80 research outputs found

    The Demand for Ethanol as a Gasoline Substitute

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    This paper estimates household preferences for ethanol as a gasoline substitute. I develop a theoretical model linking the shape of the ethanol demand curve to the distribution of price ratios at which individual households switch fuels. I estimate the model using data from many retail fueling stations. Demand is price-sensitive with a mean elasticity of 2.5–3.5. I find that preferences are heterogeneous with many households willing to pay a premium for ethanol. This reduces the simulated cost of an ethanol content standard, since some households choose ethanol without large subsidies; simulated costs are still high relative to likely environmental benefits.

    The Intergenerational Transmission of Automobile Brand Preferences

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116373/1/joie12092.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/116373/2/joie12092-sup-0001-si.pd

    Automobile Fuel Economy Standards: Impacts, Efficiency, and Alternatives

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    This paper discusses fuel economy regulations in the United States and other countries. We first describe how these programs affect the automobile market, including their impacts on fuel use and other dimensions of the vehicle fleet. We then review different methodologies for assessing the costs of fuel economy regulations and discuss what the results of these methodologies imply for policy. Following that, we compare the welfare effects of fuel economy regulations to those of fuel taxes and assess whether or not these two policies can be complements. Finally, we review arguments for transitioning away from fuel economy regulations towards a “feebate” system.

    Characterization of multinucleated giant cells in synovium and subchondral bone in knee osteoarthritis and rheumatoid arthritis

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    Background: Multinucleated giant cells have been noticed in diverse arthritic conditions since their first description in rheumatoid synovium. However, their role in the pathogenesis of osteoarthritis (OA) or rheumatoid arthritis (RA) still remains broadly unknown. We aimed to study the presence and characteristics of multinucleated giant cells (MGC) both in synovium and in subchondral bone tissues of patients with OA or RA. Methods: Knee synovial and subchondral bone samples were from age-matched patients undergoing total joint replacement for OA or RA, or non-arthritic post mortem (PM) controls. OA synovium was stratified by histological inflammation grade using index tissue sections. Synovitis was assessed by Krenn score. Histological studies employed specific antibodies against macrophage markers or cathepsin K, or TRAP enzymatic assay. Results: Inflamed OA and RA synovia displayed more multinucleated giant cells than did non-inflamed OA and PM synovia. There was a significant association between MGC numbers and synovitis severity. A TRAP negative/cathepsin K negative Langhans-like subtype was predominant in OA, whereas both Langhans-like and TRAP-positive/ cathepsin K negative foreign-body-like subtypes were most commonly detected in RA. Plasma-like and foam-like subtypes also were observed in OA and RA synovia, and the latter was found surrounding adipocytes. TRAP positive/ cathepsin K positive osteoclasts were only identified adjacent to subchondral bone surfaces. TRAP positive osteoclasts were significantly increased in subchondral bone in OA and RA compared to PM controls. Conclusions: Multinucleated giant cells are associated with synovitis severity, and subchondral osteoclast numbers are increased in OA, as well as in RA. Further research targeting multinucleated giant cells is warranted to elucidate their contributions to the symptoms and joint damage associated with arthritis

    The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description

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    On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds