"Water, Water, Every Where": Nuances for a Water Industry Critical Infrastructure Specification Exemplar

The water infrastructure is critical to human life, but little attention has been paid to the nuances of the water industry. Without such attention, evaluating security innovation in this domain without compromising the productivity goals when delivering water services is difficult. This paper proposes four nuances that need to be incorporated into a representative specification exemplar for the water industry; these provided input to the exemplar based on a fictional water company

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

Background Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications. Methods We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC). Findings In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683–0·717]). Interpretation In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required. Funding British Journal of Surgery Society

Software engineering as the design theoretic transformation of software problems

Rogers characterises engineering as: ... the practice of organising the design and construction of any artifice which transforms the physical world around us to meet some recognised need. When the artifice is software, a key challenge is learn how to recon- cile the formal world of the computing machine and its software with the non-formal physical world around it. In this paper, we describe an approach that brings both non-formal and formal aspects of software en- gineering together within a single theoretical framework, which sees soft- ware engineering practice as recordable and re-playable design theoretic transformations of software problems. The framework permits the iden- tification and clarification of software requirements, the representation of the problem world into which the software solution will be delivered, and the construction of adequacy arguments for stake-holders. Designs are recordable and re-playable through our adaptation of tactics, a (now standard) form of programming language used in transformational proof theoretic presentations. This brings to our system many other benefits of such approaches, including the ability to abstract from a captured design, and to combine programmatically captured designs. This paper provides an example-driven presentation of our framework