Fostering Student Success in the Campus Community

The article reviews the book Fostering Student Success in the Campus Community, edited by Gary L. Kramer

A Framework for Reducing the College Success Gap and Promoting Success for All

Policymakers, practitioners, and scholars have directed tremendous attention to the goal of improving “student success.” Based on a review of largely discrete existing bodies of literature, this report proposes an overarching framework that policymakers, practitioners, and researchers can use to develop, implement, and evaluate policies and practices for addressing persistent racial/ethnic and socioeconomic gaps in student success. The framework brings order to the wide array of theoretical and methodological approaches that, when considered together, provide a comprehensive understanding of the ways policymakers and practitioners can intervene more effectively to promote student success. The framework was intended to describe avenues and approaches to effective development, implementation, and evaluation of policy related to student success, eschewing the identification of a “single bullet” theory, method, policy, or practice. After defining student success and explaining our procedures, this report describes the results of a multidisciplinary examination of the theoretical and methodological approaches that researchers have used to inform knowledge and understanding across a range of student success outcomes. Then, the report presents and describes the proposed conceptual model that ties this work together and provides recommended uses of the model for policy, practice, and further research

The Chandra X-ray Spectrum of the 10.6 s Pulsar in Westerlund 1: Testing the Magnetar Hypothesis

Two sensitive Chandra X-ray observations of the heavily-reddened galactic starburst cluster Westerlund 1 in May and June 2005 detected a previously unknown X-ray pulsar (CXO J164710.20-455217). Its slow 10.6 s pulsations, moderate X-ray temperature kT $\approx$ 0.5 keV, and apparent lack of a massive companion tentatively suggest that it is an Anomalous X-ray Pulsar (AXP). An isothermal blackbody model yields an acceptable spectral fit but the inferred source radius is much less than that of a neutron star, a result that has also been found for other AXPs. We analyze the X-ray spectra with more complex models including a model that assumes the pulsar is a strongly magnetized neutron star (``magnetar'') with a light element atmosphere. We conclude that the observed X-ray emission cannot be explained as global surface emission arising from the surface of a cooling neutron star or magnetar. The emission likely arises in one or more localized regions (``hot spots'') covering a small fraction of the surface. We discuss these new results in the context of both accretion and magnetar interpretations for the X-ray emission.Comment: 14 pages, 5 figures; to appear in Ap

Apples and Oranges: Comparing the Backgrounds and Academic Trajectories of International Baccalaureate (IB) Students to a Matched Comparison Group

This report presents findings from a retrospective study of the academic histories of International Baccalaureate (IB) students and other students in the state of Florida. The IB Diploma Program is an internationally recognized college-preparatory curriculum designed to provide students with a rigorous and comprehensive academic experience. IB has grown dramatically in recent years and is thought by many to be among the best college-preparatory programs in existence. As such, there is tremendous interest in the potential impacts of IB, but any attempts to examine those impacts must deal with selection bias that results from the voluntary participation of schools and students. Failure to do so makes it impossible to determine whether the performance of participating students was actually influenced by IB, or whether the outcomes for these students would have been just as good without IB. As a critical step in understanding the impacts of IB, the analyses presented in this report examined the selection mechanisms behind IB participation across Florida, the state with the second highest representation of IB programs in the nation. We use longitudinal student and school-level data from 1995 through 2009 from the Florida K-20 Education Data Warehouse (EDW) to characterize individual students’ educational histories from elementary school through high school and into college. To address issues of selection bias, we use propensity score methods (Rosenbaum & Rubin, 1983) to adjust for preexisting differences between IB and non-IB students

The oldest X-ray supernovae: X-ray emission from 1941C, 1959D, 1968D

We have studied the X-ray emission from four historical Type-II supernovae (the newly-discovered 1941C in NGC 4631 and 1959D in NGC 7331; and 1968D, 1980K in NGC 6946), using Chandra ACIS-S imaging. In particular, the first three are the oldest ever found in the X-ray band, and provide constraints on the properties of the stellar wind and circumstellar matter encountered by the expanding shock at more advanced stages in the transition towards the remnant phase. We estimate emitted luminosities ~ 5 x 10^{37} erg/s for SN 1941C, ~ a few x 10^{37} erg/s for SN 1959D, ~ 2 x 10^{38} erg/s for SN 1968D, and ~ 4 x 10^{37} erg/s for SN 1980K, in the 0.3-8 keV band. X-ray spectral fits to SN 1968D suggest the presence of a harder component, possibly a power law with photon index ~ 2, contributing ~ 10^{37} erg/s in the 2-10 keV band. We speculate that it may be evidence of non-thermal emission from a Crab-like young pulsar.Comment: 6 pages, accepted by ApJ. Revised version with a couple of added references. Thanks to A. Kong and E. Schlegel for their comments. Credit to Holt et al. (2003) for the X-ray discovery of SN 1968D, overlooked in other recent catalog

Promoting Human Capital Development: A Typology of International Scholarship Programs in Higher Education

This article sheds light on the availability and characteristics of international scholarship programs that are sponsored by national and federal governments worldwide and that are intended to promote student mobility. Utilizing descriptive and cluster analyses, the article produces a framework for organizing the population of these programs. The analyses take into account both the central characteristics of programs and economic and political characteristics of the nations sponsoring the program. The typology produced in this analysis may be used by policy makers and researchers to facilitate cross-national comparisons of program design, implementation, and outcomes. © 2014 AERA

Ultraviolet and visible photometry of asteroid (21) Lutetia using the Hubble Space Telescope

The asteroid (21) Lutetia is the target of a planned close encounter by the Rosetta spacecraft in July 2010. To prepare for that flyby, Lutetia has been extensively observed by a variety of astronomical facilities. We used the Hubble Space Telescope (HST) to determine the albedo of Lutetia over a wide wavelength range, extending from ~150 nm to ~700 nm. Using data from a variety of HST filters and a ground-based visible light spectrum, we employed synthetic photometry techniques to derive absolute fluxes for Lutetia. New results from ground-based measurements of Lutetia's size and shape were used to convert the absolute fluxes into albedos. We present our best model for the spectral energy distribution of Lutetia over the wavelength range 120-800 nm. There appears to be a steep drop in the albedo (by a factor of ~2) for wavelengths shorter than ~300 nm. Nevertheless, the far ultraviolet albedo of Lutetia (~10%) is considerably larger than that of typical C-chondrite material (~4%). The geometric albedo at 550 nm is 16.5 +/- 1%. Lutetia's reflectivity is not consistent with a metal-dominated surface at infrared or radar wavelengths, and its albedo at all wavelengths (UV-visibile-IR-radar) is larger than observed for typical primitive, chondritic material. We derive a relatively high FUV albedo of ~10%, a result that will be tested by observations with the Alice spectrograph during the Rosetta flyby of Lutetia in July 2010.Comment: 14 pages, 2 tables, 8 figure

Optimal Transport, Convection, Magnetic Relaxation and Generalized Boussinesq equations

We establish a connection between Optimal Transport Theory and classical Convection Theory for geophysical flows. Our starting point is the model designed few years ago by Angenent, Haker and Tannenbaum to solve some Optimal Transport problems. This model can be seen as a generalization of the Darcy-Boussinesq equations, which is a degenerate version of the Navier-Stokes-Boussinesq (NSB) equations. In a unified framework, we relate different variants of the NSB equations (in particular what we call the generalized Hydrostatic-Boussinesq equations) to various models involving Optimal Transport (and the related Monge-Ampere equation. This includes the 2D semi-geostrophic equations and some fully non-linear versions of the so-called high-field limit of the Vlasov-Poisson system and of the Keller-Segel for Chemotaxis. Finally, we show how a ``stringy'' generalization of the AHT model can be related to the magnetic relaxation model studied by Arnold and Moffatt to obtain stationary solutions of the Euler equations with prescribed topology

Energy and symmetry of dddd excitations in undoped layered cuprates measured by Cu L3L_3 resonant inelastic x-ray scattering

We measured high resolution Cu $L_3$ edge resonant inelastic x-ray scattering (RIXS) of the undoped cuprates La$_2$CuO$_4$, Sr$_2$CuO$_2$Cl$_2$, CaCuO$_2$ and NdBa$_2$Cu$_3$O$_6$. The dominant spectral features were assigned to $dd$ excitations and we extensively studied their polarization and scattering geometry dependence. In a pure ionic picture, we calculated the theoretical cross sections for those excitations and used them to fit the experimental data with excellent agreement. By doing so, we were able to determine the energy and symmetry of Cu-3$d$ states for the four systems with unprecedented accuracy and confidence. The values of the effective parameters could be obtained for the single ion crystal field model but not for a simple two-dimensional cluster model. The firm experimental assessment of $dd$ excitation energies carries important consequences for the physics of high $T_c$ superconductors. On one hand, having found that the minimum energy of orbital excitation is always $\geq 1.4$ eV, i.e., well above the mid-infrared spectral range, leaves to magnetic excitations (up to 300 meV) a major role in Cooper pairing in cuprates. On the other hand, it has become possible to study quantitatively the effective influence of $dd$ excitations on the superconducting gap in cuprates.Comment: 22 pages, 11 figures, 1 tabl