Estimation of Metabolic Rate Constants in PBPK‐Models from Liver Slice Experiments: What Are the Experimental Needs?

A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori.     

简论知识经济时代创新人才的继续教育培训模式

随着以科技创新为主要特征的知识经济时代的来临 ,继续教育要适应现代社会发展的需要 ,培养具有创新意识、创新能力的高素质人才 ,必须在教育观念、培养目标、教学内容、教学方法、教学手段、师资队伍等方面进行改革和创新 ,探索出适应知识经济时代需要的创新人才继续教育培训模式。     

非拓扑孤子模型的相变特征与袋常数的温度依赖性

本文计算了在有限温度和密度下非拓扑孤子模型的有效势;得到了袋常数对温度和化学势的依赖关系;分析了禁闭解除相变的特征.结果表明:该模型的禁闭解除相变为一级;相变特征的分析表明有退禁闭相与禁闭相的两相共存.     

顾客价值创新:战略分析的基点

传统的战略分析是以竞争为基点的。其目的是如何比竞争对手做得更好。在这种思维指导下 ,企业经营往往产生竞争激烈、市场不敏感、反应性行为、缺乏创新等后果。在复杂多变的环境中 ,战略分析应转移到顾客价值创新上来。顾客价值创新战略通过为顾客提供完全新型或得到重大改进的价值而使企业经营与竞争无关。顾客价值创新战略与竞争基点战略在战略导向、对竞争的认知及态度、企业本身实力的认识等具有明显不同的特征 ;进行顾客价值创新可以按照顾客价值创新循环机制进行 ,这一循环机制以顾客消费流程分析为起点 ,由创新机会认别、资源需求分析及价值创新实施等环节构成。     

一般Gauss－Markov模型下一般可估函数的线性充分性和线性完全性

发展了Ｂａｋｓａｌａｒｙ和Ｄｒｙｇａｓ提出的一般Ｇａｕｓｓ－Ｍａｒｋｏｖ模型中线性充分性、最小充分性和完全性的概念，用Ｒａｏ的最小二乘统一理论，给出了这些概念的刻划定理。     

Costs and Rewards of Children: The Effects of Becoming a Parent on Adults' Lives

How do new parents differ from their childless counterparts in social and psychological resources, daily strains, and psychological well‐being? Using a nationally representative panel of 1,933 adults who were childless at the first interview, we compare 6 indicators of adults' lives for those who became parents and those remaining childless several years later, controlling for earlier states. Becoming a parent is both detrimental and rewarding. With the exception of social integration, which is greater for all groups of new parents compared with their childless counterparts, the effects of parental status on adults' lives vary markedly by gender and marital status. Unmarried parents report lower self‐efficacy and higher depression than their childless counterparts. Married mothers' lives are marked by more housework and more marital conflict but less depression than their childless counterparts. Parental status has little influence on the lives of married men.     

Robust confidence interval for a residual standard deviation

The residual standard deviation of a general linear model provides information about predictive accuracy that is not revealed by the multiple correlation or regression coefficients. The classic confidence interval for a residual standard deviation is hypersensitive to minor violations of the normality assumption and its robustness does not improve with increasing sample size. An approximate confidence interval for the residual standard deviation is proposed and shown to be robust to moderate violations of the normality assumption with robustness to extreme non-normality that improves with increasing sample size.     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

论政治语言的结构

分析和研究政治语言的系统结构及结构要素之间的相互关系 ,是研究政治语言的重要内容 ,有利于更好地认识和把握政治语言。政治语言结构是一种特殊的层级系统 ,其要素包括符号、符号系统、符码、文本、语境和话语。政治语言结构的要素之间相互作用、相互关联 ,共同构成了政治语言的系统 ,并以其特有的方式表达政治意义 ,服务于政治活动     

贸易开放、贸易增长与贸易平衡--对转型国家贸易发展的实证研究

本文对1992年到2002年中东欧和独联体25个转型国家贸易开放、贸易增长和贸易平衡问题进行实证研究.文章第一部分简单介绍了转型国家从经互会贸易体制到世界多边贸易体制的发展过程,并提出本文的研究目的、对象以及方法.第二部分用贸易开放、增长和平衡的分析指标对转型国家贸易发展情况作一概述,并引入贸易政策指标、宏观经济指标以及入世虚拟变量等解释因素.第三部分运用面板数据扩展模型(extended model)对转型国家贸易发展的不同作用因素进行统计检验并对结果做出相应分析.第四部分集中对两个转型国家集团-中东欧和独联体-贸易的不同发展状况及其决定因素进行统计检验和比较分析.