Resource exploitation and cross-region growth trajectories: nonparametric estimates for Chile

As a sector of primary concern for national development strategies, mining keeps stimulating an intensive debate in Chile, regarding its role for long-term growth. Partly drawn on theoretical contributions to growth and mineral resource accounting, this analysis assesses patterns of economic growth across Chilean regions. The theoretical and methodological rationale for focusing on weak sustainability, by testing convergence across regions in a distribution dynamics perspective, is first discussed. This is followed by a brief review of policy issues and previous empirical findings of concern to Chile's mining and regional growth. Panel data over the period 1960-2001 are analysed, with growth measured in terms of both income per capita as such, and sustainable measures of this variable. Kernel density and quantile regression estimates indicate persistent bimodal (if not possibly trimodal) distribution of nationally standardised regional incomes per capita, whereby conditions for cross-region convergence are matched only within the inner range of this distribution.     

薄层色谱紫外分光光度法定量测定微生物发酵产物辅酶Q10

报道了一种微生物发酵液中辅酶Q10的定量检测方法.该方法分为两个步骤:第一步是离心收集菌体和结合使用超声波处理的辅酶Q10丙酮抽提;第二步是硅胶薄层色谱,根据标样位置取产物斑点乙醇洗脱后用紫外分光光度法测定辅酶Q10含量.结果表明,该方法具有操作简便、重复性好、相对误差小等优点,可用于细菌发酵生产辅酶Q10研究过程中发酵产物的快速定量检测.图2表2参6     

亚硝酸盐型甲烷厌氧氧化微生物特性研究进展

亚硝酸盐型甲烷厌氧氧化(nitrite-dependent anaerobic methane oxidation,N-DAMO)是新近发现的生物反应,是偶联碳氮循环的关键环节,是环境领域和微生物领域的重大发现.N-DAMO的发现对于完善碳氮生物地球化学循环、丰富微生物学内容和研发新型生物脱氮除碳工艺均具有巨大的推动作用.催化N-DAMO反应的微生物为Candidatus Methylomirabilis oxyfera(M.oxyfera),其隶属于一新发现的细菌门——NC10门.近年来,M.oxyfera的生物学研究取得了许多突破性进展,如初步探明了其个体形态特征、细胞化学组分特征、富集培养特征、生理生化特征及生态学特征,最突出的例子包括发现了M.oxyfera独特的细胞(星状)形态及特殊的脂肪酸(10Me C16∶1Δ7)组分等.最近,N-DAMO的机制研究方面也有了突破性进展:发现了地球上第4种生物产氧途径.目前认为,M.oxyfera具有内产氧功能,其首先将NO-2还原为NO,然后将2分子NO进行歧化反应生成N2和O2,最后利用生成的O2对甲烷进行氧化.本文系统地介绍了M.oxyfera各方面的微生物特性.     

循环热处理对高速钢超塑性的影响

此文研究了循环热处理工艺对W6Mo5Cr4V2钢超塑性的影响.结果表明:该钢在1040℃两次循环淬火是实现其超塑性的最佳热处理工艺;按此工艺进行预处理后,在810℃、初始应变速率为5.56×10~(-1)s~(-1)的条件下,该钢的超塑延伸率可达187%.     

Ecosystems and human health: The local benefits of forest cover in Indonesia

This paper documents the effect of primary forest cover loss on increased incidence of malaria. The evidence is consistent with an ecological response. I show that land use change, anti-malarial programs or migration cannot explain the effect of primary forest cover loss on increased malarial incidence. Falsification tests reveal that the effect is specific to malaria, with forest cover having no discernible effect on other diseases with a disease ecology different from that of malaria. Back-of-the-envelope calculations indicate that the morbidity-related malaria-reducing local benefits of primary forests are at least $1-$2 per hectare.     

The ecological insurance trap

Common pool resources often insure individual livelihoods against the collapse of private endeavors. When endeavors based on private and common pool resources are interconnected, investment in one can put the other at risk. We model Senegalese pastoralists who choose whether to grow crops, a private activity, or raise livestock on common pool pastureland. Livestock can increase the likelihood of locust outbreaks via ecological processes related to grassland degradation. Locust outbreaks damage crops, but not livestock, which are used for savings and insurance. We show the incentive to self-protect (reduce grazing pressure) or self-insure (increase livestock levels) changes with various property rights schemes and levels of ecological detail. If the common pool nature of insurance exacerbates the ecological externality even fully-informed individuals may make risk management decisions that increase the probability of catastrophe, creating an “insurance trap.”