10,075 research outputs found

    A bibliometric analysis of past and emergent trends in animal welfare science

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    Characterizing the complexity of the fleet dynamics for an effective fisheries management: The case of the Cies Islands (NW Spain)

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    We analysed the fishing fleet dynamics in the CĂ­es Islands, located in a National Land-Marine Park of Galicia. By interviewing fishers we identified the fleet fishing in the study area and obtained temporal data on effort and catch. Then we performed multivariate analyses of the catch profiles to identify the fishing strategies and their temporal dynamics. Our results highlight the complexity of the fishery system, composed of 565 boats that used 19 fishing gears and 33 strategies in an area of 26.6 km2. Octopus and velvet crab pots, gillnets targeting hake, trammel nets targeting European spider crab or ballan wrasse, clam rakes, and hand harvesting of gooseneck barnacles and razor shells are the strategies most used. In addition, most of the boats are generalists and use up to seven different fishing strategies throughout the year. This flexibility of the fleet to change the target species generates a wide diversity of annual fishing patterns that increases the complexity of the fisheries and the difficulty of managing them. The implementation of data collection programmes that include fleet dynamics and spatial data are key factors for developing effective management regulations consistent with the complexity of the system

    The Arecibo 430-MHz Intermediate Galactic Latitude Survey: Discovery of Nine Radio Pulsars

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    We have used the Arecibo Radio Telescope to search for millisecond pulsars in two intermediate Galactic latitude regions (7 deg < | b | < 20 deg) accessible to this telescope. For these latitudes the useful millisecond pulsar search volume achieved by Arecibo's 430-MHz beam is predicted to be maximal. Searching a total of 130 square degrees, we have discovered nine new pulsars and detected four previously known objects. We compare the results of this survey with those of other 430-MHz surveys carried out at Arecibo and of an intermediate latitude survey made at Parkes that included part of our search area; the latter independently found two of the nine pulsars we have discovered. At least six of our discoveries are isolated pulsars with ages between 5 and 300 Myr; one of these, PSR J1819+1305, exhibits very marked and periodic nulling. We have also found a recycled pulsar, PSR J2016+1948. With a rotational period of 65 ms, this is a member of a binary system with a 635-day orbital period. We discuss some of the the properties of this system in detail, and indicate its potential to provide a test of the Strong Equivalence Principle. This pulsar and PSR J0407+16, a similar system now being timed at Arecibo, are by far the best systems known for such a test.Comment: Accepted for publication in ApJ Referee format: 22 pages, 7 figure

    Wind tunnel testing of a full scale helicopter blade section with an upstream active Gurney flap

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    Wind tunnel tests were performed on an aerofoil section comparable to that of a full scale helicopter blade section with an upstream active Gurney flap in the framework of the European project CleanSky ITD Green RotorCraft. A modified NACA0012 profile was used, with 23 Kulite pressure transducers embedded in the profile’s surface and with an integrated actuator system for the Gurney flap. The Gurney flap, positioned at 95% of the chord length and with a deployed size of 1.3% of the chord length, extended the full span width of the section. The aerofoil was supported by a mounting system with automated control of the angle of attack. The effect of the Gurney flap is assessed for various deployment strategies. The test campaign carried out was successful. The aerodynamic behaviour can be extracted from the data and contains valuable information for validation of 2D numerical models developed by other partners in the project. The most important improvement of the setup for future use is the stabilisation of the inclinometer readings, which showed a significant amount of noise

    Behavioral correlates between daily activity and sociality in wild and captive origin African lions

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    Study of behavioral correlations within and across populations has long been of interest to ethologists. An exploration of behavioral correlations between sociality and behavior of African lions (Panthera leo) was undertaken to examine if this approach is better able to reveal important aspects of lion behavior not easily discernible by looking at these behaviors separately. Resting behavior and received play interactions were correlated in 2 captive-origin prides and one wild pride, attributable to the involvement of cubs and sub-adults. Direct and exploratory movement was negatively correlated with groom centrality in 2 of the 3 prides, due to adults engaging in high levels of both of these activities. Exploration of these behavioral correlations highlighted the differences between age-groups in activity and sociality, facilitating the understanding of the complex behavior and interactions of lions. In addition, the finding of similar behavioral correlations between captive-origin and the wild prides provides confidence in the suitability if captive-origin candidates for ex-situ release. This is imperative to ensure the success of sub-groups and prides under an ex-situ reintroduction program

    Young Radio Pulsars in Galactic Globular Clusters

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    Currently three isolated radio pulsars and one binary radio pulsar with no evidence of any previous recycling are known in 97 surveyed Galactic globular clusters. As pointed out by Lyne et al., the presence of these pulsars cannot be explained by core-collapse supernovae, as is commonly assumed for their counterparts in the Galactic disk. We apply a Bayesian analysis to the results from surveys for radio pulsars in globular clusters and find the number of potentially observable non-recycled radio pulsars present in all clusters to be < 3600. Accounting for beaming and retention considerations, the implied birth rate for any formation scenario for all 97 clusters is < 0.25 pulsars per century assuming a Maxwellian distribution of velocities with a dispersion of 10 km s^{-1}. The implied birth rates for higher velocity dispersions are substantially higher than inferred for such pulsars in the Galactic disk. This suggests that the velocity dispersion of young pulsars in globular clusters is significantly lower than those of disk pulsars. These numbers may be substantial overestimates due to the fact that the currently known sample of young pulsars is observed only in metal-rich clusters. We propose that young pulsars may only be formed in globular clusters with metallicities with log[Fe/H] > -0.6. In this case, the potentially observable population of such young pulsars is 447^{+1420}_{-399} (the error bars give the 95% confidence interval) and their birth rate is 0.012^{+0.037}_{-0.010} pulsars per century. The mostly likely creation scenario to explain these pulsars is the electron capture supernova of a OMgNe white dwarf.Comment: 13 Pages, 6 Figures, 4 Tables, to appear in Ap

    Self-energy corrections to anisotropic Fermi surfaces

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    The electron-electron interactions affect the low-energy excitations of an electronic system and induce deformations of the Fermi surface. These effects are especially important in anisotropic materials with strong correlations, such as copper oxides superconductors or ruthenates. Here we analyze the deformations produced by electronic correlations in the Fermi surface of anisotropic two-dimensional systems, treating the regular and singular regions of the Fermi surface on the same footing. Simple analytical expressions are obtained for the corrections, based on local features of the Fermi surface. It is shown that, even for weak local interactions, the behavior of the self-energy is non trivial, showing a momentum dependence and a self-consistent interplay with the Fermi surface topology. Results are compared to experimental observations and to other theoretical results.Comment: 13 pages, 10 figure

    Can cold weather be a cardiovascular determinant in warm countries?

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    In almost every temperate region of the world, the number of cardiovascular mortality increases significantly during winter months. This phenomenon has been considered as a public health issue in several countries as many of these deaths are considered to be avoidable. The cause for the excess of winter deaths can be attributed to a number of factors, such as diet, exercise and exposure to cold weather. Curiously, southern European countries, such as Portugal, seem to have the highest excess winter deaths that seem to be related to exposure of cold. However, very few studies have addressed this relationship in Portugal and no quantification of the role of cold weather on cardiovascular diseases has been published. The main goal of this study is to quantify the short effect of cold weather on the cardiovascular morbidity in Portugal Generalized additive Poisson regression models were used in order to obtain the influence of a thermal comfort index (PET) on daily hospitalizations for acute myocardial Infarction in the two most developed metropolitan areas of Portugal: Lisbon and Oporto. All models were adjusted for time and other environmental variables. Influenza was also considered as a confounder. The main results reveal an increase up to 2.2% (95% CI = 0,9%; 3,3%) of daily hospital admissions in winter per degree fall in PET. The increase in daily hospitalizations was greater for the entire population than when only the elderly (>65 years) were considered. View publicationinfo:eu-repo/semantics/publishedVersio
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