Origin of espanola island and the age of terrestrial life on the galapagos islands

Geological studies of Espa?ola (Hood) Island, Galápagos, Ecuador, indicate that the island had a subaerial rather than a submarine origin. Because the younger lava flows are dated at 3 million years, Espa?ola has apparently existed as an island for at least that long. Thus terrestrial life may have existed or arrived on the Galápagos Islands at least 3 million years ago, more than twice as long as had been assumed.     

全国出入境动植物检验检疫工作会议在昆明召开

20 0 3年 2月 1 8～ 2 0日 ,国家质量监督检验检疫总局在云南昆明召开了全国出入境动植物检验检疫工作会议。来自国家质检总局直属单位和检验检疫局的 1 2 0多名代表出席会议。国家质检总局党组副书记、副局长王秦平 ,云南省人民政府副省长邵琪伟出度会议并讲话。会议由国家质检总局党组成员、动植司司长夏红民主持。王秦平副局长代表国家质检总局党组对 2 0 0 2年出入境动植物检验检疫工作所取得的成绩做了充分肯定 ,并对今后动植物检验检疫工作提出了新要求 :要抓源头 ,严把国门 ,进一步提高工作质量 ;要合理运用世界贸易组织 (ＷＴＯ)规…     

RT—PCR检测南方菜豆花叶病毒

根据南方菜豆花叶病毒（ＳＢＭＶ）两株系Ｂ和Ｃ的核酸序列设计两对引物，利用ＲＴ－ＰＣＲ可以特异地区分纯化的和０．２ｇ病叶中的两株系，ＲＴ－ＰＣＲ检测ＳＢＭＶ－Ｂ的灵敏度为１０ｐｇ。     

农业外来生物入侵种研究现状与发展趋势

目前国际上对外来生物入侵种的研究主要在个体水平上研究外来种对新环境的进化与适应,本地种对生物入侵后发生的进化调整;种群和群落水平上研究外来种的定居、潜伏、竞争和暴发;生态系统水平上研究生境的可入侵性和外来种对生态系统结构和功能的影响等几个方面。风险分析标准化与定量化、检疫鉴定快速化、除害技术安全化、信息管理全球化是全世界对外来物种入侵管理与科研的焦点问题。本文依据外来物种入侵的形成和扩散暴发过程,提出了超前预防和综合管理等未来需要解决的关键问题。     

Effect of dietary n-6-to-n-3 fatty acid ratio on complete blood and total white blood cell counts, and T-cell subpopulations in aged dogs

OBJECTIVE: To determine effect of diets with variable n-6-to-n-3 fatty acid (FA) ratio on CD4+ and CD8+ T-lymphocyte subpopulations, and on results of routine laboratory analyses (CBC and total WBC count, serum biochemical analyses, and urinalysis). ANIMALS: 20 healthy, aged (9.5 to 11.5 years old) female Beagles. PROCEDURE: Dogs were fed 1 of 3 diets that contained 6% fat by weight but differed in amounts of n-6 and n-3 FA. For 11 weeks, 6 dogs were fed a low concentration of n-3 FA (ratio, 31:1), 7 were fed a medium concentration (5.4:1), and 7 were fed a high concentration (1.4:1). Preprandial blood and urine samples were collected before beginning the study and at 8 weeks for evaluation of laboratory variables. Before and at 3, 6, and 8 weeks during the study, blood was drawn for total WBC and lymphocyte counts and for characterization of T-cell subpopulations. At 8 and 10 weeks, dogs were vaccinated with keyhole limpet hemocyanin suspension. Blood was drawn 4 days after each vaccination, and lymphocytes were isolated for flow cytometry. Effects of diet and vaccination on each variable were determined. RESULTS: After vaccination, total lymphocyte count increased and CD4+ T lymphocyte count and the CD4(+)-to-CD8+ ratio decreased in dogs consuming the diet with n-6-to-n-3 FA ratio of 1.4:1. CONCLUSION: Feeding a diet with n-6-to-n-3 FA ratio of 1.4:1 had significant effects on CD4+ T lymphocytes in healthy, aged Beagles after vaccination.     

Polymerase chain reaction tests for the identification of Ross River, Kunjin and Murray Valley encephalitis virus infections in horses

OBJECTIVE: To develop and validate specific, sensitive and rapid diagnostic tests using RT-PCR for the detection of Ross River virus (RRV), Kunjin virus (KV) and Murray Valley encephalitis virus (MVEV) infections in horses. METHODS: Primer sets based on nucleotide sequence encoding the envelope glycoprotein E2 of RRV and on the nonstructural protein 5 (NS5) of KV and MVEV were designed and used in single round PCRs to test for the respective viruses in infected cell cultures and, in the case of RRV, in samples of horse blood and synovial fluid. RESULTS: The primer pairs designed for each of the three viruses amplified a product of expected size from prototype viruses that were grown in cell culture. The identity of each of the products was confirmed by nucleotide sequencing indicating that in the context used the RT-PCRs were specific. RRV was detected in serums from 8 horses for which there were clinical signs consistent with RRV infection such that an acute-phase serum sample was taken and submitted for RRV serology testing. The RRV RT-PCR was analytically sensitive in that it was estimated to detect as little as 50 TCID50 of RRV per mL of serum and was specific in that the primer pairs did not amplify other products from the 8 serum samples. The RRV primers also detected virus in three independent mosquito pools known to contain RRV by virus isolation in cell culture. Samples from horses suspected to be infected with KV and MVEV were not available. CONCLUSION: Despite much anecdotal and serological evidence for infection of horses with RRV actual infection and associated clinical disease are infrequently confirmed. The availability of a specific and analytically sensitive RT-PCR for the detection of RRV provides additional opportunities to confirm the presence of this virus in clinical samples. The RT-PCR primers for the diagnosis of KV and MVEV infections were shown to be specific for cell culture grown viruses but the further validation of these tests requires the availability of appropriate clinical samples from infected horses.