The periphery graph of a median graph is the intersection graph of its peripheral subgraphs. We show that every graph without a universal vertex can be realized as the periphery graph of a median graph. We characterize those median graphs whose periphery graph is the join ∗Work supported by the Ministry of Science of Slovenia and by the Ministry of Science and Technology of India under the bila...

The perceived contrast of a central stimulus can be decreased (surround suppression) or increased (surround facilitation) by the presence of surround stimuli. In this report we examined center-surround interactions in foveal and peripheral vision using contrast-matching tasks. We found that: (1) surround suppression became markedly stronger as the center-surround stimulus was moved toward the p...

PURPOSE to evaluate the repercussion of portal hypertension in the indexes of the ovarian, uterine and luteus body periphery arterial resistance, at the medium luteal phase of the menstrual cycle. METHODS in an observational study with transversal cohort, 28 patients with hepatosplenic schistosomiasis mansoni, submitted to splenectomy and ligation of the left gastric vein (HESO), a similar gr...

1. We studied how responses to visual stimuli at spatially separated locations were combined by cat retinal ganglion cells. 2. The temporal signal which modulated the stimuli was a sum of sinusoids. Fourier analysis of the ganglion cell impulse train yielded first order responses at the modulation frequencies, and second order responses at sums and differences of the input frequencies. 3. Spati...