771 research outputs found

    Cryptocurrencies Are Taxable and Not Free From Fraud

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    In this report, the authors discuss cryptocurrencies ā€” especially bitcoin ā€” and argue that because the IRS lists them as property, they are taxable, and because they are not as anonymous as once thought, they are not free from fraud. Cryptocurrencies are digital assets used as a medium of exchange, but they are not really coins. They can be sent electronically from one entity to another almost anywhere in the world with an internet connection. There are many cryptocurrencies in the market, including bitcoin, ethereum, ethereum classic, litecoin, nem, dash, iota, bitshares, monero, neo, and ripple. Many of the cryptocurrency networks are not controlled by a single entity or company; instead, a decentralized network of computers keeps track of the currency using a token ID. A ledger maintains a continuously growing list of date stamped transactions in real time called ā€œblocks.ā€ This technology is known as blockchain, which records, verifies, and stores transactions without a trusted central authority. The network instead relies on decentralized autonomous organizations (DAOs) with uncertain legal standing

    Technology Development Plan for the Baseline Detector System of the X-Ray Microcalorimeter Spectrometer (XMS) of the International X-Ray Observatory (IXO)

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    The primary purpose of this document is to present the technology development plan for the XMS detector system. It covers the current status (including assessment of the Technology Readiness Level, TRL, and a justification of the level assigned), the roadmap to progress to a level between TRL 5 and TRL 6 by the middle of 2012, and an assessment of the associated cost. A secondary purpose of this document is to address the Action Items raised at the XMS Phase-A Study Mid-Term Review that pertain to the detector system (AI #4, #8, and #9)

    Implementing a Stateā€Adopted High School Health Curriculum: A Case Study

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    BACKGROUNDThe Michigan Model for Healthā„¢ (MMH) is the official health curriculum for the State of Michigan and prevailing policy and practice has encouraged its adoption. Delivering evidenceā€based programs such as MMH with fidelity is essential to program effectiveness. Yet, most schools do meet stateā€designated fidelity requirements for implementation (delivering 80% or more of the curriculum).METHODSWe collected online survey (NĀ =Ā 20) and inā€person interview (NĀ =Ā 5) data investigating fidelity and factors related to implementation of the MMH curriculum from high school health teachers across high schools in one socioeconomically challenged Michigan county and key stakeholders.RESULTSWe found that 68% of teachers did not meet stateā€identified standards of fidelity for curriculum delivery. Our results indicate that factors related to the context and implementation processes (eg, trainings) may be associated with fidelity. Teachers reported barriers to program delivery, including challenges with adapting the curriculum to suit their context, competing priorities, and meeting studentsā€™ needs on key issues such as substance use and mental health issues.CONCLUSIONSMultiple factors influence the fidelity of health curriculum delivery in schools serving lowā€income students. Investigating these factors guided by implementation science frameworks can inform use of implementation strategies to support and enhance curriculum delivery.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155483/1/josh12892_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155483/2/josh12892.pd

    Concept of Operations for Management by Trajectory

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    This document describes Management by Trajectory (MBT), a concept for future air traffic management (ATM) in which every flight operates in accordance with a four-dimensional trajectory (4DT) that is negotiated between the airspace user and the Federal Aviation Administration (FAA) to respect the airspace user's goals while complying with National Airspace System (NAS) constraints. In the present-day NAS, the ATM system attempts to predict the trajectory for each flight based on the approved flight plan and scheduled or controlled departure time. However, once the aircraft starts to move, controllers tactically manage the aircraft to implement traffic management restrictions, separate otherwise conflicting aircraft, and address arising NAS constraints. Tactical controller actions are not directly communicated to the automation systems or other stakeholders. Furthermore, the initial trajectory prediction does not anticipate these disruptions or how they will impact the flight. Consequently, and compounded by gaps in required data and models, trajectory predictions are less accurate than possible, which affects Traffic Flow Management (TFM) performance. A cornerstone of the MBT concept is that all air vehicles have, at all times, an assigned 4DT from their current state to their destination. These assigned trajectories consist of trajectory constraints and descriptions. Pilots and air traffic controllers, with the aid of automation, operate the aircraft to comply with the assigned trajectory, unless first negotiating a revision. Equipped aircraft have substantial responsibility for complying with the assigned trajectory without controller intervention. To maximize the operational flexibility available to the airspace user, the assigned trajectory only imposes trajectory constraints as required to achieve the ATM goals of NAS constraint compliance and aircraft separation. Trajectory descriptions are added to the assigned trajectory to ensure sufficient predictability. To further improve trajectory prediction accuracy, airspace users supplement the assigned trajectory by broadcasting intent information and updating it as necessary. Air vehicle intent is a more detailed description of the airspace user's plan for how the flight will fly the assigned trajectory. Air vehicle intent can change freely, without negotiation, as long as it remains in compliance with the assigned trajectory. Aircraft assigned trajectories, air vehicle intent, and predicted trajectories are shared, creating a common view among stakeholders. A NAS Constraint Service gathers and publishes information about all known NAS constraints, enabling airspace users to be informed participants in trajectory negotiation. Trajectory constraints in the assigned trajectory are mapped to NAS constraints to facilitate identifying which aircraft are affected when NAS constraints change. To support efficient trajectory negotiation, all aircraft provide current information about air vehicle capabilities. Assigned trajectories are constructed to satisfy all known NAS constraints, improving trajectory stability and predictability. Uncertainty and disruptions are handled by modifying the assigned trajectory as far in advance as possible. By proactively negotiating changes to the assigned trajectory, rather than relying on controller-selected tactical actions such as vectors to resolve traffic conflicts or implement miles-in-trail restrictions, MBT keeps aircraft on closed trajectories that are fully known to all stakeholders. Since reactive air traffic control actions cannot be predicted in advance, the downstream trajectory cannot be accurately predicted until they happen. Reliable trajectory predictions allow the system to identify needed modifications to trajectories further in advance, where they can be negotiated and communicated as amendments (i.e., additional or altered trajectory constraints) to the assigned trajectory. Decision Support Tools (DSTs) aid controllers in rapidly defining and communicating closed trajectories to the aircraft and support all stakeholders in trajectory negotiation. Anticipated MBT benefit mechanisms include more accurate trajectory predictions, improved ATM performance and robustness to off-nominal conditions, increased flexibility and operational efficiency, reduced impediments to emerging classes of airspace users accessing NAS resources, reduced environmental impacts, and enhanced safety

    Physics of the Cosmos (PCOS) Program Technology Development 2018

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    We present a final report on our program to raise the Technology Readiness Level (TRL) of enhanced chargecoupleddevice (CCD) detectors capable of meeting the requirements of Xray grating spectrometers (XGS) and widefield Xray imaging instruments for small, medium, and large missions. Because they are made of silicon, all Xray CCDs require blocking filters to prevent corruption of the Xray signal by outofband, mainly optical and nearinfrared (nearIR) radiation. Our primary objective is to demonstrate technology that can replace the fragile, extremely thin, freestanding blocking filter that has been standard practice with a much more robust filter deposited directly on the detector surface. Highperformance, backilluminated CCDs have flown with freestanding filters (e.g., one of our detectors on Suzaku), and other relatively lowperformance CCDs with directly deposited filters have flown (e.g., on the Xray Multimirror MissionNewton, XMMNewton Reflection Grating Spectrometer, RGS). At the inception of our program, a highperformance, backilluminated CCD with a directly deposited filter has not been demonstrated. Our effort will be the first to show such a filter can be deposited on an Xray CCD that meets the requirements of a variety of contemplated future instruments. Our principal results are as follows: i) we have demonstrated a process for direct deposition of aluminum optical blocking filters on backilluminated MIT Lincoln Laboratory CCDs. Filters ranging in thickness from 70 nm to 220 nm exhibit expected bulk visibleband and Xray transmission properties except in a small number (affecting 1% of detector area) of isolated detector pixels ("pinholes"), which show higherthanexpected visibleband transmission; ii) these filters produce no measurable degradation in softXray spectral resolution, demonstrating that direct filter deposition is compatible with the MIT Lincoln Laboratory backillumination process; iii) we have shown that under sufficiently intense visible and nearIR illumination, outofband light can enter the detector through its sidewalls and mounting surfaces, compromising detector performance. This 'sidewall leakage' has been observed, for example, by a previous experiment on the International Space Station during its orbitday operations. We have developed effective countermeasures for this sidewall leakage; iv) we developed an exceptionally productive collaboration with the Regolith Xray Imaging Spectrometer (REXIS) team. REXIS is a student instrument now flying on the Origins Spectral Interpretation Resource Identification Security - Regolith Explorer (OSIRISREx) mission. REXIS students participated in our filter development program, adopted our technology for their flight instrument, and raised the TRL of this technology beyond our initial goals. This Strategic Astrophysics Technology (SAT) project, a collaboration between the MKI and MIT Lincoln Laboratory, began July 1, 2012, and ended on June 30, 2018

    Improved Value for the Energy Splitting of the Ground-State Doublet in the Nucleus 229Th

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    We have made an improved estimate of the 229mTh isomer energy. The new value 7.8(5) eV includes an estimate of spectral contamination due to the out-of-band E2 transition from the 42.43-keV 7/2+ member of the [633] ground state band to the 3/2+ [631] 229mTh bandhead. We estimate a 2% branching ratio for this unobserved transition in the 42.43-keV 7/2+ [633] deexcitation. The excitation of the 229mTh level is increased from the previously reported value of 7.6(5) eV to the new value of 7.8(5) eV when this branch is included in the analysis

    Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918

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    The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized
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