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The action of ketamine on contractile response to norepinephrine consists of endothelium-dependent vasoconstricting and endothelium-independent vasodilating components. The direct vasorelaxation is largely a result of reduction of[Ca2+]i in vascular smooth muscle cells. The [Ca2+]i-reducing effects are caused by inhibitions of both voltage-gated Ca2+ influx and norepinephrine-induced Ca2+ release from the intracellular stores.

In 1987 an ice core to the bedrock at a depth of 85.6 m was drilled at the top of H0ghetta ice dome in northern Spitsbergen. Chronology of the ice core was examined by tritium and HC methods showing time gap at about 50 m depth. The age of three bottom ice samples was dete rmined as 4150-5670 year B.P. by 14C method done for frozen bacteria colonies and a frozen petal. This chronology and negative bottom temperature of -9.4 °c suggest that glaciers in Spitsbergen shrank considerably during the hyps ithermal.

The inhibitory effects of sevoflurane on both norepinephrine- and potassium chloride (KCl)-induced contractions are caused by reduction of [Ca2+]i in vascular smooth muscle and inhibition of the myofilament Ca2+ sensitivity. The [Ca2+]i-reducing effect of sevoflurane observed in both the norepinephrine- and the K+-stimulated muscle is mainly caused by inhibition of voltage-gated Ca2+ influx. The inhibitory effect of sevoflurane on Ca2+ activation of contractile proteins seems to be mediated by the cell membrane or by some diffusible substances that are lost in the beta-escin-permeabilized cells.

In systemic resistance arteries, the halothane, enflurane, isoflurane, and sevoflurane differentially influence the SR functions. Both halothane and enflurane cause Ca2+ release from the caffeine-sensitive SR. In addition, both anesthetics appear to have a stimulating action on Ca2+ uptake in addition to the Ca2+-releasing action. Halothane, enflurane, and isoflurane all enhance, while sevoflurane attenuates, the Ca2+-induced Ca2+-release mechanism. However, only sevoflurane stimulates the inositol 1,4,5-triphosphate-induced Ca2+ release mechanism. Isoflurane and sevoflurane do not stimulate Ca2+ release or influence Ca2+ uptake.

ABSTRACT. The analysis of historical avalanche data is important when developing accurate hazard maps. The record of snow-avalanche disasters on Sakhalin and the Kuril Islands is incomplete, due to the historical division into periods of Japanese and Russian rule. Here we combine and analyze data from Japanese and Russian sources to reconstruct a continuous record of avalanche catastrophes in the region from 1910 to 2010. Despite the relatively small scale of the majority of catastrophic avalanches, with a total vertical drop <200 m, we document evidence that places the region among the most avalancheaffected areas in the world. In total, 756 fatalities and >238 injuries have occurred in 275 incidents over a 100 year period (two-thirds of those killed were Japanese). This death toll is higher than that in Canada, New Zealand or Iceland, or non-recreational fatalities in France. A wave of avalanche disasters (1930s-60s) following intense colonization of Sakhalin and the Kuril Islands is evident. Although this 'wave' could be considered a local issue of the past, many presently developing countries may face similar situations. The fatality rate has decreased over time, due to social factors, and differs from that of any other region, in its absence of deaths through recreational activities. Although in recent years the fatality rate is lower than that of Iceland or the USA, the per capita avalanche casualty rate on Sakhalin and the Kuril Islands remains among the highest in the world.