PURPOSE We used the recently devised three-dimensional computer-based threshold Amsler grid test to acquire and identify typical patterns of visual field defects (scotomas) caused by age-related macular degeneration (AMD). METHODS Patients with AMD traced on a computer touch screen the borders of those areas on an Amsler grid that were missing from their field of vision. Scotomas were repeate...

Ran’s downhill slide during mitosis H asegawa et al. clarify the role of RanGTP in the formation of the mitotic spindle. Because RanGTP is prevalent in the cell, its job during spindle assembly has been difficult to nail down. One possibility is that RanGTP promotes construction of the spindle by liberating spindle assembly factors from the importins that carry them. Previous studies of Xenopus...

We present simultaneous ASCA and RXTE observations of Ark 564, the brightest known ‘narrow-line’ Seyfert 1 in the 2–10 keV band. The measured X-ray spectrum is dominated by a steep (Γ ≈ 2.7) power-law continuum extending to at least 20 keV, with imprinted Fe K-line and -edge features and an additional ‘soft excess’ below ∼ 1.5 keV. The energy of the iron K-edge indicates the presence of highly ...

We present spatial, temporal and spectral analyses of ROSAT Position Sensitive Pro-Ark 564 is a powerful narrow-line Seyfert 1 with strong Fe ii emission. Several similar narrow-line Seyfert 1 galaxies have recently been found to have remarkably steep soft X-ray continua as well as rapid X-ray variability. We nd that Ark 564 also has a very steep ((> 3) 0.1{2.5 keV spectrum and varies by 20 per...

[1] Gravity acting on topography creates differential stress, which, for sufficiently high, steep topography, can fracture intact bedrock. If static fatigue governed the time dependence of that fracturing, a feedback should exist between incision of the landscape and fracturing. The timescale for static fatigue decreases exponentially with differential stress. By creating deeper, steeper valley...