35,928 research outputs found

    Mega, Digital Storage Lockers, and the DMCA: Will Innovation Be Stifled by Fears of Piracy?

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    Kim Dotcom, founder of Megaupload Limited, has been in many news headlines over the past year. Megaupload—one of Dotcom’s many peer-to-peer sharing sites—was the center of controversy, as it allowed users to upload and share all sorts of files, including copyrighted material. After an organized effort by the Department of Justice and several foreign governments, Dotcom was arrested for (secondary) copyright infringement and his site was ultimately shut down. Dotcom has recently launched a new service, MEGA, which he claims will evade copyright laws entirely. Like other well-known cloud-sharing services such as Dropbox and Google Drive, MEGA allows users to upload files and to share them with select users. In an attempt to avoid liability, MEGA locally encrypts all files on the user’s computer before they are uploaded to the site. The private key and public key used to encrypt and decrypt the file are retained solely by the user; MEGA gets no part of that information. This, Dotcom argues, will shift the entirety of the copyright onus to the user. This Issue Brief analyzes the protections afforded cyberlocker services like MEGA by the DMCA, including tensions raised in actual litigation. This Issue Brief argues that, while an ex ante secondary-liability analysis is difficult due to its contextual nature, MEGA’s use of user-controlled encryption (UCE), deduplication, and distributed host servers may lend to an affirmative finding of liability

    The Aquila prestellar core population revealed by Herschel

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    The origin and possible universality of the stellar initial mass function (IMF) is a major issue in astrophysics. One of the main objectives of the Herschel Gould Belt Survey is to clarify the link between the prestellar core mass function (CMF) and the IMF. We present and discuss the core mass function derived from Herschel data for the large population of prestellar cores discovered with SPIRE and PACS in the Aquila rift cloud complex at d ~ 260 pc. We detect a total of 541 starless cores in the entire ~11 deg^2 area of the field imaged at 70–500 ÎŒm with SPIRE/PACS. Most of these cores appear to be gravitationally bound, and thus prestellar in nature. Our Herschel results confirm that the shape of the prestellar CMF resembles the stellar IMF, with much higher quality statistics than earlier submillimeter continuum ground-based surveys

    Molecular dynamics simulations of the rotational and translational diffusion of a Janus rod-shaped nanoparticle

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    The diffusion of a Janus rod-shaped nanoparticle in a dense Lennard-Jones fluid is studied using molecular dynamics (MD) simulations. The Janus particle is modeled as a rigid cylinder whose atoms on each half-side have different interaction energies with fluid molecules, thus comprising wetting and nonwetting surfaces. We found that both rotational and translational diffusion coefficients are larger for Janus particles with higher wettability contrast, and these values are bound between the two limiting cases of uniformly wetting and nonwetting particles. It was also shown that values of the diffusion coefficients for displacements parallel and perpendicular to the major axis of a uniformly wetting particle agree well with analytical predictions despite a finite slip at the particle surface present in MD simulations. It was further demonstrated that diffusion of Janus particles is markedly different from that of uniform particles; namely, Janus particles preferentially rotate and orient their nonwetting sides along the displacement vector to reduce drag. This correlation between translation and rotation is consistent with the previous results on diffusive dynamics of a spherical Janus particle with two hemispheres of different wettability.Comment: 27 pages, 9 figure

    Effects of heavy Majorana neutrinos at lepton-proton colliders

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    We discuss the prospects of detecting the processes e+p→Μˉeℓ+ℓâ€Č+Xe^+p\to\bar\nu_e\ell^+\ell'^+X and Îœep→eℓ+ℓâ€Č+X\nu_ep\to e\ell^+\ell'^+X (ℓ,ℓâ€Č=e,ÎŒ,τ\ell,\ell'=e,\mu,\tau) under the conditions of the present epep collider HERA and of future colliders. These high-energy processes are assumed to be mediated by the exchange of heavy Majorana neutrinos (HMN). We consider two simple scenarios for the HMN mass spectrum: the effective singlet (m1â‰Șm2<m3...m_1\ll m_2<m_3...) and the effective doublet (m1<m2â‰Șm3...m_1<m_2\ll m_3...). For the latter case, the cross section includes information about CP-violating phases.Comment: 5pages, 2 figures; published in conference proceedings: Particle Physics in Laboratory, Space and Universe, 11th. Lomonosov Conf. on Elementary Particle Physics (Moscow, 21-27 August 2003) (Singapore, World Scientific, 2005

    Rare semileptonic meson decays in R-parity violating MSSM

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    We discuss rare meson decays K+→π−ℓ+ℓâ€Č+K^ + \to \pi ^ - \ell ^ + \ell '^ + and D+→K−ℓ+ℓâ€Č+D^ + \to K^ - \ell ^ + \ell '^ + (ℓ,ℓâ€Č=e,ÎŒ\ell, \ell'=e, \mu) in a supersymmetric extension of the Standard Model with R-parity violation. Estimates of the branching ratios for these decays are presented.Comment: 5 pages, 1 figure; title modified to better reflect the contents, a normalization error corrected for D-meson decays, modifying parts of Table 1; a reference and DESY Report number added; to appear in the Proceedings of the 12th. Lomonosov Conference on Elementary Particle Physics, Moscow State University, Moscow, Russia, 25-31 August 200

    Electron angular correlation in neutrinoless double beta decay and new physics

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    The angular correlation of the electrons in the neutrinoless double beta decay (0Îœ2ÎČ0\nu2\beta) is calculated taking into account the nucleon recoil, the SS and PP-waves for the electrons and the electron mass using a general Lorentz invariant effective Lagrangian. We show that the angular coefficient is essentially independent of the nuclear matrix element models. We work out the angular coefficient in several scenarios for new physics, in particular, in the left-right symmetric models.Comment: 5 pages, 1 figure; to appear in the Proceedings of the 13th Lomonosov Conference on Elementary Particle Physics, 23 --29 August 2007, Moscow, Russi

    Bilinear R-parity Violation in Rare Meson Decays

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    We discuss rare meson decays K+→π−ℓ+ℓâ€Č+K^ + \to \pi ^ - \ell ^ + \ell '^ + and D+→K−ℓ+ℓâ€Č+D^ + \to K^ - \ell ^ + \ell '^ + (ℓ,ℓâ€Č=e,ÎŒ\ell ,\ell ' = e,\mu ) in a supersymmetric extension of the standard model with explicit breaking of R-parity by bilinear Yukawa couplings in the superpotential. Estimates of the branching ratios for these decays are given. We also compare our numerical results with analogous ones previously obtained for two other mechanisms of lepton number violation: exchange by massive Majorana neutrinos and trilinear R-parity violation.Comment: 5 pages, 1 figure; To appear in the Proceedings of the 13th Lomonosov Conference on Elementary Particle Physics, 23 -- 29 August, 2007, Moscow, Russi
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