Possibility Theory: A New Approach to Uncertainty Analysis? (3 pp)

Background, Aims and Scope The problem of the evaluation of practitioner's belief and belief-related uncertainties on LCA results obtained from different methodological choices has been addressed so far by scenario modeling, Cultural Theory perspectives and probabilistic simulation. The direct evaluation of belief and related uncertainties could be of interest, e.g. when the information available (resulting from classical uncertainty analysis or the application of the precautionary principle) do not allow one to choose between methodological alternatives leading to different LCA results and conclusions. The difficulty of modeling belief arises from the additive nature of classical measures, e.g. probabilities. Since the 1960s, non-additive measures (e.g. possibilities) have been developed and applied to model belief in real world problems. The aim of this paper is to discuss the application of possibility measures in LCA for uncertainty analysis in complement to classical approaches. Methods The nature and the meaning of possibilities are briefly introduced by comparison with probabilities (subjective or not) in order to enlighten strengths, drawbacks and complementarities. A tentative possibilistic approach based on the evaluation of a posteriori possibilities of final LCA results depending on a priori possibilities of the methodological choices behind the calculations is described, also by means of an application example. Results and Outlook. A new approach for the modeling of practitioner's belief and belief-related uncertainties in complement of classical methods of uncertainty analysis has been proposed for discussion. Uncertainty can be characterized by confidence intervals and indexes that could help practitioners in making methodological choices and could improve the interpretation and reliability of LCA results, still increasing its sophistication.     

GM plants as sources of im/possibility: a developmental systems view of stabilization

This paper generates a heuristic understanding of the stabilization dynamic of genetically modified plants. This heuristic, the paper argues, can provide a fruitful platform for studying the political dimensions embedded in GM plants. Focusing on stabilization is important, because outside laboratories a plant can have an intermediating role only as a cultivar; as something which has integrated into biological processes and human practices. The actual stabilizing entity is not just an object, but a dynamic analogous to what is called a developmental system. The empowering or suppressing consequences of GM plants depend significantly on the qualities of this spatio-temporal order stabilizing; on the “possibility space” it opens up. Moreover, stabilization connects and makes things possible, but it does not do so automatically, predictably – or for everyone. Centralized control may support stability, but it may also increase vulnerability by reducing local possibility space.     

Potentiality and human embryos

Consideration of the potentiality of human embryos to develop characteristics of personhood, such as intellect and will, has figured prominently in arguments against abortion and the use of human embryos for research. In particular, such consideration was the basis for the call of the US President's Council on Bioethics for a moratorium on stem cell research on human embryos. In this paper, I critique the concept of potentiality invoked by the Council and offer an alternative account. In contrast to the Council's view that an embryo's potentiality is determined by definition and is not affected by external conditions that may prevent certain possibilities from ever being realized, I propose an empirically grounded account of potentiality that involves an assessment of the physical and decisional conditions that may restrict an embryo's possibilities. In my view, some human embryos lack the potentiality to become a person that other human embryos have. Assuming for the sake of argument that the potential to become a person gives a being special moral status, it follows that some human embryos lack this status. This argument is then used to support Gene Outka's suggestion that it is morally permissible to experiment on 'spare' frozen embryos that are destined to be destroyed.     

Jolly—Seber法中种群存活率估算的探讨

在Jolly-Seber法中,存活率为其核心参数之一。一些作者指出,采用Jolly-Seber法估算标志重捕数据有时候会出现存活率大于1的情形。本文就这一情形做了相应的分析,认为产生这一现象的原因为标志个体间不具有等捕性或等存活率所致。在设计标志重捕取样的野外调查中,应设法提高重捕率以增加估计精度。     

水稻主要害虫最优管理决策研究

首先论述概论,其中包括:1)阐述了害虫综合管理(IPM)技术,明确了水稻害虫综合管理的现状及存在的问题,并指出;人的因素是IPM成败的关键.2)首先提出了害虫防治经历了定性研究、定量研究以及定性和定量综合一体研究3个阶段的观点.因此,能够综合利用定性信息(包括专家知识)和定量信息的专家系统(系统中包含模型)的研制和应用,有助于作出更高层次的决策.可以认为,这将是IPM,特别是生态系统综合管理的发展方向.     

Jolly-Seber法中种群存活率估算的探讨

在Jolly Seber法中 ,存活率为其核心参数之一。一些作者指出 ,采用Jolly Seber法估算标志重捕数据有时候会出现存活率大于 1的情形。本文就这一情形做了相应的分析 ,认为产生这一现象的原因为标志个体间不具有等捕性或等存活率所致。在设计标志重捕取样的野外调查中 ,应设法提高重捕率以增加估计精度     

多气候情景下中国森林火灾风险评估

森林火灾风险主要取决于致灾因子、承灾体以及防灾减灾能力,综合评估和预测森林火灾风险是制定科学的林火管理政策的基础.本文基于经典自然灾害风险模型和可获取数据构建森林火灾风险评估模型与指标体系,评估过去和未来的森林火灾风险.未来气候情景数据包括RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5下5个全球气候模式(GFDL-ESM2M、HadGEM2-ES、IPSL-CM5A-LR、 MIROC-ESM-CHEM和NorESM1-M)日值数据.根据最高温度、最小相对湿度、平均风速和每日降水量分别计算1987—2050年历史观测数据和未来气候情景下各格点每日火险天气指数系统中各个指数.结果表明: 1987—2010年,森林火灾风险高和很高的区域分别占21.2%和6.2%,主要分布在大兴安岭和长白山地区、云南大部分区域和南方零散分布的区域.森林火灾可能性高和很高的区域主要分布在东北和西南地区,分别占森林面积的13.1%和4.0%.与观测时段相比,2021—2050年RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5情景下森林火灾可能性高和很高的区域分别增加0.6%、5.5%、2.3%和3.5%,华北地区增幅明显.气候变化引起的森林火灾高风险区域有些增加,RCP 8.5情景下增幅最明显(+1.6%).     

A Simulation-Assessment Modeling Approach for Analyzing Environmental Risks of Groundwater Contamination at Waste Landfill Sites

An integrated simulation-assessment modeling approach for analyzing environmental risks of groundwater contamination is proposed in this paper. It incorporates an analytical groundwater solute transport model, an exposure dose model, and a fuzzy risk assessment model within a general framework. The transport model is used for predicting contaminant concentrations in subsurface, and the exposure dose model is used for calculating contaminant ingestion during the exposure period under given exposure pathways. Both models are solved through the Monte Carlo simulation technique to reflect the associated uncertainties. Based on consideration of fuzzy relationships between exposure doses and cancer risks, risk levels of different exposure doses for each contaminant can be calculated to form a fuzzy relation matrix. The overall risks can then be quantified through further fuzzy synthesizing operations. Thus, probabilistic quantification of different risk levels (possibilities) can be realized. Results of the case study indicate that environmental risks at the waste landfill site can be effectively analyzed through the developed methodology. They are useful for supporting the related risk-management and remediation decisions.     

History of phage research as viewed by a European

Abstract: The history of phage research as the origin of molecular biology is related as seen by a scientist located at that critical time in Geneva. The preponderant influence of Max Delbrück on these developments is traced as a consequence of his personal charisma. Jean Weigle, former professor of experimental physics in Geneva and later research fellow with Delbrück, acted as an important ambassador to the European groups.