Ames测试不确定性分析

Ames测试具有实验周期短、简便的优点,是目前普遍采用的检测化合物致突变性的初筛方法,但Ames测试仍有一定的不确定性.本文主要依据本实验室的研究结果分析了Ames测试中测试菌株、统计回复子数目的时间及2倍判定标准给测试结果带来的不确定性,对影响Ames测试结论存在假阳性及假阴性的因素做了进一步分析与讨论.图6表1参19     

城市水循环途径及影响分析

通过对城市水循环途径及人类对自然界水循环影响因素分析，确定城市水资源优先开发、利用次序，提出城市水资源形成良性循环的必要条件。     

Association between resiliency and posttraumatic growth in firefighters: the role of stress appraisal

The purpose of this study was to establish the relation between resiliency and the level of positive changes, comprising posttraumatic growth in a group of firefighters experiencing job-related traumatic events and the mediating role of stress appraisal in this relation. The study was performed on a group of 100 firefighters from firefighting and rescue brigades, out of which 75 admitted to experiencing a traumatic event. Firefighters covered by the study were on average 31.51 years old (SD?=?6.34). A Polish version of Posttraumatic Growth Inventory, the Resiliency Assessment Scale and Stress Appraisal Questionnaire were used in the study. The results have shown that 22.7% of firefighters displayed low, 58.6% average and 18.7% high intensity of positive changes resulting from a traumatic event. Resiliency poorly correlates with posttraumatic growth expressed in changes in self-perception, and strongly correlates with stress appraisal, negatively correlates with threat and harm/loss and positively correlates with challenge. Appraisal of stress as a threat and challenge appeared to be mediators of the relationship between resiliency and posttraumatic growth.     

Proactive and reactive helping: Contrasting the positive consequences of different forms of helping

Research on helping has identified positive consequences of helping for the helper, beneficiary, group, and organization. Recent research, however, raises concerns about contingencies that influence the outcomes of helping and suggests the need for a more nuanced perspective on the positive outcomes of helping. In this paper, we develop a novel theoretical perspective to address these contingencies by differentiating between proactive helping and reactive helping. Drawing from the two main theoretical frameworks, which have been used as the basis for studying helping—social exchange theory and functional motives theory—we discuss differences in the positive consequences of reactive and proactive helping for helpers, dyads, groups, and organizations. We submit that reactive helping facilitates heedful relationships, such that it creates and perpetuates social exchange norms that benefit others in the group. Conversely, we posit that proactive helping is often based on fulfilling personal needs, such that it benefits the self in terms of reputational benefits, well‐being, favorable self‐evaluations, need satisfaction, and self‐development. We discuss theoretical implications of this framework for future research on the positive consequences of helping. Copyright © 2012 John Wiley & Sons, Ltd.     

基于场动力理论的建筑工人人格特质、情绪与不安全行为关系研究*

为深入探讨建筑工人人格特质、情绪与不安全行为之间的作用关系,提高建筑工人安全认知能力,以293名一线建筑工人为调查对象,基于场动力理论,构建人格特质和情绪对不安全行为影响机制的理论模型,实证检验人格特质和情绪对不安全行为的预测作用以及情绪调节效应。研究结果表明:外倾性、神经质、开放性3种人格正向预测不安全行为显著;正负性情绪对不安全行为水平具有显著影响,正性情绪在外倾性-不安全行为和神经质-不安全行为间具有显著调节效应,负性情绪在责任心-不安全行为和开放性-不安全行为间具有显著调节效应。研究结果可为建筑施工企业根据工人个性化心理特征,溯源工人自身安全问题,为后续开展分类干预管理和矫正不安全行为提供理论支持。     

湖北省农地资源正外部性价值量估算——基于对农地社会与生态之功能和价值分类的分析

农地资源的正外部性直接或间接对人类福利产生影响，但由于市场机制的自身缺陷导致人们对其价值缺乏定量认识，致使农地资源得不到应有的保护，造成向城市的过度流转。以湖北省为例，在将农地资源正外部性划分为提供社会保障、保证粮食安全以及提供生态服务3个方面的基础上，以2006年为评估期日，尝试用市场价格评估的方法对其年价值和无限年期的总价值进行了估算。结果显示：2006年湖北省农地资源在提供社会保障方面的年价值及无限年期价值分别为87460元/hm2·a和34 70635元/hm2；粮食安全保障功能的年价值及无限年期价值分别为32209元/hm2·a和12 78135元/hm2；生态服务功能的年价值及无限年期价值分别为4 34855元/hm2·a和172 56151元/hm2。最终核算出湖北省正外部性的年价值总量及无限年期价值总量分别为5 54524元/hm2·a和220 04921元/hm2，这部分无法通过市场价格表现的价值大致与湖北省农地经济产出价值相当，甚至略高出5%~38%，无疑是农地价值中不容忽视的重要组成部分，应当引起土地管理者和社会决策者的充分重视。农地城市流转的失控和对农地保护的忽视实质上就是对农地正外部效用的抛弃和破坏，最终将阻碍社会经济的可持续发展。     

影响中小企业实施积极主动型环境策略的管理因素分析

通过对以往实证性研究文献的回溯,分析了影响中小企业作出积极主动型环境策略选择的某些管理层面的因素及其变化,并提出了今后我国在该领域的研究方向和建议。     

新乡冬季PM2.5中金属元素与水溶性离子年际变化及其来源解析

为了探究新乡地区年际间冬季PM_(2.5)组分的变化特征和污染来源,于2015年冬季和2016年冬季分别在新乡市区进行连续1个月的膜采样,测定PM_(2.5)质量浓度、金属元素含量及其水溶性离子成分含量,并结合气象因素进行分析.结果表明,新乡地区2015年和2016年冬季采样期间PM_(2.5)的质量浓度日均值分别为226μg·m~(-3)和224μg·m~(-3),污染水平较高.观测期间,新乡冬季PM_(2.5)中Cd和Pb金属元素富集明显,富集因子超过1000.且与2015年相比,2016年金属元素(除Ag和Ni)浓度下降约7. 83%～73. 33%,富集程度均趋于降低.水溶性离子以SO_4~(2-)、NO_3~-和NH_4~+这3种为主,2016年在PM_(2.5)中占比上升25. 1%.综合两种成分分析,新乡地区的PM_(2.5)污染呈现出金属污染向二次水溶性离子污染转移的趋势.综合PCA和PMF源解析结果显示,新乡市冬季有4种主要排放源,即尘土、二次源、工业源和化石燃料燃烧源,2015年冬季主要来源是土壤和建筑扬尘混合源,贡献率37. 46%,2016年主要来源是交通及工业生产中的二次气溶胶污染源,贡献率为34. 94%.     

Using biological data from field studies with multiple reference sites as a basis for environmental management: the risks for false positives and false negatives

Field surveys of biological responses can provide valuable information about environmental status and anthropogenic stress. However, it is quite usual for biological variables to differ between sites or change between two periods of time also in the absence of an impact. This means that there is an obvious risk that natural variation will be interpreted as environmental impact, or that relevant effects will be missed due to insufficient statistical power. Furthermore, statistical methods tend to focus on the risks for Type-I error, i.e. false positives. For environmental management, the risk for false negatives is (at least) equally important. The aim of the present study was to investigate how the probabilities for false positives and negatives are affected by experimental set up (number of reference sites and samples per site), decision criteria (statistical method and α-level) and effect size. A model was constructed to simulate data from multiple reference sites, a negative control and a positive control. The negative control was taken from the same distribution as the reference sites and the positive control was just outside the normal range. Using the model, the probabilities to get false positives and false negatives were calculated when a conventional statistical test, based on a null hypothesis of no difference, was used along with alternative tests that were based on the normal range of natural variation. Here, it is tested if an investigated site is significantly inside (equivalence test) and significantly outside (interval test) the normal range. Furthermore, it was tested how the risks for false positives and false negatives are affected by changes in α-level and effect size. The results of the present study show that the strategy that best balances the risks between false positives and false negatives is to use the equivalence test. Besides tests with tabulated p-values, estimates generated using a bootstrap routine were included in the present study. The simulations showed that the probability for management errors was smaller for the bootstrap compared to the traditional test and the interval test.