Opening the Classroom Door - A Survey of Middle Grades Teachers Who Mentor Preservice Teachers— Lessons from Clinical Partnerships and Implications for Practice

Mentor teachers that participate in school-university clinical experiences have a unique opportunity to support preservice middle grades teachers’ development and improve the schooling of young adolescents. This article investigates an early clinical experience and presents data from a survey of 38 middle school teachers who served as mentor teachers. Findings address how middle grades teachers view their role as mentors, their perceptions of the clinical experience as a collaborative learning partnership, and concludes with suggestions to improve clinical experiences for preservice middle grades teacher candidates

Intermediate-mass Black Holes in Galactic Nuclei

We present the first homogeneous sample of intermediate-mass black hole candidates in active galactic nuclei. Starting with broad-line active nuclei from the Sloan Digital Sky Survey, we use the linewidth-luminosity-mass scaling relation to select a sample of 19 galaxies in the mass range M_BH ~ 8 x 10^4 - 10^6 solar masses. In contrast to the local active galaxy population, the host galaxies are ~1 mag fainter than M* and thus are probably late-type systems. The active nuclei are also faint, with M_g ~ -15 to -18 mag, while the bolometric luminosities are close to the Eddington limit. The spectral properties of the sample are compared to the related class of objects known as narrow-line Seyfert 1 galaxies. We discuss the importance of our sample as observational analogues of primordial black holes, contributors to the integrated signal for future gravitational wave experiments, and as a valuable tool in the calibration of the M-sigma relation.Comment: 4 pages, 4 figures. To appear in "The Interplay among Black Holes, Stars and ISM in Galactic Nuclei," Proc. IAU 222 (Gramado, Brazil), eds Th. Storchi Bergmann, L.C. Ho, H.R. Schmit

Feedback In Luminous Obscured Quasars

We use spatially resolved long-slit spectroscopy from Magellan to investigate the extent, kinematics, and ionization structure in the narrow-line regions of 15 luminous, obscured quasars with z < 0.5. Increasing the dynamic range in luminosity by an order of magnitude, as well as improving the depth of existing observations by a similar factor, we revisit relations between narrow-line region size and the luminosity and linewidth of the narrow emission lines. We find a slope of 0.22 +/- 0.04 for the power-law relationship between size and luminosity, suggesting that the nebulae are limited by availability of gas to ionize at these luminosities. In fact, we find that the active galactic nucleus is effectively ionizing the interstellar medium over the full extent of the host galaxy. Broad (similar to 300-1000 km s(-1)) linewidths across the galaxies reveal that the gas is kinematically disturbed. Furthermore, the rotation curves and velocity dispersions of the ionized gas remain constant out to large distances, in striking contrast to normal and starburst galaxies. We argue that the gas in the entire host galaxy is significantly disturbed by the central active galactic nucleus. While only similar to 10(7)-10(8) M-circle dot worth of gas are directly observed to be leaving the host galaxies at or above their escape velocities, these estimates are likely lower limits because of the biases in both mass and outflow velocity measurements and may in fact be in accord with expectations of recent feedback models. Additionally, we report the discovery of two dual obscured quasars, one of which is blowing a large-scale (similar to 10 kpc) bubble of ionized gas into the intergalactic medium.NSF AST-0548198Astronom

Vortex dynamics

Vortex flows of interest to aerodynamicists cover a wide range of scales from a fraction of an inch in boundary layer flows to many feet in wake flows. In many applications these flows are poorly understood and, due to their complexity, present a challenge both analytically and experimentally. Four topics representing the spectrum of experimental and analytical vortex research are presented

Steep-Spectrum Radio Emission from the Low-Mass Active Galactic Nucleus GH 10

GH 10 is a broad-lined active galactic nucleus (AGN) energized by a black hole of mass 800,000 Solar masses. It was the only object detected by Greene et al. in their Very Large Array (VLA) survey of 19 low-mass AGNs discovered by Greene & Ho. New VLA imaging at 1.4, 4.9, and 8.5 GHz reveals that GH 10's emission has an extent of less than 320 pc, has an optically-thin synchrotron spectrum with a spectral index -0.76+/-0.05, is less than 11 percent linearly polarized, and is steady - although poorly sampled - on timescales of weeks and years. Circumnuclear star formation cannot dominate the radio emission, because the high inferred star formation rate, 18 Solar masses per year, is inconsistent with the rate of less than 2 Solar masses per year derived from narrow Halpha and [OII] 3727 emission. Instead, the radio emission must be mainly energized by the low-mass black hole. GH 10's radio properties match those of the steep-spectrum cores of Palomar Seyfert galaxies, suggesting that, like those Seyferts, the emission is outflow-driven. Because GH 10 is radiating close to its Eddington limit, it may be a local analog of the starting conditions, or seeds, for supermassive black holes. Future imaging of GH 10 at higher resolution thus offers an opportunity to study the relative roles of radiative versus kinetic feedback during black-hole growth.Comment: 7 pages; 2 figures; emulateapj; to appear in Ap

Design and construction of a point-contact spectroscopy rig with lateral scanning capability

The design and realization of a cryogenic rig for point-contact spectroscopy measurements in the needle-anvil configuration is presented. Thanks to the use of two piezoelectric nano-positioners, the tip can move along the vertical ($z$) and horizontal ($x$) direction and thus the rig is suitable to probe different regions of a sample \textit{in situ}. Moreover, it can also form double point-contacts on different facets of a single crystal for achieving, e.g., an interferometer configuration for phase-sensitive measurements. For the latter purpose, the sample holder can also host a Helmholtz coil for applying a small transverse magnetic field to the junction. A semi-rigid coaxial cable can be easily added for studying the behavior of Josephson junctions under microwave irradiation. The rig can be detached from the probe and thus used with different cryostats. The performance of this new probe has been tested in a Quantum Design PPMS system by conducting point-contact Andreev reflection measurements on Nb thin films over large areas as a function of temperature and magnetic field.Comment: 7 pages, 7 figures, published in Rev. Sci. Instru