938 research outputs found

    Financial and environmental behavior of the regulated firm: A case study of the United States nuclear power industry, 1974-1984

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    This dissertation is a study of the U.S. commercial nuclear power industry from 1974-1984 covering the operations of 87 power plants. It seeks to help explain the actions of a regulated firm faced with environmental constraints from the Nuclear Regulatory Commission and financial constraints from State regulatory bodies. Theoretical and applied conceptions of the regulated monopoly are reviewed in a historical and integrated format using both the neoclassical and institutional positions. For the neoclassical approach, I\u27ve attempted to find empirical support for the Averch-Johnson hypothesis by including profit maximizing and environmental constraints in my econometric model. For the institutionalist approach, I have tried to look into the institutional reasons for the behavior exhibited by the firms. The seminal hypothesis for this project was that because of the unique plant-specific characteristics of the U.S. nuclear industry that emissions were a function of specific plant characteristics, operational data, financial results and regulatory requirements. A data base which consists of financial, radioactive emissions, and technical operations information has been compiled in order to allow testing of various hypotheses drawn from theoretical and applied sources. For this longitudinal data base, a semi-log, fixed-effect model with a lagged dependent variable was estimated. The estimation requires the use of a two-stage least squares procedure which results in consistent estimates. The results of my analysis support five very clear conclusions. First, nuclear power plant emissions have dramatically trended downward since 1978/1979 across most of the elements examined. Second, there is little indication that variability in emissions is affected by variability in the firm\u27s financial results. Third, the statistics reveal the very clear individual nature of the nuclear power plants in the U.S. Fourth, in spite of these dramatic declines in emissions releases, evidence was presented that the environmental inventories of some isotopes have been increasing. Fifth, for this one example of environmental behavior by one group of regulated monopoly firms, the increased vigilance by the regulatory officials within the Nuclear Regulatory Commission and the Environmental Protection Agency has indeed had its intended effects

    Agents of Bioterrorism: Curriculum and Pedagogy in an Online Masters Program

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    The Agents of Bioterrorism course (BSBD 640, University of Maryland University College) is a graduate level course created in response to an elevated need for scientists working in the field of medical countermeasures to biological and chemical weapons in the years following 9/11. Students read and evaluate assigned current primary literature articles investigating medical countermeasures at each stage of development. In addition, students learn concepts of risk assessment, comparing and ranking several agents of terror. Student learning is assessed through a variety of assignments. A term paper focuses on a lesser known weapon of terror, with students recommending the best countermeasure in development and delivering a risk assessment comparing their agent to other major weapons of terror discussed throughout the semester. Similarly, a group project on an assigned major weapon of terror (anthrax, plague, smallpox, vesicants, or nerve agent) focuses more heavily on evaluating primary literature and concluding which countermeasure(s) in development are the best. Students complete the course with a fundamental understanding of the mechanism of action of many biological agents, information literacy for the medical literature available at PubMed and the primary scientific literature, and a basic understanding of the role of the government in biodefense research. This paper describes the pedagogical approaches used to teach this course and how they might be adopted for other courses

    Wavelength independent interferometer

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    A polychromatic interferometer utilizing a plurality of parabolic reflective surfaces to properly preserve the fidelity of light wavefronts irrespective of their wavelengths as they pass through the instrument is disclosed. A preferred embodiment of the invention utilizes an optical train which comprises three off-axis parabolas arranged in conjunction with a beam-splitter and a reference mirror to form a Twyman-Green interferometer. An illumination subsystem is provided and comprises a pair of lasers at different preselected wavelengths in the visible spectrum. The output light of the two lasers is coaxially combined by means of a plurality of reflectors and a grating beam combiner to form a single light source at the focal point of the first parabolic reflection surface which acts as a beam collimator for the rest of the optical train. By using visible light having two distinct wavelengths, the present invention provides a long equivalent wavelength interferogram which operates at visible light wherein the effective wavelength is equal to the product of the wavelengths of the two laser sources divided by their difference in wavelength. As a result, the invention provides the advantages of what amounts to long wavelength interferometry but without incurring the disadvantage of the negligible reflection coefficient of the human eye to long wavelength frequencies which would otherwise defeat any attempt to form an interferogram at that low frequency using only one light source

    Prograde and retrograde history of eclogites from the Eastern Blue Ridge, North Carolina, USA

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    The prograde metamorphism of eclogites is typically obscured by chemical equilibration at peak conditions and by partial requilibration during retrograde metamorphism. Eclogites from the Eastern Blue Ridge of North Carolina retain evidence of their prograde path in the form of inclusions preserved in garnet. These eclogites, from the vicinity of Bakersville, North Carolina, USA are primarily comprised of garnet–clinopyroxene–rutile–hornblende–plagioclase–quartz. Quartz, clinopyroxene, hornblende, rutile, epidote, titanite and biotite are found as inclusions in garnet cores. Included hornblende and clinopyroxene are chemically distinct from their matrix counterparts. Thermobarometry of inclusion sets from different garnets record different conditions. Inclusions of clinozoisite, titanite, rutile and quartz (clinozoisite + titanite = grossular + rutile + quartz + H 2 O) yield pressures (6–10 kbar, 400–600 °C and 8–12 kbar 450–680 °C) at or below the minimum peak conditions from matrix phases (10–13 kbar at 600–800 °C). Inclusions of hornblende, biotite and quartz give higher pressures (13–16 kbar and 630–660 °C). Early matrix pyroxene is partially or fully broken down to a diopside–plagioclase symplectite, and both garnet and pyroxene are rimmed with plagioclase and hornblende. Hypersthene is found as a minor phase in some diopside + plagioclase symplectites, which suggests retrogression through the granulite facies. Two-pyroxene thermometry of this assemblage gives a temperature of c. 750 °C. Pairing the most Mg-rich garnet composition with the assemblage plagioclase–diopside–hypersthene–quartz gives pressures of 14–16 kbar at this temperature. The hornblende–plagioclase–garnet rim–quartz assemblage yields 9–12 kbar and 500–550 °C. The combined P–T data show a clockwise loop from the amphibolite to eclogite to granulite facies, all of which are overprinted by a texturally late amphibolite facies assemblage. This loop provides an unusually complete P–T history of an eclogite, recording events during and following subduction and continental collision in the early Palaeozoic.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73522/1/j.1525-1314.2003.00479.x.pd

    A mission management system for a fleet of gliders

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    International audienceThe objective of AGLIMMS project, whose acronym stands for Acoustic GLIders Mission Management System, is to efficiently coordinate a fleet of underwater gliders whose missions are to obtain physical, chemical, biological and/or acoustic measurements on a large 3D sea area. This paper describes planning and supervision functions under development and their integration in a global centralised architecture. A demonstration with three SeaExplorer from Alseamar is planned late 2019

    Survival of patients with small cell lung cancer undergoing lung resection in England, 1998–2009

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    Introduction: Chemotherapy or chemoradiotherapy is the recommended treatment for small cell lung cancer (SCLC), except in stage I disease where clinical guidelines state there may be a role for surgery based on favourable outcomes in case series. Evidence supporting adjuvant chemotherapy in resected SCLC is limited but this is widely offered. Methods: Data on 359 873 patients who were diagnosed with a first primary lung cancer in England between 1998 and 2009 were grouped according to histology (SCLC or non-SCLC (NSCLC)) and whether they underwent a surgical resection. We explored their survival using Kaplan-Meier analysis and Cox regression, adjusting for age, sex, comorbidity and socioeconomic status. Results: The survival of 465 patients with resected SCLC was lower than patients with resected NSCLC (5-year survival 31% and 45%, respectively), but much higher than patients of either group who were not resected (3%). The difference between resected SCLC and NSCLC diminished with time after surgery. Survival was superior for the subgroup of 198 'elective' SCLC cases where the diagnosis was most likely known before resection than for the subgroup of 267 'incidental' cases where the SCLC diagnosis was likely to have been made after resection. Conclusions: These data serve as a natural experiment testing the survival after surgical management of SCLC according to NSCLC principles. Patients with SCLC treated surgically for early stage disease may have survival outcomes that approach those of NSCLC, supporting the emerging clinical practice of offering surgical resection to selected patients with SCLC

    A reasoned action approach to pregnant smokers’ intention to switch to e-cigarettes: Does educational attainment influence theory application?

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    Social determinant research has noted educational attainment to be among the strongest influencing factors for tobacco use during pregnancy. Concurrently, maternal e-cigarette use has doubled in recent years, with some citing it as a safer alternative to combustible cigarettes. To better understand the decision-making practices of pregnant persons based on educational attainment, the reasoned action approach (RAA) was used to evaluate factors that may be associated with the intention to switch from cigarettes to e-cigarettes. A sample of U.S. pregnant persons (n = 267) between 18-40 years of age, who smoked at least one cigarette in the past 30 days, completed an online survey about switching from cigarettes to e-cigarettes. RAA constructs (e.g., intentions, instrumental attitudes, etc.) were measured using a pre-validated scale. Using structural equation modeling, the variability of latent variables (i.e., RAA constructs) and their interaction with one another were analyzed by educational attainment via two regression models: one for those who had college experience or had completed a college degree and another for those who had not attended college. Instrumental attitudes, experiential attitudes, and descriptive norms were significantly associated with intention to switch from cigarettes to e-cigarettes among both groups; however, autonomy was only significantly associated with intention among those who had not attended college. The RAA offers a valuable framework for understanding pregnant persons’ decision to switch from cigarettes to e-cigarettes during pregnancy; however, the RAA constructs may be related to intentions differently based on upstream factors, such as educational attainment
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