Programs and Communities
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- Creators: Ohri-Vachaspati, Punam
- Creators: School of Earth and Space Exploration
We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 ≲ z ≲ 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (∼40%) are likely to have experienced a minor (fYC ≲ 10% of stellar mass) burst of recent (tYC ≲ 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 1010.5M☼) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.
Cell-sediment separation methods can potentially enable determination of the elemental composition of microbial communities by removing the sediment elemental contribution from bulk samples. We demonstrate that a separation method can be applied to determine the composition of prokaryotic cells. The method uses chemical and physical means to extract cells from benthic sediments and mats. Recovery yields were between 5% and 40%, as determined from cell counts. The method conserves cellular element contents to within 30% or better, as assessed by comparing C, N, P, Mg, Al, Ca, Ti, Mn, Fe, Ni, Cu, Zn, and Mo contents in Escherichia coli. Contamination by C, N, and P from chemicals used during the procedure was negligible. Na and K were not conserved, being likely exchanged through the cell membrane as cations during separation. V, Cr, and Co abundances could not be determined due to large (>100%) measurement uncertainties. We applied this method to measure elemental contents in extremophilic communities of Yellowstone National Park hot springs. The method was generally successful at separating cells from sediment, but does not discriminate between cells and detrital biological or noncellular material of similar density. This resulted in Al, Ti, Mn, and Fe contamination, which can be tracked using proxies such as metal:Al ratios. With these caveats, we present the first measurements, to our knowledge, of the elemental abundances of a chemosynthetic community. The communities have C:N ratios typical of aquatic microorganisms, are low in P, and their metal abundances vary between hot springs by orders of magnitude.
This study aims to examine children’s fruit, vegetable, and added sugar consumption relative to the Dietary Guidelines for Americans and the American Heart Association’s recommendations, as well as to compare children’s reported consumption with parental perception of the child’s overall diet quality. Data were drawn from 2 independent, cross sectional panels (2009–10 and 2014–15) of the New Jersey Child Health Study. The analytical sample included 2229 households located in five New Jersey cities. Daily consumption of fruit (cups), vegetables (cups), and added sugars (teaspoons) for all children (3–18 years old) were based on parent reports. Multivariate linear regression analyses estimated children’s adjusted fruit, vegetable, and added sugar consumption across parents’ perception categories (Disagree; Somewhat Agree; and Strongly Agree that their child eats healthy). Although only a small proportion of children meet recommendations, the majority of parents strongly agreed that their child ate healthy. Nonetheless, significant differences, in the expected direction, were observed in vegetable and fruit consumption (but not sugar) across parental perceptional categories for most age/sex groups. Dietary interventions tailored to parents should include specific quantity and serving-size information for fruit and vegetable recommendations, based on their child’s age/sex, and highlight sources of added sugar and their sugar content.
Disparities in healthy food access are well documented in cross-sectional studies in communities across the United States. However, longitudinal studies examining changes in food environments within various neighborhood contexts are scarce. In a sample of 142 census tracts in four low-income, high-minority cities in New Jersey, United States, we examined the availability of different types of food stores by census tract characteristics over time (2009–2017). Outlets were classified as supermarkets, small grocery stores, convenience stores, and pharmacies using multiple sources of data and a rigorous protocol. Census tracts were categorized by median household income and race/ethnicity of the population each year. Significant declines were observed in convenience store prevalence in lower- and medium-income and majority black tracts (p for trend: 0.004, 0.031, and 0.006 respectively), while a slight increase was observed in the prevalence of supermarkets in medium-income tracts (p for trend: 0.059). The decline in prevalence of convenience stores in lower-income and minority neighborhoods is likely attributable to declining incomes in these already poor communities. Compared to non-Hispanic neighborhoods, Hispanic communities had a higher prevalence of small groceries and convenience stores. This higher prevalence of smaller stores, coupled with shopping practices of Hispanic consumers, suggests that efforts to upgrade smaller stores in Hispanic communities may be more sustainable.
Objective
In response to recent national efforts to increase the availability of healthy food in small stores, we sought to understand the extent to which small food stores could implement the newly published Healthy Small Store Minimum Stocking Recommendations and reflect on the new US Department of Agriculture Food and Nutrition Service's final rule for stocking of staple foods for Supplemental Nutrition Assistance Program–approved retailers.
Design
We collected qualitative and quantitative data from 57 small stores in four states (Arizona, Delaware, Minnesota, and North Carolina) that accepted Supplemental Nutrition Assistance Program but not Special Supplemental Nutrition Assistance Program for Women, Infants, and Children benefits. Data from semistructured, in-depth interviews with managers/owners were transcribed, coded, and analyzed. We collected quantitative store inventory data onsite and later performed descriptive analyses.
Results
Store interviews revealed a reluctant willingness to stock healthy food and meet new recommendations. No stores met recommended fruit and vegetable stocking, although 79% carried at least one qualifying fruit and 74% carried at least one qualifying vegetable. Few stores met requirements for other food categories (ie, whole grains and low-fat dairy) with the exception of lean proteins, where stores carrying nuts or nut butter were more likely to meet the protein recommendation. Water and 100% juice were widely available and 68% met basic healthy beverage criteria.
Conclusions
In contrast to the inventory observed, most owners believed store stock met basic recommendations. Further, findings indicate that small stores are capable of stocking healthy products; however, technical and infrastructure support, as well as incentives, would facilitate shifts from staple to healthier staple foods. Retailers may need support to understand healthier product criteria and to drive consumer demand for new products.