Concentrated Poverty: A Change in Course

Examines how the distribution of concentrated poverty in metropolitan areas has shifted in the past two decades, using data from the Neighborhood Change Database

Have MTO Families Lost Access to Opportunity Neighborhoods Over Time?

Reviews research on families who moved to lower-poverty areas through the Moving to Opportunity program, using new data and broader indicators to assess whether their subsequent moves were also to better neighborhoods from which the families benefited

Population Growth and Decline in City Neighborhoods

Analyzes how neighborhoods in the nation's largest cities grew and declined in the 1990s and how those results compared with patterns of change in the 1980s, based on data from the U.S. Census and the Neighborhood Change Database

Concentrated Poverty: Dynamics of Change

Compares metropolitan census tracts that improved with respect to poverty in the 1990s with those that worsened, looking at the racial composition of both types and in different types of metropolitan areas nationally

A Guide to Home Mortgage Disclosure Act Data

Provides an overview of the home mortgage application data lenders are required to report and explains how to analyze trends in neighborhood investment, buyers' racial and economic composition, disparities in home loan access, and subprime lending

A New Interpretation for the Second Peak of T Coronae Borealis Outbursts: A Tilting Disk around a Very Massive White Dwarf

A new interpretation for the second peak of T Coronae Borealis (T CrB) outbursts is proposed based on a thermonuclear runaway (TNR) model. The system consists of a very massive white dwarf (WD) with a tilting accretion disk and a lobe-filling red-giant. The first peak of the visual light curve of T CrB outbursts is well reproduced by the TNR model on a WD close to the Chandrasekhar mass ($M_{\rm WD} \gtrsim 1.35 ~M_\odot$), while the second peak is reproduced by the combination of the irradiated M-giant and the irradiated tilting disk. The derived fitting parameters are the WD mass $M_{\rm WD} \sim 1.35 ~M_\odot$, the M-giant companion mass $M_{\rm RG} \sim 0.7 M_\odot$ ($0.6-1.0 M_\odot$ is acceptable), the inclination angle of the orbit i \sim 70 \arcdeg, and the tilting angle of the disk i_{\rm prec} \sim 35 \arcdeg. These parameters are consistent with the recently derived binary parameters of T CrB.Comment: 6 pages including 2 figures, to be published in ApJ Letter

Determination of Flaw Growth Characteristics of Ti-6Al-4V Sheet in the Solution-Treated and Aged Condition

The specific experimental investigation undertaken was designed to answer these questions on Ti-6Al-4V in the solution treated and aged condition. The defect growth and fracture characteristics were studied in parent (unwelded) and welded sheet material. The results of the study indicate that cryogenic proof testing will screen smaller size defects than proof testing at ambient conditions. However some unusual crack growth behavior during the proof test simulation suggests that some further study be made of stress and time duration effects

The Foreclosure Crisis and Children: A Three-City Study

Examines the characteristics of children in foreclosed homes, the likelihood of their moving to another neighborhood and/or changing schools, changes in school quality, and how school mobility affects student test scores. Outlines policy implications

How small is too small? A systematic review of center volume and outcome after cardiac transplantation

Background—The aim of this study was to assess the relationship between the volume of cardiac transplantation procedures performed in a center and the outcome after cardiac transplantation. Methods and Results—PubMed, Embase, and the Cochrane library were searched for articles on the volume–outcome relationship in cardiac transplantation. Ten studies were identified, and all adopted a different approach to data analysis and varied in adjustment for baseline characteristics. The number of patients in each study ranged from 798 to 14401, and observed 1-year mortality ranged from 12.6% to 34%. There was no association between the continuous variables of center volume and observed mortality. There was a weak association between the continuous variables of center volume and adjusted mortality up to 1 year and a stronger association at 5 years. When centers were grouped in volume categories, low-volume centers had the highest adjusted mortality, intermediate-volume centers had lower adjusted mortality, and high-volume centers had the lowest adjusted mortality but were not significantly better than intermediate-volume centers. Category limits were arbitrary and varied between studies. Conclusions—There is a relationship between center volume and mortality in heart transplantation. The existence of a minimum acceptable center volume or threshold is unproven. However, a level of 10 to 12 heart transplants per year corresponds to the upper limit of low-volume categories that may have relatively higher mortality. It is not known whether outcomes for patients treated in low-volume transplant centers would be improved by reorganizing centers to ensure volumes in excess of 10 to 12 heart transplants per year