Valuing Farmland Protection with Choice Experiments That Incorporate Preference Heterogeneity: Does Policy Guidance Depend On the Econometric Fine Print?

Although mixed logit models are common in stated preference applications, resulting welfare estimates can be sensitive to minor changes in specification. This can be of critical relevance for policy and welfare analysis, particularly if policymakers are unaware of practical implications. Drawing from an application to agricultural conservation in Georgia, this paper quantifies the sensitivity of welfare estimates to common variations in mixed logit specification and assesses practical implications for policy guidance. Results suggest that practitioners may wish to reevaluate modeling and reporting procedures to reflect the welfare and policy implications of common but often unnoticed variations in model specification.Willingness to Pay, Conservation Easement, PACE, Mixed Logit, Stated Preference, Environmental Economics and Policy, Land Economics/Use, Research Methods/ Statistical Methods, Q24, Q51,

Review of \u3ci\u3eDetermination of Organic Compounds in Soils, Sediments and Sludges\u3c/i\u3e By T. R. Crompton

T. R. Crompton has accomplished the Herculean task of summarizing the literature (up to 1998) for the determination of organic and organometallic substances in soils, aquatic, and marine sediments and sludge. Although previous books address the analysis of such compounds in water, this is the first book dedicated to the analysis of pollutants in soils, sediments, and sludges, matrices that typically contain a variety of interfering compounds and offer significant analytical challenges. Overall, the book is relatively easy to read; the “camera ready” manuscript produced by the author contains clear tables, figures, and font. Classes of compounds addressed in this text include a wide variety of mostly anthropogenic compounds such as insecticides, herbicides, fungicides, fertilizers, petroleum-related compounds, detergents, as well as humic/fulvic acids. The initial chapter provides an overview of the types of analytical instrumentation that is commonly used to analyze organic compounds in soils, sediments, and sludge. Each of the next 12 chapters is dedicated to the analysis of a class of compounds .Chapter topics include hydrocarbons, surface active agents, oxygen-containing compounds, halogen-containing compounds, nitrogen-containing compounds, phosphorous-containing compounds, sulfur-containing compounds, pesticides (insecticides, growth regulators, fungicides), mixtures of organic compounds, metalloids, organometallic compounds, and finally miscellaneous organics. In these chapters, the author briefly summarizes the scientific literature with respect to the analytical techniques covered in Chapter One.Although details are generally insufficient to permit readers to duplicate reported analyses, cited references are listed at the end of each chapter. Chapter Fourteen emphasizes the importance of sampling procedures and provides a good overview of sample homogenization, and destructive and nondestructive sampling approaches. The final two chapters discuss accumulation processes in sediments, and the disposal of wastes to land. These chapters provide an excellent justification for the importance of the material presented in this book, and would perhaps serve the reader better had they constituted the initial book chapters. The book concludes with an appendix of instrument suppliers, an extremely brief listing of the United Kingdom Ministry of Agriculture, Fisheries, and Foods Methods for soil analysis, and a subject index. This book provides a good initial reference for a variety of graduate students, scientists (chemists, biologists, soil scientists, toxicologists, environmental scientists, etc.), managers, data/grant reviewers, and public health professionals who may be faced with reviewing data and/or developing an analytical approach for the analysis of organic compounds in difficult matrices such as soils, sediments and sludges. Mostly, however, this book simply reviews the literature. The author injects very little analysis to the literature summary. For example, there is no mention of the fact that analysis by thin-layer chromatography is generally qualitative (nonquantitative) compared to analysis by gas chromatography (GC) or high performance liquid chromatography. For the analysis of halogen-containing compounds (such as organochlorine insecticides), there is no mention of the selectivity afforded by GC–electron capture detection. I believe a large number of readers would benefit greatly from a discussion section at the end of each chapter. This discussion might include a table that compares the variety of detection methods with respect to limits of detection, cost, sample throughput , and reproducibility. Because many chapters contain mostly references that are more than 20 years old (i.e., citations pertaining to the use of packed GC columns), the discussion section could help the reader determine the advantages of one technique over another and which techniques are commonly used today versus those which are antiquated. Perhaps this would be easier if individual chapters were written by pertinent experts or at least if there were multiple editors rather than having one author compile and edit the entire book. Additionally, a brief summary of the author’s experience/expertise would possibly contribute credibility to this book. Another small addition that would increase the value of the book would be the inclusion of the article titles in the cited references. This would make it easier for readers to determine the value of citations prior to obtaining the article

Cost-efficient manufacturing of composite structures

The Advanced Composites Technology (ACT) program is seeking research breakthroughs that will allow structures made of graphite epoxy materials to replace metals in the wings and fuselages of future aircrafts. NASA's goals are to reduce acquisition cost by 20 to 25 percent, structural weight for a resized aircraft by 40 to 50 percent, and the number of parts by half compared to current production aluminum aircraft. The innovative structural concepts, materials, and fabrication techniques emerging from the ACT program are described, and the relationship between aerospace developments and industrial, commercial, and sporting goods applications are discussed

Preparing composite materials from matrices of processable aromatic polyimide thermoplastic blends

Composite materials with matrices of tough, thermoplastic aromatic polyimides are obtained by blending semi-crystalline polyimide powders with polyamic acid solutions to form slurries, which are used in turn to prepare prepregs, the consolidation of which into finished composites is characterized by excellent melt flow during processing

Population-Based Fish Consumption Survey and Probabilistic Methylmercury Risk Assessment

A fish consumption survey was developed and administered by telephone to 820 Wyoming fishing license holders. Survey respondents provided the frequency, species, and quantity of Wyoming-caught and store-bought fish consumed for license holder and household members. Deterministic and probabilistic methylmercury exposure distributions were estimated by multiplying fish consumption by species-specific mercury concentrations for each household member. Risk assessments were conducted for children, women of childbearing age, and the rest of the population by comparing methylmercury exposure distributions to levels of concern. The results indicate that probabilistic risk assessment likely provides a more realistic view of the risk to the study population. The results of this study clearly indicate that: (1) there is no level of fish consumption that is without risk of methylmercury exposure, (2) fish advisories may be warranted for children and women of childbearing age, and (3) that store-bought fish generally contribute more to methylmercury exposure than do Wyoming-caught fish

Population-Based Fish Consumption Survey and Probabilistic Methylmercury Risk Assessment

A fish consumption survey was developed and administered by telephone to 820 Wyoming fishing license holders. Survey respondents provided the frequency, species, and quantity of Wyoming-caught and store-bought fish consumed for license holder and household members. Deterministic and probabilistic methylmercury exposure distributions were estimated by multiplying fish consumption by species-specific mercury concentrations for each household member. Risk assessments were conducted for children, women of childbearing age, and the rest of the population by comparing methylmercury exposure distributions to levels of concern. The results indicate that probabilistic risk assessment likely provides a more realistic view of the risk to the study population. The results of this study clearly indicate that: (1) there is no level of fish consumption that is without risk of methylmercury exposure, (2) fish advisories may be warranted for children and women of childbearing age, and (3) that store-bought fish generally contribute more to methylmercury exposure than do Wyoming-caught fish

Poly(methyl methacrylate) synthetic grit formulations sustain the delivery of nicarbazin, a contraceptive agent, in pest waterfowl

Sixty-three mallards were fed one of ten poly(methyl methacrylate) based synthetic grit formulations containing varying concentrations of a proposed wildlife contraceptive (nicarbazin), plasticizer (acetyl tributylcitrate) and/or cross-linking agent (1,4-butanediol diacrylate). Release characteristics of the contraceptive agent were monitored for the purpose of developing a contraceptive formulation for control of pest waterfowl in urban settings. The addition of plasticizer increased the erosion rate (t1/2=0.97-2.85 days), cross-linking the polymer matrix slightly decreased the erosion rate (t1/2=4.45-5.05 days) and increasing the concentration of the contraceptive agent increased the erosion rate (t1/2= 3 . 3 and 9.9 days at 60% and 7.5% active ingredient. respectively). The larger and smaller grit pieces had longer half lives at 11.0 and 11.6 days, respectively while the mid sized grit had a half life of 4.95 days. Control grit had a half life of 12.7 days based on weight loss. Analysis of blood and feces for monitoring release from the grit and approximate indirect plasma levels of the active ingredient proved feasible

Poly(methyl methacrylate) synthetic grit formulations sustain the delivery of nicarbazin, a contraceptive agent, in pest waterfowl

Sixty-three mallards were fed one of ten poly(methyl methacrylate) based synthetic grit formulations containing varying concentrations of a proposed wildlife contraceptive (nicarbazin), plasticizer (acetyl tributylcitrate) and/or cross-linking agent (1,4-butanediol diacrylate). Release characteristics of the contraceptive agent were monitored for the purpose of developing a contraceptive formulation for control of pest waterfowl in urban settings. The addition of plasticizer increased the erosion rate (t1/2=0.97-2.85 days), cross-linking the polymer matrix slightly decreased the erosion rate (t1/2=4.45-5.05 days) and increasing the concentration of the contraceptive agent increased the erosion rate (t1/2= 3 . 3 and 9.9 days at 60% and 7.5% active ingredient. respectively). The larger and smaller grit pieces had longer half lives at 11.0 and 11.6 days, respectively while the mid sized grit had a half life of 4.95 days. Control grit had a half life of 12.7 days based on weight loss. Analysis of blood and feces for monitoring release from the grit and approximate indirect plasma levels of the active ingredient proved feasible

Non-Target Hazard Assessment of Using DRC-1339 Avicide to Manage Blackbirds in Sunflower

Terrestrial hazard assessments were conducted for the spring blackbird baiting program to protect sunflower crops. Risk Assessment methodology proposed by the Ecological Committee on FIFRA Risk Assessment Methods (ECOFRAM) and the method currently used by the U.S. Environmental Protection Agency (LD50s/ft2) were compared for their predictive strengths and for the ease of adapting the assessment to site specific conditions. While the ECOFRAM and LD50s/ft2 methods identified the same groups of organisms as being at risk, the flexibility of the ECOFRAM methodology allowed more latitude in adapting the assessment to unique behaviors of individual species. These risk assessment approaches indicate that blackbird baiting with DRC-1339 presents acute hazards to select nontarget birds like western meadowlarks and mourning doves but few hazards to most mammals or small granivorous birds like sparrows and finches. However, field experiments indicate that the mitigation measures currently employed in the baiting program, minimize the nontarget hazards

Determination of Cabergoline by Electrospray Ionization Tandem Mass Spectrometry: Picogram Detection via Column Focusing Sample Introduction

An electrospray ionization tandem mass spectrometric method was developed for low-picogram detection of an ergot alkaloid, cabergoline, in coyote plasma extracts. Cabergoline is under investigation as an abortifacient in canid species. Central to the successful development of this method was the ability to introduce relatively large sample volumes into the mass spectrometer. This was achieved by focusing the analyte on a conventional high-performance liquid chromatography guard column prior to elution into the spectrometer. Volumes up to at least 900 μL could be injected onto the guard column using a 100% aqueous mobile phase. Cabergoline retained on the column was eluted as a discreet band into the mass spectrometer by the rapid addition of methanol (30%) to the mobile phase. As compared to flow injection sample introduction, the ability to inject larger sample volumes led to a greatly lowered detection limit. Using this technique and a modification of a previously reported extraction procedure, cabergoline could be determined in coyote plasma at concentrations as low as 9 pg of cabergoline/ mL of plasma