Variation in Sensitivity of Aquatic Species to Toxicants: Practical Consequences for Effect Assessment of Chemical Substances

5 –10⁶ times higher compared with less sensitive species. The use of assessment factors in effect assessment procedures may lead to an underestimation of effects on the more sensitive species. For many priority pollutants there is little information on their ecotoxicity. Predictive techniques are needed to compensate for this lack of data. Knowledge of the relation between modes of action of compounds and interspecies variation in sensitivity should be integrated in risk assessment procedures in order to make more efficient use of the limited financial resources available.     

公路交通事故危险性与事故原因的灰色关联分析

交通安全既可以采用交通事故次数来评价，也可以根据交通事故的严重度进行衡量。不同的交通事故诱因，其事故后果的危险程度也不一致。运用灰色系统理论，以某段道路上交通事故多发点的“地点危险指数”为参考数列，以这些地点的不同事故诱因为比较数列，对“事故危险指数”和引发交通事故的各类事故原因之间作灰色关联分析，可以找出该路段上危害性最大的一些交通事故成因，在交通管理和交通安全宣传教育中有针对性地进行防治。本文以107国道1716—1883公里的交通事故数据为例给出了算例。     

有机食品发展与生态保护政策相关性分析

通过对有机食品发展与“三农“问题、生物多样性保护、生态省建设、清洁生产、食品安全等国家生态保护政策之间的相关性进行了分析.在我国积极发展有机食品,是在农业领域内贯彻国家生态保护政策的具体体现.     

"九寨天堂"与九寨沟景区的互动关系

九寨天堂国际会议度假旅游中心与九寨沟景区之间存在着良性的互动关系。“九寨天堂”的开发对九寨沟景区起着积极的推动作用，九寨沟景区的发展对“九寨天堂”也有着直接的推进作用和内在优化功能，通过探讨两者之间的互动关系，旨在提出它们的良性互动模式及对策。     

2005年陕西秋淋特征分析

通过对2005年陕西秋淋特征分析认为,2005年陕西秋淋明显且偏晚,降水强度大,落区广且地区较集中;秋淋造成渭河下游、汉江干流分别出现了1981年、1983年以来最大的洪峰.西太平洋副热带高压强盛稳定及适当的副高脊线位置和西伸脊点位置是秋淋期间强降水集中的主要原因,而2005年的台风活动也为陕西秋淋天气提供了有利的气候背景.     

Prenatal diagnosis of Niemann–Pick diseases types A,B and C

Prenatal diagnosis of Niemann–Pick disease types A and B is routinely accomplished by sphingomyelinase assay. For Niemann–Pick type C disease, demonstration of an abnormal intracellular cholesterol trafficking is a complex procedure, and mutational analysis (NPC1 or NPC2/HE1 gene), whenever feasible, represents a major advance. Copyright © 2002 John Wiley & Sons, Ltd.     

Tetrasomy 12p—unusual presentation in CVS

CVS direct preparations usually achieve limited resolution and are better at detecting numerical rather than structural abnormalities. A CVS direct preparation analyzed using G-banding revealed a 47,XY,+G karyotype in 5 of 11 cells and was reported as mosaic for trisomy 21. Subsequent analysis of the CVS culture found only normal male cells. Amniocentesis revealed both normal male cells and cells with an extra F-group chromosome. Fluorescence in situ hybridization (FISH) identified this chromosome to be an isochromosome from the short arm of chromosome 12 [i(12)(p10)]. The amniocyte karyotype was reported as 47,XY,+i(12)(p10)[12]/46,XY[8].ish i(12)(p10)(wcp12+), which is associated with Pallister–Killian syndrome. Reexamination of the CVS direct preparation by FISH with a chromosome 12 centromere probe confirmed the karyotype of this tissue to be 47,XY,+mar[5]/46,XY[6].nuc ish 12cen(D12Z3 × 3)/12cen(D12Z3 × 2). Thus, multiple studies, including amniocentesis and fluorescence in situ hybridization, may be required to fully and accurately evaluate abnormalities detected by CVS. This case also indicates that mosaicism for supernumerary isochromosomes may have a complex origin. Copyright © 2003 John Wiley & Sons, Ltd.     

降解菌CDS-1产呋喃丹水解酶的条件及酶学特征

Sphingomonas sp.CDS-1是一株呋喃丹高效降解菌.为了给利用该菌产生的酶去除环境中的呋喃丹残留提供一些理论依据,对CDS-1产生的呋喃丹水解酶粗酶进行了研究.结果表明,在LB培养基中,CDS-1产生呋喃丹水解酶的最适条件为pH6～8、30℃、培养30h;该酶在20～30℃、pH>6.0的条件下比较稳定;在pH6.5和30℃时显示最大的呋喃丹水解酶活性;大多数金属离子浓度在0.2mmol/L时对其酶活有促进作用;酶定域实验结果显示该酶为胞内酶.     

论可持续发展的区际关系内涵与我国西部大开发

本文在揭示可持续发展的宏观、中观、微观区际关系内涵的基础上,对我国西部大开发和如何协调区际关系,实现可持续发展提出了建议。