This investigation purports to develop a new model for multiple autonomous aircraft mission routing. Previous research both related and unrelated to this endeavor have used classic combinatoric problems as models for Unmanned Aerial

The role of thromboxane (TP) in the vasoconstriction induced by tubuloglomerular feedback or 18-h ureteral obstruction was studied in wild type mice (TP +/+), and in heterozygous (TP +/-) and homozygous TP receptor knockout mice (TPR -/-). TGF function was assessed from the response of stop flow pressure (PSF) to a maximum increase in loop of Henle flow rate (0-30 nL min-1). PSF fell by 6.4 +/- 0.4 mmHg in wild-type mice, by 6.1 +/- 0.6 mmHg in TP +/-, and by 7.9 +/- 0.7 mmHg in TP -/- mice. In the presence of the TP receptor agonist U46,619 (10-5 M) the PSF reduction increased to 10. 4 +/- 0.8 mmHg in TP +/+, and to 10.6 +/- 2.8 mmHg in TP +/-, but was unchanged at 7.7 +/- 0.7 mmHg in TP -/-. Mean arterial blood pressures were comparable between groups (103 +/- 3 mmHg in TP +/+, 113 +/- 4.6 in TP +/- and 113 +/- 2.4 mmHg in TP -/- mice). Intratubular pressure following unilateral ureteral obstruction was significantly higher in TP -/- than in TP +/+ mice both in the early phase (0-3 h) and late phase (18 h) of obstruction. These results indicate that chronic TP receptor deficiency does not significantly alter maximum TGF responses in mice, and that it is accompanied by exaggerated vasodilatation during short-term unilateral ureteral obstruction and attenuated vasoconstriction during longer lasting obstruction. We conclude that thromboxane is primarily a regulator of renal vascular tone under pathophysiological conditions.

No abstract

It is unclear whether the impairment of NO-mediated dilation in hypertension is the cause or the consequence of high blood pressure. We therefore studied in isolated resistance arteries whether elevated transmural pressure affects NO-mediated dilation. Arteries (n=5-7) were perfused at hydrostatic pressures of either 45, 120 or 160 mmHg for 48 h. Subsequently, diameter and calcium responses (fura 2) were studied at a transmural pressure of 45 mmHg. Pre-exposure to 120 and 160 mmHg reduced resting diameters and minimal diameters after stimulation with noradrenaline and significantly increased corresponding intracellular free calcium levels in vascular smooth muscle. Moreover, the NO-mediated dilation in response to acetylcholine was significantly reduced although the increase in endothelial calcium was not altered. Dilations induced by the NO donor SNP were not affected. It is concluded that chronically elevated pressure per se impairs endothelial NO production by a mechanism distal to receptor-dependent calcium increases.

The NBME-ECFMG collaborative study yielded important information regarding the NBME SPX prototype as a performance measure for FMGs.