Effect of bottom roughness on sediment transport due to streaming beneath linear propagating waves with an angle of attack on current

The effect of bottom roughness on sediment transport due to three-dimensional wave-induced streaming in the seabed boundary layer has been investigated for following and opposing linear propagating waves and current where the wave propagation forms a non-zero angle with the current. Visualizations are given by mean Eulerian wave-averaged suspended flux profiles, as well as the time series of bed shear stress over a wave period. The bedload transport rate along with suspended flux and total sediment transport rate have been presented. For linear propagating waves, the turbulence is induced by the Longuet-Higgins streaming and the classical wave-current interaction. Sediment transport is always in the wave propagation direction for the Longuet-Higgins streaming and increases with decreasing bottom roughness, or as the mean grain diameter decreases

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

3D Numerical Modelling of Sediment Transport under Current and Waves

The sediment transport module of REEF3D is used to calculate the scour and the deposition pattern for abutment, pier and contraction under constant discharge and for pier under waves. The time development of scour for all these cases is also observed. To this effect, the Reynolds-Averaged Navier Stokes (RANS) equations are solved in all three dimensions, making it fully three dimensional. The location of the free surface is represented using level set method. The eddy viscosity in the RANS equation is determined by the use of the two-equation k-? model and k-? model. Using the conservative finite-difference framework on a structured-staggered grid, convective terms of RANS equation is discretized with the fifth-order WENO scheme. The pressure gradient term in the RANS equation is modelled using Chorin´s projection method on a staggered grid. For the implementation of waves, the CFD code is used as a numerical wave tank. For the representation of the moveable sediment bed, the level set method is used. Kovacs and Parker and Dey formulations of bed shear stress reduction due to the sloping bed is implemented along with the sand slide algorithm to take care of erosion of individual bed cells. In the first case, the numerical model results are validated against the experimental findings of the abutment scour study done at Politecnico di Milano, Dept. I.I.A.R., Milan, Italy.. This test case is used as a benchmark for validation of the sediment transport module of REEF3D. The effect of the grid size, the turbulence model, the time discretization scheme, the formulations of critical shear stress for the sloping bed and porosity was observed and compared against the experimental results.. In the second configuration, the numerical model is used to predict the scour pattern around a circular pier. The scour pattern around the pier is compared against the experimental data of the hydraulic laboratory of the Technical University Darmstadt. The performance of the turbulence model and the formulations of critical shear stress for the sloping bed was observed. The numerical model is then tested for predicting a general contraction scour. The result is compared against the physical experiments of the contraction case conducted at the laboratories of the BAW (Federal Waterways Engineering and Research Institute), Karlsruhe, Germany. For the above mentioned three cases, a constant discharge at the boundary is used. The numerical model in the above configurations predict the general evolution (geometry, location and maximum scour depth) and time development of the scour hole accurately. In the final configuration, 3D local scour around a vertical pile under waves is modelled. The numerical result is first compared with theoretical observations and then validated against the pier scour experiments conducted in the Department of Hydrodynamics and Water Resources (ISVA), Technical University of Denmark by Sumer and Fredsoe. The effect of the variation of the sediment time stepping with the decoupling of the hydrodynamic and the morphodynamic time step is tested. The numerical model shows good agreement with the experiment and theoretical erosion and deposition pattern. The de-coupled approach for the simulation of hydrodynamic and sediment transport processes is found to be a reasonable assumption.COMEMHydraulic EngineeringCivil Engineering and Geoscience

Assessment of morphological and molecular variability of some Solanum melongena L. cultivars and wild Solanum incanum L. in Saudi Arabia

The genus Solanum exhibits a wide range of variability in morphology, flavor, and tolerance to biotic and abiotic stresses. Phenotypic and genetic variability using ISSR and RAPD markers of Solanum incanum distributed in Al-Baha province of the Kingdom of Saudi Arabia is assessed. Thirty samples are representing three different locations: Baljershy, Aqeeq, and Tohama, besides twenty-five samples representing five different commercial cultivars tested. Growth type, the number of leaves per plant, fruit size (phenotypic traits), crude protein, carbohydrates, digestive organic matter, and Mg, Ca, P were the principal contributors in the PCA. Molecular analysis showed that 114 ISSR and 80 RAPD alleles with a 100% polymorphism were recorded. The polymorphism information content (PIC) values ranged from 0.84 to 0.91 for ISSR and from 0.59 to 0.89 for RAPD data. Similarity values ranged from 0.16 to 1.00, with an average of 0.47 for ISSR and from 0.01 to 0.97, with an average of 0.36 for RAPD. It resulted in a positive and significant correlation between morphological, molecular, nutritional, and chemical analysis of fruits using Mantel analysis. UPGMA and PCA for morphological traits and molecular data discriminated commercial cultivars and wild relatives. Solanum incanum was more diverse than commercial varieties. This study revealed a wide genetic diversity among and within collected eggplant accessions and may use in breeding programs of eggplants. There is a need to increase the present eggplant collection to widen the genetic diversity of cultivated eggplant varieties in Saudi Arabia

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population

Additional file 4 of Mapping age- and sex-specific HIV prevalence in adults in sub-Saharan Africa, 2000–2018

Additional file 4: Supplemental results.1. README. 2. Prevalence range across districts. 3. Prevalence range between sexes. 4. Prevalence range between ages. 5. Age-specific district ranges