No abstract

By taking into account the contributions of both locally and remotely generated internal tides, the tidal mixing in the Luzon Strait (LS) and the South China Sea (SCS) is investigated through internal-tide simulation and energetics analysis. A three-dimensional nonhydrostatic high-resolution model driven by four primary tidal constituents (M 2 , S 2 , K 1 , and O 1 ) is used for the internal-tide simulation. The baroclinic energy budget analysis reveals that the internal tides radiated from the LS are the dominant energy source for the tidal dissipation in the SCS. In the LS, the estimated depth-integrated turbulent kinetic energy dissipation exceeds O (1) and are at least one order of magnitude larger than those based solely on locally generated internal tides.

Background Remimazolam tosilate (HR7056, RT), a novel ultrashort-acting benzodiazepine, can be used for procedural sedation and general anaesthesia. However, few studies have focused on the sedative effect of RT during gastrointestinal endoscopy in elderly patients. The purpose of this study is to compare the sedative effect of RT and propofol for gastrointestinal endoscopy in elderly patients. Methods A total of 82 patients aged ≥65 years with an American Society of Anaesthesiologists (ASA) grade I-II and a body mass index (BMI) of 18.0 to 30.0 kg/m2 who were scheduled for gastrointestinal endoscopy from Jan 2021 to Aug 2021 were selected and randomly divided into a RT group and a propofol group. Alfentanil 5 μg/kg was used for analgesia in both groups. The RT group was given remimazolam tosilate 0.15 mg/kg with supplemental doses of 0.05 mg/kg as need, while the propofol group was given propofol 1.5 mg/kg with supplemental doses of 0.5 mg/kg. The supplemental doses were determined by the modified observational alertness/sedation assessment (MOAA/S) score and the patients’ body movements. Sedative effects, such as the time to loss of consciousness (LOC) (MOAA/S score ≤ 1), successful sedation in one dose, number of supplemental doses after successful induction, and recovery time, were evaluated. Sedation-related side effects, such as injection pain, haemodynamic events and respiratory depression, were also noted. Postoperative nausea and vomiting (PONV), visual analogue scale (VAS) scores at rest, remedial analgesics, and dizziness or headache were recorded. In addition, patients’ satisfaction and physician’s satisfaction of the procedure were compared between the two groups. Results Data from 77 patients were analysed. The success rate of sedation in both groups was 100%. The time to LOC (MOAA/S score ≤ 1) in the RT group was longer than that in the propofol group (20.7 ± 6.1s vs. 13.2 ± 5.2s, P < 0.001). There were fewer patients in the RT group reporting injection pain than that in the propofol group (0/39 vs. 5/38, P = 0.025). Haemodynamic events and respiratory depression in the RT group were less frequent than those in the propofol group ((6/39 vs. 17/38, P = 0.005), (2/39 vs. 9/38, P = 0.026), respectively). The number of supplemental doses after successful induction in the RT group was greater than that in the propofol group (4/9/11/13/1/1 vs. 8/4/18/6/2/0 requiring 0, 1, 2, 3, 4 or 5 supplemental doses, P = 0.014). The characteristics of the patients enrolled, postoperative parameters of the patients, and patients’ and physician’s satisfaction of the procedure were comparable in the two groups. Conclusions Compared with propofol, RT can be safely and effectively used for gastrointestinal endoscopy sedation in elderly patients, and the incidence of sedation-related adverse reactions, especially haemodynamic events and respiratory depression, is lower. When RT is used, the number of supplemental doses after successful induction may increase slightly. Trial registration Chictr.org.cn ChiCTR2000040498. Retrospectively registered (date of registration: December 1, 2020).

The current tuning process of parameters in global climate models is often performed subjectively or treated as an optimization procedure to minimize model biases based on observations. While the latter approach may provide more plausible values for a set of tunable parameters to approximate the observed climate, the system could be forced to an unrealistic physical state or improper balance of budgets through compensating errors over different regions of the globe. In this study, the Weather Research and Forecasting (WRF) model was used to provide a more flexible framework to investigate a number of issues related uncertainty quantification (UQ) and parameter tuning. The WRF model was constrained by reanalysis of data over the Southern Great Plains (SGP), where abundant observational data from various sources was available for calibration of the input parameters and validation of the model results. Focusing on five key input parameters in the new Kain-Fritsch (KF) convective parameterization scheme used in WRF as an example, the purpose of this study was to explore the utility of high-resolution observations for improving simulations of regional patterns and evaluate the transferability of UQ and parameter tuning across physical processes, spatial scales, and climatic regimes, which have important implications to UQ and parameter tuning in global and regional models. A stochastic important-sampling algorithm, Multiple Very Fast Simulated Annealing (MVFSA) was employed to efficiently sample the input parameters in the KF scheme based on a skill score so that the algorithm progressively moved toward regions of the parameter space that minimize model errors. <br><br> The results based on the WRF simulations with 25-km grid spacing over the SGP showed that the precipitation bias in the model could be significantly reduced when five optimal parameters identified by the MVFSA algorithm were used. The model performance was found to be sensitive to downdraft- and entrainment-related parameters and consumption time of Convective Available Potential Energy (CAPE). Simulated convective precipitation decreased as the ratio of downdraft to updraft flux increased. Larger CAPE consumption time resulted in less convective but more stratiform precipitation. The simulation using optimal parameters obtained by constraining only precipitation generated positive impact on the other output variables, such as temperature and wind. By using the optimal parameters obtained at 25-km simulation, both the magnitude and spatial pattern of simulated precipitation were improved at 12-km spatial resolution. The optimal parameters identified from the SGP region also improved the simulation of precipitation when the model domain was moved to another region with a different climate regime (i.e., the North America monsoon region). These results suggest that benefits of optimal parameters determined through vigorous mathematical procedures such as the MVFSA process are transferable across processes, spati...