长沙黄花国际机场鸟类群落物种多样性分析

为了获得长沙黄花国际机场鸟击防范工作所需的鸟类基础性资料,从2005年9月~2006年8月,通过对机场地区5种生境类型鸟类群落的调查与监测,记录到鸟类112种,属16目32科。其中46种属东洋界种类、45种属古北界种类、21种属广布种;留鸟46种、夏候鸟25种、冬候鸟29种、旅鸟12种。经RB频率指数测算,鸟类群落的优势种为白头鹎(Pycnonotus sinensis)、乌鸫(Turdus merula)和树麻雀(Passer montanus)。按鸟类生境分布系数划分,广布型的鸟类有44种,是该区鸟类群落组成的主体。鸟类群落的Shannon-Weiner物种多样性指数为1.607,均匀性指数为0.784。     

Ranking birdstrike risk: A case study at Huanghua International Airport, Changsha, China

Bird-aircraft collisions (birdstrikes) pose a major threat to aviation safety worldwide. The bird distribution at the airfield of Huanghua International Airport in Changsha, Hunan Province, China, was investigated between December of 2006 and December of 2008, to study birdstrike avoidance and aviation safety. A total of 60 bird species was found and their risks were assessed by a birdstrike ranking assessment system. The highest-risk species were Barn swallow (Hirundo rustica), Red-rumped swallow (H. daurica), Grey-headed lapwing (Vanellus cinereus), Pintail snipe (Gallinago stenura), Oriental skylark (Alauda gulgula), Little egret (Egretta garzetta), and Eurasian woodcock (Scolopax rusticola), whereas the lowest-risk species were Black-capped kingfisher (Halcyon pileata) and White-throated kingfisher (H. smyrnensis). Through a hierarchical cluster analysis, all species were classified as four groups: (1) the extremely high-risk group with a risk level between 84% and 100%, which includes bird species ranked from the 1st to the 16th, and is the priori group in birdstrike prevention; (2) the high-risk group with a risk level between 71% and 81%, which includes bird species ranked from the 17th to the 28th, and is the sub-prior group in birdstrikes; (3) the sub-high-risk group with a risk level between 60% and 69%, which includes bird species ranked from the 29th to the 43rd, and is the concern group in birdstrike prevention; (4) the low-risk group with a risk level between 60% and 69%, which includes bird species ranked from the 44th to the 60th, and is the negligible group in birdstrike prevention. Finally, the first 16 bird species with high-risk values, which are the main focus of birdstrike prevention, were categorized as six prevention groups by a hierarchical cluster analysis. Therefore, this study provides targeted implementations for birdstrike prevention at Huanghua International Airport, Changsha.     

心得安预防门脉高压引起初次消化道出血的疗效观察

目的:观察心得安预防门脉高压症消化道出血的疗效、不良反应及临床应用的注意事项。方法选择本院102例肝硬化食道胃底静脉曲张患者,随机分为心得安组(52例)和安慰剂组(25例)。对出血发作的病情、持续的时间、输血量的多少、对止血药物的反应、生存期以及副反应进行观察。结果随访12个月,治疗组出血发生率为19.2%,安慰剂组为28%,两组差异无显著意义。随访20个月,治疗组出血发生率28.8%,安慰剂组48%,两组比较有显著性差异(P<0.05),但生存时间无显著差异。结论心得安对预防门脉高压症消化道初次出血有明显疗效,但不能延长肝硬化病人的生存期。     

芳香羧酸衍生物驱避剂的非线性定量构效关系

【目的】驱避剂可使害虫不敢接近受用者从而保护受用者免遭其害。建立高精度、可解释性强的非线性定量构效关系(quantitative structure activity relationship, QSAR)模型对设计合成新的高效昆虫驱避剂有重要意义。【方法】基于37个芳香羧酸类化合物对家蝇Musca domestica的驱避活性,以量子化学计算软件PCLIENT获取每一化合物初始描述符,以二元矩阵重排过滤器、多轮末尾淘汰实施特征非线性筛选,以支持向量回归(support vector regression, SVR)建立非线性QSAR模型,以SVR非线性解释体系分析各保留描述符对驱避活性的影响。【结果】1 542个初始描述符的SVR模型F=1.2,特征筛选后6个保留描述符的SVR模型F=184.6,特征筛选对QSAR模型精度有重要影响。6个保留分子描述符的重要性依次为p4BCD>GATS7v>T(O..O)> JGI8>SssO>nArCONR2。【结论】保留描述符与芳香羧酸类化合物对家蝇驱避活性的非线性关系明显,获得了高精度、普适性强的非线性SVR-QSAR模型。