Hokkaido University Collection of Scholarly and Academic Papers
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HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.
Mostrando recursos 1 - 20 de 3.855
1.
Near-Infrared Spectroscopic Sensing System for Online Monitoring of Milk Quality during Milking - Kawamura, Shuso; Kawasaki, Masataka; Nakatsuji, Hiroki; Natsuga, Motoyasu
There has been a need in recent years for a method that will enable dairy farmers to monitor milk quality of individual cow during milking. We constructed a near-infrared (NIR) spectroscopic sensing system for online monitoring of milk quality on an experimental basis. This system enables NIR spectra of unhomogenized milk to be obtained during milking over a wavelength range of 600 nm to 1050 nm. We developed calibration models for predicting three major milk constituents (fat, protein and lactose), somatic cell count (SCC) and milk urea nitrogen (MUN) of unhomogenized milk, and we validated the precision and accuracy of...
2.
Localization of ruminal cellulolytic bacteria on plant fibrous materials as determined by fluorescence in situ hybridization and real-time PCR. - Shinkai, Takumi; Kobayashi, Yasuo
To visualize and localize specific bacteria associated with plant materials, a new fluorescence in situ hybridization (FISH) protocol was established. By using this protocol, we successfully minimized the autofluorescence of orchard grass hay and detected rumen bacteria attached to the hay under a fluorescence microscope. Real-time PCR assays were also employed to quantitatively monitor the representative fibrolytic species Fibrobacter succinogenes and Ruminococcus flavefaciens and also total bacteria attached to the hay. F. succinogenes was found firmly attached to not only the cut edges but also undamaged inner surfaces of the hay. Cells of phylogenetic group 1 of F. succinogenes were...
3.
Spatial variation in tree seedling density after the site preparation for planting in a cleared coniferous plantation in Hokkaido, northern Japan - Shin, ChangSeob; Shibuya, Masato
To study spatial variation in natural tree seedling density and the relationship between variation in seedling density and seed dispersal mode at a cleared site, we surveyed natural tree seedlings after the site preparation for planting in a coniferous plantation cleared by a typhoon disturbance in 2004. The site was located near Sikotsuko Lake, Hokkaido, northern Japan. Twenty-five tree seedling species were found and the mean seedling density was 9.8 seedlings/m2. Seedlings of non-animal-dispersed species (7.2 seedlings/m2) were approximately five times more abundant than those of animal-dispersed species (1.4 seedlings/m2), and 87% of all seedlings were current. The seedling density...
4.
Suppression of Damping-Off Disease in Host Plants by the Rhizoplane Bacterium Lysobacter sp. Strain SB-K88 Is Linked to Plant Colonization and Antibiosis against Soilborne Peronosporomycetes - Islam, Md. Tofazzal; Hashidoko, Yasuyuki; Deora, Abhinandan; Ito, Toshiaki; Tahara, Satoshi
We previously demonstrated that xanthobaccin A from the rhizoplane bacterium Lysobacter sp. strain SB-K88 suppresses damping-off disease caused by Pythium sp. in sugar beet. In this study we focused on modes of Lysobacter sp. strain SB-K88 root colonization and antibiosis of the bacterium against Aphanomyces cochlioides, a pathogen of damping-off disease. Scanning electron microscopic analysis of 2-week-old sugar beet seedlings from seeds previously inoculated with SB-K88 revealed dense colonization on the root surfaces and a characteristic perpendicular pattern of Lysobacter colonization possibly generated via development of polar, brush-like fimbriae. In colonized regions a semitransparent film apparently enveloping the root and...
5.
Correction of Low-altitude Thermal Images applied to estimating Soil Water Status - Sugiura, R.; Noguchi, N.; Ishii, K.
A system based on a thermal camera was developed for monitoring soil water status. This study used a thermal camera to take images of a field from a low-altitude helicopter. Thermal infrared energy captured by cameras tends to include errors because of atmospheric effects. This means that the image must be corrected for atmospheric transmissivity. The transmissivity can be determined from the ambient temperature, the humidity and the distance between the target object and the sensor. A method for correcting the image was developed using a principle of thermal imaging. The imaging accuracy was improved by the correction method. Remote-sensing...
6.
Shifting mosaic in maintaining diversity of floodplain tree species in the northern temperate zone of Japan - Nakamura, Futoshi; Shin, Nozomi; Inahara, Satomi
We examined the relationships between floodplain forest structure and disturbance frequencies in bar-braided and incised-meandering channel sections of the Rekifune River, northern Japan. This was undertaken with special reference to the life history traits at seedling and reproductively mature stages of eight dominant species (Chosenia arbutifolia, Populus maximowiczii, Toisusu urbaniana, Salix sachalinensis, Salix pet-susu, Alnus hirsuta, Ulmus japonica, and Fraxinus mandshurica var. japonica). These species were generally arranged along the flood frequency and intensity gradient represented by five geomorphic surface types: gravel bar, lower and upper floodplain, secondary channel, and terrace. However, habitat separation between seedlings and conspecific mature stands...
7.
Structural insights into unique substrate selectivity of Thermoplasma acidophilum D-aldohexose dehydrogenase - Yasutake, Yoshiaki; Nishiya, Yoshiaki; Tamura, Noriko; Tamura, Tomohiro
The D-aldohexose dehydrogenase from the thermoacidophilic archaea Thermoplasma acidophilum (AldT) belongs to the short-chain dehydrogenase/reductase (SDR) superfamily and catalyzes the oxidation of several monosaccharides with a preference for NAD+ rather than NADP+ as a cofactor. It has been found that AldT is a unique enzyme that exhibits the highest dehydrogenase activity against D-mannose. Here, we describe the crystal structures of AldT in ligand-free form, in complex with NADH, and in complex with the substrate D-mannose, at 2.1 Å, 1.65 Å, and 1.6 Å resolution, respectively. The AldT subunit forms a typical SDR fold with an unexpectedly long C-terminal tail and...
8.
Structural joints with glued-in hardwood dowels - Koizumi, Akio; Jensen, Jørgen L.; Sasaki, Takanobu
Joints with axially loaded glued-in hardwood dowels were studied. A dowel whose
length is ten times as long as diameter is glued into a loose-fit hole. The dowelhole
clearance is filled with flexible polyuretane adhesive to relieve shear-stress
concentration along a bond line. A series of pull-out tests was conducted to reveal
effects of a number of parameters. Consequently, withdrawal strength of proposed
joint with single dowel of 12 mm in diameter was proved to be about 18 kN.
Simple theoretical expressions based on Volkersen model for a lap joint fitted well
for various conditions. End joint of beams, corner joint of frames and post-sill joint
were designed...
9.
Difference in uprooting resistance among coniferous species planted in soils of volcanic origin - Koizumi, Akio; Oonuma, Naoki; Sasaki, Yoshihisa; Takahashi, Kunihide
Uprooting resistance against wind force for coniferous plantations in soils of volcanic origin was studied. The difference in uprooting resistance among Abies sachalinensis, Picea jezoensis, and Larix kaempferi was discussed. The sample site was set in Chitose plantations in Hokkaido Japan, where typhoon 0418 caused fatal uprooting damage in 2004. An uproot resistance index—the ratio of the geometrical moment of area for uprooted root-plate to the moment susceptibility to wind force—was defined to quantify relative uprooting resistance against wind force. It was calculated from the dimensional measurements for the tree forms and root-plates of 100 uprooted sample trees after the...
10.
Effects of growth ring parameters on mechanical properties of Japanese larch (Larix kaempferi) from various provenances - Koizumi, Akio; Kitagawa, Miho; Hirai, Takuro
Growth ring parameters obtained by X-ray densitometry, modulus of elasticity, bending strength, compressive strength, and shear strength of 138 Japanese larch trees belonging to 23 provenances were studied to examine the effects of growth ring parameters on mechanical properties. The considered growth ring parameters were ring width, average wood density within a ring, earlywood density, latewood density, and latewood percentage. The strength properties of the small clear specimens, particularly in the outerwood, were strongly affected by wood density. Among the growth ring parameters studied, earlywood density had a major effect on average wood density in the corewood, whereas the effect...
11.
High accumulation of soluble sugars in deep supercooling Japanese white birch xylem parenchyma cells. - Kasuga, Jun; Arakawa, Keita; Fujikawa, Seizo
• Seasonal changes in the accumulation of soluble sugars in extracellular freezing cortical parenchyma cells and deep supercooling xylem parenchyma cells in Japanese white birch (Betula platyphylla var. japonica) were compared to identify the effects of soluble sugars on the mechanism of deep supercooling, which keeps the liquid state of water in cells under extremely low temperatures for long periods.
• Soluble sugars in both tissues were analyzed by high-performance liquid chromatography (HPLC), and the concentrations of sugars in cells were estimated by histological observation of occupancy rates of parenchyma cells in each tissue. Relative and equilibrium melting points of parenchyma...
12.
Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan. - Obase, Keisuke; Tamai, Yutaka; Yajima, Takashi; Miyamoto, Toshizumi
We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populus maximowiczii, Salix hultenii var. angustifolia and Salix sachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating...
13.
Phylogenetic analysis of bacteria preserved in a permafrost ice wedge for 25,000 years - Katayama, Taiki; Tanaka, Michiko; Moriizumi, Jun; Nakamura, Toshio; Brouchkov, Anatoli; Douglas, Thomas A.; Fukuda, Masami; Tomita, Fusao; Asano, Kozo
Phylogenetic analysis of bacteria preserved within an ice wedge from the Fox permafrost tunnel was undertaken by cultivation and molecular techniques. The radiocarbon age of the ice wedge was determined. Our results suggest that the bacteria in the ice wedge adapted to the frozen conditions have survived for 25,000 years.
14.
Two Resistance Modes to Clover yellow vein virus in Pea Characterized by a Green Fluorescent Protein-Tagged Virus - Andrade, Marcelo; Sato, Masanao; Uyeda, Ichiro
This study characterized resistance in pea lines PI 347295 and PI 378159 to Clover yellow vein virus (ClYVV). Genetic cross experiments showed that a single recessive gene controls resistance in both lines. Conventional mechanical inoculation did not result in infection; however, particle bombardment with infectious plasmid or mechanical inoculation with concentrated viral inocula did cause infection. When ClYVV No. 30 isolate was tagged with a green fluorescent protein (GFP) and used to monitor infection, viral cell-to-cell movement differed in the two pea lines. In PI 347595, ClYVV replicated at a single-cell level, but did not move to neighboring cells, indicating...
15.
Effect of panicle removal on cytokinin level in the xylem and nitrogen uptake activity of rice - SHINANO, Takuro; OSAWA, Motonari; SOEJIMA, Hiroshi; OSAKI, MITSURU
To evaluate the role of cytokinin in the source–sink relationship, panicles of rice were cut from the stem at the panicle emergence stage. Xylem sap exudates were collected using the stem cut method and the cytokinin concentration in the collected sap was determined by bioassay and further analysis using enzyme-linked immunosorbent assay. The rate of cytokinin translocation from roots to shoots decreased continuously after panicle initiation, whereas, when the panicle was removed, the rate increased by up to 1.5-fold, at which time no cytokinin was found in the plants with panicles. Retardation of leaf senescence was not observed and nitrogen...
16.
Isolation and Structure Elucidation of Peronosporomycetes Hyphal Branching-Inducing Factors Produced by Pseudomonas jessenii EC-S101 - HATANO, Eduardo; HASHIDOKO, Yasuyuki; DEORA, Abhinandan; FUKUSHI, Yukiharu; TAHARA, Satoshi
Pseudomonas jessenii EC-S101 produced hyphal branching-inducing and mitosis-accelerating factors active towards Peronosporomycetes, Aphanomyces cochlioides hyphae. In searching for the active substances, EtOAc-solubles extracted from EC-S101-cultured solid medium were fractionated under the guidance of a paper disc assay using an A. cochlioides mycelium. Two active substances were subsequently isolated and the structure was elucidated by spectroscopic analysis to be (+)-4,5-didehydroacaterin (1) and 3-[(1R)-hydroxyhexyl]-5-methylene-2(5H)-furanone (2), both of which accelerated the mitotic process of A. cochlioides hyphae along with excessive branching at 1.0 μg per disc. These compounds are likely to affect the morphophysiological development of certain eukaryotic organisms in the terrestrial ecosystem.
17.
A QTL Cluster for Plant Architecture and Its Ecological Significance in Asian Wild Rice - Onishi, Kazumitsu; Horiuchi, Yuki; Ishigoh-Oka, Noriko; Takagi, Kyoko; Ichikawa, Naofumi; Maruoka, Masamichi; Sano, Yoshio
The wild progenitor (Oryza rufipogon) of Asian rice (Oryza sativa) shows a wide range of variations in life-history traits, forming an annual-perennial continuum. A conspicuous feature of an annual type of wild rice is represented by its adaptability to disturbed habitats, and its short stature with many tillers and a prostrate growth habit. The present study was carried out to examine the genetic differentiation between wild annual and cultivated (Japonica type) rice strains by quantitative trait locus (QTL) analysis. In total, 20 adaptive and/or domestication-related traits were evaluated in recombinant inbred lines (RILs). A total of 28 putative QTLs were...
18.
Cytochrome c-552 from Gram-Negative Alkaliphilic Pseudomonas alcaliphila AL15-21T Alters the Redox Properties at High pH - Matsuno, Toshihide; Morishita, Nozomu; Yamazaki, Koji; Inoue, Norio; Sato, Yukari; Ichise, Nobutoshi; Hara, Isao; Hoshino, Tamotsu; Matsuyama, Hidetoshi; Yoshimune, Kazuaki; Yumoto, Isao
A soluble class I cytochrome c of an alkaliphile was purified and characterized, and its primary structure was determined. This is the first example of a soluble class I cytochrome c in alkaliphiles. Cells the alkaliphilic gram-negative bacterium Pseudomonas alcaliphila AL15-21T grown at pH 10 had a soluble cytochrome c content that was more than twofold that of strain AL15-21T cells grown at pH 7 under air-limited conditions. Cytochrome c-552, a soluble cytochrome c with a low molecular weight, was purified from strain AL15-21T cells grown at pH 10 under air-limited conditions. Cytochrome c-552 had a molecular mass of 7.5...
19.
The N-terminal region of the starch-branching enzyme from Phaseolus vulgaris L. is essential for optimal catalysis and structural stability - Hamada, Shigeki; Ito, Hiroyuki; Ueno, Hiroshi; Takeda, Yasuhito; Matsui, Hirokazu
Starch-branching enzymes (SBEs) play a pivotal role in determining the fine structure of starch by catalyzing the syntheses of α-1,6-branch points. They are the members of the α-amylase family and have four conserved regions in a central (β/α)8 barrel, including the catalytic sites. Although the role of the catalytic barrel domain of an SBE is known, that of its N- and C-terminal regions remain unclear. We have previously shown that the C-terminal regions of the two SBE isozymes (designated as PvSBE1 and PvSBE2) from kidney bean (Phaseolus vulgaris L.) have different roles in branching enzyme activity. To understand the contribution...
20.
An antifungal compound involved in symbiotic germination of Cypripedium macranthos var. rebunense (Orchidaceae) - Shimura, Hanako; Matsuura, Mayumi; Takada, Noboru; Koda, Yasunori
Germination of orchid seeds fully depends on a symbiotic association with soil-borne fungi, usually Rhizoctonia spp. In contrast to the peaceful symbiotic associations between many other terrestrial plants and mycorrhizal fungi, this association is a life-and-death struggle. The fungi always try to invade the cytoplasm of orchid cells to obtain nutritional compounds. On the other hand, the orchid cells restrict the growth of the infecting hyphae and obtain nutrition by digesting them. It is likely that antifungal compounds are involved in the restriction of fungal growth. Two antifungal compounds, lusianthrin and chrysin, were isolated from the seedlings of Cypripedium macranthos...
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