22,091 research outputs found

    Behavioural and physiological responses of laying hens to automated monitoring equipment

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    Automated monitoring of behaviour can offer a wealth of information in circumstances where observing behaviour is difficult or time consuming. However, this often requires attaching monitoring devices to the animal which can alter behaviour, potentially invalidating any data collected. Birds often show increased preening and energy expenditure when wearing devices and, especially in laying hens, there is a risk that individuals wearing devices will attract aggression from conspecifics. We studied the behavioural and physiological response of 20 laying hens to backpacks containing monitoring devices fastened with elastic loops around the wing base. We hypothesised that backpacks would lead to a stress-induced decrease in peripheral temperature, increased preening, more aggression from conspecifics, and reduced bodyweights. This was evaluated by thermography of the eye and comb (when isolated after fitting backpacks), direct observations of behaviour (when isolated, when placed back into the group, and on later days), and weighing (before and after each 7-day experimental period). Each hen wore a backpack during one of the two experimental periods only and was used as her own control. Contrary to our hypothesis, eye temperature was higher when hens wore a backpack (No backpack: 30.2 °C (IQR: 29.0–30.6) vs. Backpack: 30.9 °C (IQR: 30.0–32.0), P < 0.001). Eye temperature of hens wearing a backpack was strongly correlated to the time spent preening (rs = 0.8, P < 0.001), suggesting that the higher temperatures may have been due to preening itself, or to a low head position or decreased heat dissipation when preening under the wings. Aggressive behaviour was very rare and no effect of the backpacks was found. In line with our hypothesis, backpacks increased preening on the day of fitting, both when isolated (No backpack: 0% (IQR: 0–1) vs. Backpack: 22% (IQR: 1–43), P < 0.01) and when back in the group (No backpack: 0% (IQR: 0–27) vs. Backpack: 43% (IQR: 5–77), P < 0.001). However, no effect on preening was observed 2–7 days afterwards. Other behavioural changes suggested that on the day of fitting hens prioritized attempts to (re)move the backpack and were less attentive to their surroundings. However, only equipment pecking (i.e., pecking the backpack or leg rings) was still affected 2–7 days after fitting (No backpack: 0 pecks/hen/minute (IQR: 0–0), vs. Backpack: 0 (IQR: 0–0.07), P < 0.05). We found no effect of our backpacks on bodyweight. In conclusion, our backpacks seem suitable to attach monitoring equipment to hens with only a very minor effect on their behaviour after a short acclimation period (≤2 days)

    Excavations at the Viking Barrow Cemetery at Heath Wood, Ingleby, Derbyshire

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    The cemetery at Heath Wood, Ingleby, Derbyshire, is the only known Scandinavian cremation cemetery in the British Isles. It comprises fifty-nine barrows, of which about one-third have been excavated on previous occasions, although earlier excavators concluded that some were empty cenotaph mounds. From 1998 to 2000 three barrows were examined. Our investigations have suggested that each of the barrows contained a burial, although not all contain evidence of a pyre. A full report of the 1998-2000 excavations is provided, alongside a summary of the earlier finds. The relationship of Heath Wood to the neighbouring site at Repton is examined, in order to understand its significance for the Scandinavian settlement of the Danelaw. It is concluded that Heath Wood may have been a war cemetery of the Viking Great Army of AD 873-8

    Clustering on very small scales from a large sample of confirmed quasar pairs: Does quasar clustering track from Mpc to kpc scales?

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    We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of g<20.85g<20.85 and proper transverse separations of 25h1\sim 25\,h^{-1}\,kpc. Our sample of binary quasars, which is about 6 times larger than any previous spectroscopically confirmed sample on these scales, is targeted using a Kernel Density Estimation technique (KDE) applied to Sloan Digital Sky Survey (SDSS) imaging over most of the SDSS area. Our sample is "complete" in that all of the KDE target pairs with 17.0R36.2h117.0 \lesssim R \lesssim 36.2\,h^{-1}\,kpc in our area of interest have been spectroscopically confirmed from a combination of previous surveys and our own long-slit observational campaign. We catalogue 230 candidate quasar pairs with angular separations of <8\arcsec, from which our binary quasars were identified. We determine the projected correlation function of quasars (Wˉp\bar W_{\rm p}) in four bins of proper transverse scale over the range 17.0R36.2h117.0 \lesssim R \lesssim 36.2\,h^{-1}\,kpc. The implied small-scale quasar clustering amplitude from the projected correlation function, integrated across our entire redshift range, is A=24.1±3.6A=24.1\pm3.6 at 26.6 h1\sim 26.6 ~h^{-1}\,kpc. Our sample is the first spectroscopically confirmed sample of quasar pairs that is sufficiently large to study how quasar clustering evolves with redshift at 25 h1\sim 25 ~h^{-1} kpc. We find that empirical descriptions of how quasar clustering evolves with redshift at 25 h1\sim 25 ~h^{-1} Mpc also adequately describe the evolution of quasar clustering at 25 h1\sim 25 ~h^{-1} kpc.Comment: 16 pages, 8 figures, 6 tables, Accepted for publication in MNRA

    The neural correlates of orienting to walking direction in 6-month-old infants: an ERP study

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    The ability to detect social signals represents a first step to enter our social world. Behavioral evidence has demonstrated that 6‐month‐old infants are able to orient their attention toward the position indicated by walking direction, showing faster orienting responses toward stimuli cued by the direction of motion than toward uncued stimuli. The present study investigated the neural mechanisms underpinning this attentional priming effect by using a spatial cueing paradigm and recording EEG (Geodesic System 128 channels) from 6‐month‐old infants. Infants were presented with a central point‐light walker followed by a single peripheral target. The target appeared randomly at a position either congruent or incongruent with the walking direction of the cue. We examined infants' target‐locked event‐related potential (ERP) responses and we used cortical source analysis to explore which brain regions gave rise to the ERP responses. The P1 component and saccade latencies toward the peripheral target were modulated by the congruency between the walking direction of the cue and the position of the target. Infants' saccade latencies were faster in response to targets appearing at congruent spatial locations. The P1 component was larger in response to congruent than to incongruent targets and a similar congruency effect was found with cortical source analysis in the parahippocampal gyrus and the anterior fusiform gyrus. Overall, these findings suggest that a type of biological motion like the one of a vertebrate walking on the legs can trigger covert orienting of attention in 6‐month‐old infants, enabling enhancement of neural activity related to visual processing of potentially relevant information as well as a facilitation of oculomotor responses to stimuli appearing at the attended location

    Characteristics of Gamma-Ray Loud Blazars in the VLBA Imaging and Polarimetry Survey

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    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey (VIPS). This large, flux-limited sample of active galactic nuclei (AGN) provides insights into the mechanism that produces strong gamma-ray emission. At lower flux levels, radio flux density does not directly correlate with gamma-ray flux. We find that the LAT-detected BL Lacs tend to be similar to the non-LAT BL Lacs, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the gamma-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lacs. It is possible that the gamma-ray loud FSRQs are fundamentally different from the gamma-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for gamma-ray loud AGN.Comment: 32 pages, 9 figures, accepted by Ap

    Contemporaneous VLBA 5 GHz Observations of Large Area Telescope Detected Blazars

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    The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA). In total, 232 sources were observed with the VLBA. Ninety sources that were previously observed as part of the VLBA Imaging and Polarimetry Survey (VIPS) have been included in the sample, as well as 142 sources not found in VIPS. This very large, 5 GHz flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. In particular, we see that γ-ray emission is related to strong, uniform magnetic fields in the cores of the host AGN. Included in this sample are non-blazar AGNs such as 3C84, M82, and NGC 6251. For the blazars, the total VLBA radio flux density at 5 GHz correlates strongly with γ-ray flux. The LAT BL Lac objects tend to be similar to the non-LAT BL Lac objects, but the LAT flat-spectrum radio quasars (FSRQs) are significantly different from the non-LAT FSRQs. Strong core polarization is significantly more common among the LAT sources, and core fractional polarization appears to increase during LAT detection

    Light-based monitoring devices to assess range use by laying hens

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    Access to an outdoor range has many potential benefits for laying hens but range use can be poor due to factors only partly understood. Techniques to monitor individual range use within commercial flocks are crucial to increase our understanding of these factors. Direct observation of individual range use is difficult and time-consuming, and automatic monitoring currently relies on equipment that is difficult to use in an on-farm setting without itself influencing range use. We evaluated the performance of a novel small, light and readily portable light-based monitoring system by validating its output against direct observations

    An ALMA 3mm continuum census of Westerlund 1

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    Context. Massive stars play an important role in both cluster and galactic evolution and the rate at which they lose mass is a key driver of both their own evolution and their interaction with the environment up to and including their terminal SNe explosions. Young massive clusters provide an ideal opportunity to study a co-eval population of massive stars, where both their individual properties and the interaction with their environment can be studied in detail. Aims. We aim to study the constituent stars of the Galactic cluster Westerlund 1 in order to determine mass-loss rates for the diverse post-main sequence population of massive stars. Methods. To accomplish this we made 3mm continuum observations with the Atacama Large Millimetre/submillimetre Array. Results. We detected emission from 50 stars in Westerlund 1, comprising all 21 Wolf-Rayets within the field of view, plus eight cool and 21 OB super-/hypergiants. Emission nebulae were associated with a number of the cool hypergiants while, unexpectedly, a number of hot stars also appear spatially resolved. Conclusions. We were able to measure the mass-loss rates for a unique population of massive post-main sequence stars at every stage of evolution, confirming a significant increase as stars transitioned from OB supergiant to WR states via LBV and/or cool hypergiant phases. Fortuitously, the range of spectral types exhibited by the OB supergiants provides a critical test of radiatively-driven wind theory and in particular the reality of the bi-stability jump. The extreme mass-loss rate inferred for the interacting binary Wd1-9 in comparison to other cluster members confirmed the key role binarity plays in massive stellar evolution. The presence of compact nebulae around a number of OB and WR stars is unexpected; by analogy to the cool super-/hypergiants we attribute this to confinement and sculpting of the stellar wind via interaction with the intra-cluster medium/wind. Given the morphology of core collapse SNe depend on the nature of the pre-explosion circumstellar environment, if this hypothesis is correct then the properties of the explosion depend not just on the progenitor, but also the environment in which it is located

    An exploration of the attitudes and perceptions of the UK public towards self-care for minor ailments

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    Aims and objectives: The purpose of this pilot study was to explore the attitudes and perceptions of members of the UK public towards self-care for minor ailments. Background: With an ageing and increasing population, and a National Health Service in extremis with plummeting performance indicators and the huge disparity between available funding and costs of treatments, methods to reduce demand upon health services are key. Increasing the use of self-care for minor ailments is one way in which this pressure could be alleviated. Design + Method: This study utilised qualitative methods including semi-structured telephone interviews. This data was then valuated, and key themes are drawn out of the data using thematic analysis. Findings: The results showed that the public are aware of the notion of self-care, and some are engaging with it. However, for a number of reasons, patients are still likely to want a face to face appointment despite the use of internet and telephone advice services. Conclusion: The study highlighted that there are multifactorial aspects impacting upon a patient’s likelihood to engage in self-care when faced with a minor illness. The results are not generalisable to every member of the UK public, but interesting questions are raised with regards to the usefulness of current public health messages being portrayed across various media when there appears to be a lack of desire from the public to use some recommended services
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