甲型流感病毒H5N1的siRNA设计

选用了甲型流感病毒10个毒株(全序列)和一个2004年越南毒株(部分序列)，采用自己编写的计算机程序sRNAFinder，对每个毒株的6个RNA片段的6个编码序列进行了siRNA设计．结合系统发育重建方法，利用sR-NAFinder的共有序列分析功能，对得到的6101个siRNA分子进行了计算机筛选．结果表明，设计的siRNA的分子，针对np和pb1应该是最有效的，而针对ha和na的siRNA分子设计，需要疾病流行期毒株的最新测序数据；从ns1的数据不能获得很保守的、可作为预防治疗药物的siRNA分子．图1表4参16     

Sperm competition and evidence of sperm fertilization patterns in the carrion ball-roller beetle Canthon cyanellus cyanellus LeConte (Scarabaeidae: Scarabaeinae)

Field observation and laboratory experiments were conducted to investigate sperm competition and patterns of sperm fertilization under different experimental conditions in the carrion ball-roller beetle Canthon cyanellus cyanellus. Males in nature can mate with females whose spermathecae contains fertile sperm from other males. Sperm precedence was investigated using a visible genetic marker. The progeny of red (homozygous recessive) virgin females mated once with a red male and afterward, once with a green beetle (homozygous dominant) and vice versa, revealed that regardless of its color, the last male to mate fertilized c.a. 50% of the eggs, suggesting strong sperm competition. Males were able to achieve higher levels of paternity (more than 80%) when mated ad libitum with previously mated females, although large amount of variance in paternity does not exclude the possibility of first male sperm precedence or female cryptic choice. These results suggest that repeated mating and sperm replacement are the mechanisms by which last males achieve sperm precedence.     

Structural perturbations of models used in mathematical biology

The paper discusses the importance of understanding structural perturbations of models used in mathematical biology, where we mainly focus on ecology and dynamical systems. We describe first briefly the classical modeling strategy and the derivation of model structures. Structural perturbations are then discussed, mainly in the framework of ODEs. We give some examples how insights obtained from this type of model could be transfered to other kinds of models. Finally we propose an alternative modeling strategy characterized by a systematic investigation of a models neighbourhood in an appropriately chosen model class.     

Influences of accumulated mileage and technological changes on emissions of regulated pollutants from gasoline passenger vehicles

In this study, the influences of accumulated mileage(deterioration) and technological changes(emission standards) on emission factors(EFs) of regulated pollutants(CO, HC, and NO_x) from gasoline passenger vehicles were investigated based on Inspection and Maintenance(I/M) data using the chassis dynamometer method. The accumulated mileage of passenger vehicles was significantly linearly correlated with vehicle age. For most cases,the average EFs of CO, HC and NO_x were significantly linearly correlated with accumulated mileage, indicating that emission deterioration had a significant impact on pollutant EFs.Implemented emission standards markedly influenced the EFs of regulated pollutants, and EFs markedly decreased with progressing emission standards. The present study also compared EFs of regulated pollutants between this study and the International vehicle emission(IVE) model, and marked differences in EFs were seen with variations in emission standards, vehicle types and accumulated mileage; NO_x EFs in this study were higher than in the IVE model. The results provide new insight into estimating regulated pollutant emissions using the IVE model.     

ON AN ECONOMIC VALUATION OF THE COLUMBIA-SNAKE RIVER COMPLEX1

This paper is an effort to establish a lower bound on the economic value of the Columbia and Snake Rivers to the State of Washington, so as to assess the economic consequences of diversion of waters of these rivers to other geographic regions. The uses recognized in this paper are for power generation and irrigation, although the dynamic-programming model constructed is capable of incorporating, with minor changes, returns from other uses of the rivers when the economic data can be obtained.     

由洪水泛滥的教训谈国家统一灾害管理

本文系统分析和总结了美国在洪泛平原管理中的经验教训，研究了减灾措施、行为反应及国家长期减灾目标等方面的内容，从综合的角度提出了统一的国家减灾计划。     

改建铁路沪汉蓉通道襄樊至安康段增建第二线关于环保问题的方案选线

改建铁路沪汉蓉通道襄樊至安康段增建第二线铁路原设计增建第二线线路全长361.824km,其中Dzk67+480-D zk79+480段有12km经过武当山风景名胜区。为相应国家环境保护的号召,为了尽量减少工程建设对武当山风景名胜景区古建筑群的影响,工程在选线过程中绕避古建筑群,以隧道隐蔽工程穿过,且对原生态环境影响最小。     

环境污染源信息管理系统的开发

污染源数据是重要的基础环境数据。为了配合全国污染源普查,全面掌握环境污染现状,提高对污染源数据的管理效率,利用Visual Basic和Microsoft Acess数据库相结合的技术,开发了环境污染源信息管理系统。进行了管理系统和数据库的总体设计、结构构建和操作界面设计。根据用户需求,利用Vb控件和SQL语句设计了六大功能模块,实现了对污染数据进行编辑、浏览、查询、统计分析和打印输出等功能。为企业制定节能减排的环保决策提供有力的技术支持。     

Genetic diversity and genetic differentiation of Squaliobarbus curriculus from the Pearl River based on mitochondrial D-loop sequences北大核心CSCD

Squaliobarbus curriculus is one of the most economically important edible freshwater fish in the Pearl River. To assess the level of genetic diversity and genetic variation of S. curriculus populations w ithin t he Pearl R iver, samples were collected from six geographical populations from six drainages. 978 base pairs of the D-loop sequence were obtained as a molecular marker. 106 haplotypes were defined among 170 S. curriculus individuals. Populations of S. curriculus in the Pearl River displayed a high haplotypic diversity index (h = 0.9820) and high nucleotide diversity index (π = 0.01353). T he results of genetic distance and genetic differentiation index show that genetic differentiation among S. curriculus populations is not significant. The neighbor-joining tree shows two clades. Clade A is composed of most haplotypes of S. curriculus. Clade B includes two private haplotypes from the Xijiang River. Haplotype network analysis is consistent with the results of genetic distance and genetic differentiation. The results of AMOVA analysis showed that most variation was found within populations (99.36%). Neutral test analysis explained that there was population expansion in the history of S. curriculus in the Pearl River. Xijiang River could be the center of origin, as supported by all the results. © 2018 Science Press. All rights reserved.     

堆沤处理对稻草厌氧消化产气的影响

采用厌氧消化后的消化液对稻草进行堆沤预处理,设计正交试验L9(34),考察温度、含水率、混合液悬浮固体(MLSS)及时间对厌氧消化产气量的影响,并对堆沤处理前后的稻草进行了不同有机负荷率下的产气试验.结果表明,堆沤处理后稻草总产气量比未处理提高了3%～49.5%,最优条件组合为温度30 ℃、含水率900 g·kg-1、时间10 d、MLSS 1 500 mg·L-1.在此最优条件下,处理后稻草消化的单位挥发性固体产气量为804.8 mL·g-1,与未处理稻草相比提高51.2%,产气高峰提前10 d左右.