Prespawning herring distribution in the Irish Celtic Sea between 2005 and 2012

Knowledge of the spatial distribution of species is fundamental to understanding trophic interactions and ecosystem structure. Intraspecies-specific dynamics and environmental factors shape species distribution within an ecosystem. Distribution patterns and the realized habitat of Atlantic herring (Clupea harengus), a key fish species in the Celtic Sea, were examined using distribution data collected during annual acoustic stock assessment surveys during 2005-2012. Distribution patterns during migration to spawning grounds were analysed using geostatistical methods, including modelling of variograms and comparing the centre of gravity (CG). Distribution patterns were further linked to oceanographic variables collected with the acoustic data to describe habitat. Herring density was greatest inshore along the spawning grounds and lower farther offshore. Herring shoals were clustered and randomly distributed during spawning migration. Variograms of fish densities described the global structure, with high local variability of the same order of magnitude as variability at a regional scale, indicating that no continuous structure can be found within the study area. The CG values showed that the average position of the population was located northeast. The realized habitat for herring encompassed a wide range of temperatures and salinities; therefore, oceanographic features were not a limiting factor for herring distribution during spawning migration. The present study changes the perception of the spatial distribution of the Celtic Sea herring stock from a more continuous distribution to a discrete model, with implications for trophic ecosystem modelling on local scales. Future studies of herring distribution and its influence within the Celtic Sea ecosystem would benefit from using the approach employed in the present study for analysing aggregation patterns

COVID-19 and pneumothorax: a multicentre retrospective case series.

INTRODUCTION: Pneumothorax and pneumomediastinum have both been noted to complicate cases of coronavirus disease 2019 (COVID-19) requiring hospital admission. We report the largest case series yet described of patients with both these pathologies (including nonventilated patients). METHODS: Cases were collected retrospectively from UK hospitals with inclusion criteria limited to a diagnosis of COVID-19 and the presence of either pneumothorax or pneumomediastinum. Patients included in the study presented between March and June 2020. Details obtained from the medical record included demographics, radiology, laboratory investigations, clinical management and survival. RESULTS: 71 patients from 16 centres were included in the study, of whom 60 had pneumothoraces (six with pneumomediastinum in addition) and 11 had pneumomediastinum alone. Two of these patients had two distinct episodes of pneumothorax, occurring bilaterally in sequential fashion, bringing the total number of pneumothoraces included to 62. Clinical scenarios included patients who had presented to hospital with pneumothorax, patients who had developed pneumothorax or pneumomediastinum during their inpatient admission with COVID-19 and patients who developed their complication while intubated and ventilated, either with or without concurrent extracorporeal membrane oxygenation. Survival at 28 days was not significantly different following pneumothorax (63.1±6.5%) or isolated pneumomediastinum (53.0±18.7%; p=0.854). The incidence of pneumothorax was higher in males. 28-day survival was not different between the sexes (males 62.5±7.7% versus females 68.4±10.7%; p=0.619). Patients aged ≥70 years had a significantly lower 28-day survival than younger individuals (≥70 years 41.7±13.5% survival versus <70 years 70.9±6.8% survival; p=0.018 log-rank). CONCLUSION: These cases suggest that pneumothorax is a complication of COVID-19. Pneumothorax does not seem to be an independent marker of poor prognosis and we encourage continuation of active treatment where clinically possible

Structural investigation of weak intermolecular interactions (Hydrogen and Halogen Bonds) in fluorine-substituted benzimidazoles

The structures of five fluorinated benzimidazoles and one intermediate (an open double amide) have been determined by X-ray crystallography. In the analysis of these heterocycles, particular attention has been paid to N-H⋯H hydrogen bonds and to fluorine-fluorine intermolecular contacts. Thus, one of the shortest F⋯F distances ever reported, 2.596(3) Å, has been observed in 4,5,6,7-tetrafluoro-1H-benzimidazole-2(3H)-one. The 13C, 15N, and 19F solid-state NMR data for all benzimidazoles are also given.Peer Reviewe