Biases in the Quasar Mass-Luminosity Plane

We find that the recently reported departure from the Eddington luminosity limit for the highest quasar black hole masses at a given redshift is an artifact due to biases in black hole mass measurements. This sub-Eddington boundary (with non-unity slope) in the quasar mass-luminosity plane was initially reported by Steinhardt & Elvis (2010a) using the FWHM-based black hole mass catalogue of Shen et al. (2008). However, the significance of the boundary is reduced when the FWHM-based mass-scaling relationship is recalibrated following Wang et al. (2009) and using the most updated reverberation mapping estimates of black hole masses. Furthermore, this boundary is not seen using mass estimates based on the line dispersion of the same quasars' MgII emission lines. Thus, the initial report of a sub-Eddington boundary with non-unity slope was due to biases in estimating masses using the FWHM of a fit of one or two Gaussians to quasar MgII emission lines. We provide evidence that using the line dispersion of the MgII line produces less biased black hole mass estimates.Comment: 11 pages, 10 figures, Accepted for publication in MNRA

Examining How International Experiences Promote Global Competency Among Engineering Graduate Students

Employers across the globe are seeking engineers that possess more “soft skills”: leadership, communication, and teamwork skills. In addition to these characteristics as well as the traditional engineering problem solving skills, engineers are required to have attributes of global competency which would help them thrive in the global workforce. A plethora of information and studies exist on undergraduate students and their global competency development. Despite these efforts, there is little information on engineering doctoral students and methods for increasing their levels of global competency. Doctoral students are at the forefront of scientific and technological innovation and discoveries, so it is critical that they are trained to work effectively in diverse environments. This study comparatively examines the intercultural experiences of a) engineering doctoral students from the U.S. who traveled abroad, and b) international engineering doctoral students who traveled to the U.S. Findings show that both groups of students prepared themselves to go abroad in multiple ways, and that some domestic students abroad reported negative experiences due to a mismatch between pre-travel expectations and actual experiences abroad. International students experienced greater adjustment outcomes when they had greater levels of support, and these students also frequently mentioned cross-cultural differences rather than similarities. Findings of our study can help U.S. and international academic institutions identify strategies to increase graduate students\u27 global competency levels

The Importance of Broad Emission-Line Widths in Single Epoch Black Hole Mass Estimates

Estimates of the mass of super-massive black holes (BHs) in distant active galactic nuclei (AGNs) can be obtained efficiently only through single-epoch spectra, using a combination of their broad emission-line widths and continuum luminosities. Yet the reliability and accuracy of the method, and the resulting mass estimates, M_BH, remain uncertain. A recent study by Croom using a sample of SDSS, 2QZ and 2SLAQ quasars suggests that line widths contribute little information about the BH mass in these single-epoch estimates and can be replaced by a constant value without significant loss of accuracy. In this Letter, we use a sample of nearby reverberation-mapped AGNs to show that this conclusion is not universally applicable. We use the bulge luminosity (L_Bulge) of these local objects to test how well the known M_BH - L_Bulge correlation is recovered when using randomly assigned line widths instead of the measured ones to estimate M_BH. We find that line widths provide significant information about M_BH, and that for this sample, the line width information is just as significant as that provided by the continuum luminosities. We discuss the effects of observational biases upon the analysis of Croom and suggest that the results can probably be explained as a bias of flux-limited, shallow quasar samples.Comment: 10 text pages + 4 Figures + 1 Table. Accepted for publication in ApJ Letter

Assessing Clinical Software User Needs for Improved Clinical Decision Support Tools

Consolidating patient and clinical data to support better-informed clinical decisions remains a primary function of electronic health records (EHRs). In the United States, nearly 6 million patients receive care from an accountable care organization (ACO). Knowledge of clinical decision support (CDS) tool design for use by physicians participating in ACOs remains limited. The purpose of this quantitative study was to examine whether a significant correlation exists between characteristics of alert content and alert timing (the independent variables) and physician perceptions of improved ACO quality measure adherence during electronic ordering (the dependent variable). Sociotechnical theory supported the theoretical framework for this research. Sixty-nine physician executives using either a Cerner Incorporated or Epic Systems EHR in a hospital or health system affiliated ACO participated in the online survey. The results of the regression analysis were statistically significant, R2 = .108, F(2,66) = 3.99, p = .023, indicating that characteristics of alert content and timing affect physician perceptions for improving their adherence to ACO quality measures. However, analysis of each independent variable showed alert content highly correlated with the dependent variable (p = .007) with no significant correlation found between workflow timing and the dependent variable (p = .724). Understanding the factors that support physician acceptance of alerts is essential to third-party software developers and health care organizations designing CDS tools. Providing physicians with improved EHR-integrated CDS tools supports the population health goal of ACOs in delivering better patient care

Reverberation Mapping Results from MDM Observatory

We present results from a multi-month reverberation mapping campaign undertaken primarily at MDM Observatory with supporting observations from around the world. We measure broad line region (BLR) radii and black hole masses for six objects. A velocity-resolved analysis of the H_beta response shows the presence of diverse kinematic signatures in the BLR.Comment: To appear in the Proceedings of the IAU Symposium No. 267: Co-Evolution of Central Black Holes and Galaxies, Rio de Janeiro, 200

Book Reviews

Book Reviews The Oppenheimer Case: The Trial of a Security System By Charles P. Curtis New York: Simon and Schuster, 1955. Pp. xi, 281. $4.00 reviewer: Ingram Bloch ============================= Trial Tactics and Methods By Robert E. Keeton New York: Prentice Hall, Inc., 1954. Pp. xxiv, 438.$6.65 reviewer: J. Raymond Denney ============================= Military Law under the Uniform Code of Military Justice By William B. Aycock and Seymour W. Wurfel Chapel Hill: University of North Carolina Press, 1955. Pp. xviii, 430. reviewer: James B. Earle ================================= Why Johnny Can\u27t Read By Rudolf Flesch New York: Harper & Brothers, 1955. Pp. ix, 222. ================================== Plain Words: Their ABC By Sir Ernest Gowers New York: Alfred A. Knopf, 1955. Pp. viii, 298. =================================== Effective Legal Writing By Frank E. Cooper Indianapolis, The Bobbs-Merrill Company, Inc., 1953. Pp. x, 313. reviewer: J. Allen Smith ================================== The Moral Decision: Right and Wrong in the Light of American law By Edmond Cahn Bloomington, Ind.: Indiana University Press, Pp. ix, 315. $5.00 reviewer: Samuel Enoch Stump

A smart telerobotic system driven by monocular vision

A robotic system that accepts autonomously generated motion and control commands is described. The system provides images from the monocular vision of a camera mounted on a robot's end effector, eliminating the need for traditional guidance targets that must be predetermined and specifically identified. The telerobotic vision system presents different views of the targeted object relative to the camera, based on a single camera image and knowledge of the target's solid geometry