The OxVALVE population cohort study (OxVALVE-PCS)-population screening for undiagnosed valvular heart disease in the elderly: study design and objectives.

INTRODUCTION: Valvular heart disease (VHD) is an increasingly important cardiac condition, driven by an ageing population and lack of progress in the development of medical therapies. There is a dearth of accurate information to guide decision-makers in the development of strategies to combat VHD, and no population-based study has been performed specifically to investigate its contemporary epidemiology. This document describes the design and methodology of the OxVALVE population cohort study (OxVALVE-PCS), which was conceived to address this need. METHODS AND ANALYSIS: Participants aged 65 years and older attending a participating general practice in Oxfordshire, UK, are invited to attend a screening examination. Exclusion criteria include previously diagnosed VHD, inability to provide consent, terminal illness or excessive frailty. Demographics, a focused cardiovascular history and vital signs are recorded at the initial screening examination, accompanied by an echocardiogram. Any finding of significant VHD triggers a separate, more formal echocardiographic assessment (including acquisition of a three-dimensional dataset) and collection of blood samples for future genetic and biomarker analysis. Participants provide consent for longitudinal follow-up and enrolment in future cohort substudies. We also assess the acceptability of community-based echocardiographic examination and compare self-assessed quality of life between those with and without VHD. CONCLUSIONS: OxVALVE-PCS will provide contemporary epidemiological data concerning the community prevalence of undiagnosed VHD, facilitate accurate deployment of scarce resources to meet the anticipated increase in demand for VHD-associated healthcare and create a series of subcohorts with carefully defined genotypes and echocardiographic phenotypes for long overdue clinical studies. ETHICS AND DISSEMINATION: This study was approved by the local research ethics committee (Southampton, UK; REC Ref: 09/H0502/58). RESULTS: Results will be submitted for publication in peer-reviewed scientific journals

Social cognition by food-caching corvids. The western scrub-jay as a natural psychologist

Food-caching corvids hide food, but such caches are susceptible to pilfering by other individuals. Consequently, the birds use several counter strategies to protect their caches from theft, e.g. hiding most of them out of sight. When observed by potential pilferers at the time of caching, experienced jays that have been thieves themselves, take further protective action. Once the potential pilferers have left, they move caches those birds have seen, re-hiding them in new places. Naive birds that had no thieving experience do not do so. By focusing on the counter strategies of the cacher when previously observed by a potential pilferer, these results raise the intriguing possibility that re-caching is based on a form of mental attribution, namely the simulation of another bird's viewpoint. Furthermore, the jays also keep track of the observer which was watching when they cached and take protective action accordingly, thus suggesting that they may also be aware of others' knowledge states