Ecological Risk Assessment Framework for Low-Altitude Aircraft Overflights: I. Planning the Analysis and Estimating Exposure

An ecological risk assessment framework for low-altitude aircraft overflights was developed, with special emphasis on military applications. The problem formulation and exposure analysis phases are presented in this article; an analysis of effects and risk characterization is presented in a companion article. The intent of this article is threefold: (1) to illustrate the development of a generic framework for the ecological risk assessment of an activity, (2) to show how the U.S. Environmental Protection Agency's ecological risk assessment paradigm can be applied to an activity other than the release of a chemical, and (3) to provide guidance for the assessment of ecological risks from low-altitude aircraft overflights. The key stressor for low-altitude aircraft overflights is usually sound, although visual and physical (collision) stressors may also be significant. Susceptible and regulated wildlife populations are the major assessment endpoint entities, although plant communities may be impacted by takeoffs and landings. The exposure analysis utilizes measurements of wildlife locations, measurements of sound levels at the wildlife locations, measurements of slant distances from aircraft to wildlife, models that extrapolate sound from the source aircraft to the ground, and bird-strike probability models. Some of the challenges to conducting a risk assessment for aircraft overflights include prioritizing potential stressors and endpoints, choosing exposure metrics that relate to wildlife responses, obtaining good estimates of sound or distance, and estimating wildlife locations.     

全球化背景下构建语言和谐环境的长远意义

面对全球化背景下英语对世界各国语言文化的冲击，我国应采取“由点到面”——从国际化大都市扩散的策略，采取“两手抓”的语言规划方针，即一方面开发研究英语学习自主策略，缩短英语教育时间；另一方面，增强语言内外和谐，平衡普通话和方言、英语和汉语关系，立足长远，降低强势方言所带来的市场价值和社会价值，提高普通话在本土的地位和使用规范，建立平等、和谐的语言环境，并为汉语国际地位的提升和传播创造平台。     

MORAL HAZARD AND THE EFFECTS OF THE DESIGNATED HITTER RULE REVISITED

New evidence seems to cast doubt on the hypothesis that the American League's adoption of the designated hitter (DH) rule in 1973 created a moral hazard problem for pitchers. In particular, the substitution of hard-hitting DHs for weak-hitting pitchers in the American League supposedly explains the lion's share of inter-league differences in hit batsmen. However, theoretical and empirical questions about the explanatory power of this alternative hypothesis lead us to the conclusion that moral hazard remains the most plausible reason why more AL than NL batters have been hit by pitches in 22 of the past 25 seasons. ( JEL D81, J28)     

FILE MANAGEMENT IN MANAGEMENT INFORMATION SYSTEMS*

The file management requirements of a particular management information system, that used for intelligence operations, are examined and a data storage and retrieval system developed that can be either manual or computer based. Scoring models are used to quantify the value of information. Values are adjusted dynamically so that decisions can be made on which items to add and which existing items to delete. Results of experiments with a police intelligence system are presented.