Transition Probability to Turbulent Transport Regime

Transition phenomena between thermal noise state and turbulent state observed in a submarginal turbulent plasma are analyzed with statistical theory. Time-development of turbulent fluctuation is obtained by numerical simulations of Langevin equation which contains hysteresis characteristics. Transition rates between two states are analyzed. Transition from turbulent state to thermal noise state occurs in entire region between subcritical bifurcation point and linear stability boundary.Comment: 9 pages, 6 figures, to be published in Plasma Phys. Control. Fusio

Primary adenocarcinoma of the stomach in von Recklinghausen's disease with high serum levels of multiple tumor markers: a case report

<p>Abstract</p> <p>Introduction</p> <p>Gastric tumors in patients affected by neurofibromatosis type 1 are usually carcinoids or stromal tumors, and rarely adenocarcinomas.</p> <p>Case presentation</p> <p>We report a case of an adenocarcinoma of the stomach in a 53-year-old Japanese man with neurofibromatosis type 1. An abdominal computed tomography scan and ultrasonography showed tumors in his liver. Gastric fibroscopy revealed a Borrmann type III tumor on his cardia that had spread to his esophagus and was highly suspicious for malignancy. Multiple biopsies showed an adenocarcinoma of the stomach, which was evaluated as gastric cancer, stage IV. Chemotherapy with TS-1 was performed. Our patient died four weeks after initial admission. Histological examination of a liver needle biopsy showed metastatic adenocarcinoma in his liver.</p> <p>Conclusion</p> <p>To the best of our knowledge, high serum levels of α-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 72-4, resulting from gastric adenocarcinoma, have not been reported previously in a patient with neurofibromatosis type 1. We report this rare case along with a review of the literature.</p

Spatial distributions of oxygenated organic compounds (dicarboxylic acids, fatty acids, and levoglucosan) in marine aerosols over the western Pacific and off the coast of East Asia: Continental outflow of organic aerosols during the ACE-Asia campaign

Aerosol sampling for major oxygenated organic compounds (dicarboxylic acids, fatty acids, and levoglucosan) was conducted from 15 March to 19 April 2001 on board the National Oceanic and Atmospheric Administration R/V Ronald H. Brown over the western North Pacific, the East China Sea, and the Sea of Japan, as part of the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) campaign. During the cruise, aerosol particles were collected on quartz fiber filters using a high-volume air sampler. Diacids were also collected using an annular denuder sampling system to assess their gas-particle partitioning. Concentrations of total diacids, total fatty acids, and levoglucosan were found to be higher off the coasts of East Asia than in the remote Pacific. Contributions of these organic compounds to total organic carbon and total organic matter (OM) were calculated to be 9.8 ± 2.3% and 19.0 ± 4.8%, respectively, assuming OM to be organic carbon x 1.6. Diacid concentrations were highly correlated with nss-SO2-/4 and NO-3, which originate from anthropogenic sources over East Asia. The temporal variations and chain-length distributions of fatty acids suggest that atmospheric transport of terrestrial organic materials is important off the coast of the continent. C2 – C5 diacids were present predominantly in the particulate phase. The relative abundances of C2 – C5 diacids stayed almost unchanged throughout the cruise, suggesting that deposition is more important than chemical decomposition as a sink of diacids and that they are relatively stable end products in the atmosphere

Traveling EEG slow oscillation along the dorsal attention network initiates spontaneous perceptual switching

An ambiguous figure such as the Necker cube causes spontaneous perceptual switching (SPS). The mechanism of SPS in multistable perception has not yet been determined. Although early psychological studies suggested that SPS may be caused by fatigue or satiation of orientation, the neural mechanism of SPS is still unknown. Functional magnetic resonance imaging (fMRI) has shown that the dorsal attention network (DAN), which mainly controls voluntary attention, is involved in bistable perception of the Necker cube. To determine whether neural dynamics along the DAN cause SPS, we performed simultaneous electroencephalography (EEG) and fMRI during an SPS task with the Necker cube, with every SPS reported by pressing a button. This EEG–fMRI integrated analysis showed that (a) 3–4 Hz spectral EEG power modulation at fronto-central, parietal, and centro-parietal electrode sites sequentially appeared from 750 to 350 ms prior to the button press; and (b) activations correlating with the EEG modulation traveled along the DAN from the frontal to the parietal regions. These findings suggest that slow oscillation initiates SPS through global dynamics along the attentional system such as the DAN

Extension of the operational regime of the LHD towards a deuterium experiment

As the finalization of a hydrogen experiment towards the deuterium phase, the exploration of the best performance of hydrogen plasma was intensively performed in the large helical device. High ion and electron temperatures, Ti and Te, of more than 6 keV were simultaneously achieved by superimposing high-power electron cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value $\left\langle \beta \right\rangle$ . The high $\left\langle \beta \right\rangle$ regime around 4% was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with a wide range of edge plasma parameters. The existence of a no impurity accumulation regime, where the high performance plasma is maintained with high power heating  >10 MW, was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region

Hygroscopic properties of particles nebulized from water extracts of aerosols collected at Chichijima Island in the western North Pacific: An outflow region of Asian dust

We present 2 year measurements of hygroscopic properties of water-soluble matter (WSM) extracted from marine aerosols from remote Chichijima Island in the western North Pacific during 2001-2002. Hygroscopic growth factors (g) of WSM were measured by a hygroscopicity tandem differential mobility analyzer with initial dry particle diameter of 100 nm. The observed g at 90% relative humidity (RH), g(90%), ranged from 1.42 to 1.89 with an average of 1.790.11. The g values are significantly lower than that of seawater (2.1) and slightly lower than those previously reported for marine aerosols (>1.8), probably due to the atmospheric processing associated with chlorine depletion; mean Cl-/Na+ molar ratio (1.100.23) was smaller than seawater (1.18), and organometal interaction (e.g., formation of water-insoluble calcium oxalate, g(90%)<1). Inorganic salts accounted for 87-98% of WSM. Na+ and Cl- are two major species, contributing 63% of total inorganic ion mass. The calculated aerosol water content (V-w/V-dry) at 85% RH during hydration experiment ranged from 1 to 3.66 (mean of 2.750.81). V-w/V-dry is negatively correlated with organic mass fraction, indicating that organics may suppress the hygroscopicity of the marine aerosol particles. The declined g(90%) and Cl-/Na+ molar ratio and increased abundance of water-soluble organics in spring demonstrated that the atmospheric mixing of anthropogenic pollutants (e.g., NO3, SOx) and water-soluble organics can decrease the growth factor of marine aerosols. The two case studies of spring aerosols demonstrated that Asian dusts were internally mixed with hygroscopic species in different ways, depending on their transport pathway

Long-term (2001-2012) observation of the modeled hygroscopic growth factor of remote marine TSP aerosols over the western North Pacific : impact of long-range transport of pollutants and their mixing states

In order to assess the seasonal and annual variability of long-range transported anthropogenic pollutants from East Asia and their effect on the hygroscopicity and precipitation process over the western North Pacific, we conducted long-term calculations of bulk hygroscopicity, g(90%)(ZSR), based on the ZSR model using chemical composition data from 2001-2012 at Chichijima Island. We found that sea-salts (Na+ and Cl-) are the major mass fraction (65%) of the total water-soluble matter followed by SO42- (20%) and WSOM (6%). The seasonal variation of g(90%)(ZSR) was high in summer to autumn and low in winter to spring months, probably due to the influence of the long-range transport of anthropogenic SO42-, dust, and organics from East Asia and their interaction with sea-salts through heterogeneous reactions. On the other hand, annual variations of g(90%)(ZSR) showed a decrease from 2001 to 2006 and then an increase from 2007 to 2012. Interestingly, the annual variations in SO42- mass fractions showed an increase from 2001 to 2006 and then a decrease from 2007 to 2012, demonstrating that SO42- seriously suppresses the hygroscopic growth of sea-salt particles over the western North Pacific. This is further supported by the strong negative correlation between SO42- and g(90%)(ZSR). Based on the MODIS satellite data, the present study demonstrates that long-range transported anthropogenic pollutants from East Asia to the North Pacific can act as efficient cloud condensation nuclei but significantly suppress the precipitation by reducing the size of cloud droplets over the western North Pacific