A New Technique for Determining Europium Abundances in Solar-Metallicity Stars

We present a new technique for measuring the abundance of europium, a representative r-process element, in solar-metallicity stars. Our algorithm compares LTE synthetic spectra with high-resolution observational spectra using a chi-square-minimization routine. The analysis is fully automated, and therefore allows consistent measurement of blended lines even across very large stellar samples. We compare our results with literature europium abundance measurements and find them to be consistent; we also find our method generates smaller errors.Comment: 10 pages, 7 figure

Lipid-based nutrient supplements: how can they combat child malnutrition?

Kathryn Dewey and Mary Arimond discuss new research in PLOS Medicine that assesses the effect of blanket provision of ready-to-use supplementary food to children at high risk of malnutrition in Chad, and highlight some of the challenges of investigating the efficacy of supplementary foods for malnourished children

A planned program for developing word perception in grade one

Thesis (Ed.M.)--Boston Universit

New Matter Effects and BBN Constraints for Mass Varying Neutrinos

The presence of light (m_a ~ 10^-6 ev) scalar fields in the early universe can modify the cosmology of neutrinos considerably by allowing their masses to vary on cosmological times. In this paper, we consider the effect of Planck-suppressed couplings of this scalar to electrons and show that such couplings can easily make new sterile states thermally inaccessible in the early universe, preserving the successes of big bang nucleosynthesis predictions. We consider the circumstances under which these effects give the proper initial conditions for recently considered models of neutrino dark energy, and consider limits from tests of the equivalence principle. The parameters which satisfy cosmological constraints naturally give rise to interesting signals in terrestrial neutrino oscillation experiments.Comment: 6 pages. References added, minor modification

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

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

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