Sculpture alcove, Kangaroo Point House, Kangaroo Point, Brisbane

Alcove to deck, as seen from garden.

Sculpture alcove, Kangaroo Point House, Kangaroo Point, Brisbane

Alcove to deck, with timber handrail in foreground.

Sculpture alcove, Kangaroo Point House, Kangaroo Point, Brisbane

Alcove to deck, as seen from garden.

Crow's nest, Kangaroo Point House, Kangaroo Point, Brisbane

Deck and seating overlooking the river.

Crow's nest, Kangaroo Point House, Kangaroo Point, Brisbane

Deck and seating overlooking river.

Outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Looking towards section of original house from outdoor room area. Hand-made spotted gum columns on edge of outdoor room on right.

Crow's nest, Kangaroo Point House, Kangaroo Point, Brisbane

Deck and seating overlooking river.

Battened roof to outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Timber battened concave roof and supporting structure over outdoor room area.

Outdoor room, Kangaroo Point House, Kangaroo Point, Brisbane

Dining setting, sculptures, timber columns and curved roof in outdoor room

Crow's nest, Kangaroo Point House, Kangaroo Point, Brisbane

Structure to underside of deck and seating area.

The effects of viscous loading of the human forearm flexors on the stability of coordination

This experiment investigated whether the stability of rhythmic unimanual movements is primarily a function of perceptual/spatial orientation or neuro-mechanical in nature. Eight participants performed rhythmic flexion and extension movements of the left wrist for 30 s at a frequency of 2.25 Hz paced by an auditory metronome. Each participant performed 8 flex-on-the-beat trials and 8 extend-on-the-beat trials in one of two load conditions, loaded and unload. In the loaded condition, a servo-controlled torque motor was used to apply a small viscous load that resisted the flexion phase of the movement only. Both the amplitude and frequency of the movement generated in the loaded and unloaded conditions were statistically equivalent. However, in the loaded condition movements in which participants were required to flex-on-the-beat became less stable (more variable) while extend-on-the-beat movements remained unchanged compared with the unload condition. The small alteration in required muscle force was sufficient to result in reliable changes in movement stability even a situation where the movement kinematics were identical. These findings support the notion that muscular constraints, independent of spatial dependencies, can be sufficiently strong to reliably influence coordination in a simple unimanual task.

Entanglement in a simple quantum phase transition

What entanglement is present in naturally occurring physical systems at thermal equilibrium? Most such systems are intractable and it is desirable to study simple but realistic systems that can be solved. An example of such a system is the one-dimensional infinite-lattice anisotropic XY model. This model is exactly solvable using the Jordan-Wigner transform, and it is possible to calculate the two-site reduced density matrix for all pairs of sites. Using the two-site density matrix, the entanglement of formation between any two sites is calculated for all parameter values and temperatures. We also study the entanglement in the transverse Ising model, a special case of the XY model, which exhibits a quantum phase transition. It is found that the next-nearest-neighbor entanglement (though not the nearest-neighbor entanglement) is a maximum at the critical point. Furthermore, we show that the critical point in the transverse Ising model corresponds to a transition in the behavior of the entanglement between a single site and the remainder of the lattice.