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Gains from trade in an asymmetric Cournot world with trade costs
Get PDFWe compare free trade with autarky in a partial equilibrium model with asymmetric Cournot competition and linear demand and costs. While the existing literature can only guarantee under strong symmetry without trade costs that trade increases world output, consumer surplus and total welfare, we show that weaker conditions such as partial symmetry guarantee these global gains from trade in a n-country world with trade costs. We also show that free entry and exit ensure that every country gains from trade. Without any additional conditions, trade always increases a social objective function that values consumers twice as much as firms.Peer reviewe
Higher dose corticosteroids in hospitalised COVID-19 patients requiring ventilatory support (RECOVERY) : a randomised, controlled, open-label, platform trial
Get PDFFunding: UK Research and Innovation (Medical Research Council) and National Institute for Health Research (Grant ref: MC_PC_19056), and Wellcome Trust (Grant Ref: 222406/Z/20/Z).Background: Low dose corticosteroids (e.g., 6 mg dexamethasone) have been shown to reduce mortality for hypoxic COVID-19 patients. We have previously reported that higher dose corticosteroids cause harm in patients with clinical hypoxia but not receiving ventilatory support (the combination of non-invasive mechanical ventilation, including high-flow nasal oxygen, continuous positive airway pressure and bilevel positive airway pressure ventilation, and invasive mechanical ventilation or extra-corporeal membrane oxygenation), but the balance of efficacy and safety in patients receiving ventilatory support is uncertain. Methods: This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) assessed multiple possible treatments in patients hospitalised for COVID-19. Eligible and consenting adult patients receiving ventilatory support were randomly allocated (1:1) to either usual care with higher dose corticosteroids (dexamethasone 20 mg once daily for 5 days followed by 10 mg once daily for 5 days or until discharge if sooner) or usual standard of care alone (which includes dexamethasone 6 mg once daily for 10 days or until discharge if sooner). The primary outcome was 28-day mortality; secondary outcomes were duration of hospitalisation and (among participants not on invasive mechanical ventilation at baseline) the composite of invasive mechanical ventilation or death. Recruitment closed on 31 March 2024 when funding for the trial ended. The RECOVERY trial is registered with ISRCTN (50189673) and clinicaltrials.gov (NCT04381936). Findings: Between 25 May 2021 and 9 January 2024, 477 COVID-19 patients receiving ventilatory support were randomly allocated to receive usual care plus higher dose corticosteroids vs. usual care alone (of whom 99% received corticosteroids during the follow-up period). Of those randomised, 221 (46%) were in Asia, 245 (51%) in the UK and 11 (2%) in Africa. 143 (30%) had diabetes mellitus. Overall, 86 (35%) of 246 patients allocated to higher dose corticosteroids vs. 86 (37%) of 231 patients allocated to usual care died within 28 days (rate ratio [RR] 0.87; 95% CI 0.64-1.18; p = 0.37). There was no significant difference in the proportion of patients discharged from hospital alive within 28 days (128 [52%] in the higher dose corticosteroids group vs. 120 [52%] in the usual care group; RR 1.04, 0.81-1.33]; p = 0.78). Among those not on invasive mechanical ventilation at baseline, there was no clear reduction in the proportion meeting the composite endpoint of invasive mechanical ventilation or death (76 [37%] of 206 vs. 93 [45%] of 205; RR 0.79 [95% CI 0.63-1.00]; p = 0.05). Interpretation: In patients hospitalised for COVID-19 receiving ventilatory support, we found no evidence that higher dose corticosteroids reduced the risk of death compared to usual care, which included low dose corticosteroids.Peer reviewe
Emerging drought sensitivity for large Norway spruce trees at high elevation in the High Tatras, Slovakia
Get PDFFunding: This research was funded by the German Research Foundation (DFG) within the Research Training Group RESPONSE (DFG RTG 2010).Understanding tree growth and forest dynamics under climate change is paramount to predict changes in carbon cycling, forest development, and ecosystem services. At temperature limited sites, such as alpine treelines, tree growth is often assumed to benefit from rising temperatures, while increased drought may offset potential benefits. Tree size is known to be related to climate sensitivity and drought induced mortality, with large trees generally suffering the most from drought. To assess the relationship of tree size and climate sensitivity for Norway spruce trees at treeline, we collected 158 tree cores at treeline and the adjacent closed canopy forest in the High Tatra Mountains in Slovakia. Size classes were established based on size class isolation of the total sample set, yielding artificial tree ring chronologies with a constant size over time. We ran moving-window correlation analyses to assess the temporal development of climate sensitivity. We found climate-growth correlations to be non-stationary and with similar trends among size classes. In general, trees are temperature limited during the growing season, but correlations have shifted from June to July in recent decades. Additionally, the largest trees show an increased and significant sensitivity to August and September drought conditions in the year preceding growth. These findings emphasize the increasing influence of drought constraints on tree growth, even at supposedly temperature limited treeline sites.Peer reviewe
Pydrofoil: accelerating Sail-based instruction set simulators
Get PDFFunding: This work was supported by EPSRC grant EP/R006865/1 and gift funding from Google.We present Pydrofoil, a multi-stage compiler that generates instruction set simulators (ISSs) from processor instruction set architectures (ISAs) expressed in the high-level, verification-oriented ISA specification language Sail. Pydrofoil shows a > 230x speedup over the C-based ISS generated by Sail on our benchmarks, and is based on the following insights. (i) An ISS is effectively an interpreter loop, and tracing just-in-time (JIT) compilers have proven effective at accelerating those, albeit mostly for dynamically typed languages. (ii) ISS workloads are highly atypical, dominated by intensive bit manipulation operations. Conventional compiler optimisations for general-purpose programming languages have limited impact for speeding up such workloads. We develop suitable domain-specific optimisations. (iii) Neither tracing JIT compilers, nor ahead-of-time (AOT) compilation alone, even with domain-specific optimisations, suffice for the generation of performant ISSs. Pydrofoil therefore implements a hybrid approach, pairing an AOT compiler with a tracing JIT built on the meta-tracing PyPy framework. AOT and JIT use domain-specific optimisations. Our benchmarks demonstrate that combining AOT and JIT compilers provides significantly greater performance gains than using either compiler alone
Benthic biofilm structure and function under abrupt flow changes
Get PDFFunding: This project has been financed by the Water Research Network Baden-Württemberg, funded by the Ministry of Science, Research and Arts of the federal state of Baden-Württemberg, Germany.Sediment accumulation reduces the capacity of dammed systems worldwide, therefore understanding sediment stability and transport within a reservoir is fundamental for sustainable management. Fluctuating hydrodynamics can alter the physical disturbance exerted on the sediment bed and can lead to substantial resuspension of bottom sediments and benthic biofilms. Removal of the biofilm can drastically alter the biochemical environment in the bed, and its ability to stabilize underlying sediments as microphytobenthic and bacteria communities are removed. In this experiment, an 8-week long hydraulic flume experiment was conducted to examine the response, adaptation and functionality of biofilms exposed to abrupt increases in flow typical of flow managed systems. Water and resuspended sediment from an oligotrophic reservoir in Germany, were used to develop biofilms on inserted flume cartridges. Developed biofilms were haphazardly distributed across two flow treatments: high bed shear stress (0.7 Pa) or low bead shear stress (0.1 Pa) for 28 days. Biochemical changes and biostabilization potential (adhesiveness) were examined over this period. Microphytobenthic biomass and composition, bacterial community diversity and extracellular polymeric carbohydrates/proteins were all initially altered by the abrupt increase in flow as the biofilm was stripped away. Biochemical properties largely recovered by the end of the experimental period (28-days) with recovery time and the degree of re-establishment dependent on the initial biofilm condition. However, sediment beds exposed to higher flows remained less stable, suggesting this functional role of the biofilm may take longer to reestablish itself after periods of higher flow. Findings suggest flow management has the potential to alter biofilm development and highlight the importance of protein content and microphytobenthic biomass in the recovery of biostabilization, Microphytobenthic diversity and carbohydrate content had less influence in the recovery of biostabilization. The findings may be useful to reservoir managers to manipulate flow to allow stable benthic biofilms to improve water quality and/or reduce infilling.Peer reviewe
Exploring the dispositional account of self-knowledge
Get PDFIn this thesis, I start with the debate between the belief-first and language-first views on self-knowledge and assess their strength and problems, before proposing the desiderata for a more satisfactory account for self-knowledge. I present what I call the dispositional account of self-knowledge as an alternative to expressivism that avoids some of its major problems, especially how it cannot account for cases where one does not express her mental states. I then show how self-knowledge is possible through the awareness of the disposition in cases where there is no public expression. In particular, the awareness of the dispositions to express is treated as a specific case of how we can be aware of our voluntary behaviours as active agents. In addition, I argue how the dispositional account could account for a wide range of mental phenomena. I then consider how we form beliefs based on the awareness of the dispositions, and how the beliefs can be justified. Lastly, I come back to the desiderata for a more satisfactory account of self-knowledge we started with, and examine if the dispositional account could satisfactorily meet our desiderata
Fermented fruits : scrumping, sharing, and the origin of feasting
Get PDFMounting evidence points to the importance of fermented fruits in the diets of tropical frugivores, especially African apes. But how has this fundamental aspect of ape ecology escaped scientific attention over the past six decades? Here we draw inspiration from the Middle Ages to fill an essential void in scientific discourse.Peer reviewe
Renewable solvents for Diels–Alder/cheletropic reaction sequences : preparation of pentaphenylbenzene and 1,2,4-triphenyltriphenylene
Get PDFPolycyclic aromatic compounds can often be made by a sequence featuring an initial Diels–Alder [4 + 2] cycloaddition reaction, followed by cheletropic extrusion of carbon monoxide. These reactions normally require heating the diene and dieneophile in petrochemical-derived aromatic hydrocarbon solvents, such as xylenes or diphenyl ether. This article summarizes the results of attempts to use renewable solvents in place of those currently in use to prepare pentaphenylbenzene and 1,2,4-triphenyltriphenylene. Dihydrolevoglucosenone, p-cymene, ethyl lactate, diethyl carbonate, and cyclopentyl methyl ether have all been successfully evaluated as renewable solvent alternatives in Diels–Alder/cheletropic reaction sequences. An analysis of the products from the reactions investigated did not show evidence of oxidative degradation of the diene reactants. Furthermore, norbornadien-7-one intermediates were not isolated from any of the reactions tested.Peer reviewe
Healthcare worker views on antimicrobial resistance in chronic respiratory disease
Get PDFFunding: This survey was supported through funding from the European Respiratory Society as part of the AMR-Lung clinical research collaboration. AS is supported by the MRC centre Grant (MR/X020258/1).Background and objective Antimicrobial resistance (AMR) is a global crisis, however, relatively little is known regarding its impact in chronic respiratory disease and the specific challenges faced by healthcare workers across the world in this field. We aimed to assess global healthcare worker views on the challenges they face regarding AMR in chronic respiratory disease. Methods An online survey was sent to healthcare workers globally working in chronic respiratory disease through a European Respiratory Society clinical research collaboration (AMR-Lung) focussed on AMR in chronic lung disease. Responses from different geographic regions were analysed. Results 279 responses were received across 60 countries. 54.5% of respondents encountered AMR in chronic respiratory disease weekly. There were differences in perceived high-priority diseases and species with AMR burden between Europe, Asia and Africa. 76.4% of respondents thought that inappropriate antimicrobial prescribing in chronic respiratory disease was common. However, only 43.4% of respondents thought that there were adequate antimicrobial stewardship programmes in their area for chronic respiratory disease, with limited availability in outpatient (29.0%) and ambulatory settings (24.7%). Developing rapid diagnostics for antimicrobial susceptibility (59.5%) was perceived to be the most common challenge in implementing antimicrobial stewardship, with an improved understanding of regional epidemiology of AMR strains the most important factor to improve outcome (55.2%). Conclusions: AMR has significant perceived burden in chronic respiratory disease by healthcare professionals globally. However, current implementation of antimicrobial stewardship is limited, with significant challenges related to the availability of rapid diagnostics and understanding of regional epidemiology of AMR strains.Peer reviewe
U–Pb apatite geochronology shows multiple thermal overprints within the Neoarchean foreland basement of the Faroe–Shetland terrane
Get PDFThe Neoarchean foreland basement of the Faroe–Shetland terrane (FST) displays abundant evidence for isotopic resetting of U–Pb systems in apatite between c. 1800 and 200 Ma, interpreted to result from episodic heating pulses associated with regional-scale tectonic events. Major apparent age peaks of c. 1800–1600 Ma broadly correspond to the timing of Nagssugtoqidian–Laxfordian orogenesis >225 km further south. These are thought to reflect widespread heating during late- to post-orogenic delamination that affected a wide area of the orogenic foreland and resulted in a low to middle greenschist-facies static overprint, affecting much of the FST basement. Late- to post-orogenic delamination might also account for major apparent age peaks at c. 1300–1100, 800 and 500–400 Ma, corresponding to, respectively, Grenvillian, Knoydartian and Caledonian orogenic events. However, east-dipping seismic reflectors in the basement west of Shetland may represent the northward extension of the Grenvillian Outer Hebrides Thrust (Zone) and/or Caledonian thrusts and so perturbation of isotherms during west-directed thrusting could therefore also account for these apparent age peaks. Minor apparent age peaks of c. 700, 600, 350 and 200 Ma are most easily interpreted as resulting from enhanced heat flux that accompanied periods of crustal extension prior to and following the Caledonian orogeny.Peer reviewe
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