2,411 research outputs found

    Exploring the Policy Implications of the Surface Mining Control and Reclamation Act

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    This paper explores how policy structure, institutions, and political climate impact the ability of the Surface Mining Control and Reclamation Act (SMCRA) to ensure the reclamation of surface coal mines. We conduct a policy review that traces the impacts of the three parts of SMCRA; Reclamation Standards, Reclamation Bonding Requirements, and the Abandoned Mine Land fund. We examine the implications the act and its approach have for the mining industry and their ability to reclaim mining areas. We find that each of the three parts of SMCRA’s approach face substantial problems in their implementation. Though largely a positive force for internalizing the environmental costs of surface mining, those issues commonly elucidated in the public choice literature reduce the efficacy of the policy approach and call into question the act’s ability to ensure reclamation occurs. Both in the structure of the bonding requirements and in the regulatory structure created by the act, misaligned incentives sometimes hamper effective reclamation. Further, the funds created under SMCRA to reclaim and restore mined lands have often been directed towards projects that are politically expedient for politicians instead of those that would best serve the fund’s original reclamation purpose. After revealing these problems and putting them in the context of the public choice literature, we suggest updates to the current policy that would align reclamation incentives and better ensure that the reclamation of surface mines occurs. We emphasize the cooperative elements of SMCRA and suggest how other countries, especially those without major existing frameworks for handling reclamation, can emulate the successes of SMCRA while avoiding its implementations snags

    Building a Quality of Life Index

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    This chapter outlines how an index measuring quality of life should be developed and then applies that work at the county level in the United States. The index we create is a unique and data‐driven approach to calculating quality of life. In the chapter, we explain the process that leads us to selecting our five indicators: public safety, health, economic development, infrastructure, and education. Each indicator breaks apart into subindicators. This chapter theoretically and statistically verifies our chosen indicators. First, we develop theoretical arguments explaining the connections between quality of life and our indicators. Then, we perform confirmatory factor analyses on our index to empirically verify our theoretical arguments for why each component should be included in the index. Further, we finally verify our theory and index using survey results. We use only publicly available data to facilitate replication by others. The results of our confirmatory factor analysis provide statistical evidence for our choice of indicators in measuring quality of life. Our findings indicate that those measuring quality of life must account for the roles of: public safety, health, economic development, infrastructure, and education. Most importantly, our results indicate that our index is a valid measure of quality of life

    Projected increase in amyotrophic lateral sclerosis from 2015 to 2040

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    Although amyotrophic lateral sclerosis (ALS) is relatively rare, the socioeconomic significance of the disease is extensive. It is therefore vital to project the epidemiologic trend of ALS. To date, there have been few published studies attempting to estimate the number and distribution of ALS cases in the upcoming years. Here we show that the number of ALS cases across the globe will increase from 222,801 in 2015 to 376,674 in 2040, representing an increase of 69%. This increase is predominantly due to ageing of the population, particularly among developing nations. This projection is likely an underestimate due to improving healthcare and economic conditions. The results should be used to inform healthcare policy to more efficiently allocate healthcare resources

    Theory-assisted determination of nano-rippling and impurities in atomic resolution images of angle-mismatched bilayer graphene

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    Ripples and impurity atoms are universally present in 2D materials, limiting carrier mobility, creating pseudo–magnetic fields, or affecting the electronic and magnetic properties. Scanning transmission electron microscopy (STEM) generally provides picometer-level precision in the determination of the location of atoms or atomic 'columns' in the in-image plane (xy plane). However, precise atomic positions in the z-direction as well as the presence of certain impurities are difficult to detect. Furthermore, images containing moiré patterns such as those in angle-mismatched bilayer graphene compound the problem by limiting the determination of atomic positions in the xy plane. Here, we introduce a reconstructive approach for the analysis of STEM images of twisted bilayers that combines the accessible xy coordinates of atomic positions in a STEM image with density-functional-theory calculations. The approach allows us to determine all three coordinates of all atomic positions in the bilayer and establishes the presence and identity of impurities. The deduced strain-induced rippling in a twisted bilayer graphene sample is consistent with the continuum model of elasticity. We also find that the moiré pattern induces undulations in the z direction that are approximately an order of magnitude smaller than the strain-induced rippling. A single substitutional impurity, identified as nitrogen, is detected. The present reconstructive approach can, therefore, distinguish between moiré and strain-induced effects and allows for the full reconstruction of 3D positions and atomic identities

    HIV infection as a risk factor for shigellosis.

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    We investigated cases of shigellosis in San Francisco and Alameda Counties identified during 1996 by active laboratory surveillance to assess the role of HIV infection as a risk factor for shigellosis. Dramatically elevated rates of shigellosis in HIV-infected persons implicate HIV infection as an important risk factor for shigellosis in San Francisco

    Recommendations of the Advisory Committee on Immunization Practices for Use of Cholera Vaccine

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    Cholera, caused by infection with toxigenic Vibrio cholerae bacteria of serogroup O1 (>99% of global cases) or O139, is characterized by watery diarrhea that can be severe and rapidly fatal without prompt rehydration. Cholera is endemic in approximately 60 countries and causes epidemics as well. Globally, cholera results in an estimated 2.9 million cases of disease and 95,000 deaths annually (1). Cholera is rare in the United States, and most U.S. cases occur among travelers to countries where cholera is endemic or epidemic. Forty-two U.S. cases were reported in 2011 after a cholera epidemic began in Haiti (2); however, <25 cases per year have been reported in the United States since 2012

    Colossal magnetocapacitance and scale-invariant dielectric response in phase-separated manganites

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    Thin films of strongly-correlated electron materials (SCEM) are often grown epitaxially on planar substrates and typically have anisotropic properties that are usually not captured by edge-mounted four-terminal electrical measurements, which are primarily sensitive to in-plane conduction paths. Accordingly, the correlated interactions in the out-of-plane (perpendicular) direction cannot be measured but only inferred. We address this shortcoming and show here an experimental technique in which the SCEM under study, in our case a 600 Angstrom-thick (La1-yPry)0.67Ca0.33MnO3 (LPCMO) film, serves as the base electrode in a metal-insulator-metal (MIM) trilayer capacitor structure. This unconventional arrangement allows for simultaneous determination of colossal magnetoresistance (CMR) associated with dc transport parallel to the film substrate and colossal magnetocapacitance (CMC) associated with ac transport in the perpendicular direction. We distinguish two distinct strain-related direction-dependent insulator-metal (IM) transitions and use Cole-Cole plots to establish a heretofore unobserved collapse of the dielectric response onto a universal scale-invariant power-law dependence over a large range of frequency, temperature and magnetic field.Comment: 32 pages, 4 figures, Supplementary section included, Submitted to Nature Physic

    Analytic Shielding Optimization to Reduce Crew Exposure to Ionizing Radiation Inside Space Vehicles

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    A sustainable lunar architecture provides capabilities for leveraging out-of-service components for alternate uses. Discarded architecture elements may be used to provide ionizing radiation shielding to the crew habitat in case of a Solar Particle Event. The specific location relative to the vehicle where the additional shielding mass is placed, as corroborated with particularities of the vehicle design, has a large influence on protection gain. This effect is caused by the exponential- like decrease of radiation exposure with shielding mass thickness, which in turn determines that the most benefit from a given amount of shielding mass is obtained by placing it so that it preferentially augments protection in under-shielded areas of the vehicle exposed to the radiation environment. A novel analytic technique to derive an optimal shielding configuration was developed by Lockheed Martin during Design Analysis Cycle 3 (DAC-3) of the Orion Crew Exploration Vehicle (CEV). [1] Based on a detailed Computer Aided Design (CAD) model of the vehicle including a specific crew positioning scenario, a set of under-shielded vehicle regions can be identified as candidates for placement of additional shielding. Analytic tools are available to allow capturing an idealized supplemental shielding distribution in the CAD environment, which in turn is used as a reference for deriving a realistic shielding configuration from available vehicle components. While the analysis referenced in this communication applies particularly to the Orion vehicle, the general method can be applied to a large range of space exploration vehicles, including but not limited to lunar and Mars architecture components. In addition, the method can be immediately applied for optimization of radiation shielding provided to sensitive electronic components

    USP6 oncogene promotes Wnt signaling by deubiquitylating Frizzleds

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    Ubiquitin-specific protease 6 (USP6) is a deubiquitylase that is overexpressed by chromosome translocation in two human neoplasms, aneurysmal bone cyst and nodular fasciitis. The relevant substrates of this ubiquitin-specific protease are not clear. Here, we identify the Wnt receptor Frizzled (Fzd) as a key target of the USP6 oncogene. Increased expression of USP6 increases the membrane abundance of Fzd, and hence increases cellular sensitivity to Wnts. USP6 opposes the activity of the ubiquitin ligase and tumor suppressor ring finger protein 43 (RNF43). This study identifies a new mechanism for pathological Wnt pathway activation in human disease and suggests a new approach to regulate Wnt activity therapeutically

    The Relationship Between HR Practices and Firm Performance: Examining Causal Order

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    Significant research attention has been devoted to examining the relationship between HR practices and firm performance, and the research support has assumed HR as the causal variable. Using data from 45 business units (with 62 data points), this study examines how measures of HR practices correlate with past, concurrent, and future operational performance measures. The results indicate that correlations with performance measures at all three times are both high and invariant, and that controlling for past or concurrent performance virtually eliminates the correlation of HR with future performance. Implications are discussed
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