16 research outputs found
Racial, Ethnic, and Socioeconomic Disparities in Multiple Measures of Blue and Green Spaces in the United States
BACKGROUND: Several studies have evaluated whether the distribution of natural environments differs between marginalized and privileged neighborhoods. However, most studies restricted their analyses to a single or handful of cities and used different natural environment measures. OBJECTIVES: We evaluated whether natural environments are inequitably distributed based on socioeconomic status (SES) and race/ethnicity in the contiguous United States. METHODS: We obtained SES and race/ethnicity data (2015â2019) for all U.S. Census tracts. For each tract, we calculated the Normalized Different Vegetation Index (NDVI) for 2020, NatureScore (a proprietary measure of the quantity and quality of natural elements) for 2019, park cover for 2020, and blue space for 1984â2018. We used generalized additive models with adjustment for potential confounders and spatial autocorrelation to evaluate associations of SES and race/ethnicity with NDVI, NatureScore, park cover, and odds of containing blue space in all tracts ([Formula: see text]) and in urban tracts ([Formula: see text]). To compare effect estimates, we standardized NDVI, NatureScore, and park cover so that beta coefficients presented a percentage increase or decrease of the standard deviation (SD). RESULTS: Tracts with higher SES had higher NDVI, NatureScore, park cover, and odds of containing blue space. For example, urban tracts in the highest median household income quintile had higher NDVI [44.8% of the SD (95% CI: 42.8, 46.8)] and park cover [16.2% of the SD (95% CI: 13.5, 19.0)] compared with urban tracts in the lowest median household income quintile. Across all tracts, a lower percentage of non-Hispanic White individuals and a higher percentage of Hispanic individuals were associated with lower NDVI and NatureScore. In urban tracts, we observed weak positive associations between percentage non-Hispanic Black and NDVI, NatureScore, and park cover; we did not find any clear associations for percentage Hispanics. DISCUSSION: Multiple facets of the natural environment are inequitably distributed in the contiguous United States. https://doi.org/10.1289/EHP1116
Costs and benefits of orthographic inconsistency in reading:evidence from a cross-linguistic comparison
We compared reading acquisition in English and Italian children up to late primary school analyzing RTs and errors as a function of various psycholinguistic variables and changes due to experience. Our results show that reading becomes progressively more reliant on larger processing units with age, but that this is modulated by consistency of the language. In English, an inconsistent orthography, reliance on larger units occurs earlier on and it is demonstrated by faster RTs, a stronger effect of lexical variables and lack of length effect (by fifth grade). However, not all English children are able to master this mode of processing yielding larger inter-individual variability. In Italian, a consistent orthography, reliance on larger units occurs later and it is less pronounced. This is demonstrated by larger length effects which remain significant even in older children and by larger effects of a global factor (related to speed of orthographic decoding) explaining changes of performance across ages. Our results show the importance of considering not only overall performance, but inter-individual variability and variability between conditions when interpreting cross-linguistic differences
On the Growth and Development of NonâLinear KelvinâHelmholtz Instability at Mars: MAVEN Observations
In this study, we have analyzed Mars Atmosphere and Volatile EvolutioN (MAVEN) observations of fields and plasma signatures associated with an encounter of fully developed KelvinâHelmholtz (KâH) vortices at the northern polar terminator along Marsâ induced magnetosphere boundary. The signatures of the KâH vortices event are: (a) quasiâperiodic, âbipolarâlikeâ sawtooth magnetic field perturbations, (b) corresponding density decrease, (c) tailward enhancement of plasma velocity for both protons and heavy ions, (d) coâexistence of magnetosheath and planetary plasma in the region prior to the sawtooth magnetic field signature (i.e., mixing region of the vortex structure), and (e) pressure enhancement (minimum) at the edge (center) of the sawtooth magnetic field signature. Our results strongly support the scenario for the nonâlinear growth of KâH instability along Marsâ induced magnetosphere boundary, where a plasma flow difference between the magnetosheath and inducedâmagnetospheric plasma is expected. Our findings are also in good agreement with 3âdimensional local magnetohydrodynamics simulation results. MAVEN observations of protons with energies greater than 10 keV and results from the WalĂ©n analyses suggests the possibility of particle energization within the mixing region of the KâH vortex structure via magnetic reconnection, secondary instabilities or other turbulent processes. We estimate the lower limit on the KâH instability linear growth rate to be âŒ5.84 Ă 10â3 sâ1. For these vortices, we estimate the instantaneous atmospheric ion escape flux due to the detachment of plasma clouds during the late nonâlinear stage of KâH instability to be âŒ5.90 Ă 1026 particles/s. Extrapolation of loss rates integrated across time and space will require further work.Key PointsMars Atmosphere and Volatile EvolutioN (MAVEN) observed magnetic field and plasma signatures consistent with the encounter of fully developed KelvinâHelmholtz (KâH) vortices along Marsâ induced magnetospheric boundary (IMB)Close agreement between 3âD magnetohydrodynamics simulation result and MAVEN observation support the scenario for KâH instability occurrence along Marsâ IMBWe estimated the instantaneous atmospheric ion escape flux due to detachment of plasma clouds from KâH instability to be âŒ5.9 Ă 1026 sâ1Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/170215/1/jgra56662.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170215/2/jgra56662_am.pd
2003-2004 Research Honors Program Abstracts (for the College of Agriculture and Life Sciences Undergraduates)
Faculty in the College of Agriculture and Life Sciences at Cornell University mentor and guide undergraduate students who have chosen to pursue a research project and graduate with honors. These abstracts reflect the depth of their scholarship and intellectual ability. The research projects encompass work in animal science, biological science, entomology, landscape studies, natural resources, physical science, plant science, and social science
Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time
International audienceObservations of the Mars upper atmosphere made from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft have been used to determine the loss rates of gas from the upper atmosphere to space for a complete Mars year (16 Nov 2014 â 3 Oct 2016). Loss rates for H and O are sufficient to remove âŒ2-3 kg/s to space. By itself, this loss would be significant over the history of the planet. In addition, loss rates would have been greater early in history due to the enhanced solar EUV and more-active Sun. Integrated loss, based on current processes whose escape rates in the past are adjusted according to expected solar evolution, would have been as much as 0.8 bar CO2 or 23 m global equivalent layer of H2O; these losses are likely to be lower limits due to the nature of the extrapolation of loss rates to the earliest times. Combined with the lack of surface or subsurface reservoirs for CO2 that could hold remnants of an early, thick atmosphere, these results suggest that loss of gas to space has been the dominant process responsible for changing the climate of Mars from an early, warmer environment to the cold, dry one that we see today
Common and Rare Coding Genetic Variation Underlying the Electrocardiographic PR Interval
BACKGROUND: Electrical conduction from the cardiac sinoatrial node to the ventricles is critical for normal heart function. Genome-wide association studies have identified more than a dozen common genetic loci that are associated with PR interval. However, it is unclear whether rare and low-frequency variants also contribute to PR interval heritability. METHODS: We performed large-scale meta-analyses of the PR interval that included 83â367 participants of European ancestry and 9436 of African ancestry. We examined both common and rare variants associated with the PR interval. RESULTS: We identified 31 genetic loci that were significantly associated with PR interval after Bonferroni correction (P<1.2Ă10-6), including 11 novel loci that have not been reported previously. Many of these loci are involved in heart morphogenesis. In gene-based analysis, we found that multiple rare variants at MYH6 (P=5.9Ă10-11) and SCN5A (P=1.1Ă10-7) were associated with PR interval. SCN5A locus also was implicated in the common variant analysis, whereas MYH6 was a novel locus. CONCLUSIONS: We identified common variants at 11 novel loci and rare variants within 2 gene regions that were significantly associated with PR interval. Our findings provide novel insights to the current understanding of atrioventricular conduction, which is critical for cardiac activity and an important determinant of health