小江流域滑坡对土地利用的敏感性

土地利用是人类活动与自然交叉最紧密的领域,不合理的土地利用方式对滑坡和泥石流等山地灾害具有明显的促进作用。选择小江流域为研究区,通过定量分析不同立地类型组中土地利用方式对滑坡的敏感性,发现易致灾的土地利用方式有:高海拔立地类型组中的旱地、密林地、疏林地、中盖度的草地、未利用地,中海拔立地类型组中的旱地、工矿交通用地、未利用地、中盖度的草地,低海拔立地类型组中的疏林地、高/中盖度草地、未利用地,它们的敏感性值均等于或大于0.5,易导致滑坡灾害的发生。并以敏感性值为依据进行了敏感性分区,可为流域土地利用方式选取、水土保持工程布局和山地灾害生物工程治理提供参考。     

我国灾害事件三层分类体系的研究分析

各类灾害事件都会对国家和人民的财产造成不同程度的损失,甚至还会对人民的生命构成严重威胁,不利于社会的稳定与和谐。因此,对灾害事件进行合理的界定与分类是防灾减灾工作的基础。在分析、讨论现有分类方法的基础上,先将灾害事件按其成因划分为2种灾型,又根据其发生环境将每一灾型划分为4种灾类,最后落实到每一具体灾种上,形成了灾害事件的三层分类体系,以供防灾减灾工作参考。     

流域水质管理优化决策模型研究

针对目前流域水污染难以有效控制的局面,依据已有的流域水文、水动力、水质、水生态相关机理模拟模型的研究,在考虑了流域社会经济发展条件的基础上,构建了流域水质管理优化决策模型框架体系.基于该框架体系,本文从简单流域系统优化模型、模拟与优化联合模型和时空尺度复杂优化模型3个方面对流域优化决策模型的研究发展历程进行综述,并指出其各自在发展过程中所出现的问题.最后,提出了优化决策模型面临的瓶颈问题,并从模型结构简化和适应性管理两个方面提出了相关的解决思路.     

Activity of root voles (Microtus oeconomus) under snow: social encounters synchronize individual activity rhythms

Microtine rodents usually display short-term activity rhythms synchronized by light. Social interactions have also been suggested to act as a zeitgeber, entraining individual activity, but evidence supporting this is scarce. In areas with a permanent snow cover during winter, small rodents spend most of the time in the subnivean space, between the snow cover and the ground, where they most likely are unaffected by otherwise dominating photoperiodic cues. The subnivean space, however, is fragmented, and this limits movement and may isolate individuals living just a few meters apart. These conditions provide excellent opportunities to test for the existence of social synchronization. During two winters, I experimentally decreased the subnivean fragmentation by placing out a network of corrugated aluminium sheets on the ground before snowfall, thus increasing the potential for movement and social interaction within the subnivean space. Other areas were left as controls. Intensive PIT-tag monitoring in the subnivean system provided individual activity data of root voles (Microtus oeconomus) without disturbing normal activity. The data revealed that microtines under snow displayed a free-running activity rhythm and that the activity was evenly distributed throughout the 24-h day, indicating a lack of photo-entrainment. Despite this lack of light, interacting individuals were synchronous, and pairwise synchrony decreased with decreasing potential for social interactions. These results suggest that social interactions indeed entrain microtine activity. Several possible adaptive advantages of the synchrony of microtine rodent activity have been proposed, and these theories are discussed in light of the result presented.     

海洋灾害系统研究及预测预报

海洋灾害研究是一个庞大的系统工程,其研究领域绝不能局限于海洋,应该从地球整体乃至包括整个地球的宇宙空间去认识海洋灾害的发生、发展机制、各种灾害类型在全球变化中的位置,进而最大限度地达到预测、预报、预防的目的。     

中国温带草地灾害类型及致灾原因与防治对策

目前,我国草地生产力水平极其落后,草地畜牧业发展缓慢,其主要原因是草地灾害的长期存在并日趋严重。本文通过对草地灾害的类型和致灾因素的分析,提出了相应的提高草地生产能力、改善草地生态环境和防止草地灾害发生、发展的对策。     

First application of preimplantation genetic diagnosis to neurofibromatosis type 2 (NF2)

Neurofibromatosis type 2 (NF2) is a dominantly inherited cancer predisposition syndrome that is caused bymutations in the NF2 gene. We report here the first clinical preimplantation genetic diagnosis (PGD) forNF2. A protocol was developed to simultaneously amplify the mutation and a single nucleotide polymorphism (SNP) located within the gene. The mutation and polymorphism were analysed by simultaneous fluorescent single-strand conformation polymorphism (SSCP) on an automated DNA sequencer. The mutation, carried by the male partner, was a single base pair substitution affecting a splice site in intron 4 of the gene. The female partner was infertile due to polycystic ovary syndrome and would require IVF to conceive. The couple was found to be informative at a linked intragenic SNP situated in the 5′ untranslated region of the gene. The SNP was included in the assay to reduce the risk of misdiagnosis due to allele dropout (ADO). The couple underwent three cycles of treatment during which a total of 43 blastomeres were biopsied from 31 embryos. Amplification at both loci was obtained in 35 cells (81%). A total of five embryos were transferred, two in the first cycle, two in the second and one in the third. No pregnancy ensued. The results of the diagnoses indicated that, in this couple, the inheritance of the mutation may be non-Mendelian. Out of a total of 32 embryos tested only four were found not to carry the mutation. The reasons for this apparent skew remain unknown. Copyright © 2002 John Wiley & Sons, Ltd.     

云南山地自然灾害类型及防治对策

本文从灾害成因的角度将云南山地自然灾害分为:坡面重力作用、沟谷泥石流、沟谷洪水、气象灾害、地震、流域水土流失、森林火灾等七个类型,并对各种灾害特征作了描述,系统地分析了山地灾害的形成因素,提出了一些防治对策。