63 research outputs found

    Optic flow stabilizes flight in ruby-throated hummingbirds

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    Flying birds rely on visual cues for retinal image stabilization by negating rotation-induced optic flow, the motion of the visual panorama across the retina, through corrective eye and head movements. In combination with vestibular and proprioceptive feedback, birds may also use visual cues to stabilize their body during flight. Here, we test whether artificially induced wide-field motion generated through projected visual patterns elicits maneuvers in body orientation and flight position, in addition to stabilizing vision. To test this hypothesis, we present hummingbirds flying freely within a 1.2 m cylindrical visual arena with a virtual surround rotated at different speeds about its vertical axis. The birds responded robustly to these visual perturbations by rotating their heads and bodies with the moving visual surround, and by adjusting their flight trajectories, following the surround. Thus, similar to insects, hummingbirds appear to use optic flow cues to control flight maneuvers as well as to stabilize their visual inputs

    Optic flow stabilizes flight in ruby-throated hummingbirds

    Get PDF
    Flying birds rely on visual cues for retinal image stabilization by negating rotation-induced optic flow, the motion of the visual panorama across the retina, through corrective eye and head movements. In combination with vestibular and proprioceptive feedback, birds may also use visual cues to stabilize their body during flight. Here, we test whether artificially induced wide-field motion generated through projected visual patterns elicits maneuvers in body orientation and flight position, in addition to stabilizing vision. To test this hypothesis, we present hummingbirds flying freely within a 1.2 m cylindrical visual arena with a virtual surround rotated at different speeds about its vertical axis. The birds responded robustly to these visual perturbations by rotating their heads and bodies with the moving visual surround, and by adjusting their flight trajectories, following the surround. Thus, similar to insects, hummingbirds appear to use optic flow cues to control flight maneuvers as well as to stabilize their visual inputs

    Chloroquine and Its Derivatives Exacerbate B19V-Associated Anemia by Promoting Viral Replication

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    Human parvovirus B19 (B19V) is typically associated with a childhood febrile illness known as erythema infectiosum. The infection usually resolves without consequence in healthy individuals. However, in patients with immunologic and/or hematologic disorders, B19V can cause a significant pathology. The virus infects and kills red cell precursors but anemia rarely supervenes unless there is pre-existing anemia such as in children living in malaria-endemic regions. The link between B19V infection and severe anemia has, however, only been confirmed in certain malaria-endemic countries in parallel with chloroquine (CQ) usage. This raises the possibility that CQ may increase the risk of severe anemia by promoting B19V infection. To test this hypothesis, we examined the direct effect of CQ and other commonly used antimalarial drugs on B19V infection in cultured cell lines. Additionally, we examined the correlation between B19V infection, hemoglobin levels and use of CQ in children from Papua New Guinea hospitalized with severe anemia. The results suggest strongly that CQ and its derivatives aggravate B19V-associated anemia by promoting B19V replication. Hence, careful consideration should be given in choosing the drug partnering artemisinin compounds in combination antimalarial therapy in order to minimize contribution of B19V to severe anemia

    Smart textiles for healthcare and medicine applications (WG1): state-of-the art report, CONTEXT Project

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    The aim of this document is to provide information on the state-of-the-art related to the topics covered by each working group within the CONTEXT project. It provides information on materials and technologies used to develop smart textiles with targeted performance, general applications of smart textiles in the field, case-studies on the use of smart textiles, opportunities for smart textiles considering the needs of each field, trends on the development of smart textiles in terms of market and technical expectations. This paper gives an overview of the potential of smart textiles for healthcare & medicine, ongoing developments, state-of-the-art products and future developments

    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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    Measurement of the W boson polarisation in ttˉt\bar{t} events from pp collisions at s\sqrt{s} = 8 TeV in the lepton + jets channel with ATLAS

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    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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    Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in pp collision data at s=8TeV\sqrt{s}=8\,\mathrm TeV{} with the ATLAS detector

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