Composites of wood and trans-1,4-isoprene rubber II: Processing conditions for production of the composites

 The occurrence of grafting between WF and MTIR through esterification, the processing conditions for production of the composites, and the effect of MAH concentration on some physical and mechanical properties as well as the biodegradability of the composites have been studied. The FTIR measurement demonstrated that grafting through esterification had been attained between OH-groups of WF and acid anhydride groups of MTIR during kneading. The optimum kneading conditions for preparing the composites were 120 °C, 30 ∼ 90 rpm for 10 min. The tensile properties of the composites with WF based filler are greater than those with CS (corn starch) based filler. Addition of 10% of MTIR•10 and 8% MAH prepared using the two-step and one-step process, respectively to the TIR-WF composites gave the best result of tensile properties. The presence of MAH in the TIR-WF composites also improved the dimensional stabilization of the resulting composites. The tensile strengh of the composites prepared using the one-step process was about 90% of the composite prepared using the two-step process. The composites of TIR-WF with MTIR compatibilizer had slightly less resistance against subterranean termite (C. formasanus), brown-rot fungus (T. palustris), and white-rot fungus (C. versicolor) and slightly more resistance against bacteria (Bacillus sp.), within the experimental conditioned adopted. Received 8 February 1999     

Screening of heterozygous DNA markers in shiitake (Lentinula edodes) using de-dikaryotization via preparation of protoplasts and isolation of four meiotic monokaryons from one basidium

A suitable screening method for heterozygous DNA markers in shiitake,Lentinula edodes (Berk.) Pegler, is reported. Monokaryons were derived from a dikaryon by de-dikaryotization via protoplast formation. Compatibility of the monokaryons was determined by pairwise culture on agar plates. We selected the primers to amplify polymorphic fragments among the original strain (Hokken600H600) and two monokaryons (H600PP-39 and H600PP-67) showing compatibility. A total of 135 fragments were selected as specific random amplified polymorphic DNAs (RAPDs) resulting from 56 primers of the 147 primers tested. Furthermore, we tested whether the polymorphic fragments segregated into 22 among four strains isolated from a basidium. Most of the polymorphic fragments (about 97.8%) showed 22 segregation among the four strains. We concluded that the polymorphic fragments were heterozygous if they were detected in either of the monokaryons (H600PP-39 and H600PP-67) and segregated to 22 among four meiotic strains (H600B-1,-2, -3, and -4). A total of 132 heterozygous DNA markers were therefore selected from a dikaryon of shiitake (Hokken600H600).Part of this report was presented at the 8th Annual Meeting of Mushroom Science and Biotechnology and the 47th Annual Meeting of the Japan Wood Research Society, Kochi, 1997     

Preparation and characterization of the phenolated wood using hydrochloric acid (HCl) as a catalyst

Summary Birch (Betula maximowicziana Regel) wood meal was liquefied in the presence of phenol using hydrochloric acid (HCl) as a catalyst at a temperature of 150 °C for 2 h in an autoclave. It was found out that HCl acid could be used as an effective catalyst for the hydroxy phenylation of wood under the experimental conditions. In this study the effect of the concentration of the acid catalyst and the phenol-to-wood ratio on the liquefaction were investigated. The results showed that the phenol-to-wood ratio and the concentration should be increased to a certain degree in order to achieve a less residual rate and sufficient amount of combined phenol. The phenolated woods had apparent flow temperatures in the range of 134.4 to 199.8 °C, being higher than that of a commercial novolak resin. Furthermore, increases in the HCl concentration during liquefaction reaction led to increase in the apparent flow temperature of the resulting phenolated woods. However, the changes in the liquid ratio did not bring about evident changes. The relationship between shear stress (τ) and shear rate showed that the phenolated wood resin melts were shear thinning fluids. The dependences of the apparent melt-viscosities (η) of the phenolated woods and a commercial novolak resin on the shear rates ( ) have the similar tendencies, however, it was found the viscosities of the phenolated woods are about one order higher than that of commercial novolak resin.     

First report of Helleborus net necrosis virus isolated from hellebores with black death syndrome in Japan

Helleborus net necrosis virus (HeNNV) in hellebores (Helleborus spp.) has been detected for the first time in Japan. Infected plants had black streaks on fresh leaves and black spots on sepals, which resembled the symptoms of black death disease. The morphology of the virus particles isolated from infected plants was comparable to that of carlaviruses. RT-PCR analysis showed that the entire HeNNV genomic sequence isolated in Japan shared 99% identity with that of HeNNV previously reported in the United States.     

Phenotypic polymorphism for superoxide dismutase in grape

Summary Multiple isoforms of superoxide dismutase (SOD) occurred in grape following an electrophoretic analysis of 75 grapevine accessions. Three activity zones were resolved, and were designated as Sod-1, Sod-2 and Sod-3 in order of their anodal electrophoretic mobility. For the banding pattern and staining intensity, no differences were observed in both ploidy level and somatic mutation. From the controlled cross tests among SOD variants, the grape SOD was presumed as a dimeric enzyme. The grapevine accessions examined exhibited a high level of phenotypic diversity which could be separated into 13 groups on the basis of SOD zymogram. A remarkable difference in SOD phenotypes was recognized between the cultivated varieties and the wild species and rootstocks. Furthermore, we discussed the associations between SOD phenotypes and agronomically important features, especially seedlessness and lime-induced chlorosis.     

Comparison of the gene expression profiles of resistant and non‐resistant Japanese black pine inoculated with pine wood nematode using a modified LongSAGE technique

The Japanese black pine (Pinus thunbergii) is highly susceptible to pine wilt disease caused by the pine wood nematode (PWN; Bursaphelenchus xylophilus). To cope with this disease, researchers and tree breeders selected PWN‐resistant individuals in a previous breeding program. In an attempt to understand the mechanisms of resistance in the Japanese black pine, we created four LongSAGE (serial analysis of gene expression) libraries. A total of 20 818 tags were studied, including 5194 tags from a PWN inoculated resistant pine, 5218 a non‐inoculated resistant pine, 5194 an inoculated non‐resistant pine, and 5212 a non‐inoculated non‐resistant pine. The analysis of the libraries indicated that 14 tag species were significantly up‐regulated (e.g., pathogenesis‐related proteins 2 and 4, osmotin, lipoxygenase, and chalcone synthase), and nine were down‐regulated (eukaryotic translation initiation factor SUI1, translationally controlled tumor protein, and xyloglucan endotransglycosylase) by the PWN inoculation in both the resistant and non‐resistant pines. On the other hand, 38 tag species were significantly expressed at a higher level only in the resistant pine (catalase, dienelactone hydrolase family protein) and 25 were expressed at a higher level in the non‐resistant pine (pathogenesis‐related proteins 1, 2, and 3, and leucoanthocyanidin dioxygenase). These differentially expressed genes are presumed to reflect some of the differences between the resistant and non‐resistant pines. Our results provide valuable information on the complex responses induced in the resistant and non‐resistant pine trees in response to PWN invasion.     

Dietary Soy Peptide Enhances Thermotolerance and Survival of Juvenile Japanese Flounder,Paralichthys olivaceus

Soy peptide (SP), a soy protein enzymatic hydrolysate, contains bioactive substances that could be utilized as an immune‐stimulating feed ingredient. The experiment evaluated the efficacy of dietary SP on promoting growth, and enhancing tolerance and survival to heat stress in juvenile Japanese flounder, Paralichthys olivaceus. Four diets were incorporated with different levels of SP (0, 2, 5, and 10%) and a 6‐wk feeding trial ensued. Following the feeding trial, the experimental groups were subjected to heat stress to measure survival rate and heat shock protein 70s (HSP70s) in gill, liver, and skin. Fish fed diets with SP inclusion showed considerable decrease in percent weight gain. Significantly higher lethal time values to 50% mortality (LT₅₀) value were recorded for fish fed 10% SP. Moreover, LT₅₀ values of fish fed 2 and 5% SP were significantly higher compared with fish fed control diet. HSP70s produced in all the tissues were significantly highest in fish fed 10% SP. HSP70s values were significantly higher in fish fed 2 and 5% SP compared with fish fed control diet. A significant reduction in HSP70s among all groups during recovery period was also observed. These results suggest that SP can be used to enhance the immune response and survival of P. olivaceus under heat stress.     

Reproduction,growth and stress response in adult red sea bream,Pagrus major (Temminck & Schlegel) exposed to different photoperiods at spawning season

Adult red sea bream, Pagrus major (body weight, 1.0–2.0 kg) was exposed to three photoperiods [12 h light:12 h dark (12L:12D), 16 h light:8 h dark (16L:8D) and 24 h light:0 h dark (24L:0D)] from 2 months before spawning till the end of the spawning season to investigate growth, spawning and stress response. During the spawning season, tanks were checked every morning for spawned eggs. The growth performance in fish under 24L:0D was stimulated with significantly higher feed intake than those under other photoperiods (P<0.05). The number of eggs and gonadal histology confirmed that three and five females out of six in each of duplicate tanks of the 16L:8D treatment spawned. In contrast, only two out of six females in one tank of the 24L:0D treatment spawned, and no spawns were observed in the 12L:12D treatment. At the end of the spawning period, both 17β‐estradiol and testosterone levels were significantly higher in fish exposed to 16L:8D followed by 12L:12D and 24L:0D photoperiods (P<0.05). Photoperiod manipulation did not cause significant stress response in fish (P>0.05). The results suggest that stimulating the growth performance of red sea bream at reproductive stage with a 24L:0D photoperiod is possible if the fish are subjected to this photoperiod long before the onset of the spawning season.     

Source Identification of Rural Precipitation Chemistry in Japan

Precipitation chemistry was discussed from the viewpoint of potential sources for four rural sites where wet-only daily-basis measurement data sets were available during the period from April 1996 to March 1997 in Japan. Annual volume-weighted mean concentrations of nss-SO₄ ^2? and NO₃ ^? ranged from 18.0 to 34.6 µeq L^?1, and from 9.3 to 23.1 µeq L^?1, respectively. The degree of neutralization of input acidity in terms of the concentration ratio, [H⁺] / ([nss-SO₄ ^2?] + [NO₃ ^?]), ranged from 0.46 to 0.63. This suggests that about half of the input acidity due to H₂SO₄ and HNO₃ was neutralized by NH₄ ⁺ and nss-Ca²⁺ to produce the pH values of 4.46 to 4.82 for these sites. Maximum likelihood factor analysis was then performed on the logarithmically transformed daily wet deposition of major ions. Two factors successfully explained a total of about 80% of the variance in the data for each site. Interpreting varimax rotated factor loadings, we could identify two source types: (1) acid source with large loadings on ln(H⁺), ln(nss-SO₄ ^2?), ln(NO₃ ^?) and ln(NH₄ ⁺), (2) sea-salt source with large loadings on ln(Na⁺), ln(Cl^?), ln(Mg²⁺) and ln(K⁺). The rural wet deposition over Japan appears to have a similar structure in terms of the kinds of sources and their relative location.