Ultra Low-Dose Radiation: Stress Responses and Impacts Using Rice as a Grass Model

We report molecular changes in leaves of rice plants (Oryza sativa L. - reference crop plant and grass model) exposed to ultra low-dose ionizing radiation, first using contaminated soil from the exclusion zone around Chernobyl reactor site. Results revealed induction of stress-related marker genes (Northern blot) and secondary metabolites (LC-MS/MS) in irradiated leaf segments over appropriate control. Second, employing the same in vitro model system, we replicated results of the first experiment using in-house fabricated sources of ultra low-dose gamma (γ) rays and selected marker genes by RT-PCR. Results suggest the usefulness of the rice model in studying ultra low-dose radiation response/s.     

Development of High Count Rate TES Microcalorimeters

To realize new TES imaging for high energy X-ray or gamma-ray spectrometer with a large pixel array and high count rate, we will try to develop a new radiation absorber self-adjusting the operating temperature and adopting an original reading out method of large pixel array using parallel biasing scheme. Our first prototype TES pixel using Au/Ti/Au tri-layer which consists of the small heat sensors and the radiation absorption area, and these are biased in serial. In this device, the current pulse with the decay time constant of less than 20 microseconds of incident X-rays from ⁵⁵Fe source were observed.      

Performance of nitrogen- and sulfur-containing carbon material derived from thiourea and formaldehyde as electrochemical capacitor

In order to investigate the performance of an electrochemical capacitor consisting of a nitrogen- and sulfur-containing carbon material, the carbon material derived from thiourea and urea was synthesized by a polymerization process of the urea resin. No solid appeared after the polymerization process. When the dried sample after the polymerization process was heated in flowing N2 gas, we obtained carbon material. However, there was no product when only thiourea was heated under the same conditions. The percentages of nitrogen and sulfur in all the samples synthesized from thiourea were roughly 5-20 wt.% and 3-8 wt.% even after washing with hot water, respectively. No specific peak derived from the redox reaction appeared in the CV graphs for the samples. The capacitance value of T-urea800W, which was synthesized by the heat treatment at 800 °C and then wash with hot water, was 138.8 F g⁻¹ at the current density of 50 mA g⁻¹ in a 1 M H₂SO₄ water solution whereas that value of a commercial activated carbon was 107.1 F g⁻¹ under the same conditions. It was presumed from the XPS measurements that the status of the nitrogen and sulfur in the materials are a pyridine-like nitrogen at the edge part of the graphitic structure, a quaternary nitrogen in the graphitic-layered structure, and S⁰, S⁴⁺, and S²⁻, respectively.     

New monitoring approach for metabolic dynamics in microbial ecosystems using stable-isotope-labeling technologies

We have developed a new approach for monitoring the metabolic dynamics in microbial ecosystems using a combination of DNA fingerprinting and metabolome analysis based on stable-isotope-labeling technologies. Stable-isotope probing of DNA (DNA-SIP) has been used previously for the evaluation of cross-feeding in microbial communities. For the development and validation of our monitoring approach, fecal microbiota were analyzed with stable-isotope-labeled glucose used as the sole carbon source. In order to link the metabolic information and the microbial variability, we performed metabolic–microbial correlation analysis based on nuclear magnetic resonance (NMR) profiles and denaturing gradient gel electrophoresis (DGGE) fingerprints, which successfully identified the glucose-utilizing bacteria and their related extracellular metabolites. Moreover, our approach revealed information regarding the carbon flux, in that the “first” wave of extracellular metabolites secreted by the glucose-utilizing bacteria were incorporated into the “secondary” group of substrate-utilizing bacteria, and that this “secondary” group further produced their own secondary metabolized substrates. Thus, this approach is a powerful tool for monitoring the metabolic dynamics in microbial ecosystems and allows for the tracking of the carbon flux within a microbial community.     

Tribological Properties and Film Formation Behavior of Thermoreversible Gel Lubricants

The tribological properties of a new and unique thermoreversible gel lubricant (TR gel lube) were investigated. TR gel lube, which includes 10–40% of amide-type gelling agent in base fluid, is able to repeatedly alter or convert phase from gel state to liquid state at the melting point of the gelling agent. High-pressure rheological tests were performed in order to characterize the behavior of base oil and TR gel lube as a function of pressure and temperature. The effect of TR gel lube on ball bearing fatigue life was carried out by systematic tests using thrust ball bearings. The results of L ₁₀ life tests of TR gel lube showed a longer life than the conventional greases. This result was investigated from the oil film formation. It was found that the gelling agent played a key role in the lubricating properties. Some mechanisms such as adsorbed film formation and solid-like formation are proposed.     

Visualization of spherical data by Yin-Yang grid

Visualization in the spherical geometry is ubiquitous in geophysical data processing. For the spherical visualization, the commonly used spherical polar coordinate system is not ideal due to its grid convergence nature near the poles. We propose to use a spherical overset grid system called Yin-Yang grid as the base grid system of the spherical visualization. The convergence-free nature of the Yin-Yang grid leads to a balanced data distribution and effective visualization processing in a sphere. The Yin-Yang grid is already used in various geophysical simulations including the geodynamo and mantle convection in the spherical geometry. Data produced by the Yin-Yang grid can be, and should be, visualized directly on the same Yin-Yang grid system without any data remapping. Since the component grid of the Yin-Yang grid is a part of (or low latitude region of) the standard spherical polar coordinate system, it is straightforward to convert an existing spherical visualization tool based on the spherical polar coordinates into a tool based on the Yin-Yang grid.     

Real-time system for measuring gaze direction and facial features: towards automatic discrimination of lies using diverse nonverbal information

Interactive and autonomous agents might be common in everyday life in the future; we expect that such agents will have the ability to communicate with people naturally. For natural communication, the agents should speculate about the intentions of the people they interact with. To enable agents to speculate about intentions like deception, we focused on unconscious expressions when people tell a lie. However, there is no system that can meet the necessary conditions for measuring nonverbal information in natural communication. Therefore, we made a real-time system for measuring gaze direction and facial features. We conducted experiments for discriminating lies by using the system in a situation similar to actual communication. As a result, we found that we could discriminate lies by using diverse nonverbal information in the same way people did.     

Preparation of thermally stable polymer electrolytes from imidazolium-type ionic liquid derivatives

Thermally stable polymer electrolytes based on ionic liquids were prepared and analyzed. Mono-functional ionic liquid monomers, ionic liquid cross-linkers, and ethylimidazolium-type ionic liquid salts were mixed and polymerized. The ionic liquid-type cross-linkers were effective to prepare thermally stable polymer films. In particular, the copolymerization of cross-linker and ethylimidazolium-type ionic liquid monomers were used to make polymer electrolytes with high ionic conductivities. The copolymerization in ethylmethylimidazolium bis(trifluoromethanesulfonyl)imide gave a transparent film showing no thermal degradation up to 400 °C.     

Multivariate evaluation of prognostic determinants for renal cell carcinomas which are metastatic at initial diagnosis

To clarify the relative importance of clinicopathological factors potentially affecting the survival of individuals initially diagnosed as having metastatic renal cell carcinoma (RCC), univariate and multivariate analyses using Cox's proportional hazards model were performed for 111 RCC patients who were admitted to four hospitals in Nagoya, Japan, between 1978 and 1993. Survival time was calculated from the date of diagnosis to the date of death or the end of May, 1995. Nineteen factors (17 clinically applicable before treatment and 2 histological in nature) were included for assessment. Univariate analysis revealed that 10 of the total 19 factors were significantly associated with patient survival. Multivariate analysis found 7 factors to be statistically significant determinants. Survival was further evaluated by categorizing the patients into three groups according to the number of the 7 factors. These groups showed clearly different survivals (log-rank test, p < 0.0001), confirming the importance of the 7 factors as definite determinants. They should therefore prove to be of advantage for classifying metastatic RCC patients when designing clinical prospective studies of immunotherapy and chemotherapy.