Combining Occurrence and Toxicity Information to Identify Priorities for Drinking-Water Mixture Research

Characterizing all possible chemical mixtures in drinking water is a potentially overwhelming project, and the task of assessing each mixture's net toxicity even more daunting. We propose that analyzing occurrence information on mixtures in drinking water may help to narrow the priorities and inform the approaches taken by researchers in mixture toxicology. To illustrate the utility of environmental data for refining the mixtures problem, we use a recent compilation of national ground-water-quality data to examine proposed U.S. Environmental Protection Agency (EPA) and Agency for Toxic Substances and Disease Registry (ATSDR) models of noncancer mixture toxicity. We use data on the occurrence of binary and ternary mixtures of arsenic, cadmium, and manganese to parameterize an additive model and compute hazard index scores for each drinking-water source in the data set. We also use partially parameterized interaction models to perform a bounding analysis estimating the interaction potential of several binary and ternary mixtures for which the toxicological literature is limited. From these results, we estimate a relative value of additional toxicological information for each mixture. For example, we find that according to the U.S. EPA's interaction model, the levels of arsenic and cadmium found in U.S. drinking water are unlikely to have synergistic cardiovascular effects, but the same mixture's potential for synergistic neurological effects merits further study. Similar analysis could in future be used to prioritize toxicological studies based on their potential to reduce scientific and regulatory uncertainty. Environmental data may also provide a means to explore the implications of alternative risk models for the toxicity and interaction of complex mixtures.     

基于教学管理信息平台的考试质量分析系统

考试质量分析是高校教学质量监控的重要环节,也是反思教学、评价教学效果的重要信息。长期以来由于方法手段的制约,大量原始数据不能转化为考试质量分析的有效信息。本文在教学管理与质量监控的操作层面上,设计了考试质量分析的管理目标框架、信息流向结构、量化分析标准、质性分析模块和信息反馈路径,构建了为教师、管理者、决策者服务的、基于教学管理信息平台的考试质量分析系统。     

试论教育资源配置的行为规范

教育资源的配置不是各种教育资源的简单分配，而是配置主体基于教育资源的稀缺性，按照教育活动规律的客观要求，以追求最大限度地实现教育系统目标为取向的一种社会行为。目的性原则、匹配性原则、齐全性原则、人本性原则、效用性原则等是配置主体在配置教育资源时必须遵守的基本的行为规范。     

“十五”期间安徽省基础研究发展情况分析

文章着重从基础研究经费投入和人力资源建设的角度分析了"十五"期间安徽省基础研究的发展情况,分析了研究机构、高等学校以及企业在安徽省基础研究活动中的作用和地位,并提出了进一步加强基础研究的建议.     

翻译过程的认知心理描述——Bell翻译过程的信息加工模式评介

翻译作为人类最复杂的认知活动之一,一直没有得到人们应有的重视,现有的多数研究总以翻译的结果--译作为对象,对翻译过程的研究相对不足.Bell的翻译过程模式以系统功能语言学为基本理论框架,从语言理解的角度,对翻译的心理过程进行了描述,虽然有种种缺陷,但基本上反映了翻译的本质,是具有科学性和一定操作性的一个模式.翻译研究应该重视对翻译过程的研究.     

股指期货信息内含股价变动信息的挖掘 ――小波框架与支持向量回归的金融建模应用

 内容提要：中国股指期货的推出指日可待，交易者多了一种投资工具的同时也带来了新的风险。建立准确的金融时间序列预测模型是逐利及避险的方法之一，一直是学者专家研究的热点。本研究结合小波转换与支持向量回归，提出一个二阶段时间序列预测模型。先以离散小波框架将预测变量分解成不同尺度的多个子序列，揭示隐藏在预测变量内的信息，再以支持向量回归为工具，以这些子序列为预测变量建构SVR模型。本研究以日经225指数开盘价为预测目标，以期货开盘价为预测变量对模型进行实证研究，结果显示，该模型的预测绩效比单纯SVR模型及随机漫步模型好。未来可尝试以不同的基底函数作进一步研究。     

Censored Kullback-Leibler Information and Goodness-of-Fit Test with Type II Censored Data

The Kulback-Leibler information has been considered for establishing goodness-of-fit test statistics, which have been shown to perform very well (Arizono & Ohta, 1989; Ebrahimi et al., 1992, etc). In this paper, we propose censored Kullback-Leibler information to generalize the discussion of the Kullback-Leibler information to the censored case. Then we establish a goodness-of-fit test statistic based on the censored Kullback-Leibler information with the type 2 censored data, and compare the test statistics with some existing test statistics for the exponential and normal distributions.     

少数民族地区民俗旅游资源开发的几点思考

我国拥有丰富的少数民族民俗旅游资源,本文论述了开发少数民族民俗旅游资源的必要性,指出开发中存在的问题并提出解决措施。     

On Bayesian estimators in multistage binomial designs

A new class of Bayesian estimators for a proportion in multistage binomial designs is considered. Priors belong to the beta-J distribution family, which is derived from the Fisher information associated with the design. The transposition of the beta parameters of the Haldane and the uniform priors in fixed binomial experiments into the beta-J distribution yields bias-corrected versions of these priors in multistage designs. We show that the estimator of the posterior mean based on the corrected Haldane prior and the estimator of the posterior mode based on the corrected uniform prior have good frequentist properties. An easy-to-use approximation of the estimator of the posterior mode is provided. The new Bayesian estimators are compared to Whitehead's and the uniformly minimum variance estimators through several multistage designs. Last, the bias of the estimator of the posterior mode is derived for a particular case.     

互联网发展与山西崛起

在全面分析山西互联网状况的基础上,对山西互联网的发展与中部六省比较中存在的差距进行了深入的论述,提出了加快山西互联网发展的针对性对策:进一步优化互联网发展环境;建设城市信息基础设施,着力建立一个宽带的、能够实现双向多媒体信息互动传播的、覆盖整个城市的城域网;加强政府对居民和企业的服务。