111 research outputs found

    Subglobal Climate Agreements and Energy-Intensive Activities: Is there a Carbon Haven for Copper?

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    Subglobal climate policies induce changes in international competitiveness and favor a relocation of carbon-emitting activities. We argue that many energy-intensive activities are also capital-intensive, so that carbon policies could affect rents rather than abatement or location. Taking copper as an example, we formulate a plant-level spatial equilibrium model of the industry, and we estimate a set of elasticities to calibrate the behavioral parameters of the model. Given 2007 market conditions, Monte Carlo simulations suggest that a $50/tCO2 tax in industrialized countries induces emissions reductions of less than one percent in the copper industry, with a mean emission leakage rate of 25%. Our results conform with empirical findings on the pollution haven effect but challenge projections from computable general equilibrium models.Massachusetts Institute of Technology. Center for Energy and Environmental Policy Researc

    JPSS-1/NOAA-20 VIIRS Early On-Orbit Geometric Performance

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    The first NOAA/NASA Join Polar Satellite System (JPSS-1) satellite was successfully launched on November 18, 2017,becoming NOAA-20. Instruments on-board the NOAA-20 satellite include the Visible Infrared Imaging RadiometerSuite (VIIRS). This instrument is the second build of VIIRS, with the first flight instrument on-board NASA/NOAASuomi National Polar-orbiting Partnership (SNPP) satellite operating since October 2011. The purpose of these VIIRSinstruments is to continue the long-term measurements of biogeophysical variables for multiple applications includingweather forecasting, rapid response and climate research. The geometric performance of VIIRS is essential to retrievingaccurate biogeophysical variables. This paper describes the early on-orbit geometric performance of the JPSS-1/NOAA-20 VIIRS. It first discusses the on-orbit orbit and attitude performance, a key input needed for accurate geolocation. Itthen discusses the on-orbit geometric characterization and calibration of VIIRS and an initial assessment of thegeometric accuracy. It follows with a discussion of an improvement in the instrument geometric model that correctssmall geometrical artifacts that appear in the along-scan direction. Finally, this paper discusses on-orbit measurements ofthe focal length and the impact of this on the scan-to-scan underlap/overlap

    Public policy and future mineral supplies

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    A widespread and pessimistic view of the availability of mineral commodities calls for strong government initiatives to ensure adequate future supplies. This article provides a more market oriented and optimistic perspective, one that focuses on production costs and prices rather than physical availability. It sees short-run shortages continuing to plague commodity markets in the future as in the past. Though painful while they last, these shortages are temporary and do not pose a serious long-run threat to human welfare. Moreover, even without government intervention, they self-correct. The sharply higher prices that they evoke create strong incentives that foster supply and curb demand. Potentially more serious are long-run shortages due to mineral depletion. Such shortages are often thought to be inevitable, a conclusion that flows directly from the physical view of depletion. For various reasons, we reject this view of depletion in favor of an economic view. The latter recognizes that depletion may create long-run shortages, but stresses that this need not be the case if new technology can continue to offset the cost-increasing effects of depletion in the future as it has in the past. The economic view also suggests that a list of mineral commodities most threatened by depletion can best be compiled using cumulative availability curves rather than the more common practice of calculating commodity life expectancies based on estimates of available stocks.<p>Validerad;2018;Nivå 2;2018-08-08 (rokbeg)</p

    Overview of JPSS VIIRS Geometric Calibration and Validation

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    The presentation stressed the importance of a pre-launch test plan and a post-launch CalVal plan in the geometric aspects of instrument focal length, spatial responses, band-to-band registration, pointing, geolocation and long-term monitoring

    Engineering HIV-Resistant Human CD4+ T Cells with CXCR4-Specific Zinc-Finger Nucleases

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    HIV-1 entry requires the cell surface expression of CD4 and either the CCR5 or CXCR4 coreceptors on host cells. Individuals homozygous for the ccr5Δ32 polymorphism do not express CCR5 and are protected from infection by CCR5-tropic (R5) virus strains. As an approach to inactivating CCR5, we introduced CCR5-specific zinc-finger nucleases into human CD4+ T cells prior to adoptive transfer, but the need to protect cells from virus strains that use CXCR4 (X4) in place of or in addition to CCR5 (R5X4) remains. Here we describe engineering a pair of zinc finger nucleases that, when introduced into human T cells, efficiently disrupt cxcr4 by cleavage and error-prone non-homologous DNA end-joining. The resulting cells proliferated normally and were resistant to infection by X4-tropic HIV-1 strains. CXCR4 could also be inactivated in ccr5Δ32 CD4+ T cells, and we show that such cells were resistant to all strains of HIV-1 tested. Loss of CXCR4 also provided protection from X4 HIV-1 in a humanized mouse model, though this protection was lost over time due to the emergence of R5-tropic viral mutants. These data suggest that CXCR4-specific ZFNs may prove useful in establishing resistance to CXCR4-tropic HIV for autologous transplant in HIV-infected individuals

    HIV interactions with monocytes and dendritic cells: viral latency and reservoirs

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    HIV is a devastating human pathogen that causes serious immunological diseases in humans around the world. The virus is able to remain latent in an infected host for many years, allowing for the long-term survival of the virus and inevitably prolonging the infection process. The location and mechanisms of HIV latency are under investigation and remain important topics in the study of viral pathogenesis. Given that HIV is a blood-borne pathogen, a number of cell types have been proposed to be the sites of latency, including resting memory CD4+ T cells, peripheral blood monocytes, dendritic cells and macrophages in the lymph nodes, and haematopoietic stem cells in the bone marrow. This review updates the latest advances in the study of HIV interactions with monocytes and dendritic cells, and highlights the potential role of these cells as viral reservoirs and the effects of the HIV-host-cell interactions on viral pathogenesis

    What primary health care services should residents of rural and remote Australia be able to access? A systematic review of "core" primary health care services.

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    BACKGROUND: There are significant health status inequalities in Australia between those people living in rural and remote locations and people living in metropolitan centres. Since almost ninety percent of the population use some form of primary health care service annually, a logical initial step in reducing the disparity in health status is to improve access to health care by specifying those primary health care services that should be considered as "core" and therefore readily available to all Australians regardless of where they live. A systematic review was undertaken to define these "core" services.Using the question "What primary health care services should residents of rural and remote Australia be able to access?", the objective of this paper is to delineate those primary health care core services that should be readily available to all regardless of geography. METHOD: A systematic review of peer-reviewed literature from established databases was undertaken. Relevant websites were also searched for grey literature. Key informants were accessed to identify other relevant reference material. All papers were assessed by at least two assessors according to agreed inclusion criteria. RESULTS: Data were extracted from 19 papers (7 papers from the peer-reviewed database search and 12 from other grey sources) which met the inclusion criteria. The 19 papers demonstrated substantial variability in both the number and nature of core services. Given this variation, the specification or synthesis of a universal set of core services proved to be a complex and arguably contentious task. Nonetheless, the different primary health care dimensions that should be met through the provision of core services were developed. In addition, the process of identifying core services provided important insights about the need to deliver these services in ways that are "fit-for-purpose" in widely differing geographic contexts. CONCLUSIONS: Defining a suite of core primary health care services is a difficult process. Such a suite should be fit-for-purpose, relevant to the context, and its development should be methodologically clear, appropriate, and evidence-based. The value of identifying core PHC services to both consumers and providers for service planning and monitoring and consequent health outcomes is paramount
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