VERA Observation of the W49N H2O Maser Outburst in 2003 October

We report on a strong outburst of the W49N H2O maser observed with VERA. Single-dish monitoring with VERA 20 m telescopes detected a strong outburst of the maser feature at V_LSR = -30.7 km/s in 2003 October. The outburst had a duration of ~100 days and a peak intensity of 7.9 x 10^4 Jy, being one of the strongest outbursts in W49N observed so far. VLBI observations with the VERA array were also carried out near to the maximum phase of the outburst, and the outburst spot was identified in the VLBI map. While the map was in good agreement with previous studies, showing three major concentrations of maser spots, we found a newly formed arc-like structure in the central maser concentration, which may be a shock front powered by a forming star or a star cluster. The outburst spot was found to be located on the arc-like structure, indicating a possible connection of the present outburst to a shock phenomenon.Comment: 4 pages, 2 figures included, to appear in PASJ letter (Vol.56, #3, 2004 June

Brown Adipose Tissue in Humans Is Activated by Elevated Plasma Catecholamines Levels and Is Inversely Related to Central Obesity

BACKGROUND: Recent studies have shown that adult human possess active brown adipose tissue (BAT), which might be important in controlling obesity. It is known that ß-adrenoceptor-UCP1 system regulates BAT in rodent, but its influence in adult humans remains to be shown. The present study is to determine whether BAT activity can be independently stimulated by elevated catecholamines levels in adult human, and whether it is associated with their adiposity. METHODOLOGY/PRINCIPAL FINDINGS: We studied 14 patients with pheochromocytoma and 14 normal subjects who had performed both ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and plasma total metanephrine (TMN) measurements during 2007-2010. The BAT detection rate and the mean BAT activity were significantly higher in patients with elevated TMN levels (Group A: 6/8 and 6.7±2.1 SUVmean· g/ml) than patients with normal TMN concentrations (Group B: 0/6 and 0.4±0.04 SUVmean· g/ml) and normal subjects (Group C: 0/14 and 0.4±0.03 SUVmean·g/ml). BAT activities were positively correlated with TMN levels (R = 0.83, p<0.0001) and were inversely related to body mass index (R = -0.47, p = 0.010), visceral fat areas (R = -0.39, p = 0.044), visceral/total fat areas (R = -0.52, p = 0.0043) and waist circumferences (R = -0.43, p = 0.019). Robust regression revealed that TMN (R = 0.81, p<0.0001) and waist circumferences (R = -0.009, p = 0.009) were the two independent predictors of BAT activities. CONCLUSIONS/SIGNIFICANCE: Brown adipose tissue activity in adult human can be activated by elevated plasma TMN levels, such as in the case of patients with pheochromocytoma, and is negatively associated with central adiposity

Distribution of Radiocarbon in the Southwestern North Pacific

From the 17th International Radiocarbon Conference held in Jerusalem, Israel, June 18-23, 2000.Radiocarbon measurements in seawater samples taken at six stations in the southwestern North Pacific visited during the International Atomic Energy Agency (IAEA) 1997 Pacific Ocean Expedition were carried out at the accelerator mass spectrometry (AMS) facility of the Japan Atomic Energy Research Institute (JAERI). Three stations were located close to GEOSECS stations, and three were in the vicinity of Bikini and Enewetak Atolls, which may be influenced by former nuclear weapons testing. Compared with the GEOSECS data (1973), our results show an increase of 14C in intermediate waters. Furthermore, it is estimated that bomb-produced 14C inventories in the water column have increased by more than 20% during the last 24 years. However, vertical profiles of ∆14C at the stations near Bikini and Enewetak Atolls show a similar general trend to those found in other stations.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202