332 research outputs found
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Environmental inequality and disparities in school readiness: The role of neurotoxic lead
Developmental science has increasingly scrutinized how environmental hazards influence child outcomes, but few studies examine how contaminants affect disparities in early skill formation. Linking research on environmental inequality and early childhood development, this study assessed whether differences in exposure to neurotoxic lead explain sociodemographic gaps in school readiness. Using panel data tracking a representative sample of 1266 Chicago children (50% female, 16% White, 30% Black, 49% Hispanic, ÎŒageâ=â5.2âmonths at baseline, collected 1994â2002), analyses quantified the contribution of lead contamination to class and racial disparities in vocabulary skills and attention problems at ages 4 and 5. Results suggested that lead contamination explains 15%â25% and 33%â66% of the disparities in each outcome, respectively, although imprecise estimates preclude drawing firm inferences about attention problems
The association between national culture, road safety performance, and support for road safety policy measures
There are considerable differences between countries when it comes to road safety performance, as indicated by the number of road fatalities per 100,000 inhabitants. These discrepancies are strongly associated with differences in wealth and prosperity, as expected, but are also related to national culture. The overall objective of this exploratory study is to identify relationships between national culture, road safety performance and public support for policy measures. Using the revised version of Hofstede's cultural dimensions, we show the strong correlation between national culture and road safety performance, which exists even after controlling for the national level of wealth as measured by the gross national income. Furthermore, by combining the national cultural dimensions with data on 29 countries from the second stage of ESRA, the E-Survey of Road users' Attitudes, this study demonstrates that culture also affects the level of public support for policy measures related to road safety. Specifically, for many measures, the degree of individualism accounts for a considerable part of the statistical variation in the public support for policy measures across countriesâexcept for those measures for which the support is very high in most countries. Possible explanations are given for the seemingly paradoxical finding that countries which witness high resistance to road safety policy measures have nevertheless managed to achieve better road safety performance
Toehold-enchanced lna probes for selective pull down and single-molecule analysis of native chromatin
Biological and Soft Matter Physic
Symmetry Breaking and Bifurcations in the Periodic Orbit Theory; 1, Elliptic Billiard
We derive an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard at zero eccentricity. Away from the circular limit and the bifurcations, it reduces to the usual (extended) Gutzwiller trace formula which for the leading-order families of periodic orbits is identical to the result of Berry and Tabor. We show that the circular disk limit of the diameter-orbit contribution is also reached through contributions from closed (periodic and non-periodic) orbits of hyperbolic type with an even number of reflections from the boundary. We obtain the Maslov indices depending on deformation and energy in terms of the phases of the complex error and Airy functions. We find enhancement of the amplitudes near the common bifurcation points of both short-diameter and hyperbolic orbits. The calculated semiclassical level densities and shell energies are in good agreement with the quantum mechanical ones
Toehold-enchanced lna probes for selective pull down and single-molecule analysis of native chromatin
Biological and Soft Matter Physic
Cell Surface Sialylation and Fucosylation Are Regulated by L1 via Phospholipase CÎł and Cooperate to Modulate Neurite Outgrowth, Cell Survival and Migration
BACKGROUND: Cell surface glycosylation patterns are markers of cell type and status. However, the mechanisms regulating surface glycosylation patterns remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using a panel of carbohydrate surface markers, we have shown that cell surface sialylation and fucosylation were downregulated in L1(-/y) neurons versus L1(+/y) neurons. Consistently, mRNA levels of sialyltransferase ST6Gal1, and fucosyltransferase FUT9 were significantly reduced in L1(-/y) neurons. Moreover, treatment of L1(+/y) neurons with L1 antibodies, triggering signal transduction downstream of L1, led to an increase in cell surface sialylation and fucosylation compared to rat IgG-treated cells. ShRNAs for both ST6Gal1 and FUT9 blocked L1 antibody-mediated enhancement of neurite outgrowth, cell survival and migration. A phospholipase Cgamma (PLCgamma) inhibitor and shRNA, as well as an Erk inhibitor, reduced ST6Gal1 and FUT9 mRNA levels and inhibited effects of L1 on neurite outgrowth and cell survival. CONCLUSIONS: Neuronal surface sialylation and fucosylation are regulated via PLCgamma by L1, modulating neurite outgrowth, cell survival and migration
The Influence of Dormitory Architecture On Resident Behavior
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66943/2/10.1177_001391657300500402.pd
Spatial and temporal heterogeneity in human mobility patterns in Holocene Southwest Asia and the East Mediterranean
We present a spatiotemporal picture of human genetic diversity in Anatolia, Iran, Levant, South Caucasus, and the Aegean, a broad region that experienced the earliest Neolithic transition and the emergence of complex hierarchical societies. Combining 35 new ancient shotgun genomes with 382 ancient and 23 present-day published genomes, we found that genetic diversity within each region steadily increased through the Holocene. We further observed that the inferred sources of gene flow shifted in time. In the first half of the Holocene, Southwest Asian and the East Mediterranean populations homogenized among themselves. Starting with the Bronze Age, however, regional populations diverged from each other, most likely driven by gene flow from external sources, which we term âthe expanding mobility model.â Interestingly, this increase in inter-regional divergence can be captured by outgroup-f-based genetic distances, but not by the commonly used F statistic, due to the sensitivity of F, but not outgroup-f, to within-population diversity. Finally, we report a temporal trend of increasing male bias in admixture events through the Holocene
Insights into the pathogenesis of vein graft disease: lessons from intravascular ultrasound
The success of coronary artery bypass grafting (CABG) is limited by poor long-term graft patency. Saphenous vein is used in the vast majority of CABG operations, although 15% are occluded at one year with as many as 50% occluded at 10 years due to progressive graft atherosclerosis. Intravascular ultrasound (IVUS) has greatly increased our understanding of this process. IVUS studies have shown that early wall thickening and adaptive remodeling of vein grafts occurs within the first few weeks post implantation, with these changes stabilising in angiographically normal vein grafts after six months. Early changes predispose to later atherosclerosis with occlusive plaque detectable in vein grafts within the first year. Both expansive and constrictive remodelling is present in diseased vein grafts, where the latter contributes significantly to occlusive disease. These findings correlate closely with experimental and clinicopathological studies and help define the windows for prevention, intervention or plaque stabilisation strategies. IVUS is also the natural tool for evaluating the effectiveness of pharmacological and other treatments that may prevent or slow the progression of vein graft disease in clinical trials
Quantifying Sources of Variability in Infancy Research Using the Infant-Directed-Speech Preference
Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infantsâ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infantsâ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infantsâ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohenâs d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure
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