1,965 research outputs found

    The Communications Decency Act: Immunity for Internet-Facilitated Commercial Sexual Exploitation

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    This paper reviews the original intent and historical application of the Communications Decency Act (CDA), most notably Section 230, with special regard to cases of Internet-facilitated commercial sexual exploitation. Although the CDA was originally created to protect children online, Section 230 of the CDA has been interpreted by the courts to grant broad immunities to websites facilitating the sexual exploitation of children and adults alike. Through analyzing the genesis and evolution of the CDA, it becomes clear that court interpretations of Section 230 are starkly inconsistent with original Congressional intent, and that the primary way to avoid de facto decriminalization of Internet-facilitated commercial sexual exploitation is to amend the Communications Decency Act

    Development of a New, Precise Near-infrared Doppler Wavelength Reference: A Fiber Fabry-Perot Interferometer

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    We present the ongoing development of a commercially available Micron Optics fiber-Fabry Perot Interferometer as a precise, stable, easy to use, and economic spectrograph reference with the goal of achieving <1 m/s long term stability. Fiber Fabry-Perot interferometers (FFP) create interference patterns by combining light traversing different delay paths. The interference creates a rich spectrum of narrow emission lines, ideal for use as a precise Doppler reference. This fully photonic reference could easily be installed in existing NIR spectrographs, turning high resolution fiber-fed spectrographs into precise Doppler velocimeters. First light results on the Sloan Digital Sky Survey III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph and several tests of major support instruments are also presented. These instruments include a SuperK Photonics fiber supercontinuum laser source and precise temperature controller. A high resolution spectrum obtained using the NIST 2-m Fourier transform spectrometer (FTS) is also presented. We find our current temperature control precision of the FFP to be 0.15 mK, corresponding to a theoretical velocity stability of 35 cm/s due to temperature variations of the interferometer cavity.Comment: 16 pages, 11 figures. To appear in the proceedings of the SPIE 2012 Astronomical Instrumentation and Telescopes conferenc

    DASI Three-Year Cosmic Microwave Background Polarization Results

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    We present the analysis of the complete 3-year data set obtained with the Degree Angular Scale Interferometer (DASI) polarization experiment, operating from the Amundsen-Scott South Pole research station. Additional data obtained at the end of the 2002 Austral winter and throughout the 2003 season were added to the data from which the first detection of polarization of the cosmic microwave background radiation was reported. The analysis of the combined data supports, with increased statistical power, all of the conclusions drawn from the initial data set. In particular, the detection of E-mode polarization is increased to 6.3 sigma confidence level, TE cross-polarization is detected at 2.9 sigma, and B-mode polarization is consistent with zero, with an upper limit well below the level of the detected E-mode polarization. The results are in excellent agreement with the predictions of the cosmological model that has emerged from CMB temperature measurements. The analysis also demonstrates that contamination of the data by known sources of foreground emission is insignificant.Comment: 13 pages Latex, 10 figures, submitted to Ap

    Cosmological Parameter Extraction from the First Season of Observations with DASI

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    The Degree Angular Scale Interferometer (\dasi) has measured the power spectrum of the Cosmic Microwave Background anisotropy over the range of spherical harmonic multipoles 100<l<900. We compare this data, in combination with the COBE-DMR results, to a seven dimensional grid of adiabatic CDM models. Adopting the priors h>0.45 and 0.0<=tau_c<=0.4, we find that the total density of the Universe Omega_tot=1.04+/-0.06, and the spectral index of the initial scalar fluctuations n_s=1.01+0.08-0.06, in accordance with the predictions of inflationary theory. In addition we find that the physical density of baryons Omega_b.h^2=0.022+0.004-0.003, and the physical density of cold dark matter Omega_cdm.h^2=0.14+/-0.04. This value of Omega_b.h^2 is consistent with that derived from measurements of the primordial abundance ratios of the light elements combined with big bang nucleosynthesis theory. Using the result of the HST Key Project h=0.72+/-0.08 we find that Omega_t=1.00+/-0.04, the matter density Omega_m=0.40+/-0.15, and the vacuum energy density Omega_lambda=0.60+/-0.15. (All 68% confidence limits.)Comment: 7 pages, 4 figures, minor changes in response to referee comment

    Geophysics

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    Contains reports on three research projects

    Modified Chaplygin Gas and Constraints on its B parameter from CDM and UDME Cosmological models

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    We study Modified Chaplygin Gas (MCG) as a candidate for dark energy and predict the values of parameters of the gas for a physically viable cosmological model. The equation of state of MCG (p=BρAραp=B \rho - \frac {A}{\rho^\alpha} ) involves three parameters: BB, AA and α\alpha. The permitted values of these parameters are determined with the help of dimensionless age parameter (HotoH_{o}t_{o}) and H(z)zH(z)-z Data. Specifically we study the allowed ranges of values of B parameter in terms of α\alpha and AsA_{s} (AsA_{s} is defined in terms of the constants in the theory). We explore the constraints of the parameters in Cold Dark Matter(CDM) model and UDME(Unified Dark Matter Energy) model respectively.Comment: 5 pages, 10 fig

    What's Behind Acoustic Peaks in the Cosmic Microwave Background Anisotropies

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    We give a brief review of the physics of acoustic oscillations in Cosmic Microwave Background (CMB) anisotropies. As an example of the impact of their detection in cosmology, we show how the present data on CMB angular power spectrum on sub-degree scales can be used to constrain dark energy cosmological models.Comment: 6 pages, proceedings to the TAUP2001 conference, LNGS, Italy, Sept. 200

    The Impact of Atmospheric Fluctuations on Degree-scale Imaging of the Cosmic Microwave Background

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    Fluctuations in the brightness of the Earth's atmosphere originating from water vapor are an important source of noise for ground-based instruments attempting to measure anisotropy in the Cosmic Microwave Background. This paper presents a model for the atmospheric fluctuations and derives simple expressions to predict the contribution of the atmosphere to experimental measurements. Data from the South Pole and from the Atacama Desert in Chile, two of the driest places on Earth, are used to assess the level of fluctuations at each site.Comment: 29 pages, 7 figures, 1 table, appears in The Astrophysical Journa

    Effects Of Cellulase Supplementation And Wheat Bran On Mineral Utilization In Broilers

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    In this experiment, 3-week-oId broiler type chicks were assigned to 24 groups of 10 chicks each for two replicates of 12 treatments. A completely randomized experiment with a 4 x 2 factorial arrangement involved feeding 0, 10 or 20% wheat bran or 20% wheat bran plus cellulase. The birds were housed in electrically heated batteries with raised wire floors. Feed and water were supplied ad libitum. The wheat bran was defatted and the cellulase (imported from Boerhinger, Mannheim, Gmn H. W. Germany) was mixed at .008% in the total diet. The enzyme supplementation to the diet was as a dry preparation

    Some Effects Of Enzyme Supplementation And Various Wheat Bran Levels In A Broiler Diet On Apparent Digestibility

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    It is generally recognized that birds do not have an enzyme in their digestive fluid which digests cellulose. However, cellulosic materials are major renewable resources available in large quantities which need to be properly utilized to help meet our needs for energy, chemicals, food and feed for a long-range solution. A variety of lignocellulosic materials containing acid-detergent fibers, are available and microorganisms capable of degrading either one or more of the three main constituents, viz., cellulose, hemicelluose and lignin, have been studied. A further variety of strategies are being explored, including thermal methods of degradation such as pyrolysis or biological methods such as enzymatic hydrolysis and fermentation
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