3,445 research outputs found

    The Big Chill: Third-Party Documents and the Reporter\u27s Privilege

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    In the wake of Philip Morris\u27 multi-billion dollar libel suit against ABC, a Virginia court has sanctioned a new method of discovery that promises to have an unsettling impact on the reporter\u27s privilege to protect confidential sources. In Philip Morris Cos. v. American Broadcasting Cos., the tobacco giant moved to compel disclosure of the identity of a former R.J. Reynolds manager who suggested on ABC\u27s Day One news program that tobacco companies add nicotine to the cigarettes they manufacture. At the same time, Philip Morris issued subpoenas for the expense records of two ABC employees who wrote and produced the story, in a novel effort to discover the source\u27s identity. In a preliminary order issued before the parties settled, the judge hearing the case denied ABC\u27s motion to quash the subpoenas. This Note argues for an expansion of the reporter\u27s privilege to documents held by third parties. Specifically, this Note first summarizes the reporter\u27s privilege under existing law and examines First Amendment justifications for the reporter\u27s privilege. This Note then surveys the present law concerning discovery of third-party records and scrutinizes the policy arguments both in favor of and against extending the reporter\u27s privilege to documents held by third parties. Finally, this Note suggests an alternative analysis to that adopted by the Virginia court when litigants seek discovery of third-party records in libel actions

    The PLC: a logical development

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    Programmable Logic Controllers (PLCs) have been used to control industrial processes and equipment for over 40 years, having their first commercially recognised application in 1969. Since then there have been enormous changes in the design and application of PLCs, yet developments were evolutionary rather than radical. The flexibility of the PLC does not confine it to industrial use and it has been used for disparate non-industrial control applications . This article reviews the history, development and industrial applications of the PLC

    Evidence for High-Frequency QPOs with a 3:2 Frequency Ratio from a 5000 Solar Mass Black Hole

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    Following the discovery of 3:2 resonance quasi-periodic oscillations (QPOs) in M82X-1 (Pasham et al. 2014), we have constructed power density spectra (PDS) of all 15 (sufficiently long) {\it XMM-Newton} observations of the ultraluminous X-ray source NGC1313X-1 (LXL_{X} \approx 2×\times1040^{40} erg/sec). We detect a strong QPO at a frequency of 0.29±\pm0.01 Hz in data obtained on 2012 December 16. Subsequent searching of all the remaining observations for a 3:2/2:3 frequency pair revealed a feature at 0.46±\pm0.02 Hz on 2003 Dec 13 (frequency ratio of 1.59±\pm0.09). The global significance of the 0.29 Hz feature considering all frequencies between 0.1 and 4 Hz is >> 3.5 σ\sigma. The significance of the 0.46±\pm0.02 Hz QPO is >> 3.5σ\sigma for a search at 2/3 and 3/2 of 0.29 Hz. We also detect lower frequency QPOs (32.9±\pm2.6 and 79.7±\pm1.2 mHz). All the QPOs are super-imposed on a continuum consisting of flat-topped, band-limited noise, breaking into a power-law at a frequency of 16±\pm3 mHz and white noise at \gtrsim 0.1 Hz. NGC1313X-1's PDS is analogous to stellar-mass black holes' (StMBHs) PDS in the so-called steep power-law state, but with the respective frequencies (both QPOs and break frequencies) scaled down by a factor of \sim 1000. Using the inverse mass-to-high-frequency QPO scaling of StMBHs, we estimate NGC1313X-1's black hole mass to be 5000±\pm1300 MM_{\odot}, consistent with an inference from the scaling of the break frequency. However, the implied Eddington ratio, LEdd_{Edd} >> 0.03±\pm0.01, is significantly lower compared to StMBHs in the steep power-law state (LEdd_{Edd} \gtrsim 0.2).Comment: Published in ApJ Letter

    Distribution of Myosin Attachment Times Predicted from Viscoelastic Mechanics of Striated Muscle

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    We demonstrate that viscoelastic mechanics of striated muscle, measured as elastic and viscous moduli, emerge directly from the myosin crossbridge attachment time, tatt, also called time-on. The distribution of tatt was modeled using a gamma distribution with shape parameter, p, and scale parameter, β. At 5 mM MgATP, β was similar between mouse α-MyHC (16.0 ± 3.7 ms) and β-MyHC (17.9 ± 2.0 ms), and p was higher (P < 0.05) for β-MyHC (5.6 ± 0.4 no units) compared to α-MyHC (3.2 ± 0.9). At 1 mM MgATP, p approached a value of 10 in both isoforms, but β rose only in the β-MyHC (34.8 ± 5.8 ms). The estimated mean tatt (i.e., pβ product) was longer in the β-MyHC compared to α-MyHC, and became prolonged in both isoforms as MgATP was reduced as expected. The application of our viscoelastic model to these isoforms and varying MgATP conditions suggest that tatt is better modeled as a gamma distribution due to its representing multiple temporal events occurring within tatt compared to a single exponential distribution which assumes only one temporal event within tatt

    The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039)

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    The WFPC2 of the HST has been used to obtain high-resolution images of NGC 4038/4039 that go roughly 3 magnitudes deeper in V than previous observations made during Cycle 2 (-14 < M_V < -6). To first order the luminosity function (LF) is a power law, with exponent \alpha = -2.12 +/- 0.04. However, after decoupling the cluster and stellar LFs, which overlap in the range -9 < M_V < -6, we find an apparent bend in the young cluster LF at approximately M_V = -10.4. The LF has a power law exponent -2.6 +/- 0.2 in the brightward and -1.7 +/- 0.2 in the faintward. The bend corresponds to a mass ~ 10^5 M_{\odot}, only slightly lower than the characteristic mass of globular clusters in the Milky Way (~2x10^5 M_{\odot}). The star clusters of the Antennae appear slightly resolved, with median effective radii of 4 +/- 1 pc, similar to or perhaps slightly larger than those of globular clusters in our Galaxy. However, the radial extents of some of the very young clusters (ages < 10 Myr) are much larger than those of old globular clusters. A combination of the UBVI colors, \Halpha morphology, and GHRS spectra enables us to age-date the clusters in different regions of The Antennae. We find two groups of young star clusters with ages <~ 20Myr and ~100Myr, as well as an intermediate-age group (~500 Myr) and a handful of old globular clusters from the progenitor galaxies. Age estimates derived from GHRS spectroscopy yield 3 +/- 1 Myr for Knot K (just south of the nucleus of NGC 4038) and 7 +/- 1 Myr for Knot S in the Western Loop, in good agreement with ages derived from the UBVI colors. Effective gas-outflow velocities from Knots S and K are estimated to be about 25-30 km/s. However, the measured widths of the interstellar absorption lines suggest dispersion velocities of ~400 km/s along the lines of sight to Knots S and K.Comment: 56 pages, 4 tables and 23 figures, texts in AAS style, to be published in A

    Petrov types of slowly rotating fluid balls

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    Circularly rotating axisymmetric perfect fluid space-times are investigated to second order in the small angular velocity. The conditions of various special Petrov types are solved in a comoving tetrad formalism. A number of theorems are stated on the possible Petrov types of various fluid models. It is shown that Petrov type II solutions must reduce to the de Sitter spacetime in the static limit. Two space-times with a physically satisfactory energy-momentum tensor are investigated in detail. For the rotating incompressible fluid, it is proven that the Petrov type cannot be D. The equation of the rotation function ω\omega can be solved for the Tolman type IV fluid in terms of quadratures. It is also shown that the rotating version of the Tolman IV space-time cannot be Petrov type D.Comment: 14 pages, version to appear in Gen. Rel. Gra

    Exploring Accretion and Disk-Jet Connections in the LLAGN M81*

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    We report on a year-long effort to monitor the central supermassive black hole in M81 in the X-ray and radio bands. Using Chandra and the VLA, we obtained quasi-simultaneous observations of M81* on seven occasions during 2006. The X-ray and radio luminosity of M81* are not strongly correlated on the approximately 20-day sampling timescale of our observations, which is commensurate with viscous timescales in the inner flow and orbital timecales in a radially-truncated disk. This suggests that short-term variations in black hole activity may not be rigidly governed by the "fundamental plane", but rather adhere to the plane in a time-averaged sense. Fits to the X-ray spectra of M81* with bremsstrahlung models give temperatures that are inconsistent with the outer regions of very simple advection-dominated inflows. However, our results are consistent with the X-ray emission originating in a transition region where a truncated disk and advective flow may overlap. We discuss our results in the context of models for black holes accreting at small fractions of their Eddington limit, and the fundamental plane of black hole accretion.Comment: Accepted for publication in Ap

    A Search for High-Energy Counterparts to Fast Radio Bursts

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    We report on a search for high-energy counterparts to fast radio bursts (FRBs) with the Fermi Gamma-ray Burst Monitor (GBM), Fermi Large Area Telescope (LAT), and the Neil Gehrels Swift Observatory Burst Alert Telescope (BAT). We find no significant associations for any of the 23 FRBs in our sample, but report upper limits to the high-energy fluence for each on timescales of 0.1, 1, 10, and 100 s. We report lower limits on the ratio of the radio to high-energy fluence, frfγ\frac{f_{r}}{f_{\gamma}}, for timescales of 0.1 and 100 s. We discuss the implications of our non-detections on various proposed progenitor models for FRBs, including analogs of giant pulses from the Crab pulsar and hyperflares from magnetars. This work demonstrates the utility of analyses of high-energy data for FRBs in tracking down the nature of these elusive sources

    Koinonia

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    In This IssueThe Fabric of Our Faithfulness: Part 1, David S. Guthrie What is the Sophomore Slump-and Why Should We Care?: Excerpted from Visible Solutions for Invisible Students: Helping Sophomores Succeed, by Laurie A. Schreiner & Jerry Pattengale Around CampusServant Leadership, Tess Bradley The 7 Be\u27s of Student Leader Supervision, Jesse Brown Spotlight on SpeakersJohn 7:53-8:11: The Politically Correct Version, Calvin Miller Regular FeaturesPresident\u27s Corner Editor\u27s Disk ACSD Business: Placement Services 2001, Conference Thoughts: Something Old...Something New..., Submissions Soughthttps://pillars.taylor.edu/acsd_koinonia/1031/thumbnail.jp
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