2,376 research outputs found
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Proximate controls on semiarid soil greenhouse gas fluxes across 3 million years of soil development
Soils are important sources and sinks of three greenhouse gases (GHGs): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, it is unknown whether semiarid landscapes are important contributors to global fluxes of these gases, partly because our mechanistic understanding of soil GHG fluxes is largely derived from more humid ecosystems. We designed this study with the objective of identifying the important soil physical and biogeochemical controls on soil GHG fluxes in semiarid soils by observing seasonal changes in soil GHG fluxes across a three million year substrate age gradient in northern Arizona. We also manipulated soil nitrogen (N) and phosphorus availability with 7 years of fertilization and used regression tree analysis to identify drivers of unfertilized and fertilized soil GHG fluxes. Similar to humid ecosystems, soil N2O flux was correlated with changes in N and water availability and soil CO2 efflux was correlated with changes in water availability and temperature. Soil CH4 uptake was greatest in relatively colder and wetter soils. While fertilization had few direct effects on soil CH4 flux, soil nitrate was an important predictor of soil CH4 uptake in unfertilized soils and soil ammonium was an important predictor of soil CH4 uptake in fertilized soil. Like in humid ecosystems, N gas loss via nitrification or denitrification appears to increase with increases in N and water availability during ecosystem development. Our results suggest that, with some exceptions, the drivers of soil GHG fluxes in semiarid ecosystems are often similar to those observed in more humid ecosystems
Neuronal Signaling: A reflection on the Biochemical Society's newest journal and an exciting outlook on its next steps
The inaugural Editor-in-Chief of Neuronal Signaling, Aideen M. Sullivan, reflects on the journal's journey so far and welcomes the new Editor-in-Chief, Clare Stanford, as she shares some of the exciting initiatives and plans for its future
Intracranial internal carotid aneurysm causing diplopia
Internal carotid intracranial aneurysms are a relatively rare form of intracranial aneurysm that presents with diplopia, retro-orbital pain and unilateral headaches. The symptoms are progressive and the diagnosis should be considered in a patient presenting with these complaints. Underlying hypertension and advanced age are specific risk factors
Social phobia following maprotiline: the first case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
A novel cell-type deconvolution algorithm reveals substantial contamination by immune cells in saliva, buccal and cervix
AIM: An outstanding challenge in epigenome studies is the estimation of cell-type proportions in complex epithelial tissues. MATERIALS & METHODS: Here, we construct and validate a DNA methylation reference and algorithm for complex tissues that contain epithelial, immune and nonimmune stromal cells. RESULTS: Using this reference, we show that easily accessible tissues such as saliva, buccal and cervix exhibit substantial variation in immune cell (IC) contamination. We further validate our reference in the context of oral cancer, where it correctly predicts an increased IC infiltration in cancer but suppressed in patients with highest smoking exposure. Finally, our method can improve the specificity of differentially methylated CpG calls in epithelial cancer. CONCLUSION: The degree and variation of IC contamination in complex epithelial tissues is substantial. We provide a valuable resource and tool for assessing the epithelial purity and IC contamination of samples and for identifying differential methylation in such complex tissues
Integration of airborne and ground observations of nitryl chloride in the Seoul metropolitan area and the implications on regional oxidation capacity during KORUS-AQ 2016
Nitryl chloride (ClNO2) is a radical reservoir species that releases chlorine radicals upon photolysis. An integrated analysis of the impact of ClNO2 on regional photochemistry in the Seoul metropolitan area (SMA) during the Korea-United States Air Quality Study (KORUS-AQ) 2016 field campaign is presented. Comprehensive multiplatform observations were conducted aboard the NASA DC-8 and at two ground sites (Olympic Park, OP; Taehwa Research Forest, TRF), representing an urbanized area and a forested suburban region, respectively. Positive correlations between daytime Cl2 and ClNO2 were observed at both sites, the slope of which was dependent on O3 levels. The possible mechanisms are explored through box model simulations constrained with observations. The overall diurnal variations in ClNO2 at both sites appeared similar but the nighttime variations were systematically different. For about half of the observation days at the OP site the level of ClNO2 increased at sunset but rapidly decreased at around midnight. On the other hand, high levels were observed throughout the night at the TRF site. Significant levels of ClNO2 were observed at both sites for 4-5 h after sunrise. Airborne observations, box model calculations, and back-trajectory analysis consistently show that these high levels of ClNO2 in the morning are likely from vertical or horizontal transport of air masses from the west. Box model results show that chlorine-radical-initiated chemistry can impact the regional photochemistry by elevating net chemical production rates of ozone by 25% in the morning
The Complete Star Formation History of the Universe
The determination of the star-formation history of the Universe is a key goal
of modern cosmology, as it is crucial to our understanding of how structure in
the Universe forms and evolves. A picture has built up over recent years,
piece-by-piece, by observing young stars in distant galaxies at different times
in the past.
These studies indicated that the stellar birthrate peaked some 8 billion
years ago, and then declined by a factor of around ten to its present value.
Here we report on a new study which obtains the complete star formation history
by analysing the fossil record of the stellar populations of 96545 nearby
galaxies. Broadly, our results support those derived from high-redshift
galaxies elsewhere in the Universe. We find, however, that the peak of star
formation was more recent - around 5 billion years ago. Our study also shows
that the bigger the stellar mass of the galaxy, the earlier the stars were
formed. This striking result indicates a very different formation history for
high- and low-mass formation.Comment: Accepted by Nature. Press embargo until publishe
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The impact generated by public and charity-funded research in the UK: A systematic literature review
Objective: To identify, synthesize and critically assess the empirical evidence of the impact generated by public and charity funded health research in the United Kingdom.
Methods: We conducted a systematic literature review of the empirical evidence published in English in peer-reviewed journals between 2006 and 2017. Studies meeting the inclusion criteria were selected and their findings were analysed using the Payback Framework into five main categories: knowledge, benefits to future research and research use, benefits from informing policy and product development, health and health sector benefits and broader economic benefits. We assessed the studies for risk of selection, reporting and funding bias.
Results: Thirteen studies met the inclusion criteria. The majority of the studies (10 out of 13) assessed impact at multiple domains including the main 5 key themes of the Payback Framework. All of them showed a positive impact of funded research on outcomes. Of those studies, one presented low risk of bias (8%), 6 studies were classified as presenting moderate risk of bias (46%) and 6 studies presented high risk of bias (46%).
Conclusions: Empirical evidence on the impact of public and charity funded research is still limited and subject to funding and selection bias. More work is needed to establish the causal effects of funded research on academic outcomes, policy, practice and the broader economy
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