Effects of phosphorus addition with and without ammonium, nitrate, or glucose on N2O and NO emissions from soil sampled under Acacia mangium plantation and incubated at 100 % of the water-filled pore space     

Taiki Mori  Seiichi Ohta  Shigehiro Ishizuka  Ryota Konda  Agus Wicaksono  Joko Heriyanto  Arisman Hardjono 《Biology and Fertility of Soils》2013,49(1):13-21

An incubation experiment was conducted to examine the effects of phosphorus (P) addition with and without ammonium, nitrate, or glucose on N₂O and NO emissions from soil taken under Acacia mangium plantation and incubated at 100 % water-filled pore space (WFPS). Additions of NO ₃ ^? stimulated the N₂O and NO emissions while NH ₄ ⁺ did not, showing that denitrification was the main process of N₂O and NO production in the study condition. When NO ₃ ^? was added with P significantly (P?<?0.05) increased N₂O emissions regardless of the ratio of the added nitrogen and carbon, suggesting that P addition stimulated denitrification activity. The activation of denitrification by P addition is possibly attributed to two mechanisms: (1) the added-P stimulated denitrification by relieving P shortage for denitrifying bacteria and (2) the added-P stimulated activity of heterotrophic soil microflora with increased O₂ consumption promoting the development of anaerobic conditions with stimulation of denitrification.  相似文献   

Effects of sedimentation on an endangered benthic fish,Cobitis shikokuensis: is sediment‐free habitat a requirement or a preference?          下载免费PDF全文

Ryota Kawanishi  Ryota Dohi  Asuka Fujii  Mikio Inoue 《Ecology of Freshwater Fish》2015,24(4):584-590

A negative correlation between the degree of fine sediment deposition and the abundance of stream benthic fishes has often been reported, although the causal mechanisms for this effect are not fully understood. To better understand the influence of sedimentation, it is important to clarify whether it alters the habitat required by fish, or merely preferred by them. We conducted two enclosure experiments in the field to examine (i) whether an endangered benthic fish, Cobitis shikokuensis, prefers sediment‐free substrate and (ii) whether fine sediment deposition has negative effects on the physiological condition of C. shikokuensis. The first experiment, which used three types of substrates, ‘cobble’, ‘pebble’ and ‘mixture of fine sediment and pebbles’, showed that C. shikokuensis avoided the mixture. The second experiment, which compared the physiological condition of fish reared in enclosures with either a pebble or mixture substrate, showed that the condition of the fish in the latter group declined more quickly. These results suggest that, for C. shikokuensis, sediment‐free substrate is a habitat requirement, not merely a preference, and that excessive input of fine sediment due to human activities can cause a decline in the population of this species.  相似文献   

Serum cystatin C concentration can be used to evaluate glomerular filtration rate in small dogs     

Yuichi MIYAGAWA  Ryota AKABANE  Mizuki OGAWA  Masayoshi NAGAKAWA  Hirosumi MIYAKAWA  Naoyuki TAKEMURA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(12):1828

Serum cystatin C levels (CysC) are used in human medicine to document progressive kidney failure. Although CysC are not thought to be useful for the diagnosis of kidney dysfunction in dogs, there has been no specific consideration of body weight as a confounding issue. The aim of this study was to assess that the utility of CysC for the diagnosis of decreased glomerular filtration rate (GFR) in smaller vs. larger dogs. In clinically healthy dogs, serum creatinine (Cre) and CysC correlate directly with body weight; we found that dogs weighing <20 kg had significantly lower CysC than those weighing ≥20 kg (0.27 ± 0.07 vs. 0.34 ± 0.05 mg/l, respectively, P<0.001). In dogs weighing <20 kg, CysC had superior diagnostic accuracy for the detection of mildly decreased plasma iohexol clearance (PCio) (<1.8 ml/min/kg) compared with Cre (sensitivity 100% vs. 80.9% and specificity 100% vs. 85.7%); this was not true for dogs weighing ≥20 kg. Additionally, using a cut-off PCio of <1.8 ml/min/kg, the area under receiver-operating characteristics curve (AUC) of CysC was significantly higher than that of Cre in dogs weighing <20 kg (P<0.05); this was not true for dogs weighing ≥20 kg (P=0.695). In conclusion, CysC is a useful marker for the detection of a mild decreasing GFR compared with Cre in dogs weighing <20 kg.  相似文献   

The biological activities of cardenolide triglycosides from stems, twigs, and leaves of Nerium oleander     

Yuhua Bai  Ming Zhao  Liming Bai  Ryo Hasegawa  Jun-ichi Sakai  Toshiaki Hasegawa  Tomokazu Mitsui  Hirotsugu Ogura  Takao Kataoka  Katsutoshi Hirose  Masayoshi Ando 《Journal of Wood Science》2011,57(1):56-65

Sixteen cardenolide triglycosides (1?C16) were isolated from stems, twigs, and leaves of Nerium oleander. Among them, 3??-O-(4-O-gentiobiosyl-d-diginosyl)-7??,8-epoxy-14-hydroxy-5??,14??-card-20(22)-enolide, named cardenolide B-3 (16), was isolated from natural sources for the first time. The in vitro anti-inflammatory activities of compounds 1?C16 were examined on the basis of inhibitory activity against the induction of intercellular adhesion molecule-1 (ICAM-1). Compounds 1?C5 were active at an IC50 value of less than 7 ??M. The cytotoxic activity of isolated compounds was evaluated against three human cell lines: normal human fibroblast cells (W-38), malignant tumor cells induced from WI-38 (VA-13), and human liver tumor cells (HepG2). Compounds 1?C5 were active toward WI-38 cells; compounds 1, 3, and 5 were active toward VA-13 cells; and compounds 1?C5 were active toward HepG2 cells at IC₅₀ values of less than 10 ??M. The multidrug-resistant (MDR) cancer-reversal activity of compounds 1?C16 was evaluated on the basis of the amount of calcein accumulated in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compounds 13 and 14 showed significant effects on calcein accumulation.  相似文献   

Amino-terminal amino Acid sequence of the silkworm prothoracicotropic hormone: homology with insulin     

Nagasawa H  Kataoka H  Isogai A  Tamura S  Suzuki A  Ishizaki H  Mizoguchi A  Fujiwara Y  Suzuki A 《Science (New York, N.Y.)》1984,226(4680):1344-1345

Three molecular forms of prothoracicotropic hormone were isolated from the head of the adult silkworm, Bombyx mori, and the amino acid sequence of 19 amino acid residues in the amino terminus of these prothoracicotropic hormones was determined. These residues exhibit significant homology with insulin and insulin-like growth factors.  相似文献   

A dinuclear Ni(mu-H)Ru complex derived from H2     

Ogo S  Kabe R  Uehara K  Kure B  Nishimura T  Menon SC  Harada R  Fukuzumi S  Higuchi Y  Ohhara T  Tamada T  Kuroki R 《Science (New York, N.Y.)》2007,316(5824):585-587

Models of the active site in [NiFe]hydrogenase enzymes have proven challenging to prepare. We isolated a paramagnetic dinuclear nickel-ruthenium complex with a bridging hydrido ligand from the heterolytic cleavage of H2 by a dinuclear NiRu aqua complex in water under ambient conditions (20 degrees C and 1 atmosphere pressure). The structure of the hexacoordinate Ni(mu-H)Ru complex was unequivocally determined by neutron diffraction analysis, and it comes closest to an effective analog for the core structure of the proposed active form of the enzyme.  相似文献   

alpha-Klotho as a regulator of calcium homeostasis     

Imura A  Tsuji Y  Murata M  Maeda R  Kubota K  Iwano A  Obuse C  Togashi K  Tominaga M  Kita N  Tomiyama K  Iijima J  Nabeshima Y  Fujioka M  Asato R  Tanaka S  Kojima K  Ito J  Nozaki K  Hashimoto N  Ito T  Nishio T  Uchiyama T  Fujimori T  Nabeshima Y 《Science (New York, N.Y.)》2007,316(5831):1615-1618

alpha-klotho was identified as a gene associated with premature aging-like phenotypes characterized by short lifespan. In mice, we found the molecular association of alpha-Klotho (alpha-Kl) and Na+,K+-adenosine triphosphatase (Na+,K+-ATPase) and provide evidence for an increase of abundance of Na+,K+-ATPase at the plasma membrane. Low concentrations of extracellular free calcium ([Ca2+]e) rapidly induce regulated parathyroid hormone (PTH) secretion in an alpha-Kl- and Na+,K+-ATPase-dependent manner. The increased Na+ gradient created by Na+,K+-ATPase activity might drive the transepithelial transport of Ca2+ in cooperation with ion channels and transporters in the choroid plexus and the kidney. Our findings reveal fundamental roles of alpha-Kl in the regulation of calcium metabolism.  相似文献   

Group B Betacoronavirus in Rhinolophid Bats,Japan     

Jin SUZUKI  Ryota SATO  Tomoya KOBAYASHI  Toshiki AOI  Ry? HARASAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(9):1267-1269

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Strawberry cultivar identification based on hypervariable SSR markers     

Masanori Honjo  Tsukasa Nunome  Sono Kataoka  Takayoshi Yano  Hiromichi Yamazaki  Megumi Hamano  Susumu Yui  Masami Morishita 《Breeding Science》2011,61(4):420-425

We genotyped strawberry cultivars by two newly selected and two previously reported SSR markers. All four markers produced interpretable electropherograms from 75 accessions consisting of 72 Fragaria × ananassa cultivars or lines and three octoploid Fragaria species accessions. These SSR markers were highly polymorphic; in particular, one of the newly developed markers, FxaHGA02P13, was capable of distinguishing all of the accessions except for a mutant strain that was derived from another accession in the set. When two markers were combined, all 48 full-sib individuals could be distinguished. Fingerprinting patterns were reproducible between multiple samples, including the leaves, sepals, and fruit flesh of the same accession. Principal-coordinate analysis of the 75 accessions detected several groups, which reflect taxon and breeding site. Together with other available markers, these SSR markers will contribute to the management of strawberry genetic resources and the protection of breeders’ rights.  相似文献   

Phosphorus application reduces N2O emissions from tropical leguminous plantation soil when phosphorus uptake is occurring     

Taiki Mori  Seiichi Ohta  Shigehiro Ishizuka  Ryota Konda  Agus Wicaksono  Joko Heriyanto 《Biology and Fertility of Soils》2014,50(1):45-51

We examined the effects of phosphorus (P) fertilization on N₂O emissions from an Acacia mangium plantation in Indonesia. We focused on the roles of microbial and plant root activities using a trenching method to prepare root-excluded and root-including plots. In root-excluded plots, P application did not change the amount of N₂O emissions. By contrast, in root-including plots, P application significantly reduced N₂O emissions (from 71.1?±?20.2 to 19.3?±?5.1 mg N m^?2 106 days^?1). Lower total P, Bray-2 P, and Bio-P (microbial P determined by chloroform fumigation extraction method) contents in the soils of root-including plots as compared to root-excluded plots a few days after P application shows that acacia trees absorbed P fertilizer rapidly. This rapid P uptake probably relieved the P limitation of acacia and might have consistently increased root N uptake. This interpretation is supported by lower inorganic N content in P-applied soils (the average of three sampling times is 8.9 and 11.3 μg N g soil^?1 in P-applied soils and soils without P application, respectively), which in turn decreased N₂O emissions. Our study suggests that P fertilizer suppresses N₂O emissions from tropical leguminous forest plantations.  相似文献