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11.
In order to clarify the effects of a mixture of deciduous broad-leaved trees on soil fertility, we investigated litter biomass
accumulation, mineral soil chemical and physical characteristics, characteristics of nitrogen mineralization, and the mutual
relationships between them in Japanese cypress (Chamaecyparis obtusa) stands mixed with deciduous broad-leaved trees at different ratios (mixture ratio; MR = 0, 16, 33, 43, 100% by basal area)
in the northern Kanto region of Japan. Litter biomass in the forest floor and mineral soil was 19.1 Mg ha−1 in MR 0% and decreased approximately 60 % in MR 33%, MR 43% and MR100%. The permeability at 0–5 cm soil depth in MR100% was
twice as much as that in MR 0%. Increases in soil permeability were likely due to larger soil pores in the higher MR with
much accumulated deciduous broad-leaves. At 0–5 cm soil depth, the differences in carbon concentration among the plots were
not clear. On the other hand, carbon concentrations at 5–10 cm depth increased from 90 g kg−1 to 147 g kg−1 with increases in MR from 0% to 100%. Concentrations of exchangeable bases increased two to four times with increases in
MR from 0 to 100% at 0–10 cm depth. Soil pH (H2O) generally increased with increases in MR at each depth. The rates of net nitrogen mineralization at 0–5 cm depthin vitro increased from 25 to 87 mg kg−1 2 weeks−1 with increases in MR from 0 to 100%. However, increases in nitrification with increases in MR were not clear compared with
nitrogen mineralization. These results indicated that a mixture of deciduous broad-leaved trees in a Japanese cypress stand
was effective in preventing soil fertility decline.
This study was supported by a grant from the Showa Shell Sekiyu Fundation for Promotion of Environmental Research. A part
of this study was presented at the 7th International Congress of Ecology (1998). 相似文献
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13.
Black scurf on carrot roots was found in Hokkaido, Japan, in 2010. An isolate of a binucleate Rhizoctonia was obtained from sclerotia on the root surface. This isolate was identified as anastomosis group (AG)-U based on cultural characteristics, hyphal fusions and the sequence of ribosomal DNA-internal transcribed spacer region. The AG-U isolate caused black scurf symptoms on carrot roots in an inoculation test. The reference isolate of Rhizoctonia solani AG-2-2 IV, which causes carrot root rot, a disease with symptoms that differ from the black scurf symptom. This is the first report of carrot black scurf caused by binucleate Rhizoctonia AG-U. 相似文献
14.
Taste receptors have been defined at the molecular level in the past decade, and cell-based assays have been developed using cultured cells heterologously expressing these receptors. The most popular approach to detecting the cellular response to a tastant is to measure changes in intracellular Ca(2+) concentration using Ca(2+)-sensitive fluorescent dyes. However, this method cannot be applied to food-derived samples that contain fluorescent substances. To establish an assay system that would be applicable to fluorescent samples, we tested the use of Ca(2+)-sensitive photoproteins, such as aequorin and mitochondrial clytin-II, as Ca(2+) indicators in a human sweet taste receptor assay. Using these systems, we successfully detected receptor activation in response to sweetener, even when fluorescent compounds coexisted. This luminescence-based assay will be a powerful tool to objectively evaluate the sweetness of food-derived samples even at an industry level. 相似文献
15.
Genetic variation in the height growth curves was investigated by analyzing data from three clonal trials of sugi (Crytomeria japonica D. Don) in Kyushu. Average height of twelve clones measured at each of five years until 30 years of age were fitted to the
Chapman-Richards function with two parameters model. Clonal variation in the two parameters (an upper asymptote and a rate
of growth parameter) was statistically significant across the tests, indicating that height growth pattern is under genetic
control. The type of growth curve was clearly classified with the two parameters and agreed with the empirical classifications
of the growth habit of local varieties. The rate of growth parameter was correlated with total height up to 20 years of age,
while the upper asymptote was correlated only with the last ten years’ increment from 21 to 30 years where the clonal repeatability
was decreasing. This indicates that a clonal selection for long rotation management system would not be reliable unless the
height is measured accurately with more advanced devices or it is adjusted by the current increment of diameter. 相似文献
16.
Kobayashi I Kusakabe H Toda H Moritomo T Takahashi T Nakanishi T 《Veterinary immunology and immunopathology》2008,126(1-2):74-82
Primitive hematopoietic cells in mammalian bone marrow are purified by flow cytometry using Hoechst 33342 (Hoechst) and rhodamine-123 (Rho), because these dyes efflux activities of hematopoietic cells widely conserved in mammals. Hematopoietic stem cells (HSCs) are identified as side population (SP) cells, characterized by specific Hoechst efflux pattern in flow cytometric analysis. We previously demonstrated that SP cells from teleost body kidney (BK) had the HSC activity by a transplantation experiment using clonal ginbuna crucian carp (Carassius auratus langsdorfii). In the present study, to isolate HSCs and hematopoietic progenitor cells (HPCs) from teleosts using Hoechst and Rho, we compared the hematopoietic activity of Rho-negative (Rho(-)) cells with that of SP cells by ginbuna transplantation experiments. Rho(-) cells were clearly identified from ginbuna BK, and the majority of these cells (85%) showed a non-SP phenotype. Transplantation experiments showed that long-term repopulating activity (HSC activity) of Rho(-) cells was lower than that of SP cells, while Rho(-) cells had higher short-term repopulating activity (HPC activity) than SP cells. These results suggest that Rho(-) cells in ginbuna BK contain various stages of hematopoietic cells, while SP cells are highly enriched for HSCs, and that these dyes are useful for purification of HSCs and HPCs in teleosts. 相似文献
17.
We discovered that some isolated eel skeletal muscle cells exhibited green fluorescence under a fluorescence stereomicroscope,
and we successfully isolated a novel fluorescent protein from the eel muscle homogenate. The protein was a monomer with a
molecular mass of 16.5–17 kDa and showed minor and major peaks at 280 and 493 nm, respectively, in the absorption spectrum.
The molar extinction coefficient at 493 nm was 41,300 M−1 cm−1 and A280/A493 was 0.083. Excitation and emission spectra of the protein showed maxima at 493 and 527 nm, respectively. Heat
treatment at 95°C for 10 min or 5% trichloroacetic acid treatment of the protein caused aggregation of the protein but did
not release any fluorescent components such as FAD into the supernatant after centrifugation. Fluorescence of the protein
remained after native PAGE, but not after SDS-PAGE. These results indicate that the purified fluorescent protein is not a
flavoprotein, and that its fluorescent chromophore is a covalently bound one, such as green fluorescent protein (GFP) from
jellyfish Aequoria victoria, but that its fluorescence requires its native conformation within the protein. Based on these results, we can conclude that
the fluorescent protein obtained from eel skeletal muscle is a novel GFP-like protein. 相似文献
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19.
Kei Sawata Masahiko Toda Satoru Kanetaka Yoshihisa Sasaki Takuro Hirai 《Journal of Wood Science》2011,57(6):536-541
When it is necessary to repair conventional Japanese wooden houses, the decayed lower parts of columns should be replaced
with new wood material. The bending resistance of columns repaired by four methods and the shear resistance of opening frames
with those repaired columns were investigated in this study. Bending tests of the repaired columns showed differences in initial
bending stiffness and maximum bending moment related to the repair methods and loading direction. Racking tests were conducted
on door opening frames with conventional door head members or upper partial walls sheathed with 12-mmthick plywood. The conventional
frame specimens broke at door head-column joints with no obvious bending deformation of the columns, resulting in little difference
in load-shear deformation curves among the repair methods. The columns of plywood-sheathed specimens, on the other hand, clearly
were bent after the nails at the plywood-to-wood frame joints started to pull off. The load-shear deformation curves of the
plywood-sheathed specimens did not vary regardless of the repair methods when shear deformations were small but were affected
by repair methods as shear deformation increased. 相似文献
20.
Toda H Yabu T Shiba H Moritomo T Nakanishi T 《Veterinary immunology and immunopathology》2011,141(1-2):168-172
Granzyme B plays an important role in granule-mediated apoptosis by CTL. It is a well characterized component of the cytolytic machinery in mammals and a candidate for the evaluation of cytotoxic activity of CTL as an alternative to conventional cytotoxicity assay. In this study, we examined the effects of granzyme inhibitors to assess the characteristics of fish granzymes in terms of substrate specificity and the involvement of granzyme B-like in the cytotoxic response. 3,4-dichloroisocoumarin (DCI), which inhibit the activity of serine protease including all members of the granzyme family, markedly suppressed the cytotoxic activity of CTL. However, CTL-mediated cytotoxicity was significantly but not completely suppressed by the addition of carbobenzyloxy-Ile-Glu-Thr-Asp-fluoromethyl ketone (Z-IETD-FMK) that specifically blocks granzyme B activity. These results suggest that additional serine proteases as well as granzyme B-like are involved in cytotoxicity of CTL in fish. We further compared cytotoxicity with the granzyme B-like hydrolytic activity against fluorogenic substrate acetyl-Ile-Glu-Thr-Asp-4-methylcoumaryl-7-amide (Ac-IETD-MCA) and found that granzyme B-like activity correlated well with the cytotoxicity of CTL in ginbuna crucian carp. Present results suggest that the granzyme activity assays is useful to assess cytotoxic activity of CTL in fish in which genetic information on granzymes and specific tools for cytotoxicity assay are not available because of well conserved catalytic triad residues and substrate binding sites in granzyme B throughout vertebrates. 相似文献