Mosleykendall5237

Surface tension influences the fraction of atmospheric particles that become cloud droplets. Although surfactants are an important component of aerosol mass, the surface tension of activating aerosol particles is still unresolved, with most climate models assuming activating particles have a surface tension equal to that of water. By studying picoliter droplet coalescence, we demonstrate that surfactants can significantly reduce the surface tension of finite-sized droplets below the value for water, consistent with recent field measurements. Significantly, this surface tension reduction is droplet size-dependent and does not correspond exactly to the macroscopic solution value. A fully independent monolayer partitioning model confirms the observed finite-size-dependent surface tension arises from the high surface-to-volume ratio in finite-sized droplets and enables predictions of aerosol hygroscopic growth. This model, constrained by the laboratory measurements, is consistent with a reduction in critical supersaturation for activation, potentially substantially increasing cloud droplet number concentration and modifying radiative cooling relative to current estimates assuming a water surface tension. The results highlight the need for improved constraints on the identities, properties, and concentrations of atmospheric aerosol surfactants in multiple environments and are broadly applicable to any discipline where finite volume effects are operative, such as studies of the competition between reaction rates within the bulk and at the surface of confined volumes and explorations of the influence of surfactants on dried particle morphology from spray driers. Copyright © 2020 the Author(s). Published by PNAS.In bacteria, the first two steps of gene expression-transcription and translation-are spatially and temporally coupled. Uncoupling may lead to the arrest of transcription through RNA polymerase backtracking, which interferes with replication forks, leading to DNA double-stranded breaks and genomic instability. How transcription-translation coupling mitigates these conflicts is unknown. Here we show that, unlike replication, translation is not inhibited by arrested transcription elongation complexes. Instead, the translating ribosome actively pushes RNA polymerase out of the backtracked state, thereby reactivating transcription. We show that the distance between the two machineries upon their contact on mRNA is smaller than previously thought, suggesting intimate interactions between them. selleck chemicals llc However, this does not lead to the formation of a stable functional complex between the enzymes, as was once proposed. Our results reveal an active, energy-driven mechanism that reactivates backtracked elongation complexes and thus helps suppress their interference with replication. Copyright © 2020 the Author(s). Published by PNAS.The European continent was subject to two major migrations of peoples during the Holocene the northwestward movement of Anatolian farmer populations during the Neolithic and the westward movement of Yamnaya steppe peoples during the Bronze Age. These movements changed the genetic composition of the continent's inhabitants. The Holocene was also characterized by major changes in vegetation composition, which altered the environment occupied by the original hunter-gatherer populations. We aim to test to what extent vegetation change through time is associated with changes in population composition as a consequence of these migrations, or with changes in climate. Using ancient DNA in combination with geostatistical techniques, we produce detailed maps of ancient population movements, which allow us to visualize how these migrations unfolded through time and space. We find that the spread of Neolithic farmer ancestry had a two-pronged wavefront, in agreement with similar findings on the cultural spread of farming from radiocarbon-dated archaeological sites. link2 This movement, however, did not have a strong association with changes in the vegetational landscape. In contrast, the Yamnaya migration speed was at least twice as fast and coincided with a reduction in the amount of broad-leaf forest and an increase in the amount of pasture and natural grasslands in the continent. We demonstrate the utility of integrating ancient genomes with archaeometric datasets in a spatiotemporal statistical framework, which we foresee will enable future studies of ancient populations' movements, and their putative effects on local fauna and flora. Copyright © 2020 the Author(s). Published by PNAS.Recent pediatric clinical research has begun to focus on risk stratification tools using multibiomarker models. C-reactive protein (CRP) and ferriti biomarkers are widely available and used to varying degrees in daily practice, but there is no single source examining the evidence behind their use.We set out to summarize the evidence behind the use of CRP and ferritin biomarkers in pediatric practice and to begin development of a consensus for their future use for pediatricians.All the literature involving CRP and ferritin in pediatrics available on PubMed was surveyed. Research applicable to daily pediatric practice was summarized in the body of the article. Pediatric clinicians of various subspecialties contributed to the summary of the use of CRP and ferritin biomarkers in clinical practice in various disease processes. A clinical decision pathway is described, and evidence is summarized.CRP and ferritin biomarkers have diverse uses with various cutoff values in the literature, making their use in daily practice difficult. Elevation of these markers coincides with their significant elevation in uncontrolled inflammation.CRP and ferritin biomarkers are widely used in pediatrics. This review provides a resource summarizing evidence into a single source. There is sufficient evidence to indicate that these biomarkers of inflammation can be useful in guiding clinical decision making in specific clinical scenarios; however, further work is needed to improve their use in clinical practice. © American Academy of Pediatrics, 2020. All rights reserved.BACKGROUND AND OBJECTIVES Use of specific services may help to optimize health for children with autism spectrum disorder (ASD); however, little is known about their service use patterns. We aimed to (1) define service use groups and (2) determine associations of sociodemographic, developmental, behavioral, and health characteristics with service use groups among school-aged children with ASD. METHODS We analyzed cross-sectional data on 1378 children aged 6 to 18 years with an ASD diagnosis from the Autism Speaks Autism Treatment Network registry for 2008-2015, which included 16 US sites and 2 Canadian sites. Thirteen service use indicators spanning behavioral and medical treatments (eg, developmental therapy, psychotropic medications, and special diets) were examined. Latent class analysis was used to identify groups of children with similar service use patterns. RESULTS By using latent class analysis, school-aged children with ASD were placed into 4 service use classes limited services (12.0%), multimodal services (36.4%), predominantly educational and/or behavioral services (42.6%), or predominantly special diets and/or natural products (9.0%). Multivariable analysis results revealed that compared with children in the educational and/or behavioral services class, those in the multimodal services class had greater ASD severity and more externalizing behavior problems, those in the limited services class were older and had less ASD severity, and those in the special diets and/or natural products class had higher income and poorer quality of life. CONCLUSIONS In this study, we identified 4 service use groups among school-aged children with ASD that may be related to certain sociodemographic, developmental, behavioral, and health characteristics. Study findings may be used to better support providers and families in decision-making about ASD services. Copyright © 2020 by the American Academy of Pediatrics.Research suggests that the prevalence of obesity in children with autism spectrum disorder (ASD) is higher than in typically developing children. link3 The US Preventive Services Task Force and the American Academy of Pediatrics (AAP) have endorsed screening children for overweight and obesity as part of the standard of care for physicians. However, the pediatric provider community has been inadequately prepared to address this issue in children with ASD. The Healthy Weight Research Network, a national research network of pediatric obesity and autism experts funded by the US Health Resources and Service Administration Maternal and Child Health Bureau, developed recommendations for managing overweight and obesity in children with ASD, which include adaptations to the AAP's 2007 guidance. These recommendations were developed from extant scientific evidence in children with ASD, and when evidence was unavailable, consensus was established on the basis of clinical experience. It should be noted that these recommendations do not reflect official AAP policy. Many of the AAP recommendations remain appropriate for primary care practitioners to implement with their patients with ASD; however, the significant challenges experienced by this population in both dietary and physical activity domains, as well as the stress experienced by their families, require adaptations and modifications for both preventive and intervention efforts. These recommendations can assist pediatric providers in providing tailored guidance on weight management to children with ASD and their families. Copyright © 2020 by the American Academy of Pediatrics.BACKGROUND AND OBJECTIVES Children with autism spectrum disorder (ASD) have a higher prevalence of epilepsy compared with general populations. In this pilot study, we prospectively identified baseline risk factors for the development of seizures in individuals with ASD and also identified characteristics sensitive to seizure onset up to 6 years after enrollment in the Autism Speaks Autism Treatment Network. METHODS Children with ASD and no history of seizures at baseline who either experienced onset of seizures after enrollment in the Autism Treatment Network or remained seizure free were included in the analysis. RESULTS Among 472 qualifying children, 22 (4.7%) experienced onset of seizures after enrollment. Individuals who developed seizures after enrollment exhibited lower scores at baseline on all domains of the Vineland Adaptive Behavior Scales, greater hyperactivity on the Aberrant Behavior Checklist (25.4 ± 11.8 vs 19.2 ± 11.1; P = .018), and lower physical quality of life scores on the Pediatric Quality of Life Inventory (60.1 ± 24.2 vs 76.0 ± 18.2; P less then .001). Comparing change in scores from entry to call-back, adjusting for age, sex, length of follow-up, and baseline Vineland II composite score, individuals who developed seizures experienced declines in daily living skills (-8.38; 95% confidence interval -14.50 to -2.50; P = .005). Adjusting for baseline age, sex, and length of follow-up, baseline Vineland II composite score was predictive of seizure development (risk ratio = 0.95 per unit Vineland II composite score, 95% confidence interval 0.92 to 0.99; P = .007). CONCLUSIONS Individuals with ASD at risk for seizures exhibited changes in adaptive functioning and behavior. Copyright © 2020 by the American Academy of Pediatrics.