Publications by authors named "Kozue Shiomi"

Article Synopsis
  • Central-place foragers, like the European shag, make complex decisions about where to feed, but limited data on their foraging habits has hindered testing of the optimal foraging hypothesis.
  • Researchers used time-depth-acceleration data loggers to study how different habitats and foraging behaviors affected feeding rates in 24 male shags during chick-rearing.
  • The study found that shags did not change feeding sites or habitats based on feeding rates, contradicting the optimal foraging theory, suggesting that their feeding behavior is influenced more by prey density and competition than previously thought.
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Elucidating determinants of interspecies variation in brain size has been a long-standing challenge in cognitive and evolutionary ecology. As the brain is an energetically expensive organ, energetic tradeoffs among organs are considered to play a key role in brain size evolution. This study examined the tradeoff between the brain and locomotion in birds by testing the relationship between brain size, flight modes with different energetic costs (flapping and soaring), and migratory behavior, using published data on the whole-brain mass of 2242 species.

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Advances in biologging technology have enabled 3D dead-reckoning reconstruction of marine animal movements at spatiotemporal scales of meters and seconds. Examining high-resolution 3D movements of sharks (, N = 4; , N = 1), sea turtles (, N = 3), penguins (, N = 6), and marine mammals (, N = 4; , N = 1), we report the discovery of circling events where animals consecutively circled more than twice at relatively constant angular speeds. Similar circling behaviors were observed across a wide variety of marine megafauna, suggesting these behaviors might serve several similar purposes across taxa including foraging, social interactions, and navigation.

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Background: In July 2018, a rare and serious adverse effect (AE), namely, communicating hydrocephalus unrelated to meningitis or bleeding, was reported in relation to five patients treated with nusinersen for spinal muscular atrophy (SMA). Some patients were managed using a ventriculo-peritoneal shunt (VPS) implant and continued to receive nusinersen treatment. However, there is limited information concerning the effectiveness and safety of nusinersen treatment for patients with a VPS.

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Ocean-scale monitoring of pollution is challenging. Seabirds are useful indicators because they travel over a broad foraging range. Nevertheless, this coarse spatial resolution is not fine enough to discriminate pollution in a finer scale.

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In diving birds and mammals, bradycardia and peripheral vasoconstriction potentially isolate muscle from the circulation. During complete ischemia, ATP production is dependent on the size of the myoglobin oxygen (O(2)) store and the concentrations of phosphocreatine (PCr) and glycogen (Gly). Therefore, we measured PCr and Gly concentrations in the primary underwater locomotory muscle of emperor penguin and modeled the depletion of muscle O(2) and those energy stores under conditions of complete ischemia and a previously determined muscle metabolic rate.

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At some point in a dive, breath-hold divers must decide to return to the surface to breathe. The issue of when to end a dive has been discussed intensively in terms of foraging ecology and behavioral physiology, using dive duration as a temporal parameter. Inevitably, however, a time lag exists between the decision of animals to start returning to the surface and the end of the dive, especially in deep dives.

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Emperor penguins (Aptenodytes forsteri), both at sea and at an experimental dive hole, often have minimal surface periods even after performance of dives far beyond their measured 5.6 min aerobic dive limit (ADL: dive duration associated with the onset of post-dive blood lactate accumulation). Accelerometer-based data loggers were attached to emperor penguins diving in these two different situations to further evaluate the capacity of these birds to perform such dives without any apparent prolonged recovery periods.

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It has been predicted that geometrically similar animals would swim at the same speed with stroke frequency scaling with mass(-1/3). In the present study, morphological and behavioural data obtained from free-ranging penguins (seven species) were compared. Morphological measurements support the geometrical similarity.

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A neonate presented with multiple brain abscesses caused by very unusual infection with the Gram-negative bacterium, Edwardsiella tarda. Serial changes in magnetic resonance imaging findings including diffusion-weighted imaging demonstrated the development from the late cerebritis to late capsule stages. The patient was successfully treated by external drainage, and has since reached normal development milestones.

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