Ommatidial rotation in the Drosophila eye provides a striking example of the precision with which tissue patterning can be achieved. Ommatidia in the adult eye are aligned at right angles to the equator, with dorsal and ventral ommatidia pointing in opposite directions. This pattern is established during disc development, when clusters rotate through 90 degrees, a process dependent on planar ce...

Sensing and following the chemical plume of food odors is a fundamental challenge faced by many organisms. For flying insects, the task is complicated by wind that distorts the plume and buffets the fly. To maintain an upwind heading, and thus stabilize their orientation in a plume, insects such as flies and moths make use of strong context-specific visual equilibrium reflexes. For example, fly...

BACKGROUND Knowledge about the pattern of rotation during arm elevation is necessary for a full understanding of shoulder function, and it is also useful for planning of rehabilitation protocols to restore range of motion in shoulders in disorder. However, there are insufficient in vivo data available. METHODS; We investigated dynamic arm rotation during elevation in different planes using 30 s...

The rotation of the tibia and subtalar motion are being taken into account in some of the newer techniques for leg bracing. It is the purpose of this paper to investigate the precise relationship between these two movements. The rotation of the tibia in a horizontal plane, occurring during stance, is rotation about a simple vertical axis to a limited degree only. The major range of tibial rotat...

Using high frequency (12-22 GHz) VLBA observations we confirm the existence of a Faraday rotation measure gradient of ∼500 rad m −2 mas −1 transverse to the jet axis in the quasar 3C 273. The gradient is seen in two epochs spaced roughly six months apart. This stable transverse rotation measure gradient is expected if a helical magnetic field wraps around the jet. The overall order to the magne...

We report the discovery of Faraday rotation toward radio source 3C 84, the active galactic nucleus in NGC1275 at the core of the Perseus Cluster. The rotation measure (RM), determined from polarization observations at wavelengths of 1.3 and 0.9 mm, is (8.7± 2.3)×10 rad m−2, among the largest ever measured. The RM remained relatively constant over a 2 year period even as the intrinsic polarizati...

the effective factors of forward speed, cylinder rotation, and clearance between a combine’s cylinder and concave on wheat kernel breakage and seed germination were studied in karaj area using a 955 model john dear combine. this study was conducted on three levels of adjustment for each of the variables, 1.2, 1.8 and 2.5 km/hr for forward speed, 800, 900, 1000 rpm for cylinder rotation as well ...

True polar wander (TPW), a reorientation of the rotation axis relative to the solid body, is driven by mass redistribution on the surface or within the planet and is stabilized by two aspects of the planet’s viscoelastic response: the delayed viscous readjustment of the rotational bulge and the elastic stresses in the lithosphere. The latter, following Willemann (1984), is known as remnant bulg...