Relationship between listening difficulty and acoustical objective measures in reverberant sound fields

The previous work [Morimoto et al., J. Acoust. Soc. Am. 116, 1607-1613] showed that listening difficulty ratings can be used to evaluate speech transmission performance more exactly and sensitively than intelligibility. Meanwhile, speech transmission performance is usually evaluated using acoustical objective measures, which are directly associated with physical parameters of room acoustic design. However, the relationship between listening difficulty ratings and acoustical objective measures was not minutely investigated. In the present study, a total of 96 impulse responses were used to investigate the relationship between listening difficulty ratings and several objective measures in unidirectional sound fields. The result of the listening test showed that (1) the correlation between listening difficulty ratings and speech transmission index (STI) is the strongest of all tested objective measures, and (2) A-weighted D(50), C(50), and center time, which are obtained from the impulse responses passed through an A-weighted filter, also strongly correlate with listening difficulty ratings, and their correlations with listening difficulty ratings are not statistically different from the correlation between listening difficulty ratings and STI.     

Overexpression of the Gene Encoding Neurosecretory Protein GL Precursor Prevents Excessive Fat Accumulation in the Adipose Tissue of Mice Fed a Long-Term High-Fat Diet

We previously identified a novel small hypothalamic protein, neurosecretory protein GL (NPGL), which induces feeding behavior and fat accumulation in rodents depending on their diet. In the present study, we explored the effects of NPGL on feeding behavior and energy metabolism in mice placed on a long-term high-fat diet with 60% calories from fat (HFD 60). Overexpression of the NPGL precursor gene (Npgl) over 18 weeks increased food intake and weight. The weekly weight gain of Npgl-overexpressing mice was higher than that of controls until 7 weeks from induction of overexpression, after which it ceased to be so. Oral glucose tolerance tests showed that Npgl overexpression maintained glucose tolerance and increased blood insulin levels, and intraperitoneal insulin tolerance tests showed that it maintained insulin sensitivity. At the experimental endpoint, Npgl overexpression was associated with increased mass of the perirenal white adipose tissue (WAT) and decreased mass of the epididymal WAT (eWAT), resulting in little effect on the total WAT mass. These results suggest that under long-term HFD 60 feeding, Npgl overexpression may play a role in avoiding metabolic disturbance both by accelerating energy storage and by suppressing excess fat accumulation in certain tissues, such as the eWAT.     

Measurement of butyltin contamination of water and sediment in Osaka Bay,Japan

The concentration of tributyltin (TBT) in surface water from Osaka Bay ranged from 0.023 to 0.061 µg l⁻¹ in 1989 and from not detected (ND) to 0.059 µg l⁻¹ in 1990 while the proportion of TBT as a percentage of the total butyltins (BTs) was more than 40%. The concentration of TBT was also surveyed in the Port of Osaka and the Yodo River basin. TBT levels were highest in the estuary (the Port of Osaka), followed by sea areas (Osaka Bay) and rivers (Yodo River basin). A fairly high correlation coefficient between TBT concentration and salinity in water from the estuary and the sea areas was observed. This result shows that the TBT in the estuary water is diluted by seawater. Generally, the TBT concentrations in the water columns were distributed uniformly and the composition of the BTs was also constant. TBT was detected in sediment from Osaka Bay in the range from ND to 0.023 mg kg⁻¹ dry weight with a high ratio of monobutyltin (MBT) to the total BTs. TBT in sediment core was also measured; its concentration decreased with core depth. It was estimated from these measurements that the release of TBT into Osaka Bay began in the 1960s. Copyright © 1998 John Wiley & Sons, Ltd.     

Some integral representations of multivariable hypergeometric functions

The present paper is devoted to establish two integral representation formulas of multivariable hypergeometric functions. An application of the formulas yields some integral representations of Lauricella hypergeometric seriesF _A ⁽ⁿ⁾ ,F _B ⁽ⁿ⁾ ,F _C ⁽ⁿ⁾ andF _D ⁽ⁿ⁾ inn variables. AMS (1980) Subject Classification, 33A30, 33A35     

Absorption spectra of viral components of Sendai virus in the wavelength region from 130 to 320 nm.

Using synchrotron radiation as a light source, the absorption spectra of purified viral components of the Sendai virus, i.e. messenger RNA, lipids, spike (envelope) proteins, reconstructed envelopes, core proteins and whole virions, were obtained in the wavelength region 130-320 nm by measuring the transmission of thin films. Viral (messenger) RNA two peaks at 260 and 190 nm, and a large increase below 160 nm. The absorption spectrum of lipids exhibited a broad peak at 190 nm and a very sharp increase below 160 nm. With spike proteins, a slight peak at 280 nm and a shoulder at 230 nm were observed in addition to a sharper peak at 190 nm and a rather slow increasing absorption below 160 nm. Reconstructed envelopes showed the features of a combination of lipids and proteins. The absorption spectra of core proteins and whole virions exhibited similar characteristics to spike proteins. Conventional UV data were also obtained in the wavelength range 210-320 nm with RNA and lipids. The UV and synchrotron radiation data were in good agreement in terms of the mass absorption coefficients. The molecular splitting of spike proteins was also examined. Proteins gave more diffuse reflection than their subunits, causing a reduction in absorption. This was explained by a loss of transparency with increasing molecular weight.     

Synthesis, crystal structure and electrochemical properties of bis(ethylenedioxy)tetraselenafulvalene (BEDO-TSeF)

Bis(ethylenedioxy)tetraselenafulvalene (BEDO-TSeF) has been synthesized using elemental selenium as the only source of the selenium atoms, and its crystal structure and electrochemical properties are examined and compared with its sulfur analogues.     

Enzyme-mediated enantioselective hydrolysis of poly(ethylene glycol)-supported carbonates

Kinetic resolution of poly(ethylene glycol)(PEG)-supported carbonates by enzymatic hydrolysis is discussed. Water-soluble carbonates are prepared by immobilization of racemic secondary alcohols onto low-molecular weight monomethoxy PEG (MPEG) through a carbonate linker. Porcine pancreas lipase (PPL) enantioselectively catalyzes the hydrolysis of the substrates to give optically active compounds. In this system, the separation of the resulting alcohols and the remaining substrates is achieved by an extraction process without laborious column chromatography. The carbonates are easily hydrolyzed with K₂CO₃ to afford the corresponding alcohols.     

Kinetics analysis of colloidal crystallization of silica spheres modified with polymers on their surfaces in acetonitrile

 The nucleation and growth rates in the colloidal crystallization of silica spheres (136 nm in diameter) modified with polymers on their surface were measured by time-resolved reflection spectroscopy. The polymers were poly(maleic anhydride-co-styrene) [P(MA-ST)] and poly(methyl methacrylate) (PMMA). The induction period for nucleation decreased sharply when the sphere concentration increased. The crystal growth process consisted of a fast growing step leading to metastable crystals (rate v ₁) and a slow growth rate accompanied by the formation of stable crystals. The crystal size of the P(MA-ST)/SiO₂ particles decreased from 0.4 to 0.06 mm, whereas v ₁ increased from 13 to 37 μm/s, when the particle concentration increased. The slow step was also observed for almost all the samples but was not analyzed since the rate was too small. For PMMA/SiO₂ dispersions, the crystal size (0.17–0.3 mm) and v ₁ (43–166 μm/s) did not show any relation to the particle concentration but showed a linear relationship with the molecular weight of PMMA. These results suggest the important role of the excluded-volume effects of the polymer layers around the silica surface. The contribution of the repulsion due to the electrical double layers is still effective in the colloidal crystallization in acetonitrile. Received: 6 June 2001 Accepted: 20 September 2001     

Voronoi space division of a polymer: topological effects, free volume, and surface end segregation

In order to investigate the topological effects of chain molecules, united-atom molecular dynamics simulations of a 500-mer polyethylene linked by 50 hexyl groups (a grafted polymer having 52 ends) are carried out and analyzed in terms of Voronoi space division. We find that the volume of a Voronoi polyhedron for a chain end is larger than that for an internal or junction atom, and that it is the most sensitive to temperature, both of which suggest higher mobility of chain ends. Moreover, chain ends dominantly localize at the surface of the globule: The striking evidence is that while the ratio of surface atoms is only 24% of all atoms, the ratio of ends at the surface is 91% out of all ends. The shape of Voronoi polyhedra for internal atoms is prolate even in the bulk, and near the surface it becomes more prolate. We propose the concept of bonding faces, which play a significant role in the Voronoi space division of covalently bonding polymers. Two bonding faces occupy 38% of the total surface area of a Voronoi polyhedron and determine the prolate shape.