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Hokkaido University Collection of Scholarly and Academic Papers (135.711 recursos)

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.

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  1. Molecular cloning and characterization of the AVR-Pia locus from a Japanese field isolate of Magnaporthe oryzae.

    Miki, Shinsuke; Matsui, Kotaro; Kito, Hideki; Otsuka, Keisuke; Ashizawa, Taketo; Yasuda, Nobuko; Fukiya, Satoru; Sato, Junko; Hirayae, Kazuyuki; Fujita, Yoshikatsu; Nakajima, Toshihiko; Tomita, Fusao; Sone, Teruo
    In order to clone and analyse the avirulence gene AVR-Pia from Japanese field isolates of Magnaporthe oryzae, a mutant of the M. oryzae strain Ina168 was isolated. This mutant, which was named Ina168m95-1, gained virulence towards the rice cultivar Aichi-asahi, which contains the resistance gene Pia. A DNA fragment (named PM01) that was deleted in the mutant and that co-segregated with avirulence towards Aichi-asahi was isolated. Three cosmid clones that included the regions that flanked PM01 were isolated from a genomic DNA library. One of these clones (46F3) complemented the mutant phenotype, which indicated clearly that this clone contained the...

  2. Growth and photosynthetic response of Fagus crenata seedlings to ozone and/or elevated carbon dioxide

    Watanabe, Makoto; Umemoto-Yamaguchi, Michiko; Koike, Takayoshi; Izuta, Takeshi
    We investigated the effects of ozone (O3) and/or elevated CO2 concentration ([CO2]) on the growth and photosynthetic traits of Fagus crenata seedlings. Two-year-old seedlings were grown in four experimental treatments comprising two O3 treatments (charcoal-filtered air and 100 nmol mol^[-1] O3; 6 h/day, 3 days/week) in combination with two CO2 treatments (350 and 700 μmol mol^[-1]) for 18 weeks in environmental control growth chambers. The four treatments were designated as control, elevated O3, elevated CO2, and elevated CO2 + O3. Dry matter growth of the seedlings was greater in elevated CO2 + O3 than in elevated CO2. In elevated CO2...

  3. Eco-balance analysis of land use combinations to minimize environmental impacts and maximize farm income in northern Japan

    Kimura, Sonoko D.; Toma, Yo; Mu, Zhijian; Yamada, Hiroyuki; Hatano, Ryusuke
    Relationships between global warming potential (GWP), farmland surplus nitrogen (FSN) and income for major land uses in Ikushunbetsu watershed were compared using the eco-balance method. An empirical model was created for carbon dioxide, methane and nitrous oxide for both uplands and paddy rice using monitoring data from 22 fields. The greenhouse gas emissions were converted into GWP, whereas yield and FSN were obtained from farmers' interviews and literature survey. Land use distribution was obtained by ground surveys in 2002, 2005 and 2007. The analysis showed that paddy rice and soybean were characterized by a high GWP, low FSN and high...

  4. Calcium deficiency in the early stages after weaning is associated with the enhancement of a low level of adrenaline-stimulated lipolysis and reduction of adiponectin release in isolated rat mesenteric adipocytes

    Shinoki, Aki; Hara, Hiroshi
    Dysregulation of visceral adipocytes increases the incidence of metabolic syndrome. Higher production of non-esterified fatty acid (NEFA) and changes in adipocytokine release may trigger insulin resistance. Many studies have suggested that calcium (Ca) deficiency is associated with insulin resistance; however, the mechanisms are poorly understood. We examined the effects of Ca deficiency on adrenaline-induced lipolysis and adipocytokine release in the early stages after weaning using freshly isolated adipocytes from mesenteric fat tissue of 3-week-old male Sprague-Dawley rats fed a normal-Ca (5 g/kg diet) or low Ca (1 g/kg diet) diet for 4 weeks. The release rate of NEFA in the...

  5. Effect of Zero-Valent Iron Application on Cadmium Uptake in Rice Plants Grown in Cadmium-Contaminated Soils

    Watanabe, Toshihiro; Murata, Yasutoshi; Nakamura, Takashi; Sakai, Yuki; Osaki, Mitsuru
    Cadmium (Cd) contamination in soils is a serious problem for crop production in the world. Zero-valent iron (Fe(0)) is a reactive material with reducing power capable of stabilizing toxic elements in a solution. In the present study, we examined the effect of zero-valent iron (Fe(0)) application on Cd accumulation in rice plants growing in Cd-contaminated paddy soils. The Fe(0) application significantly decreased the Cd accumulation in the leaves and seeds of rice plants grown in Cd-contaminated soils. The form of Cd in soil was determined by sequential extraction. The Fe(0) application increased the free-oxides-occluded (less available) Cd content, and decreased...

  6. Aligned 18S for Zoraptera (Insecta) : Phylogenetic position and molecular evolution

    Yoshizawa, Kazunori; Johnson, Kevin P.
    The order Zoraptera (angel insects) is one of the least known insect groups, containing only 32 extant species. The phylogenetic position of Zoraptera is poorly understood, but it is generally thought to be closely related to either Paraneoptera (hemipteroid orders: booklice, lice, thrips, and bugs), Dictyoptera (blattoid orders: cockroaches, termites, and mantis), or Embioptera (web spinners). We inferred the phylogenetic position of Zoraptera by analyzing nuclear 18S rDNA sequences, which we aligned according to a secondary structure model. Maximum likelihood and Bayesian analyses both supported a close relationship between Zoraptera and Dictyoptera with relatively high posterior probability. The 18S sequences...

  7. Evaluation of drag coefficients of poplar-tree crowns by a field test method

    Koizumi, Akio; Motoyama, Jun-ichi; Sawata, Kei; Sasaki, Yoshihisa; Hirai, Takuro
    To estimate the wind force that causes windthrow damage to a tree, the drag coefficients of actual-sized trees were evaluated by a field test method. In this method, the wind velocity and stem deflection were monitored simultaneously. The wind force acting on a tree crown was calculated from the stem deflection; the stem stiffness was evaluated by conducting tree-bending tests. The results of tests conducted on three poplar trees showed that the drag coefficients decreased with an increase in the wind velocity. Although the variation in the drag coefficients was large at low wind velocity because of the vibrating behavior...

  8. Molecular systematics of the suborder Trogiomorpha (Insecta: Psocodea: 'Psocoptera')

    Yoshizawa, Kazunori; Lienhard, Charles; Johnson, Kevin P.
    Phylogenetic relationships among extant families in the suborder Trogiomorpha (Insecta: Psocodea: ‘Psocoptera’) were inferred from partial sequences of the nuclear 18S rRNA and Histone 3 and mitochondrial 16S rRNA genes. Analyses of these data produced trees that largely supported the traditional classification; however, monophyly of the infraorder Psocathropetae ( = Psyllipsocidae + Prionoglarididae) was not recovered. Instead, the family Psyllipsocidae was recovered as the sister taxon to the infraorder Atropetae ( = Lepidopsocidae + Trogiidae + Psoquillidae), and the Prionoglarididae was recovered as sister to all other families in the suborder. Character states previously used to diagnose Psocathropetae are shown...

  9. The first record of sucking louse, Neohaematopinus callosciuri, infesting pallas squirrels in Japan.

    Shinozaki, Yasuo; Yoshizawa, Kazunori; Murata, Koichi; Shiibashi, Takashi; Kimura, Junpei; Maruyama, Soichi; Hayama, Yoshikazu; Yoshida, Hironobu; Nogami, Sadao

  10. How stable is the "Polyphyly of Lice" hypothesis (Insecta: Psocodea)? : A comparison of phylogenetic signal in multiple genes

    Yoshizawa, Kazunori; Johnson, Kevin P.
    Recent molecular phylogenetic analyses of 18S rDNA have indicated that parasitic lice (order Phthiraptera) are possibly polyphyletic. These analyses recovered one of the parasitic louse suborders, Amblycera, as the sister group to the free-living booklouse family Liposcelididae. We further tested this hypothesis using DNA sequences from five genes: nuclear 18S rDNA, Histone 3, and wingless and mitochondrial 16S rDNA and COI. Combined analyses of these five genes provided reasonably strong support for the Amblycera + Liposcelididae clade, supporting the polyphyly of lice hypothesis. To explore the robustness of this result, we examined the phylogenetic signal contained in each gene independently...

  11. Mating behavior and genital damage during copulation in the leaf beetle Lema coronata (Chrysomelidae: Criocerinae)

    Matsumura, Yoko; Akimoto, Shin-ichi
    The criocerine leaf beetle Lema coronata Baly has extremely long genitalia that reach more than twice the body length in both sexes. We observed mating behavior of this species in the laboratory and inspected the male genital morphology using a scanning electron microscope. The males did not perform pre-copulatory courtship and post-copulatory guarding of the mates, and copulation lasted only for about 30 min. The surface of male genitalia is smooth without any special structures at the tip. A fragment of broken male genitalia was detected in the spermathecal duct of one female. We discuss the adaptive significance of male...

  12. ATP-Dependent but Proton Gradient-Independent Polyphosphate-Synthesizing Activity in Extraradical Hyphae of an Arbuscular Mycorrhizal Fungus

    Tani, Chiharu; Ohtomo, Ryo; Osaki, Mitsuru; Kuga, Yukari; Ezawa, Tatsuhiro
    Arbuscular mycorrhizal fungi benefit their host plants by supplying phosphate obtained from the soil. Polyphosphate is thought to act as the key intermediate in this process, however, little is currently understood about how polyphosphate is synthesized or translocated within arbuscular mycorrhizas. Glomus sp. HR1 was grown with marigold in a mesh bag compartment system, and extraradical hyphae were harvested and fractionated by density gradient centrifugation. Using this approach, three distinct layers were obtained: Layers 1 and 2 were composed of amorphous and membranous materials, together with mitochondria, lipid bodies, and electron-opaque bodies, and layer 3 was composed mainly of partially...

  13. Gene Cloning and Expression of Pyridoxal 5'-Phosphate-Dependent L-threo-3-Hydroxyaspartate Dehydratase from Pseudomonas sp. T62, and Characterization of the Recombinant Enzyme

    Murakami, Tomoko; Maeda, Takayuki; Yokota, Atsushi; Wada, Masaru
    L-threo-3-Hydroxyaspartate dehydratase (L-THA DH, EC, which catalyses the cleavage of L-threo-3-hydroxyaspartate (L-THA) to oxalacetate and ammonia, has been purified from the soil bacterium Pseudomonas sp. T62. In this report, the gene encoding L-THA DH was cloned and expressed in Escherichia coli, and the gene product was purified and characterized in detail. A 957-bp nucleotide fragment was confirmed to be the gene encoding L-THA DH, based on the agreement of internal amino acid sequences. The deduced amino acid sequence, which belongs to the serine/threonine dehydratase family, shows similarity to YKL218c from Saccharomyces cerevisiae (64%), serine racemase from Schizosaccharomyces pombe (64%),...

  14. Difructose anhydride III promotes iron absorption in the rat large intestine

    Hara, Hiroshi; Onoshima, Satoshi; Nakagawa, Chie
    Objectives: We examined the intestinal segment responsible for and the mechanisms involved in the nondigestible disaccharide difructose anhydride III (DFA) III-mediated enhancement of iron absorption. Methods: Net iron and calcium absorption (%) were observed in male SD rats fed an AIN93G-based diet with or without DFAIII (30 g/kg diet) for 2 weeks after cecectomy or laparotomy (Exp. 1). The absorption rates of calcium and iron from ligated jejunal loops (Exp. 2) or ligated cecal sacs (Exp. 3) in anesthetized rats fed a control or DFA diet were observed with or without the addition of DFAIII to the instilled mucosal fluid....

  15. Dietary fat and bile juice, but not obesity, are responsible for the increase in small intestinal permeability induced through the suppression of tight junction protein expression in LETO and OLETF rats

    Suzuki, Takuya; Hara, Hiroshi
    Background: An increase in the intestinal permeability is considered to be associated with the inflammatory tone and development in the obesity and diabetes, however, the pathogenesis of the increase in the intestinal permeability is poorly understood. The present study was performed to determine the influence of obesity itself as well as dietary fat on the increase in intestinal permeability. Methods: An obese rat strain, Otsuka Long Evans Tokushima Fatty (OLETF), and the lean counter strain, Long Evans Tokushima Otsuka (LETO), were fed standard or high fat diets for 16 weeks. Glucose tolerance, intestinal permeability, intestinal tight junction (TJ) proteins expression,...

  16. Watershed controls on the export of large wood from stream corridors

    Fremier, Alexander K.; Seo, Jung Il; Nakamura, Futoshi
    Large wood maintains in-channel and floodplain habitats by influencing the biophysical character of the river corridor. Large wood dynamics in a river corridor are a product of both watershed-wide processes but also of local recruitment, transport, and storage. This complexity of scales added to the logistical constraints in taking measurements limits our understanding of large wood dynamics through the watershed. To begin to unravel this issue, we compiled a dataset of the volume of large wood deposited annually into 131 reservoirs across Japan, and compared large wood export to both flow discharge and watershed characteristics (watershed size, latitude, channel slope,...

  17. Response of Gut Microbiota to Fasting and Hibernation in Syrian Hamsters

    Sonoyama, Kei; Fujiwara, Reiko; Takemura, Naoki; Ogasawara, Toru; Watanabe, Jun; Ito, Hiroyuki; Morita, Tatsuya
    Although hibernating mammals wake occasionally to eat during torpor, this period represents a state of fasting. Fasting is known to alter the gut microbiota in non-hibernating mammals; therefore, hibernation may also affect the gut microbiota. However, there are few reports of gut microbiota in hibernating mammals. The present study aimed to compare the gut microbiota in hibernating torpid Syrian hamsters with that in active counterparts by using culture-independent analyses. Hamsters were allocated to either torpid, fed active, or fasted active groups. Hibernation was successfully induced by maintaining darkness at 4℃. Flow cytometry analysis of cecal bacteria showed that 96-h-fasting reduced...

  18. A revised interpretation of the wing base structure in Odonata

    Ninomiya, Tomoya; Yoshizawa, Kazunori
    Homology of the wing base structure in the Odonata is highly controversial, and many different interpretations for this structure have been proposed to date. In extreme cases, two independent origins of the insect wings have been suggested based on comparative morphology between the odonate and other pterygote wing bases. Difficulties in establishing homology of the wing base structures between Odonata and other Pterygota are mainly due to their extreme differences in morphology and function. In the present paper, we established homology of the wing base structures between Neoptera, Ephemeroptera and Odonata using highly conservative and unambiguously identifiable characters (the basal...

  19. A challenge to dam improvement for the protection of both salmon and human livelihood in Shiretoko, Japan's third Natural Heritage Site

    Nakamura, Futoshi; Komiyama, Eishige
    The Shiretoko Peninsula was placed on the World Heritage List in July 2005 as Japan's third Natural Heritage Site, being valued for its unique ecosystems formed by the interaction between marine and terrestrial environments. Prior to its listing, however, the International Union for Conservation of Nature and Natural Resources requested the development of measures to allow for the free movement of salmonids through the nominated area via artificial in-stream structures. This report introduces a pioneering effort to modify check dams in order to improve ecosystem linkages. The River Construction Working Group has intensively discussed and implemented restoration projects for three...

  20. Site preference and occurrence patterns of Picea jezoensis and Abies sachalinensis on decayed logs in natural coniferous forests in Hokkaido, northern Japan

    Yano, Keisuke; Shibuya, Masato
    The objectives of this study were to investigate differences in the site preferences of seedlings of Picea jezoensis and Abies sachalinensis on decayed logs, and to examine the occurrence patterns of seedlings and saplings of the two species and whether they occur together or separately on logs. We characterized the habitats of 1-2-year-old seedlings of the two species on logs and examined the relationship of the two species on logs by growth stages in two plots. One plot had been disturbed about 50 years ago, whereas the other had not for a long time. Although the thickness of moss and...

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