13,298 research outputs found
Meta Analysis in Model Implementation: Choice Sets and the Valuation of Air Quality Improvements
We document the sensitivity of welfare estimates derived from discrete choice models to assumptions about the choice set. Such assumptions can affect welfare estimates through both the estimated parameters of the model and, conditional on the parameters, the substitution among alternatives. Our analysis involves estimates of the benefits of air quality improvements in Los Angeles based on discrete choices of neighborhood and housing. We further illustrate the use of meta analysis to document and summarize voluminous information derived from repeated sensitivity analyses.Meta analysis, random utility model, choice set, air quality, housing
Deep-water corals along the Norwegian contintental margin: Multidisciplinary studies on Sula Ridge, Traena Reef, Røst Reef, Floholmen and Sotbakken
General Equilibrium Benefit Transfers for Spatial Externalities: Revisiting EPA's Prospective Analysis
Environmental policy analyses increasingly require the evaluation of benefits from large changes in spatially differentiated public goods. Such changes are likely to induce general equilibrium effects through changes in household expenditures and local migration, yet current practice "transfers" constant marginal values for even the largest changes. Moreover, it ignores important distributional effects of policy. This paper demonstrates that recently developed locational equilibrium models can provide transferable general equilibrium benefit measures. Our results suggest that taking account of the potential for adjustment and household heterogeneity is important. Applying benefits estimated from this method to the effect of the Clean Air Act amendments in Los Angeles, we find that the estimated annual general equilibrium benefits in 2000 and 2010 are dramatically different by income group and location. The gains range from 2,400 per household. These differences arise from variations in the air quality conditions, income, and the effects of general equilibrium price adjustment.air quality, clean air act, non-market valuation, Tiebout model
Community-level response of coastal microbial biofilms to ocean acidification in a natural carbon dioxide vent ecosystem.
The version on PEARL: Corrected proofs are Articles in Press that contain the authors' corrections. Final citation details, e.g., volume/issue number, publication year and page numbers, still need to be added and the text might change before final publication. Although corrected proofs do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI , as follows: author(s), article title, journal (year), DOIThe impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent areas provide an opportunity to make predictions about the impacts of ocean acidification. We compared biofilms that colonised glass slides in areas exposed to ambient and elevated levels of pCO(2) along a coastal pH gradient, with biofilms grown at ambient and reduced light levels. Biofilm production was highest under ambient light levels, but under both light regimes biofilm production was enhanced in seawater with high pCO(2). Uronic acids are a component of biofilms and increased significantly with high pCO(2). Bacteria and Eukarya denaturing gradient gel electrophoresis profile analysis showed clear differences in the structures of ambient and reduced light biofilm communities, and biofilms grown at high pCO(2) compared with ambient conditions. This study characterises biofilm response to natural seabed CO(2) seeps and provides a baseline understanding of how coastal ecosystems may respond to increased pCO(2) levels
Trojan Horses and Fake Immunity Idols: Molecular Mimicry of Host Immune Mediators by Human Cytomegalovirus
Teacher absenteeism: Characteristics and implications in selected Iowa school districts
The consequences of employee absences can have a significant effect on an organization\u27s expected outcomes. The problem of this study is to determine what effect, if any, teacher absences have on school district costs (dollar and time) as well as the effect of teacher absences on student learning;The overall goal was to provide insight into the characteristics that might help schools predict when and how often absences might occur, and to provide recommendations that will help school districts manage or reduce absences;In an attempt to provide answers to these questions, this investigation sought information in the following areas: Characteristics related to teacher absences such as district size, age, gender, socioeconomic status, teacher effectiveness, and building level; district attendance information; principal perceptions of concerns related to absences; and district plans for managing or reducing absences;The 436 public school districts in Iowa were selected to serve as a sample. In addition to the basic questionnaire, additional questions were included to verify the 1368 principals\u27 perceptions of the consequences of teacher absences in their buildings;The data indicate that teacher absences are on the increase. Further analyses of the data imply that characteristics such as larger district size, lower socioeconomic status of students, reduced teacher effectiveness, and teacher gender are linked to higher absence rates;A possible cause of the increased teacher absence rates is the emergence of collective bargaining in school districts, and the corresponding increase in the kinds and number of leave days available to teachers;Improved methods of monitoring teacher absences, along with a plan for recognizing and rewarding good attendance provide the potential for reducing teacher absences. This in turn will cut dollar costs to districts, and more importantly will reduce the loss in student learning created when the regular teacher is gone
The Cytomegalovirus Homolog of Interleukin-10 Requires Phosphatidylinositol 3-Kinase Activity for Inhibition of Cytokine Synthesis in Monocytes
Human cytomegalovirus (CMV) has evolved numerous strategies for evading host immune defenses, including piracy of cellular cytokines. A viral homolog of interleukin-10, designated cmvIL-10, binds to the cellular IL-10 receptor and effects potent immune suppression. The signaling pathways employed by cmvIL-10 were investigated, and the classic IL-10R/JAK1/Stat3 pathway was found to be activated in monocytes. However, inhibition of JAK1 had little effect on cmvIL-10-mediated suppression of tumor necrosis factor alpha (TNF-α) production. Inhibition of the phosphatidylinositol 3-kinase/Akt pathway had a more significant impact on TNF-α levels but did not completely relieve the immune suppression, demonstrating that cmvIL-10 stimulates multiple signaling pathways to modulate cell function
Egg-laying substrate selection for optimal camouflage by quail
Camouflage is conferred by background matching and disruption, which are both affected by microhabitat [1]. However, microhabitat selection that enhances camouflage has only been demonstrated in species with discrete phenotypic morphs [2 and 3]. For most animals, phenotypic variation is continuous [4 and 5]; here we explore whether such individuals can select microhabitats to best exploit camouflage. We use substrate selection in a ground-nesting bird (Japanese quail, Coturnix japonica). For such species, threat from visual predators is high [6] and egg appearance shows strong between-female variation [7]. In quail, variation in appearance is particularly obvious in the amount of dark maculation on the light-colored shell [8]. When given a choice, birds consistently selected laying substrates that made visual detection of their egg outline most challenging. However, the strategy for maximizing camouflage varied with the degree of egg maculation. Females laying heavily maculated eggs selected the substrate that more closely matched egg maculation color properties, leading to camouflage through disruptive coloration. For lightly maculated eggs, females chose a substrate that best matched their egg background coloration, suggesting background matching. Our results show that quail “know” their individual egg patterning and seek out a nest position that provides most effective camouflage for their individual phenotyp
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