548 research outputs found

    Responses of king penguin Aptenodytes patagonicus adults and chicks to two food-related odours

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    Increasing evidence suggests that penguins are sensitive to dimethyl sulphide (DMS), a scented airborne compound that a variety of marine animals use to find productive areas of the ocean where prey is likely to be found. Here we present data showing that king penguins Aptenodytes patagonicus are also sensitive to DMS. We deployed DMS on a lake near a king penguin colony at Ratmanoff beach in the Kerguelen archipelago. We also presented DMS to ‘sleeping’ adults on the beach. On the lake, penguins responded to the DMS deployments by swimming more, while on the beach, penguins twitched their heads and woke up more for the DMS than for the control presentations. Interestingly, penguins did not respond to cod liver oil deployments on the lake; mirroring at-sea studies of other penguins. Although at-sea studies are needed to confirm that king penguins use DMS as a surface cue that informs them of productivity under the water, this study is an important first step in understanding how these birds locate prey over significant distances

    Learning Environment Simulator: A Tool for Local Decision Makers and First

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    Abstract – The National Infrastructure Simulation and Analysis Center (NISAC) has developed a prototype learning environment simulator (LES) based on the Critical Infrastructure Protection Decision Support System (CIPDSS) infrastructure and scenario models. The LES is designed to engage decision makers at the grass-roots level (local/city/state) to deepen their understanding of evolving crises, enhance their intuition and allow them to test their own strategies for events before they occur. An initial version is being developed, centered on a pandemic influenza outbreak and has been successfully tested with a group of hospital administrators and first responders. LES is not a predictive tool but rather a simulated environment allowing the user to experience the complexities of a crisis before it happens. Users can contrast various approaches to the crisis, competing with alternative strategies of their own or other participants. LES is designed to assist decision makers in making informed choices by functionally representing relevant scenarios before they occur, including impacts to critical infrastructures with their interdependencies and estimating human health & safety and economic impacts. In this paper a brief overview of the underlying models are given followed by a description of the LES, its interface, usage and testing experience

    Acoustic Probing of the Jamming Transition in an Unconsolidated Granular Medium

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    Experiments with acoustic waves guided along the mechanically free surface of an unconsolidated granular packed structure provide information on the elasticity of granular media at very low pressures that are naturally controlled by the gravitational acceleration and the depth beneath the surface. Comparison of the determined dispersion relations for guided surface acoustic modes with a theoretical model reveals the dependencies of the elastic moduli of the granular medium on pressure. The experiments confirm recent theoretical predictions that relaxation of the disordered granular packing through non-affine motion leads to a peculiar scaling of shear rigidity with pressure near the jamming transition corresponding to zero pressure. Unexpectedly, and in disagreement with the most of the available theories, the bulk modulus depends on pressure in a very similar way to the shear modulus

    MULTIPASS: gestion des consentements pour accéder aux données des exploitations dans une chaîne de confiance afin de favoriser l'émergence de nouveaux services pour les agriculteurs

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    12th EFITA International Conference, Rhode island, GRC, 27-/06/2019 - 29/06/2019International audienceWith the emergence of digital technologies, farms become a relevant source of data to meet the challenges of multi-performance agriculture. Beyond the services provided, access to farmers' data depends on a clear understanding of their use, which must be done in a transparent way. Several codes of conduct at a national or international level push for a voluntary commitment to respect some good practices in the use of agricultural data. To provide a tool and answer farmer's questions on the control of their data and the transparency of the data processing, the partners of the MULTIPASS project, have imagined an interoperable ecosystem of farmer consents management, protecting farmers from no consented uses of their data.Farmers' expectations of such an ecosystem have been expressed during workshops. They want to better identify existing data flows, including actors, data processes, and data clusters. Based on the farmers' expectations, the MULTIPASS project stakeholders have proposed the architecture of an ecosystem integrating two consent management tools as "pilots". This ecosystem should take in charge the interoperability between each consent management tools or with future tools. This solution is based on a shared typology of data and data processes as well as on the specifications of the consent message content. All these elements should be easily accessible to meet the interoperability need of the ecosystem. It is also based on a router, which provides unified access to consent management tools (using API). In particular, it provides the farmer (beneficiary) with an exhaustive view of his/her consents (which can be distributed on several consent management systems), meeting farmers' expectations for transparency. It is also the point where a data provider can check whether the consent required to provide data exists, without needing to know which consent management system is concerned. In this project, the stakeholders want to demonstrate to agricultural professional organizations the benefits and feasibility of a consent management ecosystem. By strengthening the confidence of farmers to share data, the project will allow the emergence of new knowledge and new services

    Explosive joining of precious metals

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    Beyond aggression: Androgen-receptor blockade modulates social interaction in wild meerkats

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    In male vertebrates, androgens are inextricably linked to reproduction, social dominance, and aggression, often at the cost of paternal investment or prosociality. Testosterone is invoked to explain rank-related reproductive differences, but its role within a status class, particularly among subordinates, is underappreciated. Recent evidence, especially for monogamous and cooperatively breeding species, suggests broader androgenic mediation of adult social interaction. We explored the actions of androgens in subordinate, male members of a cooperatively breeding species, the meerkat (Suricata suricatta). Although male meerkats show no rank-related testosterone differences, subordinate helpers rarely reproduce. We blocked androgen receptors, in the field, by treating subordinate males with the antiandrogen, flutamide. We monitored androgen concentrations (via baseline serum and time-sequential fecal sampling) and recorded behavior within their groups (via focal observation). Relative to controls, flutamide-treated animals initiated less and received more high-intensity aggression (biting, threatening, feeding competition), engaged in more prosocial behavior (social sniffing, grooming, huddling), and less frequently initiated play or assumed a ‘dominant’ role during play, revealing significant androgenic effects across a broad range of social behavior. By contrast, guarding or vigilance and measures of olfactory and vocal communication in subordinate males appeared unaffected by flutamide treatment. Thus, androgens in male meerkat helpers are aligned with the traditional trade-off between promoting reproductive and aggressive behavior at a cost to affiliation. Our findings, based on rare endocrine manipulation in wild mammals, show a more pervasive role for androgens in adult social behavior than is often recognized, with possible relevance for understanding tradeoffs in cooperative systems

    Age-related differences in the cloacal microbiota of a wild bird species

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    Background: Gastrointestinal bacteria play a central role in the health of animals. The bacteria that individuals acquire as they age may therefore have profound consequences for their future fitness. However, changes in microbial community structure with host age remain poorly understood. We characterised the cloacal bacteria assemblages of chicks and adults in a natural population of black-legged kittiwakes (Rissa tridactyla), using molecular methods. Results: We show that the kittiwake cloaca hosts a diverse assemblage of bacteria. A greater number of total bacterial OTUs (operational taxonomic units) were identified in chicks than adults, and chicks appeared to host a greater number of OTUs that were only isolated from single individuals. In contrast, the number of bacteria identified per individual was higher in adults than chicks, while older chicks hosted more OTUs than younger chicks. Finally, chicks and adults shared only seven OTUs, resulting in pronounced differences in microbial assemblages. This result is surprising given that adults regurgitate food to chicks and share the same nesting environment. Conclusions: Our findings suggest that chick gastrointestinal tracts are colonised by many transient species and that bacterial assemblages gradually transition to a more stable adult state. Phenotypic differences between chicks and adults may lead to these strong differences in bacterial communities. These data provide the framework for future studies targeting the causes and consequences of variation in bacterial assemblages in wild birds

    First-principles study of helium, carbon, and nitrogen in austenite, dilute austenitic iron alloys, and nickel

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    An extensive set of first-principles density functional theory calculations have been performed to study the behaviour of He, C and N solutes in austenite, dilute Fe-Cr-Ni austenitic alloys and Ni in order to investigate their influence on the microstructural evolution of austenitic steel alloys under irradiation.Comment: 29 pages, 19 figure
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