14 research outputs found
Adjoint of the global Eulerian-Lagrangian coupled atmospheric transport model (A-GELCA v1.0): development and validation
We present the development of the Adjoint of the Global EulerianâLagrangian Coupled Atmospheric (A-GELCA) model that consists of the National Institute for Environmental Studies (NIES) model as an Eulerian three-dimensional transport model (TM), and FLEXPART (FLEXible PARTicle dispersion model) as the Lagrangian Particle Dispersion Model (LPDM). The forward tangent linear and adjoint components of the Eulerian model were constructed directly from the original NIES TM code using an automatic differentiation tool known as TAF (Transformation of Algorithms in Fortran; http://www.FastOpt.com), with additional manual pre- and post-processing aimed at improving transparency and clarity of the code and optimizing the performance of the computing, including MPI (Message Passing Interface). The Lagrangian component did not require any code modification, as LPDMs are self-adjoint and track a significant number of particles backward in time in order to calculate the sensitivity of the observations to the neighboring emission areas. The constructed Eulerian adjoint was coupled with the Lagrangian component at a time boundary in the global domain. The simulations presented in this work were performed using the A-GELCA model in forward and adjoint modes. The forward simulation shows that the coupled model improves reproduction of the seasonal cycle and short-term variability of CO2. Mean bias and standard deviation for five of the six Siberian sites considered decrease roughly by 1 ppm when using the coupled model. The adjoint of the Eulerian model was shown, through several numerical tests, to be very accurate (within machine epsilon with mismatch around to ±6 eâ14) compared to direct forward sensitivity calculations. The developed adjoint of the coupled model combines the flux conservation and stability of an Eulerian discrete adjoint formulation with the flexibility, accuracy, and high resolution of a Lagrangian backward trajectory formulation. A-GELCA will be incorporated into a variational inversion system designed to optimize surface fluxes of greenhouse gases
Healing and Ritual Imagination in Chinese Medicine: The Multiple Interpretations of Zhuyou
In the Chinese medical corpus, ritual healing largely fell under the rubric of zhuyou ç„ç± to uncover and expel the unknown, imperceptible, and occult causes of illness. Often dealing with uncertain or incurable cases, zhuyou remained at the cutting-edge of contemporary medicine. For a rising medical elite after the Northern Song, zhuyou was the branch of medicine to flexibly incorporate and critique the variety of ritual therapies into orthodox practice. Zhuyou employed prayer, incantations, talismans, gestures, and drugs in a nuanced clinical encounter to reveal the hidden root of disorder ranging from a blockage of qi, spirit possession, emotional imbalance, or loss of virtue. These rituals opened an imaginative space for therapeutic play where patients and healers could use spiritual proxies and props to address difficult emotions or issues that were often the hidden cause of affliction. The development of zhuyou also reflected the changing role of ritual in the history of Chinese medicine and the exchanges among physicians, Daoist priests, and other ritual healers. The significance of ritual in Chinese medical history has largely remained unclear as most editions of medical classics republished since the early twentieth century excise relevant chapters and zhuyou manuscripts, until recently, were uncatalogued
Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system
We estimated the CH4 budget in Finland for 2004?2014 using the CTE-CH4 data assimilation system with an extended atmospheric CH4 observation network of seven sites from Finland to surrounding regions (HyytiÀlÀ, Kj?lnes, Kumpula, Pallas, Puijo, SodankylÀ, and Utö). The estimated average annual total emission for Finland is 0.6?±?0.5 Tg CH4 yr?1. Sensitivity experiments show that the posterior biospheric emission estimates for Finland are between 0.3 and 0.9 Tg CH4 yr?1, which lies between the LPX-Bern-DYPTOP (0.2 Tg CH4 yr?1) and LPJG-WHyMe (2.2 Tg CH4 yr?1) process-based model estimates. For anthropogenic emissions, we found that the EDGAR v4.2 FT2010 inventory (0.4 Tg CH4 yr?1) is likely to overestimate emissions in southernmost Finland, but the extent of overestimation and possible relocation of emissions are difficult to derive from the current observation network. The posterior emission estimates were especially reliant on prior information in central Finland. However, based on analysis of posterior atmospheric CH4, we found that the anthropogenic emission distribution based on a national inventory is more reliable than the one based on EDGAR v4.2 FT2010. The contribution of total emissions in Finland to global total emissions is only about 0.13%, and the derived total emissions in Finland showed no trend during 2004?2014. The model using optimized emissions was able to reproduce observed atmospheric CH4 at the sites in Finland and surrounding regions fairly well (correlation > 0.75, biasPeer reviewe
Global methane emission estimates for 2000â2012 from CarbonTracker Europe-CH4 v1.0
We present a global distribution of surface
methane (CH4) emission estimates for 2000â2012 derived
using the CarbonTracker Europe-CH4 (CTE-CH4) data assimilation system. In CTE-CH4, anthropogenic and biospheric CH4 emissions are simultaneously estimated based
on constraints of global atmospheric in situ CH4 observations. The system was configured to either estimate only
anthropogenic or biospheric sources per region, or to estimate both categories simultaneously. The latter increased
the number of optimizable parameters from 62 to 78. In
addition, the differences between two numerical schemes
available to perform turbulent vertical mixing in the atmospheric transport model TM5 were examined. Together,
the system configurations encompass important axes of uncertainty in inversions and allow us to examine the robustness of the flux estimates. The posterior emission estimates are further evaluated by comparing simulated atmospheric CH4 to surface in situ observations, vertical profiles of CH4 made by aircraft, remotely sensed dry-air total column-averaged mole fraction (XCH4) from the Total
Carbon Column Observing Network (TCCON), and XCH4
from the Greenhouse gases Observing Satellite (GOSAT).
The evaluation with non-assimilated observations shows that
posterior XCH4 is better matched with the retrievals when
the vertical mixing scheme with faster interhemispheric exchange is used. Estimated posterior mean total global emissions during 2000â2012 are 516 ± 51 Tg CH4 yrâ1
, with an
increase of 18 Tg CH4 yrâ1
from 2000â2006 to 2007â2012.
The increase is mainly driven by an increase in emissions
from South American temperate, Asian temperate and Asian
tropical TransCom regions. In addition, the increase is hardly
sensitive to different model configurations (< 2 Tg CH4 yrâ1
difference), and much smaller than suggested by EDGAR
v4.2 FT2010 inventory (33 Tg CH4 yrâ1
), which was used
for prior anthropogenic emission estimates. The result is in
good agreement with other published estimates from inverse
modelling studies (16â20 Tg CH4 yrâ1
). However, this study
could not conclusively separate a small trend in biospheric
emissions (â5 to +6.9 Tg CH4 yrâ1
) from the much larger
trend in anthropogenic emissions (15â27 Tg CH4 yrâ1
). Finally, we find that the global and North American CH4 balance could be closed over this time period without the previously suggested need to strongly increase anthropogenic
CH4 emissions in the United States. With further developments, especially on the treatment of the atmospheric CH4
sink, we expect the data assimilation system presented here
will be able to contribute to the ongoing interpretation of
changes in this important greenhouse gas budget.peer-reviewe
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28â2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65â3·22], p\textless0·0001), American Society of Anesthesiologists grades 3â5 versus grades 1â2 (2·35 [1·57â3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01â2·39], p=0·046), emergency versus elective surgery (1·67 [1·06â2·63], p=0·026), and major versus minor surgery (1·52 [1·01â2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Global methane emission estimates for 2000â2012 from CarbonTracker Europe-CH<sub>4</sub> v1.0
We present a global distribution of surface methane (CH4) emission estimates for 2000â2012 derived using the CarbonTracker Europe-CH4 (CTE-CH4) data assimilation system. In CTE-CH4, anthropogenic and biospheric CH4 emissions are simultaneously estimated based on constraints of global atmospheric in situ CH4 observations. The system was configured to either estimate only anthropogenic or biospheric sources per region, or to estimate both categories simultaneously. The latter increased the number of optimizable parameters from 62 to 78. In addition, the differences between two numerical schemes available to perform turbulent vertical mixing in the atmospheric transport model TM5 were examined. Together, the system configurations encompass important axes of uncertainty in inversions and allow us to examine the robustness of the flux estimates. The posterior emission estimates are further evaluated by comparing simulated atmospheric CH4 to surface in situ observations, vertical profiles of CH4 made by aircraft, remotely sensed dry-air total column-averaged mole fraction (XCH4) from the Total Carbon Column Observing Network (TCCON), and XCH4 from the Greenhouse gases Observing Satellite (GOSAT). The evaluation with non-assimilated observations shows that posterior XCH4 is better matched with the retrievals when the vertical mixing scheme with faster interhemispheric exchange is used. Estimated posterior mean total global emissions during 2000â2012 are 516âŻÂ±âŻ51âŻTg CH4âŻyrâ1, with an increase of 18âŻTg CH4âŻyrâ1 from 2000â2006 to 2007â2012. The increase is mainly driven by an increase in emissions from South American temperate, Asian temperate and Asian tropical TransCom regions. In addition, the increase is hardly sensitive to different model configurations (â<ââŻ2âŻTg CH4âŻyrâ1 difference), and much smaller than suggested by EDGAR v4.2 FT2010 inventory (33âŻTg CH4âŻyrâ1), which was used for prior anthropogenic emission estimates. The result is in good agreement with other published estimates from inverse modelling studies (16â20âŻTg CH4âŻyrâ1). However, this study could not conclusively separate a small trend in biospheric emissions (â5 to +6.9âŻTg CH4âŻyrâ1) from the much larger trend in anthropogenic emissions (15â27âŻTg CH4âŻyrâ1). Finally, we find that the global and North American CH4 balance could be closed over this time period without the previously suggested need to strongly increase anthropogenic CH4 emissions in the United States. With further developments, especially on the treatment of the atmospheric CH4 sink, we expect the data assimilation system presented here will be able to contribute to the ongoing interpretation of changes in this important greenhouse gas budget
Growth Rate, Seasonal, Synoptic, Diurnal Variations and Budget of Methane in the Lower Atmosphere
We have used an AGCM (atmospheric general circulation model)-based Chemistry Transport Model (ACTM) for the simulation of methane (CH4) in the height range of earthâs surface to about 90 km. The model simulations are compared with measurements at hourly, daily, monthly and interannual time scales by filtering or
averaging all the timeseries appropriately. From this model-observation comparison, we conclude that the recent
(1990â2006) trends in growth rate and seasonal cycle at most measurement sites can be fairly successfully modeled
by using existing knowledge of CH4 flux trends and seasonality. A large part of the interannual variability
(IAV) in CH4 growth rate is apparently controlled by IAV in atmospheric dynamics at the tropical sites and forest
fires in the high latitude sites. The flux amplitudes are optimized with respect to the available hydroxyl radical (OH) distribution and model transport for successful reproduction of latitudinal and longitudinal distribution of observed CH4 mixing ratio at the earthâs surface