To graze or gorge: consistency and flexibility of individual foraging tactics in tits.

An individual's foraging behaviour and time allocated to feeding have direct consequences for its fitness. Despite much research on population-level foraging decisions, few studies have investigated individual differences in fine-scale daily foraging patterns among wild animals. Here, we explore the consistency and plasticity of feeding tactics of individual great tits (Parus major) and blue tits (Cyanistes caeruleus), using a grid of 65 automated feeding stations in a 385-ha woodland, during three winters. We use a principal component analysis to describe individual variation in six feeding parameters and examine how these differences covary with dominance-linked attributes (species, age and sex), the personality trait 'exploration behaviour', distance to territory and local competition intensity. Analysis of 933 086 feeder visits by 3134 individuals revealed that the majority of variation in the timing of feeding was explained by two principal components. PC1 ('binge-eating'), accounting for 38% of variation, captured temporal clustering of feeding, with high repeatability both within and between years (r range: 0·42-0·55). PC2 ('transience'), accounting for 27% of variance, described how much individuals used feeders and was also repeatable (r: 0·34-0·62). While exhibiting consistent individual differences, birds also showed flexibility in foraging patterns, binge-eating less and using feeders more when they experienced greater local competition. Individuals in behaviourally dominant states (great tits, males and adults) binged more than subordinate birds (blue tits, females and juveniles) when their territories were distant from feeding stations. Moreover, great tits and males used feeders more than blue tits and females respectively, while birds feeding further from their territory used feeders less than those feeding closer. 'Exploration behaviour' was unrelated to both measures of daily foraging behaviour. This study presents some of the first evidence that birds use consistent alternative foraging tactics at a fine temporal scale. Individuals are consistent in their tactics, and also adjust their foraging behaviour with changes in local competition. Hence, studies of foraging behaviour should consider the extent to which such individual-level variability in foraging behaviour is under selection.

Nontuberculous Mycobacterium Infections Associated With Heater-Cooler Devices.

BACKGROUND: Disseminated nontuberculous mycobacterium infections have occurred following surgical procedures involving extracorporeal circulation; contaminated water from heater-cooler devices (HCDs) has been implicated as the source. The purpose of this review was to evaluate the public health concern and to educate physicians who care for this patient population. METHODS: The Food and Drug Administration Medical Device Reporting (MDR) database was queried for reports received between January 2010 and August 2016 for patient infections and device contaminations associated with the use of HCDs. Reports were reviewed for type of infection, patient demographics or outcome, reporting country, HCD manufacturer, and the time to event occurrence. RESULTS: A total of 339 MDR reports involving 99 facilities and 5 HCD manufacturers were found. MDR reports originated within (n = 154) and outside the United States (n = 185), and included 107 MDR reports describing patient infections involving at least 86 patients and 232 MDR reports describing HCD contamination without known patient infections. The MDR reports identified the surgical procedure in 94 reports and infection location in 83 reports. The time from surgical procedure using an HCD to infection diagnosis was calculable in 67 reports and was reported up to 60 months following the initial surgery. Nontuberculous mycobacterium was the most frequent organism identified, with M. chimaera being the predominate isolate. CONCLUSIONS: Nontuberculous mycobacterium infections associated with HCDs used during cardiothoracic surgery may have a long latency period and may be lethal. Cardiothoracic surgeon awareness or involvement in this issue is critical in helping to mitigate this emerging public health concern.

The role of social and ecological processes in structuring animal populations: a case study from automated tracking of wild birds.

Both social and ecological factors influence population process and structure, with resultant consequences for phenotypic selection on individuals. Understanding the scale and relative contribution of these two factors is thus a central aim in evolutionary ecology. In this study, we develop a framework using null models to identify the social and spatial patterns that contribute to phenotypic structure in a wild population of songbirds. We used automated technologies to track 1053 individuals that formed 73 737 groups from which we inferred a social network. Our framework identified that both social and spatial drivers contributed to assortment in the network. In particular, groups had a more even sex ratio than expected and exhibited a consistent age structure that suggested local association preferences, such as preferential attachment or avoidance. By contrast, recent immigrants were spatially partitioned from locally born individuals, suggesting differential dispersal strategies by phenotype. Our results highlight how different scales of social decision-making, ranging from post-natal dispersal settlement to fission-fusion dynamics, can interact to drive phenotypic structure in animal populations.

In vitro characterization of bicuspid aortic valve hemodynamics using particle image velocimetry.

The congenital bicuspid aortic valve (BAV) is associated with increased leaflet calcification, ascending aortic dilatation, aortic stenosis (AS) and regurgitation (AR). Although underlying genetic factors have been primarily implicated for these complications, the altered mechanical environment of BAVs could potentially accelerate these pathologies. The objective of the current study is to characterize BAV hemodynamics in an in vitro system. Two BAV models of varying stenosis and jet eccentricity and a trileaflet AV (TAV) were constructed from excised porcine AVs. Particle Image Velocimetry (PIV) experiments were conducted at physiological flow and pressure conditions to characterize fluid velocity fields in the aorta and sinus regions, and ensemble averaged Reynolds shear stress and 2D turbulent kinetic energy were calculated for all models. The dynamics of the BAV and TAV models matched the characteristics of these valves which are observed clinically. The eccentric and stenotic BAV showed the strongest systolic jet (V = 4.2 m/s), which impinged on the aortic wall on the non-fused leaflet side, causing a strong vortex in the non-fused leaflet sinus. The magnitudes of TKE and Reynolds stresses in both BAV models were almost twice as large as comparable values for TAV, and these maximum values were primarily concentrated around the central jet through the valve orifice. The in vitro model described here enables detailed characterization of BAV flow characteristics, which is currently challenging in clinical practice. This model can prove to be useful in studying the effects of altered BAV geometry on fluid dynamics in the valve and ascending aorta. These altered flows can be potentially linked to increased calcific responses from the valve endothelium in stenotic and eccentric BAVs, independent of concomitant genetic factors.