1,645 research outputs found

    Cancer risk: Are we well behaved?

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    Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics

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    Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures

    Wild fledgling tits do not mob in response to conspecific or heterospecific mobbing calls

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    This research was funded by the Natural Environment Research Council (NE/J018694/1), the Royal Society (RG2012R2), the M. J. Murdock Charitable Trust (2014199) and the University of St Andrews (University of St Andrews 600th Year Scholarship and the St Leonard’s Fee Scholarship).Mobbing, where birds harass a predator through a combination of vocalizations and stereotyped behaviours, is an effective anti‐predator behaviour for many species. Mobbing may be particularly important for juveniles, as these individuals are often more vulnerable than adults. Although the component behaviours of mobbing are often considered to be un‐learned, there are few confirmatory data, and the developmental trajectory of mobbing is unknown. In this study, we tested whether conspecific or heterospecific mobbing calls initiated mobbing behaviour in juvenile Blue Tits Cyanistes caeruleus. We located wild adult and recently fledged juvenile Blue Tits and presented them with playback recordings of adult conspecific (Blue Tit) and heterospecific (Great Tit Parus major) mobbing alarm calls. Although adult birds readily mob in response to these types of playbacks, juveniles did not exhibit characteristic mobbing behaviour. Some juveniles did, however, exhibit individual components of mobbing behaviour found in mobbing, despite not producing adult‐like mobbing behaviour in response to either conspecific or heterospecific playback. These results suggest that, although birds might be capable of mobbing as juveniles, the associations between the non‐vocal stereotyped mobbing behaviours and mobbing calls may be learned.PostprintPeer reviewe

    The dietary impact of the Norman Conquest: A multiproxy archaeological investigation of Oxford, UK

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    Archaeology has yet to capitalise on the opportunities offered by bioarchaeological approaches to examine the impact of the 11th-century AD Norman Conquest of England. This study utilises an integrated multiproxy analytical approach to identify and explain changes and continuities in diet and foodways between the 10th and 13th centuries in the city of Oxford, UK. The integration of organic residue analysis of ceramics, carbon (δ13C) and nitrogen (δ15N) isotope analysis of human and animal bones, incremental analysis of δ13C and δ15N from human tooth dentine and palaeopathological analysis of human skeletal remains has revealed a broad pattern of increasing intensification and marketisation across various areas of economic practice, with a much lesser and more short-term impact of the Conquest on everyday lifestyles than is suggested by documentary sources. Nonetheless, isotope data indicate short-term periods of instability, particularly food insecurity, did impact individuals. Evidence of preferences for certain foodstuffs and cooking techniques documented among the elite classes were also observed among lower-status townspeople, suggesting that Anglo-Norman fashions could be adopted across the social spectrum. This study demonstrates the potential for future archaeological research to generate more nuanced understanding of the cultural impact of the Norman Conquest of England, while showcasing a method which can be used to elucidate the undocumented, everyday implications of other large-scale political events on non-elites

    Management of hemiplegic shoulder pain: A UK-wide online survey of physiotherapy and occupational therapy practice

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    Purpose: The purpose of this study was to explore, via an online survey, how therapists assess, diagnose and manage hemiplegic shoulder pain (HSP) in the United Kingdom. The objectives were to explore (1) how therapists assessed HSP, (2) what the aims of therapy were, (3) what interventions therapists used, (4) what outcome measures therapists used, (5) what training of HSP therapists had, and (6) what barriers therapists experienced in the management of HSP. Methods: An online survey was distributed to physiotherapists (PTs) and occupational therapists (OTs) working in stroke rehabilitation via professional bodies' interest groups. Results: Sixty-seven responses were received: 40 (60%) were PTs and 27 (40%) were OTs. Therapists routinely screened for HSP (n = 59, 89%). When HSP was assessed, 33 (50%) spent 10 min on assessment. Patient-reported pain was used for assessment of HSP by 66 (99%) of respondents. Frequent interventions included positioning (n = 62, 94%), posture re-education (n = 57, 86%), and range of motion exercises (n = 55, 83%). Range of movement was used as an outcome measure by 31 (47%). Sixty (91%) respondents reported receiving training in HSP management. Time constraints (n = 41, 62%) and lack of diagnosis of HSP (n = 33, 54%) were identified as barriers to providing appropriate care to people with HSP. Conclusion: Study findings showed varied practice in the assessment and treatment for HSP and indicate that time constraints are a considerable barrier to the management of these patients. Further research is required to establish best practice which may help improve outcomes and care for people with poststroke shoulder pain

    The roles of migratory and resident birds in local avian influenza infection dynamics

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    Migratory birds are an increasing focus of interest when it comes to infection dynamics and the spread of avian influenza viruses (AIV ). However, we lack detailed understanding of migratory birds’ contribution to local AIV prevalence levels and their downstream socio‐economic costs and threats. To explain the potential differential roles of migratory and resident birds in local AIV infection dynamics, we used a susceptible‐infectious‐recovered (SIR ) model. We investigated five (mutually non‐ exclusive) mechanisms potentially driving observed prevalence patterns: (1) a pronounced birth pulse (e.g. the synchronised annual influx of immunologically naïve individuals), (2) short‐term immunity, (3) increase in susceptible migrants, (4) differential susceptibility to infection (i.e. transmission rate) for migrants and residents, and (5) replacement of migrants during peak migration. SIR models describing all possible combinations of the five mechanisms were fitted to individual AIV infection data from a detailed longitudinal surveillance study in the partially migratory mallard duck (Anas platyrhynchos ). During autumn and winter, the local resident mallard community also held migratory mallards that exhibited distinct AIV infection dynamics. Replacement of migratory birds during peak migration in autumn was found to be the most important mechanism driving the variation in local AIV infection patterns. This suggests that a constant influx of migratory birds, likely immunological naïve to locally circulating AIV strains, is required to predict the observed temporal prevalence patterns and the distinct differences in prevalence between residents and migrants. Synthesis and applications . Our analysis reveals a key mechanism that could explain the amplifying role of migratory birds in local avian influenza virus infection dynamics; the constant flow and replacement of migratory birds during peak migration. Apart from monitoring efforts, in order to achieve adequate disease management and control in wildlife—with knock‐on effects for livestock and humans,—we conclude that it is crucial, in future surveillance studies, to record host demographical parameters such as population density, timing of birth and turnover of migrants

    Population change in breeding boreal waterbirds in a 25-year perspective : What characterises winners and losers?

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    Understanding drivers of variation and trends in biodiversity change is a general scientific challenge, but also crucial for conservation and management. Previous research shows that patterns of increase and decrease are not always consistent at different spatial scales, calling for approaches combining the latter. We here explore the idea that functional traits of species may help explaining divergent population trends. Complementing a previous community level study, we here analyse data about breeding waterbirds on 58 wetlands in boreal Fennoscandia, covering gradients in latitude as well as trophic status. We used linear mixed models to address how change in local abundance over 25 years in 25 waterbird species are associated with life history traits, diet, distribution, breeding phenology, and habitat affinity. Mean abundance increased in 10 species from 1990/1991 to 2016, whereas it decreased in 15 species. Local population increases were associated with species that are early breeders and have small clutches, an affinity for luxurious wetlands, an herbivorous diet, and a wide breeding range rather than a southern distribution. Local decreases, by contrast, were associated with species having large clutches and invertivorous diet, as well as being late breeders and less confined to luxurious wetlands. The three species occurring on the highest number of wetlands all decreased in mean abundance. The fact that early breeders have done better than late fits well with previous research about adaptability to climate change, that is, response to earlier springs. We found only limited support for the idea that life history traits are good predictors of wetland level population change. Instead, diet turned out to be a strong candidate for an important driver of population change, as supported by a general decrease of invertivores and a concomitant increase of large herbivores. In a wider perspective, future research needs to address whether population growth of large-bodied aquatic herbivores affects abundance of co-occurring invertivorous species, and if so, if this is due to habitat alteration, or to interference or exploitative competition.Peer reviewe
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