Shifting Sands: The Limits of Science in Setting Risk Standards

Regulators need to rely on science to understand problems and predict the consequences of regulatory actions, but overreliance on science can actually contribute to, or at least deflect attention from, incoherent policymaking. In this article, we explore the problems with using science to justify policy decisions by analyzing the Environmental Protection Agency's recently revised air quality standards for ground-level ozone and particulate matter, some of the most significant regulations ever issued. In revising these standards, EPA mistakenly invoked science as the exclusive basis for its decisions and deflected attention from a remarkable series of inconsistencies. For example, even though EPA claimed to base its standards on a singular concern for public health, it set its standards at levels that will still lead to hundreds, if not thousands, of deaths each year. In other ways, EPA's positions were like shifting sands, changing at points that apparently were expedient for the agency. Such an outcome should not be unexpected when an agency misuses science as a policy rationale, but it also need not be inevitable if agencies learn to respect the limits of science in justifying risk standards. We conclude by offering a set of principles to give direction to standard setting by EPA and other agencies. In the case of EPA's air quality program, Congress will likely need to amend the Clean Air Act to enable EPA to break free of the conceptual incoherence in which it now finds itself mired. Decisionmakers in any setting, though, can avoid the problem of shifting sands by carefully understanding what science can and cannot do.Environment, Regulatory Reform

Flight evaluation of the x-15 ball-nose flow-direction sensor as an air-data system

Modification of ball-nose flow direction sensor for Mach number and air pressure altitude measurement

Effect of two-dimensional multiple sine-wave protrusions of the pressure and heat-transfer distributions for a flat plate at Mach 6

Effect of two dimensional multiple sine wave protrusions on pressure and heat transfer distributions for flat plate in hypersonic flo

The Relationship Between Formative Assessment and Student Engagement at Walters State Community College.

The purpose of this study was to determine whether there was a relationship between formative assessment and student engagement at Walters State Community College. Additionally, a secondary purpose examined differences in the in the dimensions of student engagement dimensions (skills engagement, emotional engagement, participation or interaction, performance) based on gender, school classification (freshman, sophomore), and age. Two hundred thirty-nine Walters State Community College students taught with face-to-face pedagogy comprised the population for the study. The survey instruments included a 15-item formative assessment survey selected from the Walters State Community College Student Opinion of Teaching and Course (WSCCSOTC) and the Student Course Engagement Questionnaire (SCEQ) developed by Handelsman, Briggs, Sullivan, and Towler (2005) to ascertain measures of student course engagement. The primary finding of the study was that formative assessment had a positive relationship on student engagement at Walters State Community College. The study also offered some evidence that certain teaching strategies proposed in the literature could contribute to formative assessment and increase student engagement. In the context of student engagement dimensions, there were significant differences between female study skills engagement and male performance engagements results. The results for freshman and sophomore students on the student engagement dimensions yielded no significant difference. Interestingly, 24 year old students consistently had higher or equally as high scores on all of the student engagement dimensions

Compendium of NASA Langley reports on hypersonic aerodynamics

Reference is made to papers published by the Langley Research Center in various areas of hypersonic aerodynamics for the period 1950 to 1986. The research work was performed either in-house by the Center staff or by other personnel supported entirely or in part by grants or contracts. Abstracts have been included with the references when available. The references are listed chronologically and are grouped under the following general headings: (1) Aerodynamic Measurements - Single Shapes; (2) Aerodynamic Measurements - Configurations; (3) Aero-Heating; (4) Configuration Studies; (5) Propulsion Integration Experiment; (6) Propulsion Integration - Study; (7) Analysis Methods; (8) Test Techniques; and (9) Airframe Active Cooling Systems

Thrifty Viability and Traditional Mortgage Lending: A Simultaneous Equations Analysis of the Risk-Return Trade-Off

A number of studies have argued that the thrift industry is not viable as it is presently structured and regulated because mortgage yields are inadequate to cover interest and operating costs. This hypothesis suggests that observed profitability is primarily the result of the tendency of the industry to "ride" the yield curve by borrowing short and lending long. To evaluate this argument, we construct a simultaneous-equations model of thrift risk (maturity gap positions) and return (net interest margin). We find support for the notion that the industry could not be reasonably profitable if it did not take on significant interest-rate risk. For instance, a zero gap position produces a return on assets of only 19 basis points and a return on equity of only 4%. We also estimate the amount of interest-rate risk the industry can employ to increase returns on equity and assets. Our estimates show that over 50% of thrift profits earned during this period are the result of negative gap positions and interest-rate speculation. As earlier research shows, changes in regulations affecting thrift asset and liability choices can be counterproductive.

Resolving environmental drivers of microbial community structure in Antarctic soils

Antarctic soils are extremely cold, dry, and oligotrophic, yet harbour surprisingly high bacterial diversity. The severity of environmental conditions has constrained the development of multi-trophic communities, and species richness and distribution is thought to be driven primarily by abiotic factors. Sites in northern and southern Victoria Land were sampled for bacterial community structure and soil physicochemical properties in conjunction with the US and New Zealand Latitudinal Gradient Project. Bacterial community structure was determined using a high-resolution molecular fingerprinting method for 80 soil samples from Taylor Valley and Cape Hallett sites which are separated by five degrees of latitude and have distinct soil chemistry. Taylor Valley is part of the McMurdo Dry Valleys, while Cape Hallett is the site of a penguin rookery and contains ornithogenic soils. The influence of soil moisture, pH, conductivity, ammonia, nitrate, total nitrogen and organic carbon on community structure was revealed using Spearman rank correlation, Mantel test, and principal components analysis. High spatial variability was detected in bacterial communities and community structure was correlated with soil moisture and pH. Both unique and shared bacterial community members were detected at Taylor Valley and Cape Hallett despite the considerable distance between the sites