不同地貌背景下民族村农户生计脆弱性及其影响因子

基于2014年贫困户实地调查数据,运用集对分析和障碍度模型对宁夏海原县农户生计脆弱性及其胁迫因子进行实证分析.结果表明: 海原县农户生计脆弱性总体较高且呈现地貌和民族差异化,平原区、河谷川地山间洼地农户生计脆弱性低于土石山区、黄土梁区和中山地貌区;回汉混居村农户生计脆弱性高于纯回族与纯汉族村.农户自身必要资产的缺乏和外部地理环境敏感性的胁迫是海原县农户生计脆弱的深层原因.生计结构不合理与生计方式单一导致生计脆弱性长期积累;地理环境的不易改变使扶贫资源的地区可进入性降低.农户生计应对能力的提高需建立明确的村级水权分配制度,实施教育贫困户对口帮扶,加大生计方式多元化转型的成本投入,开发村域连锁综合商品市场.农户生计脆弱性的治理应把“公路村村通”建设放在“村村通工程”更突出的位置,坚持气象防灾和保险企业减灾相结合,开发农业生产保险系统.     

Ecological risk assessment for key industrial development zones in the areas surrounding the Bo Sea in China

Although industrial zones have been attracting attention around the world due to their huge regional economic contributions, ecological risk assessment for industrial zones has gained little attention. In high ecological risk locations, landslides, earthquakes, and floods often occur, often causing extensive damage, including loss of human lives and property. However, during planning, development, and management of industrial zones, only the socioeconomic risks are usually taken into account and the risks of ecological factors affecting industries are often ignored. In this article, we put forward a procedure to link different risk factors and their GIS-determined spatial variation to estimate the ecological risk to key industrial zones in the 98,200 km² area surrounding the Bo Sea. The ecological risk factors in this region are mainly rainstorms, geological risks, storm surges, seawater intrusion, soil erosion, and earthquakes. The key industrial development zones located in this area were classified into three industry types according to the sensitivity of the industry to different ecological risk factors. Using historical data and hierarchical analytic process as well as weighted ecological risk values, industry susceptibility was determined. We integrated the risk values of each ecological factor with the susceptibility of each industry type to each ecological factor in order to quantify the total risk associated with each key industry zone in the region. The results showed that high ecological risk existed in Liaodong and Laizhou Bay and Tianjin and Dalian seashore.     

Sequential monitoring of randomization tests: stratified randomization

In many clinical trials, it is desirable to establish a sequential monitoring plan, whereby the test statistic is computed at an interim point or points in the trial and a decision is made whether to stop early due to evidence of treatment efficacy. In this article, we will set up a sequential monitoring plan for randomization-based inference under the permuted block design, stratified block design, and stratified urn design. We will also propose a definition of information fraction in these settings and discuss its calculation under these different designs.     

群落排表分类的两种数学方法

本文描述两种执行群落排表分类的数学方法:X²分类法和信息熵分类法,并以德国西北部草地数据为例进行了应用和分析。结果表明这两个方法都是有效的群落排表分类方法,它们所排的群落表可直接地反映群落类型和种类组成之间的关系,体现了Braun-Blanquet传统排表法的特点。     

Changes of Chlorophyll Metabolism During the Albinic Stage of a Wheat Mutant

Changes of chlorophyll metabolism during the albinic stage including both degreening and regreening processes were studied. The results indicated that an decrease of Cato content was nor the cause of mutant degreening, and that the mutant belonged to the total Chl-dificient type. The changes of Chlase activity level indicated that Chi breakdown was not the main factor which led to degreen of the mutant. A greater changes of content of intermediates of Chl biosynthesis during the albinic period δ-aminolevulinic acid (ALA) and porphohilinogen (PBG) were accumulated, but uroporphyrin Ⅲ (Uro Ⅲ ), protoporphyrin IX (Proto IX ), Mg-protoporphyrin IX (Mg-Proto IX ) and protochlorophyll (ide) (Pchl (lide)) were decreased. Specialy during the degreening process Uro Ⅲ was gradually decreased, but an initiation of regreening, the Uro Ⅲ was markedly accmulated. It was proved that there was a blockage in Chi biosynthesis in the mutant, which could be somewhere in the formation of uroporphyrinogen Ⅲ (Urogen Ⅲ ).     

灰旱獭年龄鉴定的方法

有关灰旱獭Marmota baibacina的年龄鉴定,等(1973)曾以臼齿磨损度作过描述,并划分出6个年龄组,但缺少年龄与个体发育关系的资料。国内以牙齿磨损度鉴定灰旱獭年龄与种群年龄组成尚未见报道。 灰旱獭为天山山地的优势鼠种,分布广,数量多,既是自然疫源性疾病的宿主动物,又是重要的毛皮兽。我们于1983年6-8月对该旱獭的年龄鉴定方法及其年龄组成进行了研究,现将结果报道如下。     

神经刺激仪经肌间沟定位臂丛神经分支行臂丛麻醉效果分析

目的：比较神经刺激仪经肌间沟定位臂丛神经分支行肌间沟臂丛神经阻滞麻醉的效果及安全性。方法：选择拟行肌间沟臂丛神经阻滞的上肢手术的患者80例,ASAI或II级,随机均分为A组和B组,每组40例患者。两组均给予1％的利多卡因＋0．375％耐乐品20mL。记录完成操作所需时间、感觉神经阻滞起效时间、感觉神经阻滞完善时间、运动神经阻滞起效时间、运动神经阻滞完善时间;评价手术区域麻醉效果（优、良、差、失败）;观察并记录并发症。结果：A组完成操作所需时间（5．01±1．40）min,明显长于B组（2．83＋O．87）min（P〈0．01）。A组感觉阻滞起效时间（4．48±1．36）min,明显短于B组（7．0±2．06）min（P〈0．01）;A组运动阻滞起效时间（4．88＋±1．18）min,明显短于B组（7．0±1．67）min（P〈0．01）。A组感觉阻滞完善时间（11．73±3．62）短于B组（13．33±3．02）min（P=0．033）。A组运动阻滞完善时间（11．18±2．73）短于B组（12．41±2．48）min（P=0．038）;麻醉效果优等率A组为87．5％,B组为67．5％,差异有统计学意义x^2=4．588,P=0．032;优良率A组为97．5％,B组为90．0％,差异无统计学意义x2=1．920,P=0．166;A组、B组均未出现严重麻醉并发症。结论：A组行肌间沟臂丛神经阻滞比B组阻滞操作时间长,但神经阻滞麻醉效果好,神经阻滞完善率高。     

Estimation of rates of oxygen uptake and carbon dioxide evolution of animal cell culture using material and energy balances

Material and degree of reductance balance equations are used to estimate the rates of oxygen uptake and carbon dioxide evolution of animal cell cultures. Lumped compositions, molecular weight and reductance degree of cellular protein, monoclonal antibody, biomass and amino acid consumption (excluding glutamine and alanine) are found to be relatively constant for different hybridoma cell lines and may be used as regularities. The calculated rates of oxygen uptake and carbon dioxide evolution agree well with experimental values of several different cultures reported in the literature. This simple method gives the same results as calculated on the basis of a detailed metabolic reaction network. This revised version was published online in July 2006 with corrections to the Cover Date.     

Localization of the K+ lock-In and the Ba2+ binding sites in a voltage-gated calcium-modulated channel. Implications for survival of K+ permeability.

Using Ba2+ as a probe, we performed a detailed characterization of an external K+ binding site located in the pore of a large conductance Ca2+-activated K+ (BKCa) channel from skeletal muscle incorporated into planar lipid bilayers. Internal Ba2+ blocks BKCa channels and decreasing external K+ using a K+ chelator, (+)-18-Crown-6-tetracarboxylic acid, dramatically reduces the duration of the Ba2+-blocked events. Average Ba2+ dwell time changes from 10 s at 10 mM external K+ to 100 ms in the limit of very low [K+]. Using a model where external K+ binds to a site hindering the exit of Ba2+ toward the external side (Neyton, J., and C. Miller. 1988. J. Gen. Physiol. 92:549-568), we calculated a dissociation constant of 2.7 mircoM for K) at this lock-in site. We also found that BK(Ca) channels enter into a long-lasting nonconductive state when the external [K+] is reduced below 4 microM using the crown ether. Channel activity can be recovered by adding K+, Rb+, Cs+, or NH4+ to the external solution. These results suggest that the BK(Ca) channel stability in solutions of very low [K+] is due to K+ binding to a site having a very high affinity. Occupancy of this site by K+ avoids the channel conductance collapse and the exit of Ba2+ toward the external side. External tetraethylammonium also reduced the Ba2+ off rate and impeded the channel from entering into the long-lasting nonconductive state. This effect requires the presence of external K+. It is explained in terms of a model in which the conduction pore contains Ba2+, K+, and tetraethylammonium simultaneously, with the K+ binding site located internal to the tetraethylammonium site. Altogether, these results and the known potassium channel structure (Doyle, D.A., J.M. Cabral, R.A. Pfuetzner, A. Kuo, J.M. Gulbis, S.L. Cohen, B.T. Chait, and R. MacKinnon. 1998. Science. 280:69-77) imply that the lock-in site and the Ba2+ sites are the external and internal ion sites of the selectivity filter, respectively.