Medicinal foodstuffs. V. Moroheiya. (1): Absolute stereostructures of corchoionosides A, B, and C, histamine release inhibitors from the leaves of Vietnamese Corchorus olitorius L. (Tiliaceae)

Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corchorus olitorius, commonly called "moroheiya" in Japanese, together with seven known compounds, an ionone glucoside (6S,9R)-roseoside, a monoterpene glucoside betulalbuside A, two flavonol glucosides astragalin and isoquercitrin, two coumarin glucosides scopolin and cichoriine, and chlorogenic acid. The absolute stereostructures of corchoionosides A, B, and C were determined by chemical and physiochemical evidence, which included the result of application of a modified Mosher's method, the CD helicity rule, and chemical correlation with (6S,9R)-roseoside. Corchoionosides A and B and (6S,9R)-roseoside were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.     

Metabolic engineering for the production of carotenoids in non-carotenogenic bacteria and yeasts

This article deals with a topic being controversially discussed in public for several years now: violence in school. Following the outlining of the current state of research and the naming of causes is a representation of the research-project "Violence in School' sponsored by the German Research Community (Deutsche Forschungsgemeinschaft, DFG). This four-stage program which was designed to analyze and prevent violence in school has set itself the aim to get a comprehensive idea of extent and appearance of violent behavior as well as to find condition-constellations in the school environment and also externally. Finally, some ideas for prevention and intervention of violence in school are given. Those recommendations represent a set of proposals that can be found in the bibliography.     

Towards communityware

This paper summarizes our recent activities to support people to communicate with each other using public computer network systems. Unlike conventional teleconferencing systems, which are mainly for business meetings, we focus on informal communication in open orgnizations. So far, three different systems have been developed and actually tested.

Detecting innovative topics based on user-interest ontology

In this paper, we detect “innovative topics”, those that are new and hopefully interesting to the user. We try to expand user interests significantly by letting the user browse those topics.We first generate user-interest ontologies that allow user profiles to be constructed as a hierarchy of classes where a user interest weight is assigned to each class and instance. Next, we measure the similarity between user interests by using interest weights on their user-interest ontologies and generate user group G_U that has high similarity to user u. The innovative topics for u are then detected by determining a suitable size of G_U and analyzing the ontologies in G_U.     

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.     

Assessment of the offshore wind resource in Japan with the ASCAT microwave scatterometer

We analysed wind speed and direction off the coast of Japan using data from the satellite-borne Advanced Scatterometer (ASCAT) and the Weather Research and Forecasting model (WRF), validated these data using in situ wind measurements from 20 buoys, and evaluated the effect of the long time intervals from ASCAT observations on wind resource assessment. More than 25 km from the coast, and at heights of 10 m, the ASCAT wind speed has negative biases of up to 3.4% and root mean square errors of up to 18.5%; its wind direction has 11° to 27° of mean absolute error compared to buoy measurements at a height of 10 m. These accuracies are better than either the expected accuracies reported in the technical manual or those simulated with WRF with its spatial resolution of 10 km. We also evaluated long-term average ASCAT wind speeds in comparison to 4- and 5-year averages of in situ buoy wind speeds measured at three buoys, with resulting differences of –0.3%, –6.3%, and – 1.6%. Furthermore, wind roses show that appearance frequencies of the ASCAT wind direction for the long term are in a good agreement with those of the measurements at the three buoys. Our results show that the ASCAT-derived wind speed and direction are appropriate more than 25 km from the coast, and that the long time interval between ASCAT observations has an insignificant effect on wind resource assessment, if at least 4 or 5 years of averaged ASCAT data are used.     

Impact damage behaviour of CVD-coated silicon nitride for gas turbines

Impact tests were conducted on the silicon nitride substrates coated with Si₃N₄ and SiC by chemical vapour deposition (CVD). For both 100- and 200-m-thick Si₃N₄-coated silicon nitride, Hertzian crack extension was reduced by debonding at the interface. Although Hertzian crack extension was not reduced for 100-m-thick SiC-coated silicon nitride, it was reduced for 200-m-thick SiC-coated silicon nitride. Theoretical calculations suggest that debonding at the interface consumed the fracture energy of Hertzian crack extension in the case of Si₃N₄ coatings, but it was observed that Hertzian cracks were not arrested at the interface.     

A technique for precise depth representation in stereoscopic display

In observing a virtual 3D object displayed stereoscopically on a large screen, there is often a difference between the calculated depth and the perceived depth. This paper presents a method for reducing such differences of depth. To do this, we modify both the viewing position and the screen position in the stereoscopic calculation. The optimal amount of modification was determined from sample values of depth differences. The effectiveness of the proposed method is discussed on the merits of the experimental results. This technique decreased the average difference from 4.3 mm to 1.3 mm.     

Study on the oxidative rate and prooxidant activity of free fatty acids

Oleic, linoleic and linolenic acids were autoxidized more rapidly than their corresponding methyl esters. Addition of stearic acid accelerated the rate of autoxidation of methyl linoleate and the decomposition of methyl linoleate hydroperoxides. Therefore, the higher oxidative rate of FFA’s than their methyl esters could be due to the catalytic effect of the carboxyl groups on the formation of free radicals by the decomposition of hydroperoxides. Addition of stearic acid also accelerated the oxidative rate of soybean oil. This result suggests that particular attention should be paid to the FFA content that affects the oxidative stability of oils.     

Photocatalytic treatments on dental mirror surfaces using hydrolysis of titanium alkoxide

Anatase titanium dioxide (TiO₂) photocatalytic thin films were directly formed on glass slide and commercial dental mirror substrate surfaces by a hydrolysis of titanium alkoxide, and the hydrophilicity, the degree of oxidizing power and the transparency of the anatase TiO₂-coated substrate surfaces. The contact angles of water and the decomposition rates of methylene blue on the anatase TiO₂ photocatalytic thin films improved with the increasing duration of a tetraethyl orthotitanate (TEOT) hydrolysis, but they hardly changed for the longer duration. The reflectance of anatase TiO₂ photocatalytic thin films coated on glass slide substrate surfaces was higher as the duration of a TEOT hydrolysis increased. Similar tendencies concerning hydrophilicity and transparency were recognized in cases of commercial dental mirror substrate surfaces. A hydrolysis of titanium alkoxide obtained superhydrophilic and antibacterial treatments with excellent transparency on commercial dental mirror substrate surfaces.