137Cs loss via soil erosion from a mountainous headwater catchment in central Japan

Eroded sediment and coarse organic material were sampled for a year at the outlet of the study catchment in central Japan to investigate characteristics of 137Cs loss and to quantify erosional 137Cs loss in a forested headwater catchment. Results showed that loss of both eroded sediment and 137Cs varied markedly according to the magnitude of rainfall events. About 90% of the total sediment delivery and the total 137Cs loss was associated with only two storm rainfall events. The significant contribution of high-magnitude-low-frequency storm events to 137Cs loss from the catchment was emphasized. To quantify the contribution of erosional 137Cs loss to 137Cs cycling, the current mean 137Cs inventory of the study catchment was estimated from direct measurements of 137Cs in soil cores collected from 27 points. The input of 137Cs through litterfall to the soil was estimated from monitoring the annual litterfall of the study catchment. The present 137Cs fallout input was estimated from published 137Cs fallout data. Consequently, the loss of 137Cs associated with eroded sediment was estimated to represent 0.013% of the 137Cs inventory of the study catchment, which is comparable to the input through litterfall. The equivalent value for 137Cs runoff with coarse organic material was estimated as 0.0003%. Therefore, the effect of 137Cs loss in association with coarse organic material on estimates of erosion rate obtained by measuring 137Cs inventories in soil core samples was inferred to be negligible in Japanese cypress plantations. Results confirm the applicability of 137Cs measurements to estimate erosion rates in other relatively stable forested areas.     

Ultra-Structural Imaging Provides 3D Organization of 46 Chromosomes of a Human Lymphocyte Prophase Nucleus

Three dimensional (3D) ultra-structural imaging is an important tool for unraveling the organizational structure of individual chromosomes at various stages of the cell cycle. Performing hitherto uninvestigated ultra-structural analysis of the human genome at prophase, we used serial block-face scanning electron microscopy (SBFSEM) to understand chromosomal architectural organization within 3D nuclear space. Acquired images allowed us to segment, reconstruct, and extract quantitative 3D structural information about the prophase nucleus and the preserved, intact individual chromosomes within it. Our data demonstrate that each chromosome can be identified with its homolog and classified into respective cytogenetic groups. Thereby, we present the first 3D karyotype built from the compact axial structure seen on the core of all prophase chromosomes. The chromosomes display parallel-aligned sister chromatids with familiar chromosome morphologies with no crossovers. Furthermore, the spatial positions of all 46 chromosomes revealed a pattern showing a gene density-based correlation and a neighborhood map of individual chromosomes based on their relative spatial positioning. A comprehensive picture of 3D chromosomal organization at the nanometer level in a single human lymphocyte cell is presented.     

γ-Tocotrienol Reduces Squalene Hydroperoxide-Induced Inflammatory Responses in HaCaT Keratinocytes

Squalene hydroperoxide (SQ-OOH), the primary peroxidation product of squalene (SQ), accumulates at the surface of sunlight-exposed human skin. There are however only a few studies on the pathogenic actions (i.e., inflammatory stimuli) of SQ-OOH. Here, we evaluated whether SQ-OOH induced inflammatory responses in immortalized human keratinocytes (HaCaT). We found that SQ-OOH caused an increase in the expression of inflammatory genes such as the interleukins as well as cyclooxygenase-2 (COX-2). In concordance with the upregulation of COX-2 mRNA, SQ-OOH enhanced reactive oxygen species generation, nuclear factor kappa B activation, COX-2 protein expression, and prostaglandin E2 production. Therefore, the pro-inflammatory effects of SQ-OOH may be mediated in part via COX-2. On the other hand, γ-tocotrienol (γ-T3, an unsaturated form of vitamin E) was found to ameliorate the SQ-OOH actions. These results suggest that SQ-OOH induces inflammatory responses in HaCaT, implying that SQ-OOH plays an important role in inflammatory skin disorders. As a preventive strategy, inflammation could be reduced via the use of γ-T3.     

Three-dimensional visualization of void fraction distribution in steady two-phase flow by thermal neutron radiography

Three-dimensional void fraction distributions of a steady air–water two-phase flow in a 4×4 rod-bundle with circular ferrule type spacers were measured by neutron radiography using a CT method. The high flux thermal neutron radiography system at JRR-3M in JAERI was used. Two-phase flow was visualized with a SIT tube camera and time-averaged one-dimensional cross sectional averaged void fraction distributions were calculated. Visualization with high spatial resolution up to 0.18 mm was carried out by using a cooled CCD camera. Projections in 250 directions were obtained and were reconstructed by a filtered back projection method after using some image processing techniques. Animations were made to show the three-dimensional distributions. One-dimensional and three-dimensional void fraction distributions of the steady state two-phase flow in the rod bundle near the spacer were clearly visualized.     

Functional expression of Fas antigen (CD95) on hematopoietic progenitor cells

We investigated the expression of an apoptosis-associated antigen (Fas) (CD95) on hematopoietic progenitor cells in the presence or absence of interferon-gamma (IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha). CD34+ cells freshly isolated from bone marrow did not express Fas. However, IFN-gamma and/or TNF-alpha induced the expression of both the mRNA of Fas and Fas itself in a dose-dependent fashion on the surface of CD34+ cells after 48 hours of serum-free culture. IFN-gamma and TNF-alpha had a synergistic effect on the induction of Fas, when both cytokines were added to the culture. The TNF-alpha-induced Fas expression is mediated by p55 TNF-alpha receptor. CD34+ cells cultured in medium alone or with stem cell factor (SCF) showed some slight expression of Fas. When anti-Fas antibody (IgM) was added to CD34+ cells after the induction of Fas expression, CD34+ cells underwent apoptosis, as shown by a decrease in the number of viable cells, morphologic changes, the induction of DNA fragmentation, and a decrease in the number of colony-forming cells (CFC) including colony-forming unit granulocytes/macrophages (CFU-GM) and burst-forming unit erythroids (BFU-E). These observations indicate that IFN-gamma and/or TNF-alpha, well known as negative hematopoietic regulators, induce functional Fas on hematopoietic progenitor cells. The suppression of hematopoiesis by negative hematopoietic regulators may be mediated in part by Fas induction.     

H∞ control approach to a magnetic levitation system by 4-point attraction with nonlinear characteristics

An H_∞ control system design for a magnetic levitation system by 4 points attraction is presented. In the levitation system, a vehicle which runs as the secondary in a reluctance-type linear motor is levitated by four pairs of attraction forces and guided by two pairs of attraction forces. Because it has contactlessness, in the field of semiconductor products, its application is favorable for ultraclean environments in microscopic processing. In the control system design, the influence of both disturbances and uncertainties in the model is considered. The main disturbances stem from the position sensors. The uncertainties are divided into electromagnetic and mechanical ones: the former are due to the gain change in the current amplifier, the influence of leakage flux and linearization error in the magnetic circuit, and the latter are due to the changes of the mass and the moment of inertia of the vehicle. Therefore, the designed controller is indispensable to guarantee robustness of this system for both stability and performance. The controller design is based on the standard H_∞-optimal control problem. As the novel features in this paper, the low sensitivity and the robust stability for this system design is obtained. Further, there are two-poles on jω-axis in the controlled model, and an integrator is included in the controller so that equivalently there are three poles on the jω-axis in the model. Finally, several experiments, comparisons and simulations are carried out to verify the low sensitivity and robustness of the designed control system.     

Polarisation insensitive deep-ridge vertical-groove DFB waveguidefor all-optical switching

A deep-ridge vertical-groove distributed feedback (DFB) waveguide has been fabricated. Structural birefringence of the fabricated device was completely eliminated by controlling waveguide width. Additionally, polarisation independence of the grating coupling coefficient was accomplished by adjusting grating depth     

Experimental study on flow pattern and heat transfer of inverted annular flow

Experimental results are presented on flow pattern and heat transfer in the regions from inverted annular flow to dispersed flow in a vertical tube using freon R-113 as a working fluid at atmospheric pressure to discuss the correspondence between them. Axial distributions of heat transfer coefficient are measured and flow patterns are observed. The heat transfer characteristics are divided into three regions and a heat transfer characteristics map is proposed. The flow pattern changes from inverted annular flow (IAF) to dispersed flow (DF) through inverted slug flow (ISF) for lower inlet velocities and through agitated inverted annular flow (AIAF) for higher inlet velocities. A flow pattern map is obtained which corresponds well with the heat transfer characteristic map.     

Virus-associated haemophagocytic syndrome caused by rubella in an adult

Haemophagocytic syndrome is a systemic clinicopathological entity characterized by systemic proliferation of benign haemophagocytic histiocytes, fever, cytopenia, abnormal liver function and, frequently, coagulopathy and hepatosplenomegaly. Its occurrence has been documented in association with viral, bacterial, fungal and parasitic infections, a wide spectrum of malignant neoplasms, autoimmune diseases and drugs. We report a case of rubella virus-associated haemophagocytic syndrome in a previously healthy 29-year-old woman. Blood tests showed cytopenia, especially severe thrombocytopenia, liver dysfunction, hyperferritinaemia and hypercytokinaemia. Bone marrow examination showed many mature histiocytes with active haemophagocytosis. A skin biopsy from the rash revealed perivascular lymphohistiocytic infiltrates with haemophagocytic histiocytes in the upper and mid-dermis. The patient was treated with antibiotics and immunoglobulin, and by supportive measures including platelet transfusion, and recovered completely.     

A control method for improving ac input current waveform of current-type PWM rectifiers

Recently, PWM rectifiers which realize high-power factor and almost sinusoidal ac input current have been proposed and some of them have already been put into practice. In many cases the PWM rectifiers are of current type, that is, they have a smoothing reactor on the dc side. In such rectifiers, an LC filter has to be inserted on the ac side to reduce current harmonics due to the PWM operation. However, the LC filter may cause waveform distortion and transient oscillation of the ac side current. As a solution to this problem, a new control method is proposed introducing ac side current control by means of state feedback of the LC filter. In this case, both the dc output current and the ac input current controls should be achieved by the PWM operation of the rectifier. Furthermore, to obtain sufficient controllability regardless of the operating condition, the dc output and ac input current controls should be done independently. To meet these requirements, existing control methods for PWM rectifiers are not directly applicable. In this paper, a novel control circuit configuration and a method of generating a PWM pulse pattern suitable for the proposed control method are described in detail. From the viewpoint of stability, feedback coefficients and circuit parameters are investigated on the basis of root locus analysis. Some experimental results also are shown to confirm the effectiveness of the proposed control method and the validity of the analytical results. Improvement of the ac side current waveform and the stability of the transient response are demonstrated by these experimental results.