Pyogenic abdominal wall and psoas abscesses in children

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Habitat stability, predation risk and 'memory syndromes'

ArticleThis is the author's accepted version. The article has been published Open Access and is available at http://www.nature.com/srep/2015/150527/srep10538/full/srep10538.htmlCopyright © 2015 Macmillan Publishers Limited. All Rights Reserved.Habitat stability and predation pressure are thought to be major drivers in the evolutionary maintenance of behavioural syndromes, with trait covariance only occurring within specific habitats. However, animals also exhibit behavioural plasticity, often through memory formation. Memory formation across traits may be linked, with covariance in memory traits (memory syndromes) selected under particular environmental conditions. This study tests whether the pond snail, Lymnaea stagnalis, demonstrates consistency among memory traits (‘memory syndrome’) related to threat avoidance and foraging. We used eight populations originating from three different habitat types: i) laboratory populations (stable habitat, predator-free); ii) river populations (fairly stable habitat, fish predation); and iii) ditch populations (unstable habitat, invertebrate predation). At a population level, there was a negative relationship between memories related to threat avoidance and food selectivity, but no consistency within habitat type. At an individual level, covariance between memory traits was dependent on habitat. Laboratory populations showed no covariance among memory traits, whereas river populations showed a positive correlation between food memories, and ditch populations demonstrated a negative relationship between threat memory and food memories. Therefore, selection pressures among habitats appear to act independently on memory trait covariation at an individual level and the average response within a population.Leverhulme Trus

Social information use and collective foraging in a pursuit diving seabird

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data files are available from an online data repository (DOI: 10.6084/m9.figshare.9798491).Individuals of many species utilise social information whilst making decisions. While many studies have examined social information in making large scale decisions, there is increasing interest in the use of fine scale social cues in groups. By examining the use of these cues and how they alter behaviour, we can gain insights into the adaptive value of group behaviours. We investigated the role of social information in choosing when and where to dive in groups of socially foraging European shags. From this we aimed to determine the importance of social information in the formation of these groups. We extracted individuals’ surface trajectories and dive locations from video footage of collective foraging and used computational Bayesian methods to infer how social interactions influence diving. Examination of group spatial structure shows birds form structured aggregations with higher densities of conspecifics directly in front of and behind focal individuals. Analysis of diving behaviour reveals two distinct rates of diving, with birds over twice as likely to dive if a conspecific dived within their visual field in the immediate past. These results suggest that shag group foraging behaviour allows individuals to sense and respond to their environment more effectively by making use of social cues

Creation of orbital angular momentum states with chiral polaritonic lenses

Controlled transfer of orbital angular momentum to exciton-polariton Bose-Einstein condensate spontaneously created under incoherent, off-resonant excitation conditions is a long-standing challenge in the field of microcavity polaritonics. We demonstrate, experimentally and theoretically, a simple and efficient approach to generation of nontrivial orbital angular momentum states by using optically-induced potentials -- chiral polaritonic lenses.Comment: 5 pages, 5 figure