Estimation of habitat quality based on plant community, and effects of isolation in a network of butterfly habitat patches

Minimum viable site networks are crucial for many threatened species but their design is always a difficult procedure. The present study investigated methods to estimate habitat quality of patches, in an ecological network for five butterfly species (Brenthis ino, Clossiana selene, Lycaena helle, Lycaena hippothoe, Proclossiana eunomia) inhabiting wet meadows. Abundance predictions were performed on the basis of botanical relevés with a multiple-species approach combining canonical correspondence analysis and multiple regression. Models are defined on a reference site set and are evaluated on a test site set. All the fitted models predicted the abundance of the butterfly species considerably well (from 61 to 86% of the variation). We evaluated the potential consequences of isolation on local populations, by comparing predicted and observed abundance. It was expected that greater differences would be observed when sites were more isolated. On the test set, differences between predicted and observed abundance were largely correlated to site isolation for L. helle and P. eunomia. The most isolated sites had greater chances to be empty, even if they had high-quality habitat. Reciprocally, when the sites were less isolated, the abundance observed was always greater than predicted, seeming to confirm the role of rescue effects. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved

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