Influence of pH on performance of sodium phosphinate for decreasing the particle size

To clarify the influence of pH on performance of sodium phosphinate (NaPH₂O₂) for decreasing particle size of Pt nanoparticles, carbon-supported Pt nanoparticles that contained phosphorus (P–Pt/C) were synthesised by an electron-beam irradiation reduction method (EBIRM) under four different pH conditions (pH = 3, 6, 9, and 12) and under five different NaPH₂O₂ concentrations (0.0, 0.5, 1.0, 3.0, and 5.0 mM). The relationship among pH, NaPH₂O₂ concentration, average particle size of Pt nanoparticle, and Pt loading weight was investigated in this study. The average particle size of Pt nanoparticles was in the range of 0.8–3.4 nm and lower in the order; pH12 > pH3 > pH6 > pH9; for example, under the same NaPH₂O₂ concentrations of 3.0 mM, the particle size of P–Pt/C prepared at pH = 12 and pH = 9 was 1.5 and 0.8 nm, respectively. In addition, Pt loading weight was also lower in the order; pH12 > pH3 > pH6 > pH9. In summary, these results indicated that the pH in the precursor solution affected the performance of NaPH₂O₂. These findings would be useful for controlling the particle size of monometallic Pt and Pt-based bimetallic nanoparticles supported on carbon particles for fuel cell applications.     

Learning word meanings and grammar for verbalization of daily life activities using multilayered multimodal latent Dirichlet allocation and Bayesian hidden Markov models

Intelligent systems need to understand and respond to human words to enable them to interact with humans in a natural way. Several studies attempted to realize these abilities by investigating the symbol grounding problem. For example, we proposed multilayered multimodal latent Dirichlet allocation (mMLDA) to enable the formation of various concepts and inference using grounded concepts. We previously reported on the issue of connecting words to various hierarchical concepts and also proposed a simple preliminary algorithm for generating sentences. This paper proposes a novel method that enables a sensing system to verbalize an everyday scene it observes. The method uses mMLDA and Bayesian hidden Markov models (BHMM) and the proposed algorithm improves the word inference of our previous work. The advantage of our approach is that grammar learning based on BHMM not only boosts concept selection results but enables our method to process functional words. The proposed verbalization algorithm produces results that are far superior to those of previous methods. Finally, we developed a system to obtain multimodal data from human everyday activities. We evaluate language learning and sentence generation as a complete process under this realistic setting. The results demonstrate the effectiveness of our method.     

Locating congested segments over the Internet by clustering the delay performance of multiple paths

Delay variation-based detection and location of congestion in a large network is considered. Since the Internet is still highly prone to performance deterioration due to transient large delays, locating a part of the network (segments) responsible is vital to ensure that Internet Service Providers can mitigate or prevent such performance deterioration. In the proposed method, the end-to-end packet delays from multiple origins to multiple destinations are actively and continuously measured. By analyzing those data on delay variation along each monitored path, congestion is detected by finding a delay performance deterioration worse than a predefined criteria and a congested segment responsible could be inferred by finding a set of paths among which delay variations are strongly correlated. This is a network tomographic approach based on a clustering technique that effectively tackles the correlation among packet delay variation along individual paths. The proposed method was evaluated through a real-world long-term experiment on the Japan’s commercial Internet, and was shown to have considerable potential to promptly locate congested segments through various analyses on the experimental results.     

Computer-aided diagnosis: the emerging of three CAD systems induced by Japanese health care needs

The aim of this paper is to describe three emerging computer-aided diagnosis (CAD) systems induced by Japanese health care needs. CAD has been developing fast in the last two decades. The idea of using a computer to help in medical image diagnosis is not new. Some pioneer studies are dated back to the 1960s. In 1998, the first U.S. FDA (Food and Drug Administration) approved commercial CAD system, a film-digitized mammography system, was launched by R2 Technologies, Inc. The success was quickly repeated by a number of companies. The approval of Medicare CAD reimbursement in the U.S. in 2001 further boosted the industry. Today, CAD has its significance in the economy of the medical industry. FDA approved CAD products in the field of breast imaging (mammography, ultrasonography and breast MRI) and chest imaging (radiography and CT) can be seen. In Japan, as part of the "Knowledge Cluster Initiative" of the government, three computer-aided diagnosis (CAD) projects are hosted at the Gifu University since 2004. These projects are regarding the development of CAD systems for the early detection of (1) cerebrovascular diseases using brain MRI and MRA images by detecting lacunar infarcts, unruptured aneurysms, and arterial occlusions; (2) ocular diseases such as glaucoma, diabetic retinopathy, and hypertensive retinopathy using retinal fundus images; and (3) breast cancers using ultrasound 3-D volumetric whole breast data by detecting the breast masses. The projects are entering their final development stage. Preliminary results are presented in this paper. Clinical examinations will be started soon, and commercialized CAD systems for the above subjects will appear by the completion of this project.     

Anisotropy in ac losses near the irreversibility field of Bi2Sr2CaCu2O8

The ac susceptibility under a biased dc field near the irreversibility field (H _irr) of a Bi₂Sr₂CaCu₂O₈ single crystal has been measured. The frequency dependence, the ac-power dependence, and the nearly lossless character of the vs.H _dc curve forHa-axis have been roughly explained from a reversible (elastic) fluxoid motion, while those forH c-axis have been explained from a thermally assisted flux-flow (TAFF) model. The obtained parameters are discussed in relation to anisotropic flux-pinning mechanisms in the layered structure of this compound.     

Influence of the atmosphere on organic–organic interfacial layers and deterioration in organic light‐emitting diodes

The influence of organic–organic interfacial contaminants and deterioration in organic light‐emitting diodes (OLEDs) was investigated. There was deterioration of the device characteristics when atmospheric contamination was introduced to the emission site. We simultaneously observed a decrease of the maximum capacitance, C_max, of the OLEDs, implying that there was charge accumulation at the interface. Our study demonstrates that maintaining the interface adjacent to emission site free from contaminants is crucial to protect the device from deterioration.     

Trial Realization of Human-Centered Multimedia Navigation for Video Retrieval

A trial realization of human-centered navigation for video retrieval is presented in this article. This system consists of the following functions: (a) multimodal analysis for collaborative use of multimedia data, (b) preference extraction for the system to adapt to users' individual demands, and (c) adaptive visualization for users to be guided to their desired contents. By using these functions, users can find their desired video contents more quickly and accurately than with the conventional retrieval schemes since our system can provide new pathways to the desired contents. Experimental results verify the effectiveness of the proposed system.     

Monitoring x-ray beam damage on lipid films by an integrated Brewster angle microscope/x-ray diffractometer

We describe an integrated Brewster angle microscope (BAM), Langmuir trough, and grazing incidence x-ray diffraction assembly. The integration of these three techniques allows for the direct observation of radiative beam damage to a lipid monolayer at the air-water interface. Although beam damage has been seen in x-ray measurements, it has not been directly observed in situ at the micron scale. Using this integrated assembly, we examined the effects of radiative beam damage on Langmuir monolayers of 1,2-dimyristoyl-sn-glycero-3-[phospho-L-serine] (DMPS), 1:1 DMPS:1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1:1 DMPS:1,2-dioleoyl-sn-glycero-3-phosphocholine held at a constant surface pressure. For constant surface pressure experiments, we observed a marked decrease in the surface area of the film upon exposure to the beam due to photodissociation. For a condensed lipid film, a change in refractive index of the film was observed post-beam-exposure, indicating areas of damage. For DMPS in an oxygenated environment, the Bragg peak intensity decreased with beam exposure. In mixed monolayer systems, with saturated and unsaturated lipids, an increase in the number of small saturated lipid domains was seen as the unsaturated lipid was preferentially damaged and lost from the monolayer. We show that BAM is a highly effective technique for in situ observation of the effects of radiative damage at the air/water interface during a synchrotron experiment.     

Cold-active enzymes from cold-adapted bacteria

The properties of amylase, lipase and protease, excreted by newly isolated bacteria from snow-covered soil, salmon intestine and crab intestine, have been investigated. One amylase, one lipase, and three proteases have been characterized by shifts in their apparent optimal activities toward low temperatures and by reductions in their activation energy values. The discovered enzymes were rapidly inactivated at temperatures above the optimum (30 to 40°C). These results suggest that the enzymes are cold-active. The best cold-active protease producer, isolated from salmon intestine, has been identified as Flavobacterium balustinum by the analysis of 16S rRNA. The optimal growth temperature of this bacterium was 20°C, but a higher amount of protease activity was present at 10°C.     

Oxidation rate of conjugated linoleic acid and conjugated linolenic acid is slowed by triacylglycerol esterification and α-tocopherol

We have recently shown that α-eleostearic acid (α-ESA), a conjugated linolenic acid, has a stronger antitumor effect than conjugated linoleic acid (CLA), both in vitro and in vivo. In this study, the oxidative stability of α-ESA was examined compared with linoleic acid (LA), α-linolenic acid (LnA), and CLA. Thin layers of the FA (LA, 9Z, 11E-CLA, 10E,12Z-CLA, LnA, and α-ESA) were auto-oxidized at 37°C, and the FA remaining, the absorbed oxygen volume, the lipid hydroperoxide content, and the TBARS content were determined. The oxidation rate of α-ESA was faster than that of the unconjugated FA and CLA (9Z,11E-CLA and 10E,12Z-CLA). However, the lipid hydroperoxide and TBARS contents following α-ESA oxidation were low, suggesting production of only small amounts of rapid-reacting secondary oxidation products. Furthermore, the oxidative stability of conjugated FA (CLA and CLnA) in which the carboxylic acid group was esterified with triacylglycerol was greater than that of the FFA. Addition of an antioxidant (α-tocopherol) also increased the stability of the conjugated FA to a level similar to that of the unconjugated FA.