样品位于同一个分支,与已知的YHV/鳃联病毒(gill-associated virus,GAV)株均不相同,其亲缘关系与YHV较近,而与GAV较远。用新研发的YHV快速高灵敏检测试剂盒检测,结果表明,所有样品均为YHV强阳性。以上表明患AHPNS的养殖对虾中存在一种YHV的新株型的感染,这也是我国首次检测到YHV的感染。  相似文献   

White spot syndrome virus inactivation study by using gamma irradiation     

Marzieh Heidareh  Farahnaz Motamedi Sedeh  Mehdi Soltani  Saeed Rajabifar  Mohammad Afsharnasab  Aghil Dashtiannasab 《中国海洋湖沼学报》2014,32(5):1024-1028

The present study was conducted to investigate the effect of gamma irradiation on white spot syndrome virus(WSSV). White spot syndrome virus is a pathogen of major economic importance in cultured penaeid shrimp industries. White spot disease can cause mortalities reaching 100% within 3–10 days of gross signs appearing. During the period of culture, immunostimulant agents and vaccines may provide potential methods to protect shrimps from opportunistic and pathogenic microrganisms. In this study, firstly, WSSV was isolated from infected shrimp and then multiplied in crayfish. WSSV was purified from the infected crayfish haemolymph by sucrose gradient and confirmed by transmission electron microscopy. In vivo virus titration was performed in shrimp, Penaeus semisulcatus. The LD50 of live virus stock was calculated 10 5.4 /mL. Shrimp post-larvae(1–2 g) were treated with gamma-irradiated(different doses) WSSV(10 0 to 10-4 dilutions) for a period of 10 days. The dose/survival curve for irradiated and un-irradiated WSSV was drawn; the optimum dose range for inactivation of WSSV and unaltered antigenicity was obtained 14–15 kGy. This preliminary information suggests that shrimp appear to benefit from treatment with gammairradiated WSSV especially at 14–15 KGy.  相似文献   

The application of GIS for flood defence in the Anglian Region: developing for the future     

Daniel J. Leggett  Anthony Jones 《International journal of geographical information science》2013,27(1):103-116

The spatio‐temporal relationship between unusual sightings of dead birds and human West Nile virus infections has been observed in many studies and has been proposed as an indicator of an intense amplification cycle between birds and mosquitoes. However, to date, no single study has provided quantitative evidence that the amplification cycle occurs at the local level and that it operates within certain temporal parameters. Here, we use a novel geostatistical and spatial analytic methodology and present the first evidence that the localized unusual space–time correspondence of dead birds models the amplification cycle and that this cycle peaks 15–16 days prior to human onset of West Nile virus infections. During the process of establishing this relationship, we extend the traditional Knox space–time interaction measure to overcome pair‐dependency limitations and use a novel implementation of the kappa non‐chance agreement measure to identify the temporal characteristics of the association of bird deaths to human West Nile infections.  相似文献   

A study on pathogens of Chinese prawn (Penaeus Chinensis) virus diseases     

Sun Xiu-qin  Zhang Jin-xing 《中国海洋湖沼学报》1995,13(3):284-288

This pathogenic study shows that the viral diseases of Chinese prawns (Penaeus chinensis, O'sbeck) is due to three kinds of viruses: epithelium envelope baculovirus ofPenaeus chinensis (EEBV-PC, detected by the authors in 1993), infections hypodermal and hematopoietic necrosis virus, and hepatopancreatic parvo-like virus, and that the first two viruses seem to be the main pathogens of the epidemic in the northern regions in 1993.  相似文献   

烟草普通花叶病与气象条件的关系   总被引：6，自引：0，他引：6  

郑美秀  蒋宗孝 《气象科技》2006,34(6):715-718

分析了气象条件对闽西北烟草普通花叶病(TMV)发生发展的影响。分析得出:温度、湿度、降水及日照等气象因子对TMV发生发展均有明显的影响,但影响程度和关键时段不尽相同,影响最大的是湿度和降水,温度次之,日照最小;TMV始发时温度起主要作用,而流行时起主要作用的是湿度和降水。建立了闽西北地区TMV发生程度的中期预测模式,并提出了防治措施。  相似文献   

骨干网络安全防护技术探讨   总被引：1，自引：2，他引：1  

周琰 《气象科技》2006,34(Z1):65-68

目前网络的开放性和共享性在方便人们使用的同时,也更容易受到攻击,网络安全问题越来越引起人们的关注。文章通过对现有中国气象局骨干网络安全防护系统的简要分析,结合当今主流的网络安全防护理论和相关软硬件技术,阐述了在骨干网络中建立集入侵检测系统、安全漏洞扫描、防火墙系统和防病毒系统于一体的多层次、全方位的网络安全防护体系的必要性,并对骨干网络安全防护系统的改进方向提出了建议。  相似文献   

肠道病毒病毒感染的季节和年龄分布特征及其与气象条件的分析     

席林华  刘培宁 《气象科学》2001,21(3):374-378

本文利用苏州市二院和苏州中医院1990-1995年住院病例资料，研究肠道感染，病毒感染的年龄、季节分布特征及其肠道发病住院与气象要素变化的关系，以求探索一定规律、指标供防病保健对策应用。  相似文献   

Sentinels in the bay: using farm fish to monitor for pathogens in the environment     

St-Hilaire  S.; Stephen  C.; Kent  M.; Ribble  C. 《ICES Journal of Marine Science》2001,58(2):369-373

  相似文献   

臭氧对空气中IBV冠状病毒的杀灭效果的研究     

洪波  王品虹  纪义国  熊祥云  汪笑宇  张立斌 《中国海洋大学学报(自然科学版)》2003,33(6):861-864

本文利用强氧化剂臭氧 O3 对空气中的冠状病毒进行杀灭试验。经不同臭氧浓度、湿度、温度处理灭活的冠状病毒于 1 0日龄鸡胚培养一代 ,进行对流免疫电泳试验检测。结果表明 ,臭氧浓度在高于 2 0 .3mg/ m3 ,作用时间超过 1 5 min时就可将病毒完全杀灭。湿度和温度对臭氧的杀毒效果也有显著影响 ,即湿度越大灭活效果越好 ,温度越高杀毒效果越明显  相似文献