An efficient maximum-likelihood-decoding algorithm for linear blockcodes with algebraic decoder

A new soft decoding algorithm for linear block codes is proposed. The decoding algorithm works with any algebraic decoder and its performance is strictly the same as that of maximum-likelihood-decoding (MLD). Since our decoding algorithm generates sets of different candidate codewords corresponding to the received sequence, its decoding complexity depends on the received sequence. We compare our decoding algorithm with Chase (1972) algorithm 2 and the Tanaka-Kakigahara (1983) algorithm in which a similar method for generating candidate codewords is used. Computer simulation results indicate, for some signal-to-noise ratios (SNR), that our decoding algorithm requires less average complexity than those of the other two algorithms, but the performance of ours is always superior to those of the other two     

Deformation rate dependence of mechanical properties of epoxy resin at cryogenic temperatures

Effects of deformation rate on the mechanical properties of epoxy resin used in superconducting magnets have been studied at cryogenic temperatures. Compressive and flexural tests were made to reveal the mechanical behaviour. In the case of compressive tests, the increase in the deformation rate caused on increase of elastic modulus and a decrease of breaking stress and strain. In the case of flexural tests, different results in breaking stress were obtained. The results indicate that the following two problems must be elucidated for practical use of polymers in magnets, ie (i) impact strength of the polymers, (ii) the stress condition applied to the polymers in the magnet.     

Schottky barrier height variation with metallurgical reactions in aluminum-titanium-gallium arsenide contacts

The behaviour of A1/Ti/n-GaAs Schottky contacts under heat treatment at around 400°C have been studied for their application to GaAs MESFETs. Barrier heights have been determined using both I-V and C-V measurements as a function of heat treatment time. Reaction products due to heat treatment have been studied by X-ray diffraction and Auger electron spectroscopy. The A1/Ti/n-GaAs Schottky contacts barrier height shows an $\text{“N”-}\text{shaped}$ variation in response to heat treatment time. A marked reduction in barrier height follows a slight increase at the initial annealing stage. The barrier height then takes a minimum value. The slight increase in barrier height at the initial stage in the heat treatment is brought about by a Ti and GaAs reaction. The marked barrier height reduction is closely correlated to formation of the compound Al₃Ti. The increase in barrier height observed after the reduction can be explained in terms of GaAlAs formation at the metal-semiconductor interface. This seems to indicate that heat treatment is essential for application of Al/Tin-GaAs Schottky contacts to practical devices.     

Characterization of Aspergillus oryzae glycoside hydrolase family 43 β-xylosidase expressed in Escherichia coli

This is the first report of glycoside hydrolase family 43 β-xylosidase from Aspergillus oryzae. To characterize this enzyme, the recombinant enzyme was expressed in Escherichia coli. Unlike known β-xylosidases from fungal origins, the enzyme did not show substrate ambiguity and was stable at alkaline pH.     

Production of recombinant tumor necrosis factor receptor/Fc fusion protein by genetically manipulated chickens

We previously reported the production of recombinant proteins using genetically manipulated chickens and quails. In this study, we constructed a retroviral vector encoding an expression cassette for a fusion protein of the extracellular domain of the human tumor necrosis factor (TNF) receptor 2 and Fc region of human IgG1 (TNFR/Fc), which is expected as an effective drug for inflammatory diseases such as rheumatoid arthritis. The concentrated viral vector was injected into developing chicken embryos. The chickens that hatched stably produced TNFR/Fc in the serum and egg yolk for six months. It appears that the fused protein is transported and accumulated into yolk from the serum, which is mediated by the Fc receptor. The protein purified from the yolk and serum inhibited the cytotoxic activity of TNF-* toward L929 cells, indicating that the protein produced by the chickens is biologically active. These results indicate the effectiveness of the recovery of Fc-fused proteins from the yolk of genetically manipulated chickens.     

The Anti-Inflammatory Effects of the Methanolic Extract and Fractions from Davilla elliptica St. Hil. (Dilleniaceae) on Bothrops jararaca Envenomation

Inflammation and haemorrhage are the main characteristics of tissue injury in botropic envenomation. Although some studies have shown that anti-venom prevents systemic reactions, it is not efficient in preventing tissue injury at the site of the bite. Therefore, this work was undertaken to investigate the anti-inflammatory effects of the methanolic extract and fractions from D. elliptica and to evaluate the role of matrix metalloproteinases (MMPs) in this process. Effects of the extract and fractions from D. elliptica were evaluated using a carrageenan-induced paw oedema model in rats, and leukocyte rolling was visualized by intravital. The quantification of MMPs activities (MMP-2 and MMP-9) extracted from the dermis of mice treated with extract and fractions alone or incubated with venom was determined by zymographic analyses. Our results show that intraperitoneal (i.p.) injection of fractions significantly reduced paw oedema after the carrageenan challenge. Treatment with the tannins fraction also resulted in considerable inhibition of the rolling of leukocytes and this fraction was able to decrease the activation of MMP-9. These results confirmed the anti-inflammatory activity of the methanolic extract and tannins fraction of D. elliptica and showed that the dermonecrosis properties of B. jararaca venom might be mediated through the inhibition of MMP-9 activity.     

Movie films consumption in Brazil: an analysis of support vector machine classification

We employ the support vector machine (SVM) classifier, over different types of kernels, to investigate whether observable variables of individuals and their household information are able to describe their consumption decision of film at theaters in Brazil. Using a very big dataset of 340,000 individuals living in metropolitan areas of a whole large developing economy, we performed a Knowledge Discovery in Databases to classify the film consumers, which results in 80% instances correctly classified. To reduce the degrees of freedom for SVM and to learn the more important determinants of film consumption, we apply the Linear Discriminant Analysis that allows us to identify the key determinants of this consumption. The main individual characteristics are age, education (that merges to be a student), income, and preferences for cultural goods. Regarding the main geographic characteristics, these are the timing of sample, population concentration, and supply of movie theaters. The results point to an ineffective policy for the sector at the time investigated.

     

Chlorine Gas Sensing Properties of ZnO-CaO Ceramics

The chlorine gas sensing properties of pure ZnO (PZ) and CaO-added ZnO (CAZ) ceramics with relative densities of 48–65% were investigated from 25–380°C in Cl₂ concentration range from 0.9 ppm to 20 ppm using air or N₂ as a carrier gas. In the entire temperature range, the conductivity of PZ and CAZ ceramics decreased by introducing Cl₂ gas. 3 mol% CAZ showed a Cl₂ sensitivity ((0)/(Cl₂)) of 10 for 0.9 ppm Cl₂ in air at 300°C, suggesting its usefulness for sensing of a low-concentration Cl₂ gas below 1 ppm. The CaO addition was found to decrease the Cl₂ sensitivity but to improve the recovery process after removing Cl₂ gas. These effects are attributed to changes in the amount and stability of adsorbed oxygen and to subsequent changes in Cl₂ adsorption behavior.     

Composition of gaseous combustion products of polymers

The gaseous products generated by the flaming combustion of ten kinds of synthetic polymers and a kind of wood (cedar) under the same conditions (sample weight, 0.1 g; temperature, 700°C air flow rates, 50 and 100 l./hr) were quantitatively analyzed by infrared spectrophotometry, gas chromatography, and colorimetric tube method. The main hydrocarbons generated were methane, ethylene, and acetylene. The amount of acetylene generated by the flaming combustion of polymers was much larger than the amount of acetylene formed by pyrolysis at 700°C in nitrogen. Acetylene increased in quantity with increasing air. For nitrogen compounds, hydrogen cyanide was generated from every polymer containing nitrogen used, but ammonia was detected only for nylon 66 and polyacrylamide. Nitrogen monoxide and nitrogen dioxide were detected only in small amounts. Nitrous oxide was detected in the gaseous products generated by the nonflaming combustion of urea resin and melamin resin. It was also found that about 70% of the nitrogen in N-66 and PAA was converted into nitrogen gas (N₂) by combustion under the conditions described above.