Uncertainty surrounds the fate of the orogenic plateau in what is now the Great Basin in western Utah and Nevada, which resulted from the Mesozoic and earliest Cenozoic contractile deformations and crustal thickening. Although there is some consensus regarding the gravitational collapse of the plateau by extensional faulting and consequent crustal thinning, whether or not the plateau existed during the middle Cenozoic Great Basin ignimbrite flareup -one of the grandest expressions of continental volcanism in the geologic record -had remained in doubt. We use compositions of contemporaneous calc-alkaline lava flows as well as configurations of the ignimbrite sheets to show that the Great Basin area during the middle Cenozoic was a relatively smooth plateau underlain by unusually thick crust. We compare analyses of 376 intermediate-composition lava flows in the Great Basin that were extruded at 42 -17 Ma with compositions of .6000 analyses of the late Cenozoic lava flows in continental volcanic arcs that correlate roughly with known crustal thickness. This comparison indicates that the middle Cenozoic Great Basin crust was much thicker than the present ca. 30 km thickness, likely as much as 60 -70 km. If isostatic equilibrium prevailed, this unusually thick continental crust must have supported high topography. This high terrain in SE Nevada and SW Utah was progressively smoothed as successive ignimbrite outflow sheets were emplaced over areas currently as much as tens of thousands of square kilometres to aggregate thicknesses of as much as hundreds of metres. The generally small between-site variations in the palaeomagnetic directions of individual sheets lend further support for a relatively smooth landscape over which the sheets were draped. We conclude that during the middle Cenozoic, especially towards the close of the ignimbrite flareup, this Great Basin area was a relatively flat plateau, and because it was also high in elevation, we refer to it as an Altiplano. It was not unlike the present-day Altiplano-Puna in the tectonically similar central Andes, where an ignimbrite flareup comparable to that in the Great Basin occurred at ca. 9-3 Ma. Outflow ignimbrite sheets that were deposited from 35 to 23 Ma on the progressively smoothed Altiplano in south-eastern Nevada were derived from source calderas to the west. Of the 12 major sheets from seven sources, nine are distributed unevenly east of their sources while the remaining three sheets are spread about as far east as west of their sources. This eccentricity of sources near the western margin of 75% of the sheets indicates the existence of a NS-trending topographic barrier in central Nevada that restricted westward dispersal of ash flows. In a symmetric manner, eastward dispersal of ash flows from sources farther west seemed to have been impeded by this same topographic barrier. The westward dispersal was controlled in part by westward-draining stream valleys incised in the sloping flank of the Great Basin Vol. 51, Nos. 7 -8, July-August 2009, 589-633 A...

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Two groups of normal volunteers had regional cerebral blood flow (rCBF) measured, by the 133Xenon inhalation technique, before and 30 minutes after 250 mg or 500 mg caffeine given orally. rCBF was measured in a third group of subjects, twice, at a similar interval under identical laboratory conditions. Subjects who received caffeine showed significant decreases in rCBF while the others showed no rCBF change from the first to the second measurement. However, the two caffeine groups did not differ in degrees of rCBF reduction. There were no regional variations in the post-caffeine decrease in cerebral blood flow. The three groups did not show significant changes in end-tidal carbon dioxide, pulse rate, blood pressure, forehead skin temperature and respiratory rate.

The extraversion-introversion dimension of personality is believed to have an inverse relationship with cortical arousal. Brain capillary perfusion is a well established index of brain function and arousal. Regional cerebral blood flow was measured in 51 right-handed females whose personality structure was examined with the Eysenck Personality Inventory (EPI). Significant inverse correlations were found between the brain blood flow and the extraversion-introversion score of EPI.

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Neuropsychological investigations utilizing serial regional cerebral blood flow (rCBF) measurements have been inconsistent in their finding of run order effects. This study investigated the significance of run order when utilizing extended rCBF intermeasure intervals. Subjects were 20 healthy adult female volunteers. The 133-xenon inhalation technique was utilized in obtaining two rCBF measurements per subject. The mean intermeasure interval was 14.7hS.6 days. All measurements were performed during morning hours under conditions of minimal external sensory stimulation. No significant run order effect was obtained. Results are compared with relevant previous studies. Effect of intermeasure interval length on subject anxiety, habituation, fatigue, and on order effects are discussed.Int J Neurosci Downloaded from informahealthcare.com by University of Newcastle Upon Tyne on 12/20/14For personal use only.

This study examined pulmonary function of pipers and cardiac adaptation to the playing of the Great Highland bagpipe. Pipers (n = 13) of varying ages (31-65 years) and playing experiences (2-20+ years) were evaluated for vital capacity (VC), maximal voluntary ventilation (MVV), and forced vital capacity (FVC) using a RIKO AS-600 spirometer. Subjects were monitored by impedance cardiograph for heart rate (HR), stroke volume (SV), and cardiac output (CO) at rest and during 5 minutes of playing. An automatic blood pressure (BP) monitor collected BP values over the same time period. Eleven weeks after initial cardiac data collection, the BP and cardiac measurements were repeated using the same protocols. Mean values for HR, SV, and CO were calculated for rest and each minute (1-5) of playing. A 2 (data session) by 6 (rest, min 1–5) repeated-measures ANOVA was performed. Analysis revealed a significant overall time effect (p < 0.001) on HR. A-priori contrast comparing all playing times with rest showed significant differences at all time points. Analysis of SV and CO failed to find significance. Heart rate values calculated for percent of maximum ranged from 68% to 89% of maximum overall while playing (session 1) and from 55% to 81% of maximum (session 2). Predicted percent of maximum values for VC and MVV found 77% of players above their maximum predicted values.