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

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

An explicit nonstandard finite difference scheme for the Allen–Cahn equation

We design explicit nonstandard finite difference schemes for the nonlinear Allen-Cahn reaction diffusion equation in the limit of very small interaction length ". In the proposed scheme, the perturbation parameter is part of the argument of the functional step size, thereby minimis- ing the restrictions normally associated with standard explicit finite difference schemes. The derivation involves splitting the equation into the space independent and the time independent different models. An exact nonstandard scheme is proposed for the space independent model and energy conservative schemes are proposed for the time independent model. We show the power of the derived scheme over the existing schemes through several numerical examples.South African DST/NRF SARChI Chair on Mathematical Models and Methods in Bioengineering and Biosciences (M3B2).http://www.tandfonline.com/loi/gdea202016-07-31hb201

On a fractional step-splitting scheme for the Cahn-Hilliard equation

PURPOSE – For a partial differential equation with a fourth-order derivative such as the Cahn-Hilliard equation, it is always a challenge to design numerical schemes that can handle the restrictive time step introduced by this higher order term. The purpose of this paper is to employ a fractional splitting method to isolate the convective, the nonlinear second-order and the fourth-order differential terms. DESIGN / METHODOLOGY / APPROACH – The full equation is then solved by consistent schemes for each differential term independently. In addition to validating the second-order accuracy, the authors will demonstrate the efficiency of the proposed method by validating the dissipation of the Ginzberg-Lindau energy and the coarsening properties of the solution. FINDINGS – The scheme is second-order accuracy, the authors will demonstrate the efficiency of the proposed method by validating the dissipation of the Ginzberg-Lindau energy and the coarsening properties of the solution. ORIGINALITY / VALUE – The authors believe that this is the first time the equation is handled numerically using the fractional step method. Apart from the fact that the fractional step method substantially reduces computational time, it has the advantage of simplifying a complex process efficiently. This method permits the treatment of each segment of the original equation separately and piece them together, in a way that will be explained shortly, without destroying the properties of the equation.http://www.emeraldinsight.com/loi/echb201

MAPPING HIGH-ANGLE BASEMENT FAULTS IN THE MIDDLE BENUE TROUGH, NIGERIA FROM GRAVITY INVERSION SURFACE

High-angle faults appear as vertical off-sets on a topographic surface including that derived through the inversion of gravity data. In this study of the middle Benue trough, Nigeria, gravity data for the area was bandpass filtered and inverted to generate a topographic surface map of the basement. Furthermore, a topographic slope surface map was produced by calculating the horizontal gradient magnitude over the surface. An automatic method was used to scan the horizontal gradient magnitude grid to identify maxima whose loci were mapped as high-angle faults in the basement.Three major NE-SW trending faults of regional dimension were identified. There are also shorter but significant NW-SE trendingfaults. The NE-SW and NW-SE sets are interpreted as conjugate pairs within the fracture system of the Nigerian Basement Complex.In places, segments of these faults represent bounding faults enclosing the four major sub-basins which were identifiedaround Bashar, Mutum Biyu, Wukari and Lafia

Mapping high-angle basement faults in the middle benue trough, nigeria from gravity inversion surface

High-angle faults appear as vertical off-sets on a topographic surface including that derived through the inversion of gravity data. In this study of the middle Benue trough, Nigeria, gravity data for the area was bandpass filtered and inverted to generate a topographic surface map of the basement. Furthermore, a topographic slope surface map was produced by calculating the horizontal gradient magnitude over the surface. An automatic method was used to scan the horizontal gradient magnitude grid to identify maxima whose loci were mapped as high-angle faults in the basement.Three major NE-SW trending faults of regional dimension were identified. There are also shorter but significant NW-SE trendingfaults. The NE-SW and NW-SE sets are interpreted as conjugate pairs within the fracture system of the Nigerian Basement Complex.In places, segments of these faults represent bounding faults enclosing the four major sub-basins which were identifiedaround Bashar, Mutum Biyu, Wukari and Lafia