Ulla M Lindhe Norberg

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The kinematics, aerodynamics, and energetics of Plecotus auritus in slow horizontal flight, 2-35 m s-1, are analysed. At this speed the inclination of the stroke path is ca. 58 degrees to the horizontal, the stroke angle ca. 91 degrees, and the stroke frequency ca. 11-9 Hz. A method, based on steady-state aerodynamic and momenthum theories, is derived to(More)
High-speed film analysis showed that the wing beat kinematics in Glossophaga soricina change gradually with increasing flight speed, indicating that there is no sudden gait change at any particular, critical, flight speed. The flight of two adult specimens was studied over a range of flight speeds (1.23-7.52 ms(-1)) in a 30 m long flight tunnel. During the(More)
Energy expenditure during flight in animals can best be understood and quantified when both theoretical and empirical approaches are used concurrently. This paper examines one of four methods that we have used to estimate the cost of flight in a neotropical nectar-feeding bat Glossophaga soricina (Phyllostomidae), namely the use of kinematic and(More)
Steady-state aerodynamic and momentum theories were used for calculations of the lift and drag coefficients of Plecotus auritus in hovering flight. The lift coefficient obtained varies between 3-1 and 6-4, and the drag coefficient between --5-0 and 10-5, for the possible assumptions regarding the effective angles of attack during the upstroke. This(More)
To examine the hydrodynamic propulsion mechanism of a diving great crested grebe (Podiceps cristatus), the three-dimensional kinematics was determined by digital analysis of sequential video images of dorsal and lateral views. During the acceleration phase of this foot-propelled bird, the feet move through an arc in a plane nearly normal to the bird's line(More)
Muscle force production and speed of movement of a bone are not only highly dependent on muscle properties but also on the biomechanical arrangements of the musculoskeletal systems. The aim of this study was to investigate whether the leverages of a leg flexion system alone could be used to trace adaptations to different locomotion patterns by different(More)
The ability to fly opens up ecological opportunities but flight mechanics and muscle energetics impose constraints, one of which is that the maximum body size must be kept below a rather low limit. The muscle power available for flight increases in proportion to flight muscle mass and wingbeat frequency. The maximum wingbeat frequency attainable among(More)
The Company of Biologists Limited, founded in 1925, is a 'Company Limited by Guarantee' having tax-exempt charitable status. There is a Board of Directors consisting of about 20 professional biologists, two of them appointed annually by the Society for Experimental Biology, who receive no salary or fees for their services. The Company's main function is to(More)
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