It is widely believed that male mammals have better spatial ability than females. A large number of evolutionary hypotheses have been proposed to explain these differences, but few species have been tested. The authors critically review the proposed evolutionary explanations for sex differences in spatial cognition and conclude that most of the hypotheses are either logically flawed or, as yet, have no substantial support. Few of the data exclusively support or exclude any current hypotheses. The hypothesis with the strongest support proposes that range size was the selection pressure that acted to increase spatial ability. The authors suggest ways in which these hypotheses could be tested by presenting explicit predictions and suggesting suitable test species or conditions.

SUMMARY1. Foetal and maternal plasma catecholamine concentrations were measured during and after hypoxia (mean maternal P.,02 44 mmHg) in chronically catheterized sheep, 118-141 days pregnant.2. In most foetuses the initial plasma catecholamines were < 007 ng/ml.During hypoxia plasma adrenaline and noradrenaline always rose; there was a rise in arterial pressure and a fall in heart rate.3. The initial catecholamine concentration in the ewes was < 005-2-3 ng/ml. During hypoxia there was no consistent change; the maternal plasma concentrations were less than the foetal.4. Infusion of adrenaline at 03 ,tg kg-1 min-to the ewe resulted in plasma catecholamine concentrations higher than those observed during hypoxia. There was a rise in heart rate but no consistent change in arterial pressure.5. Infusion of adrenaline 04 jug kg-1 min-' into the foetal jugular vein caused a rise in plasma concentration similar to that seen during hypoxia. There was a rise in heart rate but no significant change in arterial pressure.6. The half-life of adrenaline and of noradrenaline in the maternal and foetal circulation was 0-25-1 min. There was no evidence of transfer of labelled catecholamine across the placenta.

The status of pollinating insects is of international concern, but knowledge of the magnitude and extent of declines is limited by a lack of systematic monitoring. Standardized protocols are urgently needed, alongside a better understanding of how different methods and recorders (data collectors) influence estimates of pollinator abundance and diversity. We compared two common methods for sampling wild pollinating insects (solitary bees, bumblebees and hoverflies), pan traps and transects, in surveys of 1 km countryside squares (agricultural and semi‐natural habitats) and flowering crop fields across Great Britain, including the influence of local floral resources (nectar sugar availability or crop flower density) on the insects sampled. Further, we compared the performance of recorders with differing expertise (non‐specialist research staff, taxonomic experts and non‐expert volunteers) in applying methods. Pan traps and transects produced compositionally distinct samples of pollinator communities. In the wider countryside, pan traps sampled more species of solitary bee and hoverfly. In flowering crops, transects recorded a greater number of individual bumblebees, but fewer species. Across all taxonomic groups and countryside and crop samples, transects generally had lower rates of species accumulation per individual collected than pan traps. This demonstrates that differences between methods in estimating richness are not due to sampling effort alone. However, recorders possessing greater taxonomic expertise can produce species accumulation data from transects that are almost commensurate with pan trapping. The abundance and species richness of pollinators (except solitary bees) on transects in the wider countryside was positively related to the availability of estimated nectar sugar. In crops, pollinator abundance responses to flower densities were idiosyncratic according to crop type, but overall the response was positive and negative for transects and pan traps, respectively. Given these taxonomic and context‐specific differences in method performance, we assess their suitability for monitoring pollinating insect communities and pollination services. We discuss the relevance of these findings within the context of achieving standardized, large‐scale monitoring of pollinating insects.

Earplugs and eye masks are a useful adjunct to strategies promoting sleep in critical care areas.

Background Chest x-rays are widely used in clinical practice; however, interpretation can be hindered by human error and a lack of experienced thoracic radiologists. Deep learning has the potential to improve the accuracy of chest x-ray interpretation. We therefore aimed to assess the accuracy of radiologists with and without the assistance of a deeplearning model. MethodsIn this retrospective study, a deep-learning model was trained on 821 681 images (284 649 patients) from five data sets from Australia, Europe, and the USA. 2568 enriched chest x-ray cases from adult patients (≥16 years) who had at least one frontal chest x-ray were included in the test dataset; cases were representative of inpatient, outpatient, and emergency settings. 20 radiologists reviewed cases with and without the assistance of the deep-learning model with a 3-month washout period. We assessed the change in accuracy of chest x-ray interpretation across 127 clinical findings when the deep-learning model was used as a decision support by calculating area under the receiver operating characteristic curve (AUC) for each radiologist with and without the deep-learning model. We also compared AUCs for the model alone with those of unassisted radiologists. If the lower bound of the adjusted 95% CI of the difference in AUC between the model and the unassisted radiologists was more than -0•05, the model was considered to be non-inferior for that finding. If the lower bound exceeded 0, the model was considered to be superior. Findings Unassisted radiologists had a macroaveraged AUC of 0•713 (95% CI 0•645-0•785) across the 127 clinical findings, compared with 0•808 (0•763-0•839) when assisted by the model. The deep-learning model statistically significantly improved the classification accuracy of radiologists for 102 (80%) of 127 clinical findings, was statistically non-inferior for 19 (15%) findings, and no findings showed a decrease in accuracy when radiologists used the deeplearning model. Unassisted radiologists had a macroaveraged mean AUC of 0•713 (0•645-0•785) across all findings, compared with 0•957 (0•954-0•959) for the model alone. Model classification alone was significantly more accurate than unassisted radiologists for 117 (94%) of 124 clinical findings predicted by the model and was non-inferior to unassisted radiologists for all other clinical findings. Interpretation This study shows the potential of a comprehensive deep-learning model to improve chest x-ray interpretation across a large breadth of clinical practice. Funding Annalise.ai.

No abstract

SUMMARY1. The extent to which the adrenal gland contributes to neuroendocrine responses to electrical stimulation of the peripheral end of the splanchnic nerve has been investigated in conscious calves in which the right nerve was stimulated either at 4 Hz continuously for 10 min or at 40 Hz in 1 s bursts at 10 s intervals for the same period.2. It was confirmed that the release of neuropeptide Y (NPY) and of gastrinreleasing peptide (GRP) is potentiated by stimulation in bursts at a relatively high frequency and shown that the adrenal gland made a negligible contribution to these responses.3. There was no detectable change in the concentration of vasoactive intestinal peptide (VIP) in the arterial plasma but the existence of a very small but highly significant rise in the output of VIP from the adrenal provided evidence that it was released within the gland in response to splanchnic nerve stimulation.4. The concentration of calcitonin gene-related peptide (CGRP) in the arterial and adrenal venous effluent plasma was consistently below the level of detection of the assay.5. Splanchnic nerve stimulation resulted in an abrupt rise in the output of both free and total met5-enkephalin-like immunoreactivity from the adrenal gland which was substantially potentiated by stimulating in bursts. This pattern of stimulation also increased the proportion released in a high-molecular-weight form.6. Stimulation in bursts significantly enhanced the output of both adrenaline and noradrenaline from the adrenal and resulted in the release of proportionately more noradrenaline. Small amounts of dopamine and DOPAC were also released during splanchnic nerve stimulation and the output of dopamine was significantly increased by stimulating in bursts.7. Both patterns of stimulation elicited an abrupt rise in mean plasma adrenocorticotrophic hormone (ACTH) concentration, which was associated with an increase in mean adrenal cortisol output and the former effect was significantly enhanced by stimulating in bursts.

Biological invasions are facilitated by the global transportation of species and climate change. Given that invasions may cause ecological and economic damage and pose a major threat to biodiversity, understanding the mechanisms behind invasion success is essential.Both the release of non-native populations from natural enemies, such as parasites, and the genetic diversity of these populations may play key roles in their invasion success.We investigated the roles of parasite communities, through enemy release and parasite acquisition, and genetic diversity in the invasion success of the non-native bumblebee, Bombus hypnorum, in the United Kingdom.The invasive B. hypnorum had higher parasite prevalence than most, or all native congeners for two high-impact parasites, probably due to higher susceptibility and parasite acquisition. Consequently parasites had a higher impact on B. hypnorum queens’ survival and colony-founding success than on native species. Bombus hypnorum also had lower functional genetic diversity at the sex-determining locus than native species. Higher parasite prevalence and lower genetic diversity have not prevented the rapid invasion of the United Kingdom by B. hypnorum. These data may inform our understanding of similar invasions by commercial bumblebees around the world.This study suggests that concerns about parasite impacts on the small founding populations common to re-introduction and translocation programs may be less important than currently believed.