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We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.  相似文献   
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The 1994 eruption of Rabaul, in Papua New Guinea, involved a small plinian eruption at Vulcan and a vulcanian eruption on the opposite side of the caldera at Tavurvur. Vulcan's ash leachates indicate seawater interaction that is consistent with earlier observations of low sulfur dioxide emissions and the presence of ice crystals in the initial plinian eruption cloud. In contrast, Tavurvur ash leachates indicate no seawater interaction, and later sulfur dioxide emissions remained high despite low-level eruptive activity. Silicic melt inclusions indicate that the andesitic melt contained about 2 weight percent water and negligible carbon dioxide. Mafic melt inclusions in Tavurvur ash have water and carbon dioxide contents that vary systematically over the course of the eruption. The mafic melt inclusions suggest that a mafic dike intruded from below the silicic chamber and provide further evidence that mafic intrusions drive caldera unrest.  相似文献   
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Human taste papillae are sensitive to two or more chemical stimuli. Individual papillae produce stable response patterns (quality and intensity) over a month's time. Hence, the response pattern does not appear to be affected by turnover of receptor cells.  相似文献   
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Pioglitazone is a thiazolidinedione class of antidiabetic agent with proven efficacy in increasing insulin sensitivity in humans with noninsulin-dependent diabetes mellitus, a syndrome of insulin resistance sharing similarities with equine metabolic syndrome. The purpose of this study was to determine the pharmacokinetics of pioglitazone in adult horses following multiple oral dose administration. Pioglitazone hydrochloride (1 mg/kg) was administered orally for 11 doses at 24-h intervals, and plasma samples were collected. Initially, a pilot study was performed using one horse; and thereafter the drug was administered to six horses. Samples were analyzed by liquid chromatography with tandem mass spectrometry, and pharmacokinetic parameters were calculated using noncompartmental modeling. The maximum plasma concentration was 509.1 ± 413.5 ng/mL achieved at 1.88 ± 1.39 h following oral administration of the first dose, and 448.1 ± 303.5 ng/mL achieved at 2.83 ± 1.81 h (mean ± SD) following the eleventh dose. Apparent elimination half-life was 9.94 ± 4.57 and 9.63 ± 5.33 h after the first and eleventh dose, respectively. This study showed that in healthy horses, pioglitazone administered at a daily oral dose of 1 mg/kg results in plasma concentrations and total drug exposure approximating, but slightly below, those considered therapeutic in humans.  相似文献   
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A field study conducted for two crop cycles of five cropping systems supplied with six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping systems having a legume increased organic C content over initial level by 0.02?–?0.05%, available N by 3.5?–?14.1?kg ha???1, whereas the rice-wheat cropping system resulted in a reduction in organic C and available N over initial level by 0.05% and 1.5?kg ha???1, respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK?+?FYM showed the highest increase in organic C, available N, available P and available K content in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P and K content in soil. Integrated nutrient management is one of the best methods for resilience of soil fertility under rice-wheat cropping system.  相似文献   
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To test the hypotheses that glucose transport capacity across the brush border membrane (BBM) of the large colon is lower than that of the small intestine in equids, and that small intestinal transport capacity in equids is lower than suids. d-glucose transport capacity (Vmax) and affinity (KM) across the BBM of the distal jejunum (DJ) and proximal large colon (PLC) of the pony and pig were measured. Mucosa was collected from the DJ and PLC of ponies (n = 4) and pigs (n = 3), flash-frozen in liquid nitrogen, and stored at −80°C. Jejunal and colonic BBM vesicles were manufactured, and d-glucose transport was determined. There was no detectable active uptake of glucose in the equine PLC. Compared with the pig DJ, d-glucose transport capacity was lower (2595 ± 331 vs. 655 ± 286 ρmol·mg protein−1·s−1, respectively, P < .01) and transport affinity tended to be lower (0.09 ± 0.07 vs. 0.27 ± 0.06 mM, respectively, P = .11) in the pony DJ. Compared with the pig DJ, d-glucose transport capacity (2,595 ± 331 vs. 571 ± 331 ρmol·mg protein−1·s−1, respectively, P < .001) and transport affinity (0.09 ± 0.07 vs. 0.54 ± 0.07 mM, respectively, P < .001) in the pig PLC were lower. Results show there is negligible d-glucose uptake across pony PLC, and capacity for d-glucose absorption across DJ BBM is fourfold lower in the pony compared with the pig. Results further exemplify, at a physiological level, the limited capacity of the equid small intestine to transport glucose relative to an omnivorous mammal, and the likely evolutionary adaptation of equids to low dietary levels of nonstructural carbohydrates.  相似文献   
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