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

On The Automation of Agency in Algorithmic Music Composition

A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Special Case Doctor of Philosophy in Interdisciplinary Sutdies, University of Regina. xi, 335 p.This thesis, and the artworks that accompany it, are the products of my Special Case, Interdisciplinary PhD program. The program allowed me to develop artworks where programmable computers are granted agency over music structure, contrasting with my prior composing practice centred on digital audio workstations and linear scores. Here I seek bridges between my established practice of linear composition and those where algorithm-design facilitates interactivity, nonlinearity, and contact be- tween human agents through innovative computer-based interfaces. I establish three types of contribution: one third my contribution to computer science, one third the artworks which I developed, and one third my critical re ection on the process. This re ection centres on my creative methodology, and ve main artistic works. These artworks include an original album of songs written from the perspective of hypo- thetical future, arti cially-intelligent machines, three exploratory interactive digital works, and a nal major project called \Shards of Memory," a composition in the form of a smartphone app. This body of work has emerged from my e orts to bal- ance the compositional a ordances of programming code with my desire to facilitate the authentic expression of human agents, including myself. I chart my traversal of an interdisciplinary borderland between music composition and computer science, and uncover fertile territories where interdisciplinary artists may challenge musical conventions by using programming languages as compositional media supporting an interplay of multiple agencies. I conclude by arguing that interdisciplinary algorithmic composers are on the vanguard of an evolution of music, and that the chronological evolution of my own doctoral work as an example of how a composer's practice may be transformed and energized by exerting composerly agency through acts of coding.Studentye

The Enumeration of 2,4-D Degraders in Saskatchewan Soils

Different Saskatchewan soils were studied to determine their populations of 2,4-D [(2,4-dichlorophenoxy) acetic acid] degraders and gross aerobic bacteria. Soil from Indian Head field plots receiving relatively high field rates (1.12 or 1.68 kg/ha) of 2,4-D amine or ester applied annually over the previous 32 yr contained the highest population of degraders, ranging from 103 to 104 degraders/g soil. Control plots recorded lower populations of degraders (2.5 ± 0.5 × 103 degraders/g soil). Five soils from around the province were also studied, and a relationship was found between the rate of breakdown of 14C-2,4-D in the soil and the number of degraders. Another soil from a different site at Indian Head, but of a similar type to that in the field plots, displayed a much slower rate of 2,4-D degradation and also a much lower degrader population (7 ± 2 degraders/g soil) when compared to the other four soils (4 × 102 to 9 × 102 degraders/g soil). The ratio of degraders to the total bacterial flora varied in all studies between 1:6.5 × 102 and 1:3 × 105. When 1030 soil isolates were screened for their ability to degrade 2,4-D using an agar-block extraction technique, none possessed this feature. This would support the hypothesis that the ratio of 2,4-D degraders to the total microbial flora was indeed large (at least 1:103).</jats:p

Adsorption of Cadmium from Aqueous Solutions by Edible Mushrooms (Agaricus bisporus and Lentinus edodes)

Abstract Fungal organisms can remove heavy metals from aqueous solutions. Macro fungi such as Agaricus bisporus and Lentinus edodes (shiitake), commonly called mushrooms, are edible and are grown commercially. Laboratory batch studies were conducted at room temperature (21 ± 1°C) to determine the potential of these fungal biomasses for adsorption of cadmium from aqueous solutions containing 1 mg/L cadmium. Results from batch studies showed that biomasses prepared from A. bisporus and L. edodes had good potential for removing cadmium from aqueous solutions. The maximum adsorption capacity of A. bisporus and L. edodes for uptake of cadmium from aqueous solutions was 2.08 and 0.716 mg/g, respectively. The equilibrium time for adsorption was found to be 6 and 1 h for A. bisporus and L. edodes, respectively. 68% cadmium removal was achieved with A. bisporus and 45% with L. edodes. The optimum initial pH was found to be 6.0 and 5.0 for A. bisporus and L. edodes, respectively. Isotherm studies suggested that cadmium adsorption by both the mushrooms followed the Freundlich isotherm. Desorption of cadmium from mushrooms by dilute HCl was minimal (19%), but rapid.</jats:p