392 research outputs found

    All In, But Left Out: How the Unlawful Internet Gambling Enforcement Act Seeks to Eradicate Online Gambling in the United States

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    In recent years, gambling on the Internet has evolved into a multi-billion dollar enterprise. The industry has been particularly entrenched in the United States, whose citizens at one time accounted for up to one-half of all Internet gambling revenues. However, the landscape of Internet gambling in the United States changed drastically in 2006, when President George W Bush signed into law the Unlawful Internet Gambling Enforcement Act (UIGEA). The crucial provision of the UIGEA is its prohibition of the acceptance of payments, made by United States banks and creditors, to purveyors of unlawful Internet gambling enterprises. By targeting United States financial institutions instead of individual gamblers, the UIGEA attempts to indirectly prohibit Internet gambling within U.S. borders. The UIGEA, however, is not without both legal and pragmatic problems. This Note seeks to illustrate those problems and to predict how the UIGEA will continue to affect the Internet gambling industry. First, the Note provides a background of prior attempts at regulation of Internet gambling, both at the state and federal level. Second, it engages in a textual analysis of the UIGEA, recognizing potential legal arguments both for and against the law. Third, the Note touches on how the UIGEA has affected an ongoing trade dispute between the United States and Antigua and Barbuda. Finally, the Note recognizes potential enforcement problems raised by the UIGEA, even if all of its provisions are legally sound

    Entanglement properties of optical coherent states under amplitude damping

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    Through concurrence, we characterize the entanglement properties of optical coherent-state qubits subject to an amplitude damping channel. We investigate the distillation capabilities of known error correcting codes and obtain upper bounds on the entanglement depending on the non-orthogonality of the coherent states and the channel damping parameter. This work provides a first, full quantitative analysis of these photon-loss codes which are naturally reminiscent of the standard qubit codes against Pauli errors.Comment: 7 pages, 6 figures. Revised version with small corrections; main results remain unaltere

    GPS radio occultation with CHAMP and SAC-C: global monitoring of thermal tropopause parameters

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    In this study the global lapse-rate tropopause (LRT) pressure, temperature, potential temperature, and sharpness are discussed based on Global Positioning System (GPS) radio occultations (RO) from the German CHAMP (CHAllenging Minisatellite Payload) and the U.S.-Argentinian SAC-C (Satelite de Aplicaciones Cientificas-C) satellite missions. Results with respect to seasonal variations are compared with operational radiosonde data and ECMWF (European Centre for Medium-Range Weather Forecast) operational analyses. Results on the tropical quasi-biennial oscillation (QBO) are updated from an earlier study. CHAMP RO data are available continuously since May 2001 with on average 150 high resolution temperature profiles per day. SAC-C data are available for several periods in 2001 and 2002. In this study temperature data from CHAMP for the period May 2001-December 2004 and SAC-C data from August 2001-October 2001 and March 2002-November 2002 were used, respectively. The bias between GPS RO temperature profiles and radiosonde data was found to be less than 1.5K between 300 and 10hPa with a standard deviation of 2-3K. Between 200-20hPa the bias is even less than 0.5K (2K standard deviation). The mean deviations based on 167699 comparisons between CHAMP/SAC-C and ECMWF LRT parameters are (-2.1±37.1)hPa for pressure and (0.1±4.2)K for temperature. Comparisons of LRT pressure and temperature between CHAMP and nearby radiosondes (13230) resulted in (5.8±19.8)hPa and (-0.1±3.3)K, respectively. The comparisons between CHAMP/SAC-C and ECMWF show on average the largest differences in the vicinity of the jet streams with up to 700m in LRT altitude and 3K in LRT temperature, respectively. The CHAMP mission generates the first long-term RO data set. Other satellite missions will follow (GRACE, COSMIC, MetOp, TerraSAR-X, EQUARS) generating together some thousand temperature profiles daily

    GPS radio occultation with CHAMP: monitoring of climate change parameters

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    International audienceThe Global Positioning System (GPS) radio occultation (RO) technique offers a valuable new data source for global and continuous monitoring of the Earth's atmosphere. Refractivity, temperature and water vapor profiles with high accuracy and vertical resolution can be derived from this method. The GPS RO technique requires no calibration, is not affected by clouds, aerosols or precipitation, and the occultations are almost uniformly distributed over the globe. In this paper the potential of GPS RO for monitoring of the temperature is demonstrated exemplarily for the tropical upper troposphere and lower stratosphere (UTLS) region using GPS RO data from the German CHAMP (CHAllenging Minisatellite Payload) satellite mission. In addition, results of a 1DVAR retrieval scheme to derive tropospheric water vapor profiles using ECMWF data as background will be discussed. CHAMP RO data are available since 2001 with up to 200 high resolution temperature profiles per day. The temperature bias between CHAMP temperature profiles and radiosonde data as well as ECMWF analyses is less than 0.5 K between 300?30 hPa. The CHAMP RO experiment generates the first long-term RO data set. Other satellite missions will follow (GRACE, TerraSAR-X, COSMIC, METOP) generating some thousand profiles of atmospheric parameters daily

    Efficient Heralding of Photonic Qubits with Apllications to Device Independent Quantum Key Distribution

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    We present an efficient way of heralding photonic qubit signals using linear optics devices. First we show that one can obtain asymptotically perfect heralding and unit success probability with growing resources. Second, we show that even using finite resources, we can improve qualitatively and quantitatively over earlier heralding results. In the latte r scenario, we can obtain perfect heralded photonic qubits while maintaining a finite success probability. We demonstrate the advantage of our heralding scheme by predicting key rates for device independent quantum key distribution, taking imperfections of sources and detectors into account

    Open-source Arduino-compatible data loggers designed for field research

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    Automated electronic data loggers revolutionized environmental monitoring by enabling reliable high-frequency measurements. However, the potential to monitor the complex environmental interactions involved in global change has not been fully realized due to the high cost and lack of modularity of commercially available data loggers. Responding to this need, we developed the ALog (Arduino logger) series of three open-source data loggers, based on the popular and easy-to-program Arduino microcontroller platform. ALog data loggers are low cost, lightweight, and low power; they function between −30 and +60&thinsp;∘C, can be powered by readily available alkaline batteries, and can store up to 32&thinsp;GB of data locally. They are compatible with standard environmental sensors, and the ALog firmware library may be expanded to add additional sensor support. The ALog has measured parameters linked to weather, streamflow, and glacier melt during deployments of days to years at field sites in the USA, Canada, Argentina, and Ecuador. The result of this work is a robust and field-tested open-source data logger that is the direct descendant of dozens of individuals' contributions to the growing open-source electronics movement.</p

    Gravity waves above the Andes detected from GPS radio occultation temperature profiles: Jet mechanism?

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    A significant wave activity (WA) in the upper troposphere and lower stratosphere, mainly during winter, was detected at midlatitudes in the southern hemisphere (30-40S) above the Andes Range, from an analysis of Global Positioning System Radio Occultation (GPS RO) temperature profiles retrieved by CHAMP (CHAllenging Mini-satellite Payload) and SAC-C (Satélite de Aplicaciones Científicas-C) Low Earth Orbit (LEO) satellites, between May 2001 and February 2006. The possible main gravity wave sources in this region are: i) orographic forcing, ii) geostrophic adjustment and iii) deep convection. The available vertical resolution of GPS RO soundings does not rule out any of these alternatives. Based on satellite imaginary, the WA enhancements cannot be attributed to deep convection events. Inertia-gravity waves (IGWs) could be generated after a geostrophic adjustment process, following a perturbation of the zonal jet situated above the Andes Mountains by mountain waves (MWs). The monthly WA intensity follows the zonal wind velocity strength according to its seasonal variability at jet altitudes. As the GPS-LEO lines of sight are roughly meridionally aligned and the morphology of the Andes at middle latitudes is predominantly north-south, it was possible to detect MWs as well as IGWs from GPS RO temperature profiles. This characteristic does not apply for other mountain range alignments. From the analysis of a numerical simulation at the time and location of a single RO event with very strong WA, two main modes of oscillation with horizontal wavelength around 40 and 200 km were identified. The first one is attributed to a MW and the second one to an IGW. Copyright 2006 by the American Geophysical Union.Fil:de la Torre, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Alexander, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Llamedo, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Menéndez, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
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