93 research outputs found

    Anthropogenic aerosols, greenhouse gases, and the uptake, transport, and storage of excess heat in the climate system

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    Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters, 46(9), (2019):4894-4903, doi:10.1029/2019GL082015.The largest contributor to the planetary energy imbalance is well‐mixed greenhouse gases (GHGs), which are partially offset by poorly mixed (and thus northern midlatitude dominated) anthropogenic aerosols (AAs). To isolate the effects of GHGs and AAs, we analyze data from the CMIP5 historical (i.e., all natural and anthropogenic forcing) and single forcing (GHG‐only and AA‐only) experiments. Over the duration of the historical experiment (1861–2005) excess heat uptake at the top of the atmosphere and ocean surface occurs almost exclusively in the Southern Hemisphere, with AAs canceling the influence of GHGs in the Northern Hemisphere. This interhemispheric asymmetry in surface heat uptake is eliminated by a northward oceanic transport of excess heat, as there is little hemispheric difference in historical ocean heat storage after accounting for ocean volume. Data from the 1pctCO2 and RCP 8.5 experiments suggests that the future storage of excess heat will be skewed toward the Northern Hemisphere oceans.We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model output. CMIP data can be accessed at the ESGF website (https://esgfnode.llnl.gov/projects/esgfllnl/). For CMIP the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. We also thank Paola Petrelli from the ARC Centre of Excellence for Climate Extremes, for her assistance with downloading/managing the CMIP5 data archive at the National Computational Infrastructure

    Adenosine A1 receptor activation attenuates lung ischemia–reperfusion injury

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    ObjectivesIschemia–reperfusion injury contributes significantly to morbidity and mortality in lung transplant patients. Currently, no therapeutic agents are clinically available to prevent ischemia–reperfusion injury, and treatment strategies are limited to maintaining oxygenation and lung function. Adenosine can modulate inflammatory activity and injury by binding to various adenosine receptors; however, the role of the adenosine A1 receptor in ischemia–reperfusion injury and inflammation is not well understood. The present study tested the hypothesis that selective, exogenous activation of the A1 receptor would be anti-inflammatory and attenuate lung ischemia–reperfusion injury.MethodsWild-type and A1 receptor knockout mice underwent 1 hour of left lung ischemia and 2 hours of reperfusion using an in vivo hilar clamp model. An A1 receptor agonist, 2-chloro-N6-cyclopentyladenosine, was administered 5 minutes before ischemia. After reperfusion, lung function was evaluated by measuring airway resistance, pulmonary compliance, and pulmonary artery pressure. The wet/dry weight ratio was used to assess edema. The myeloperoxidase and cytokine levels in bronchoalveolar lavage fluid were measured to determine the presence of neutrophil infiltration and inflammation.ResultsIn the wild-type mice, 2-chloro-N6-cyclopentyladenosine significantly improved lung function and attenuated edema, cytokine expression, and myeloperoxidase levels compared with the vehicle-treated mice after ischemia–reperfusion. The incidence of lung ischemia–reperfusion injury was similar in the A1 receptor knockout and wild-type mice; and 2-chloro-N6-cyclopentyladenosine had no effects in the A1 receptor knockout mice. In vitro treatment of neutrophils with 2-chloro-N6-cyclopentyladenosine significantly reduced chemotaxis.ConclusionsExogenous A1 receptor activation improves lung function and decreases inflammation, edema, and neutrophil chemotaxis after ischemia and reperfusion. These results suggest a potential therapeutic application for A1 receptor agonists for the prevention of lung ischemia–reperfusion injury after transplantation

    Obesity and pronated foot type may increase the risk of chronic plantar heel pain : a matched case-control study

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    Background : Chronic plantar heel pain (CPHP) is one of the most common musculoskeletal disorders of the foot, yet its aetiology is poorly understood. The purpose of this study was to examine the association between CPHP and a number of commonly hypothesised causative factors.Methods : Eighty participants with CPHP (33 males, 47 females, mean age 52.3 years, S.D. 11.7) were matched by age (&plusmn; 2 years) and sex to 80 control participants (33 males, 47 females, mean age 51.9 years, S.D. 11.8). The two groups were then compared on body mass index (BMI), foot posture as measured by the Foot Posture Index (FPI), ankle dorsiflexion range of motion (ROM) as measured by the Dorsiflexion Lunge Test, occupational lower limb stress using the Occupational Rating Scale and calf endurance using the Standing Heel Rise Test.Results : Univariate analysis demonstrated that the CPHP group had significantly greater BMI (29.8 &plusmn; 5.4 kg/m2 vs. 27.5 &plusmn; 4.9 kg/m2; P &lt; 0.01), a more pronated foot posture (FPI score 2.4 &plusmn; 3.3 vs. 1.1 &plusmn; 2.3; P &lt; 0.01) and greater ankle dorsiflexion ROM (45.1 &plusmn; 7.1&deg; vs. 40.5 &plusmn; 6.6&deg;; P &lt; 0.01) than the control group. No difference was identified between the groups for calf endurance or time spent sitting, standing, walking on uneven ground, squatting, climbing or lifting. Multivariate logistic regression revealed that those with CPHP were more likely to be obese (BMI &ge; 30 kg/m2) (OR 2.9, 95% CI 1.4 &ndash; 6.1, P &lt; 0.01) and to have a pronated foot posture (FPI &ge; 4) (OR 3.7, 95% CI 1.6 &ndash; 8.7, P &lt; 0.01).Conclusion : Obesity and pronated foot posture are associated with CPHP and may be risk factors for the development of the condition. Decreased ankle dorsiflexion, calf endurance and occupational lower limb stress may not play a role in CPHP.<br /

    Analysis of microRNA turnover in mammalian cells following Dicer1 ablation

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    Although microRNAs (miRNAs) are key regulators of gene expression, little is known of their overall persistence in the cell following processing. Characterization of such persistence is key to the full appreciation of their regulatory roles. Accordingly, we measured miRNA decay rates in mouse embryonic fibroblasts following loss of Dicer1 enzymatic activity. The results confirm the inherent stability of miRNAs, the intracellular levels of which were mostly affected by cell division. Using the decay rates of a panel of six miRNAs representative of the global trend of miRNA decay, we establish a mathematical model of miRNA turnover and determine an average miRNA half-life of 119 h (i.e. ∼5 days). In addition, we demonstrate that select miRNAs turnover more rapidly than others. This study constitutes, to our knowledge, the first in-depth characterization of miRNA decay in mammalian cells. Our findings indicate that miRNAs are up to 10× more stable than messenger RNA and support the existence of novel mechanism(s) controlling selective miRNA cellular concentration and function

    Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

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    The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000ĝ€-mmĝ€-yrĝ'1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000ĝ€-mmĝ€-yrĝ'1. Author(s) 2016.Fil: Wagner, Fabien H.. Instituto Nacional de Pesquisas Espaciais; BrasilFil: Hérault, Bruno. Ecologie Des Forets de Guyane; BrasilFil: Bonal, Damien. Institut National de la Recherche Agronomique; FranciaFil: Stahl, Clment. Universiteit Antwerp; BélgicaFil: Anderson, Liana O.. National Center For Monitoring And Early Warning Of Natural Disasters; BrasilFil: Baker, Timothy R.. University Of Leeds; Reino UnidoFil: Sebastian Becker, Gabriel. Universidad de Hohenheim; AlemaniaFil: Beeckman, Hans. Royal Museum For Central Africa; BélgicaFil: Boanerges Souza, Danilo. Ministério da Ciência, Tecnologia, Inovações. Instituto Nacional de Pesquisas da Amazônia; BrasilFil: Cesar Botosso, Paulo. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; BrasilFil: Bowman, David M. J. S.. University of Tasmania; AustraliaFil: Bräuning, Achim. Universitat Erlangen-Nuremberg; AlemaniaFil: Brede, Benjamin. Wageningen University And Research Centre; Países BajosFil: Irving Brown, Foster. Universidade Federal Do Acre; BrasilFil: Julio Camarero, Jesus. Instituto Boliviano de Investigacion Forestal Bolivia; BoliviaFil: Camargo, Plnio Barbosa. Universidade de Sao Paulo; BrasilFil: Cardoso, Fernanda C.G.. Universidade Federal do Paraná; BrasilFil: Carvalho, Fabrcio Alvim. Universidade Federal de Juiz de Fora; BrasilFil: Castro, Wendeson. Universidade Federal Do Acre; BrasilFil: Koloski Chagas, Rubens. Universidade de Sao Paulo; BrasilFil: Chave, Jrome. Centre National de la Recherche Scientifique; FranciaFil: Chidumayo, Emmanuel N.. University Of Zambia; ZambiaFil: Clark, Deborah A.. University Of Missouri-st. Louis; Estados UnidosFil: Regina Capellotto Costa, Flavia. Ministério da Ciência, Tecnologia, Inovações. Instituto Nacional de Pesquisas da Amazônia; BrasilFil: Couralet, Camille. Royal Museum For Central Africa; BélgicaFil: Henrique Da Silva Mauricio, Paulo. Universidade Federal Do Acre; BrasilFil: Dalitz, Helmut. Universidad de Hohenheim; AlemaniaFil: Resende De Castro, Vinicius. Universidade Federal de Vicosa; BrasilFil: Milani, Jaanan Eloisa De Freitas. Universidade Federal do Paraná; BrasilFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla; Argentin

    Natural resource wars in the shadow of the future: Explaining spatial dynamics of violence during civil war

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    Previous studies on natural resources and civil wars find that the presence of natural resources increases both civil conflict risk and duration. At the same time, belligerents often cooperate over resource extraction, suggesting a temporal variation in the contest over this subnational space. This study argues that parties fight over natural resources primarily when they expect that the conflict is about to end, as the importance of controlling them increases in the post-conflict setting. In contrast, belligerents that anticipate a long war have incentives to avoid fighting near natural resources since excessive violence will hurt the extraction, trade, and subsequent taxation that provide conflict actors with income from the resource. We test our argument using yearly and monthly grid-cell-level data on African civil conflicts for the period 1989–2008 and find support for our expected spatial variation. Using whether negotiations are underway as an indicator about warring parties’ expectations on conflict duration, we find that areas with natural resources in general experience less intense fighting than other areas, but during negotiations these very areas witness most of the violence. We further find that the spatial shift in violence occurs immediately when negotiations are opened. A series of difference-in-difference estimations show a visible shift of violence towards areas rich in natural resources in the first three months after parties have initiated talks. Our findings are relevant for scholarship on understanding and predicting the trajectories of micro-level civil conflict violence, and for policymakers seeking to prevent peace processes being derailed

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Molnupiravir plus usual care versus usual care alone as early treatment for adults with COVID-19 at increased risk of adverse outcomes (PANORAMIC): an open-label, platform-adaptive randomised controlled trial

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    Background: The safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population. Methods: PANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older—or aged 18 years or older with relevant comorbidities—and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (&lt;50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031. Findings: Between Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81–1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir. Interpretation: Molnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community

    Molnupiravir plus usual care versus usual care alone as early treatment for adults with COVID-19 at increased risk of adverse outcomes (PANORAMIC): an open-label, platform-adaptive randomised controlled trial

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    BackgroundThe safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population.MethodsPANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older—or aged 18 years or older with relevant comorbidities—and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (<50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031.FindingsBetween Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81–1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir.InterpretationMolnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community
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