PURPOSE Pokorny and Smith (J Opt Soc Am A Opt Image Sci Vis. 1997;14:2477-2486) described a laboratory method to behaviorally measure magnocellular and parvocellular pathway sensitivity. We investigated whether their method may be more efficiently applied to clinical populations by reducing adaptation times. METHODS We measured contrast detection thresholds to a 30-ms increment on a 30 cd/m2 ...

One traditional psychophysical measure of increment threshold presents a brief increment in an ongoing stimulus pedestal for detection. In another class of experiments, the signal can be either an increment or a decrement, and the subject must say which. These configurations are illustrated in Fig. 1. It shows a pedestal alone, S(0), the pedestal plus an incremental signal, S(+), and the pedest...

Contrast integration across space was studied in respect to stimulus extent and the spatial layout, using high-contrast stimuli. Contrast discrimination thresholds were measured (2AFC) by either increasing the size of a peripheral (2.4 degrees) Gabor signal (GS: lambda = 0.08 degree) or by increasing the number of GS elements in a circular arrangement. The supra-threshold mask (pedestal) was ei...

In human vision, the response to luminance contrast at each small region in the image is controlled by a more global process where suppressive signals are pooled over spatial frequency and orientation bands. But what rules govern summation among stimulus components within the suppressive pool? We addressed this question by extending a pedestal plus pattern mask paradigm to use a stimulus with u...

Measurements of long wavelength density fluctuations in the pedestal region of DIII-D plasmas have revealed several important features of edge instabilities during type I edge localized mode (ELMing) and ELMfree discharges. These features, measured with a 2D array of beam emission spectroscopy channels, include: toroidal field and spatial dependence of two distinct frequency bands (50–150 kHz a...

High-resolution charge-exchange recombination spectroscopic measurements of B 5+ ions have enabled the first spatially resolved calculations of the radial electric field (E r) in the Alcator C-Mod pedestal region [E. offer new challenges for theory and simulation and provide for important comparisons with other devices. Qualitatively, the field structure observed on C-Mod is similar to that on ...

Upon intestinal colonization, enterohemorrhagic Escherichia coli (EHEC) induces epithelial cells to generate actin "pedestals" beneath bound bacteria, lesions that promote colonization. To induce pedestals, EHEC utilizes a type III secretion system to translocate into the mammalian cell bacterial effectors such as translocated intimin receptor (Tir), which localizes in the mammalian cell membra...

We consider the effects of a finite pedestal radial electric field on ion orbits using a unified approach. We then employ these modified orbit results to retain finite E×B drift departures from flux surfaces in an improved drift kinetic equation. The procedure allows us to make clear distinction between transit averages and flux surface averages when solving this kinetic equation. The technique...

When comparing the average citation impact of research groups, universities and countries, field normalisation reduces the influence of discipline and time. Confidence intervals for these indicators can help with attempts to infer whether differences between sets of publications are due to chance factors. Although both bootstrapping and formulae have been proposed for these, their accuracy is u...