444 research outputs found

    Progress Being Made in Getting a Quality Leader in Every School

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    Reviews the progress made by the SREB states in improving their school leadership through redesigning the process of preparation and development of school principals. Describes promising practices being implemented, and offers practical guidance

    Are SREB States Making Progress? Tapping, Preparing and Licensing School Leaders Who Can Influence Student Achievement

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    Looks at the progress SREB states are making in developing systems to identify, prepare, and assess future school leaders

    Black holes die hard: can one spin-up a black hole past extremality?

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    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for a variety of black hole geometries, from black holes in higher dimensions to black rings. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.Comment: 10 pages, 7 figures. RevTex4

    Pulsar Nulling and Vacuum Radio Emission from Axion Clouds

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    Non-relativistic axions can be efficiently produced in in the polar caps of pulsars, resulting in the formation of a dense cloud of gravitationally bound axions. Here, we investigate the interplay between such an axion cloud and the electrodynamics in the pulsar magnetosphere, focusing specifically on the dynamics in the polar caps, where the impact of the axion cloud is expected to be most pronounced. For sufficiently light axions ma≲10−7m_a \lesssim 10^{-7} eV, we show that the axion cloud can occasionally screen the local electric field responsible for particle acceleration and pair production, inducing a periodic nulling of the pulsar's intrinsic radio emission. At larger axion masses, the small-scale fluctuations in the axion field tend to suppress the back-reaction of the axion on the electrodynamics; however, we point out that the incoherent oscillations of the axion in short-lived regions of vacuum near the neutron star surface can produce a narrow radio line, which provides a complementary source of radio emission to the plasma-resonant emission processes identified in previous work. While this work focuses on the leading order correction to pair production in the magnetosphere, we speculate that there can exist dramatic deviations in the electrodynamics of these systems when the axion back-reaction becomes non-linear.Comment: v1: 6 pages, 1 figure, Supplementary Material (7 pages

    Bayes' Rays: Uncertainty Quantification for Neural Radiance Fields

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    Neural Radiance Fields (NeRFs) have shown promise in applications like view synthesis and depth estimation, but learning from multiview images faces inherent uncertainties. Current methods to quantify them are either heuristic or computationally demanding. We introduce BayesRays, a post-hoc framework to evaluate uncertainty in any pre-trained NeRF without modifying the training process. Our method establishes a volumetric uncertainty field using spatial perturbations and a Bayesian Laplace approximation. We derive our algorithm statistically and show its superior performance in key metrics and applications. Additional results available at: https://bayesrays.github.io

    The Grizzly, October 7, 1983

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    Career Workshops Held • What\u27s in a Name • Fago Opens Lecture Series • Lantern Makes National Anthology • Campus Memo • Letters to the Editor • Red and Gold Days Inaugurated • Sorority Pledging Underway • Half-Price Student Rushes for Genty! • Keep it Clean • Renaissance Play at Ursinus Commemoration • ATO Incident at Penn • Politics Sells Papers • Yearbook Sale Begins Monday • Ursinus Soccer Romps Over Hopkins • Volleyball Scores Second Victory • Grizzlies Fall to Swarthmorehttps://digitalcommons.ursinus.edu/grizzlynews/1103/thumbnail.jp

    The Grizzly, October 28, 1983

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    CampusBooks Speaks Out • C and C Course Offered • Zack Is Back In Bronze • Peace Rally Held • Give Us A Little Bit Of Credit • Respect Is Goal Of Liberal Education • Homecoming: A Big Success • Nobel Prize Awarded • Spirit Week Begins • The Talented Two-Some • The Stone Age is Back • Crown Royal Features Ultimate Competition • Lady Bears Prepare For Penn State Rivalry • U.C. Soccer Continues Winning Ways • Grizziles Roll Over Lebanon Valleyhttps://digitalcommons.ursinus.edu/grizzlynews/1105/thumbnail.jp
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