152 research outputs found

    Modeling the Influence of Early Skin-to-Skin Contact on Exclusive Breastfeeding in a Sample of Hispanic Immigrant Women

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    Using data from a longitudinal study of breastfeeding in Hispanics, this study evaluated the influence of early skin-to-skin contact (SSC) on initiation and sustained exclusive breastfeeding (EBF) at 1 month postpartum. Two-thirds of the women in the sample participated in early SSC. At discharge, over half of the women were EBF; this proportion decreased to one-third at 1 month postpartum. Controlling for demographic and clinical variables in the model, participation in early SSC was associated with a greater than sevenfold increase in the odds of EBF at discharge (p = .005) but was not predictive of EBF at 1 month post-discharge (p = .7). Younger maternal age and increased prenatal infant feeding intention were associated with an increased likelihood of EBF across both timepoints. Promoting early SSC may help with initiation of EBF, while further breastfeeding support may be needed to maintain EBF following discharge for this vulnerable population

    Characteristics of brown carbon in Western United States wildfires

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    Brown carbon (BrC) associated with aerosol particles in western United States wildfires was measured between Jul. and Aug. 2019 onboard the NASA DC-8 research aircraft during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) study. Two BrC measurement methods are investigated; highly spectrally-resolved light absorption in solvent (water and methanol) extracts of particles collected on filters and in-situ bulk aerosol particle light absorption measured at three wavelengths (405, 532, 664 nm) with a photo acoustic spectrometer (PAS). A light absorption closure analysis for wavelengths between 300 and 700 nm was performed. The combined light absorption of particle pure black carbon material, including enhancements due to internally mixed materials, plus soluble BrC and a Mie-predicted factor for conversion of soluble BrC to aerosol particle BrC, was compared to absorption spectra from a power law fit to the three PAS wavelengths. For the various parameters used, at a wavelength of roughly 400 nm they agreed, at lower wavelengths the individual component-predicted particle light absorption significantly exceeded the PAS and at higher wavelengths the PAS absorption was consistently higher, but more variable. Limitations with extrapolation of PAS data to wavelengths below 405 nm and missing BrC species of low solubility that more strongly absorb at higher wavelengths may account for the differences. Based on measurements closest to fires, the emission ratio of PAS measured BrC at 405 nm relative to carbon monoxide (CO) was on average 0.13 Mm−1 ppbv−1, emission ratios for soluble BrC are also provided. As the smoke moved away from the burning regions the evolution over time of BrC was observed to be highly complex; BrC enhancement, depletion, or constant levels with age were all observed in the first 8 hours after emission in different plumes. Within 8 hours following emissions, 4-nitrocatechol, a well characterized BrC chromophore commonly found in smoke particles, was largely depleted relative to the bulk BrC. In a descending plume where temperature increased by 15 K, 4-nitrocatechol dropped possibly due to temperature-driven evaporation, but bulk BrC remained largely unchanged. Evidence was found for reactions with ozone, or related species, as a pathway for secondary formation of BrC under both low and high oxides of nitrogen (NOx) conditions, while BrC was also observed to be bleached in regions of higher ozone and low NOx, consistent with complex behaviors of BrC observed in laboratory studies. Although the evolution of smoke in the first hours following emission is highly variable, a limited number of measurements of more aged smoke (15 to 30 hours) indicate a net loss of BrC. It is yet to be determined how the near-field BrC evolution in smoke affects the characteristics of smoke over longer time and spatial scales, where its environmental impacts are likely to be greater

    Measurement report: Emission factors of NH3 and NHx for wildfires and agricultural fires in the United States.

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    Ammonia (NH3) is an important trace gas in the atmosphere and fires are among the poorly investigated sources. During the FIREX-AQ aircraft campaign in 2019, we measured gaseous ammonia and particulate ammonium (NH4+) in smoke plumes emitted from six wildfires in the Western US and 66 small agricultural fires in the Southeastern US. We herein present a comprehensive set of emission factors of NH3 and NHx, with NHx = NH3 + NH4+

    Regulation of Gene Expression in Plants through miRNA Inactivation

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    Eukaryotic organisms possess a complex RNA-directed gene expression regulatory network allowing the production of unique gene expression patterns. A recent addition to the repertoire of RNA-based gene regulation is miRNA target decoys, endogenous RNA that can negatively regulate miRNA activity. miRNA decoys have been shown to be a valuable tool for understanding the function of several miRNA families in plants and invertebrates. Engineering and precise manipulation of an endogenous RNA regulatory network through modification of miRNA activity also affords a significant opportunity to achieve a desired outcome of enhanced plant development or response to environmental stresses. Here we report that expression of miRNA decoys as single or heteromeric non-cleavable microRNA (miRNA) sites embedded in either non-protein-coding or within the 3′ untranslated region of protein-coding transcripts can regulate the expression of one or more miRNA targets. By altering the sequence of the miRNA decoy sites, we were able to attenuate miRNA inactivation, which allowed for fine regulation of native miRNA targets and the production of a desirable range of plant phenotypes. Thus, our results demonstrate miRNA decoys are a flexible and robust tool, not only for studying miRNA function, but also for targeted engineering of gene expression in plants. Computational analysis of the Arabidopsis transcriptome revealed a number of potential miRNA decoys, suggesting that endogenous decoys may have an important role in natural modulation of expression in plants

    A novel MMP12 locus is associated with large artery atherosclerotic stroke using a genome-wide age-at-onset informed approach.

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    Genome-wide association studies (GWAS) have begun to identify the common genetic component to ischaemic stroke (IS). However, IS has considerable phenotypic heterogeneity. Where clinical covariates explain a large fraction of disease risk, covariate informed designs can increase power to detect associations. As prevalence rates in IS are markedly affected by age, and younger onset cases may have higher genetic predisposition, we investigated whether an age-at-onset informed approach could detect novel associations with IS and its subtypes; cardioembolic (CE), large artery atherosclerosis (LAA) and small vessel disease (SVD) in 6,778 cases of European ancestry and 12,095 ancestry-matched controls. Regression analysis to identify SNP associations was performed on posterior liabilities after conditioning on age-at-onset and affection status. We sought further evidence of an association with LAA in 1,881 cases and 50,817 controls, and examined mRNA expression levels of the nearby genes in atherosclerotic carotid artery plaques. Secondly, we performed permutation analyses to evaluate the extent to which age-at-onset informed analysis improves significance for novel loci. We identified a novel association with an MMP12 locus in LAA (rs660599; p = 2.5×10⁻⁷), with independent replication in a second population (p = 0.0048, OR(95% CI) = 1.18(1.05-1.32); meta-analysis p = 2.6×10⁻⁸). The nearby gene, MMP12, was significantly overexpressed in carotid plaques compared to atherosclerosis-free control arteries (p = 1.2×10⁻¹⁵; fold change = 335.6). Permutation analyses demonstrated improved significance for associations when accounting for age-at-onset in all four stroke phenotypes (p<0.001). Our results show that a covariate-informed design, by adjusting for age-at-onset of stroke, can detect variants not identified by conventional GWAS

    Genetic overlap between diagnostic subtypes of ischemic stroke

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    Background and Purpose: Despite moderate heritability, the phenotypic heterogeneity of ischemic stroke has hampered gene discovery, motivating analyses of diagnostic subtypes with reduced sample sizes. We assessed evidence for a shared genetic basis among the 3 major subtypes: large artery atherosclerosis (LAA), cardioembolism, and small vessel disease (SVD), to inform potential cross-subtype analyses. Methods: Analyses used genome-wide summary data for 12 389 ischemic stroke cases (including 2167 LAA, 2405 cardioembolism, and 1854 SVD) and 62 004 controls from the Metastroke consortium. For 4561 cases and 7094 controls, individual-level genotype data were also available. Genetic correlations between subtypes were estimated using linear mixed models and polygenic profile scores. Meta-analysis of a combined LAA-SVD phenotype (4021 cases and 51 976 controls) was performed to identify shared risk alleles. Results: High genetic correlation was identified between LAA and SVD using linear mixed models (rg=0.96, SE=0.47, P=9×10-4) and profile scores (rg=0.72; 95% confid

    Mucedorus: the last ludic playbook, the first stage Arcadia

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    This article argues that two seemingly contradictory factors contributed to and sustained the success of the anonymous Elizabethan play Mucedorus (c. 1590; pub. 1598). First, that both the initial composition of Mucedorus and its Jacobean revival were driven in part by the popularity of its source, Philip Sidney's Arcadia. Second, the playbook's invitation to amateur playing allowed its romance narrative to be adopted and repurposed by diverse social groups. These two factors combined to create something of a paradox, suggesting that Mucedorus was both open to all yet iconographically connected to an elite author's popular text. This study will argue that Mucedorus pioneered the fashion for “continuations” or adaptations of the famously unfinished Arcadia, and one element of its success in print was its presentation as an affordable and performable version of Sidney's elite work. The Jacobean revival of Mucedorus by the King's Men is thus evidence of a strategy of engagement with the Arcadia designed to please the new Stuart monarchs. This association with the monarchy in part determined the cultural functions of the Arcadia and Mucedorus through the Interregnum to the close of the seventeenth century
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