Migration history of Sakhalin taimen <Emphasis Type="Italic">Hucho perryi</Emphasis> captured in the Sea of Okhotsk,northern Japan,using otolith Sr:Ca ratios

Sakhalin taimen Hucho perryi populations have decreased drastically to near extinction. It is urgent to establish an effective conservation strategy based on an understanding of the characteristics of migration and habitat use of this species. We examined the migration history of anadromous Sakhalin taimen captured off the Sarufutsu coast, northern Hokkaido, Japan, using otolith Sr:Ca ratios and also examined the relationship between their otolith Sr:Ca ratios during freshwater and seawater residence in a rearing experiment. Otolith Sr:Ca ratios of some fish from the Sarufutsu coast showed freshwater levels (0.5–4.0 × 10⁻³) near the core, which thereafter increased to brackish water levels (4.0–6.0 × 10⁻³), and then to seawater levels (6.0–10.0 × 10⁻³) in the outermost regions. Those findings indicate that specimens from the Sarufutsu coast migrated to the brackish water region or the sea and spent most of their lives there. The anadromous migration pattern including the timing of downstream migration seems to be flexible among individuals in the species. They migrate between freshwater and seawater or brackish water several times during their lives, showing extensive habitat use. It is essential to secure the continuity among the freshwater, brackish water, and seawater areas for their effective conservation.     

Distribution of boron in wood treated with aqueous and methanolic boric acid solutions

The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)₃] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)₃ was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution. PGA confirmed that B(OH)₃ was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than the methanolic solution. Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281     

Productivity of kayu putih (Melaleuca leucadendron LINN) tree plantation managed in non-timber forest production systems in Java,Indonesia

Kayu putih oil, extracted from the kayu putih tree (Melaleuca leucadendron), is an important non-timber forest product (NTFP) in Indonesia. We compared productivity of kayu putih tree plantations among three different sites in East, Central, and West Java, Indonesia. Leaf-twig, and branch production per tree differed significantly among the three sites. Tree biomass production was highest at the site in West Java practicing tumpangsari (a form of shifting cultivation) of kayu putih with rice (Oryza sativa) on alluvial soils. Tree biomass production was lowest at the site in East Java, practicing tumpangsari of kayu putih with maize (Zea mays) and cassava (Mani- hot esculenta). At this site, tree biomass production increased with increasing stand age and low production was compensated by greater biomass yield of companion crops. Intermediate tree biomass production was observed at the site in Central Java where intercropping is only practiced for the first two years after plantation establishment. Production of tree biomass and kayu putih oil did not increase with increasing stand density, indicating that at a given site, high tree stocking did not lead to high production. Stand-level productivity of the plantations increased with increasing stand age and maximum productivity was attained at 15 to 35 years, after which productivity declined. This suggested unsustainable stand productivity as plantations increase in age.     

Evaluating the durability of wood-based panels using internal bond strength results from accelerated aging treatments

In this study, the durability of wood-based panels was evaluated by comparing the internal bond (IB) strength retention after five different laboratory-based accelerated aging tests with the IB retention after 5 years of outdoor exposure in Shizuoka City. In each accelerated aging test, the IB retention of MDI-bonded panels showed high retention compared to other panels. Outdoor exposure in Shizuoka City resulted in an IB retention value for particleboard (PF) and oriented strandboard (aspen) of less than 10% after the 5-year exposure period. Medium-density fiberboards maintained their initial IB strength over the same period. Calculation of the mean IB retention for all board types allowed comparison of the severity of aging between the accelerated test methods and outdoor exposure. The ASTM six-cycle test method was the most severe among the standard treatment cycles applied.     

Effect of 3-O-octanoyl-(+)-catechin on the responses of GABA(A) receptors and Na+/glucose cotransporters expressed in xenopus oocytes and on the oocyte membrane potential

Recently, 3-O-octanoyl-(+)-catechin (OC) was synthesized from (+)-catechin (C) by incorporation of an octanoyl chain into C in the light of (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), which are the major polyphenols found in green tea and have strong physiological activities. OC was found to inhibit the response of ionotropic gamma-aminobutyric acid (GABA) receptors (GABA(A) receptors) and Na+/glucose cotransporters expressed in Xenopus oocytes in a noncompetitive manner more strongly than does C. OC also induced a nonspecific membrane current and decreased the membrane potential of the oocyte, and thus death of the oocyte occurred even at lower concentrations than that induced by C or EGCg. Although EGCg produced H2O2 in aqueous solution, OC did not. This newly synthesized catechin derivative OC possibly binds to the lipid membrane more strongly than does C, Ecg, or EGCg and as a result perturbs the membrane structure.     

Forecast of Sulfur Deposition in Japan for Various Energy Supply and Emission Control Scenarios

In order to contribute to the analysis and solution of regional scale environmental problems in East Asia, we developed a tool for the comprehensive assessment of alternative policy options to improve air quality. This tool projects the future regional energy supply, calculates the emission levels of sulfur dioxide and estimates the geographical pattern of sulfur deposition resulting from emissions. Sulfur deposition in Japan through 2030 was forecasted for various energy supply and emission control scenarios using the analysis tool. Future sulfur depositions were calculated from the source-receptor matrix for 1995 and the growth rate of emission for the source subregion. In the case of the current legislation scenario, anthropogenic SO₂ emissions in East Asia would grow by 34 percent and sulfur deposition in Japan would increase by approximately 20 percent between 1995 and 2030. This increase in sulfur deposition over these 35 years is sligthly less than the contribution from volcanic emission to sulfur deposition in Japan. In the case of the hypothetical dirty scenario for China, sulfur deposition in several grids which face the Sea of Japan would double by 2030.     

The functional effect of Gly209 and Ile213 substitutions on lysozyme activity of family 19 chitinase encoded by cyanophage Ma-LMM01

ORF69 in the cyanophage infecting Microcystis aeruginosa, Ma-LMM01, shows homology to the family 19 chitinases where the catalytic domain has structural similarity to lysozyme. Chitinases hydrolyze chitin, a β-1, 4-linked monopolymer of N-acetylglucosamine (GlcNAc); whereas lysozymes hydrolyzes peptidoglycan, alternating β-1, 4-linked copolymers of N-acetylmuramic acid (MurNAc) and GlcNAc. Using amino acid sequence comparison to ORF69, the putative sugar binding residues, Gln162 and Lys165, from the barley chitinase (the model enzyme for the family 19 chitinases) corresponding to subsites −4 and −3 were found to be replaced with Gly209 and Ile213, respectively, in ORF69. To analyze their contribution to substrate binding affinity, ORF69 was cloned into Escherichia coli; and two mutant proteins G209Q and I213K were prepared using site-directed mutagenesis. The wild-type gene product (gp69) showed both lysozyme and chitinase activities. In contrast, the I213K mutant showed a decrease (70%) in lysozyme activity and a significant increase (50%) in chitinase activity; whereas, the G209Q mutant almost completely abolished both enzyme activities. The data suggest the Ile213 residue is involved in recognizing the substrate MurNAc; and Gly209 has significant contribution in chitinase and lysozyme activities for the wild-type gp69.