The discharge characteristics of postsubicular head-direction cells in a fixed environment were described in the previous paper (Taube et al., 1990). This paper reports changes in the firing properties of head-direction cells following changes in the animal's environment. Head-direction cells were recorded from rats as they moved freely in a 76-cm-diameter gray cylinder. A white card, occupying...

Human vision is adept at inferr ing surface shape from a projection of curves lying across a surface, part icular ly from paral lel undulating curves. Since the image projection loses 3-D information, the interpretation must be constrained by certain a p r io r i assumptions. A theory of constraint on this problem [Stevens 1981a] proposes three assumptions, namely that neither the viewpoint nor...

The motion of tracer particles used for visualization in a steady axisymmetric swirling flow in a closed rotating disk–cylinder system is studied numerically. It is assumed that there exists a density mismatch between the particles and the fluid. It is shown that such a slight density mismatch leads to a deviation of the particle motion from steady axisymmetric streamlines, which in its turn yi...

Three-dimensional instability of axisymmetric flow in a rotating disk–cylinder configuration is studied numerically for the case of low cylinders with the height/radius aspect ratio varying between 1 and 0.1. A complete stability diagram for the transition from steady axisymmetric to oscillatory threedimensional flow regime is reported. A good agreement with the experimental results is obtained...

For flow at a fixed gap ratio and Froude number, two distinctly different wake states are observed with the flow passing over the cylinder tending to switch from a state of attachment to the free surface, to one of separation from it, and then back again in a pseudo periodic fashion. The two dimensional numerically predicted behaviour is found to compare favourably with the experimental observa...

Cylinder deactivation (CDA) is a technology that can improve the fuel economy and exhaust thermal management of compression ignition engines (diesel and natural gas), especially at low loads and engine idling conditions. The reduction in engine displacement during CDA improves fuel efficiency at low loads primarily through a reduction in pumping work. During deactivation of a given cylinder, th...

colza (canola) is a crop with high rate of grain loss during harvesting. at harvest, semi-dried grains of canola’s pods are either opened or dropped due to mechanical impacts. therefore, lots of grains drop before entering combine head. another obstacle to successful harvest of canola is that ripe grain's pods are twisted together. this results in heavy grain loss at dividers of combine pi...

This paper reports aldehyde emissions from two-stroke and four-stroke, single cylinder spark ignition (SI) engines with gasohol (80 vol. % gasoline, 20 vol. % ethanol) having copper coated engine (copper-coated thickness, 300 μm) on piston crown and inner side of cylinder head) provided with catalytic converter with sponge iron as catalyst and compared with conventional SI engine with gasoline ...

The symmetric core of the nuclear pore complex can be considered schematically as a series of concentric cylinders. A peripheral cylinder coating the pore membrane contains the previously characterized, elongated heptamer that harbors Sec13-Nup145C in its middle section. Strikingly, Sec13-Nup145C crystallizes as a hetero-octamer in two space groups. Oligomerization of Sec13-Nup145C was confirme...