Best approximation by Heaviside perceptron networks.

In Lp-spaces with p an integer from [1, infinity) there exists a best approximation mapping to the set of functions computable by Heaviside perceptron networks with n hidden units; however for p an integer from (1, infinity) such best approximation is not unique and cannot be continuous.     

Effects of Alcohol on Intrauterine Oxygen Tension in the Rat

The effects of alcohol on the availability of oxygen within the uterine lumen of rats were determined on Day 4 of pseudopregnancy. Intraluminal oxygen tension (pO₂) was measured in vivo in anesthetized rats using a 22-gauge polarographic oxygen sensor. Intrauterine pO₂ was measured for 15 min before and after intravenous injection of alcohol (1.0 g/kg: 100% ethanol/saline, 1:2 v/v) or vehicle (physiological saline). Alcohol administration increased mean intrauterine pO₂ (mm Hg) from a pretreatment level of 28.3 ± 2.8 to 38.7 ± 3.8 mm Hg ( p < 0.05, n = 10) at 15 min postinjection. The rapid rise in oxygen tension was accompanied by increased frequency of fluctuation (peaks/hr) in intraluminal pO₂ (prealcohol: 64.2 ± 8.8 vs. postalcohol 96.0 ± 7.7 peaks/hr; ( p < 0.05, n = 10). Injection of saline did not alter any aspect of intrauterine pO₂. During the period of measurement of luminal pO₂, blood alcohol levels increased from 0 during pretreatment to 106 mg% within 10 min of injection. These results indicate that alcohol increases the availability of oxygen within the uterus during the time of endometrial sensitivity to deciduogenic stimuli and blastocyst implantation.