Estimation of global warming potential from upland cropping systems in central Hokkaido, Japan   总被引：1，自引：0，他引：1  

Zhijian MU  Sonoko D. KIMURA  Ryusuke HATANO 《Soil Science and Plant Nutrition》2006,52(3):371-377

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Spontaneous mosaicism occurred in normally fertilized and gynogenetically induced progeny of the kokanee salmon Oncorhynchus nerka     

MINORU  TANAKA  SHIZUO  KIMURA  TAKAFUMI  FUJIMOTO  SUZU  SAKAO  ETSURO  YAMAHA  KATSUTOSHI  ARAI 《Fisheries Science》2003,69(1):176-180

ABSTRACT:   In normally fertilized progeny of the kokanee salmon Oncorhynchus nerka , DNA content flow cytometry revealed that all the externally normal embryos were diploid, whereas abnormal embryos exhibited haplo-diploid, diplo-tetraploid and haplo-diplo-tetraploid mosaicisms, together with a few haploid and diploid individuals. When gynogenetic development was artificially induced by fertilization of eggs obtained from a female of the same kokanee brood stock with UV-irradiated sperm, haplo-diploid mosaics appeared most frequently. These mosaics were likely to happen by certain cytological events, such as meiotic or mitotic errors during the process of maturation, fertilization or early cleavage.  相似文献   

Hepatic lesions in young rabbits experimentally infected with rabbit haemorrhagic disease virus   总被引：3，自引：0，他引：3  

O. MIKAMI  J. H. PARK  T. KIMURA  K. OCHIAI  C. ITAKURA   《Research in veterinary science》1999,66(3):237-242

Twenty young rabbits (eleven 2-week-old and nine 4-week-old) were experimentally infected with rabbit haemorrhagic disease virus (RHDV) to clarify susceptibility. They were killed chronologically up to 96 hours post-inoculation (PI) and examined for lesions. All inoculated rabbits were clinically normal, but grossly minute white or grey spots were detected throughout the liver. Histologically, the lesions consisted of aggregates of lymphocytes, macrophages and heterophils, with or without acidophilic bodies and necrotic hepatocytes. Immunohistochemically, RHDV antigens were found in the degenerated hepatocytes and in macrophages. The cellular aggregates were considered to be a reaction to necrotic hepatocytes infected with RHDV. It was concluded that some hepatocytes are susceptible to RHDV in young rabbits.  相似文献   

Characteristics and issues related to regional-scale modeling of nitrogen flows     

Sonoko D. KIMURA  Ryusuke HATANO  Masanori OKAZAKI 《Soil Science and Plant Nutrition》2009,55(1):1-12

This paper summarizes the characteristics of regional-scale nitrogen (N) flow models. The regional scale is generally considered to be an area that ranges from more than 10 km² to the size of a continent. Parameterization is the key process in creating a regional-scale model. During parameterization, transfer functions that reflect the controlling factors must be created at the target scale because the influence of different factors will change with the size of the scale. Watersheds are the most useful unit for evaluating overall N discharge; however, regional activity data is most often available for municipal units. Thus, municipal units must be reaggregated into watershed units. A longer time period is desirable to normalize seasonal and annual variations at regional scales. Parameters that influence N flow must match the investigated spatial and temporal scales. Given the need to use a range of parameters that vary in terms of the quality of the data, models exhibit inevitable uncertainties. Quantification of the uncertainties and verification of the estimated results are required. Error propagation, the Monte Carlo simulation method and maximum and minimum values have been used to obtain different threshold values of uncertainty. To verify regional-scale N flow models, the following five approaches have been used or proposed: (1) calibration of the model by detailed monitoring at multiple sites, (2) verification of the most important process of the extrapolation mechanisms, (3) verification of the N budget, paying particular attention to water quality, (4) comparison with the results quantified by different models, (5) comparison with aerial or satellite image analysis. As regional-scale modeling of N flow will become more important in the future, it is important to develop models than can accurately estimate N dynamics at this scale.  相似文献   

Nitrogen uptake by sago palm (Metroxylon sagu Rottb.) in the early growth stages     

Suzette B. LINA  Masanori OKAZAKI  Dorothea Sonoko KIMURA  Yoshiharu YANO  Koyo YONEBAYASHI  Masato IGURA  Marcelo A. QUEVEDO  Alan B. LORETO 《Soil Science and Plant Nutrition》2009,55(1):114-123

Previous trials have revealed variable responses of sago palm ( Metroxylon sagu Rottb.) to fertilizer application, particularly nitrogen (N). In the present study, we quantified the fertilizer use efficiency (FUE) of sago palm for the first time using ¹⁵N-labeled fertilizer in pot and field experiments. The pot experiment was conducted in Japan using a 2:1 mixture of sand to Philippine soil. The field experiment was conducted in Leyte in the Philippines. Both experiments consisted of three replicates in each of three treatments: control, ¹⁵N urea at 50 kg N ha⁻¹ and ¹⁵N urea at 100 kg N ha⁻¹. The N uptake of sago palm increased significantly, but inconsistently with increasing N application. The few instances of a significant increase in N uptake did not translate into significant improvements in growth parameters, except for the number of leaflets in the pot experiment. The FUE values for sago seedlings (< 6 months) in the pot experiment treated with 50 and 100 kg N ha⁻¹ were 10.5 and 13.2%, respectively, whereas for the 2-year-old sago palms in the field, the corresponding FUE values were 14.8 and 12.0%. The FUE values were similar at the two levels of N application in both experiments. Sago growth parameters appeared to be insensitive to N application, suggesting that the form of N and the timing of N fertilization are important factors for sago palms. Therefore, the use of N fertilizer in sago production can only be justified after determining and fully understanding the response of sago palm to N application.  相似文献   

Element interconnections in Lotus japonicus: A systematic study of the effects of element additions on different natural variants   总被引：1，自引：0，他引：1  

Zheng CHEN  Toshihiro WATANABE  Takuro SHINANO  Tatsuhiro EZAWA  Jun WASAKI  Kazuhiko KIMURA  Mitsuru OSAKI  Yong-Guan ZHU 《Soil Science and Plant Nutrition》2009,55(1):91-101

Lotus japonicus was used to study the distribution and interconnections of 15 elements in plant tissues, including essential and non-essential elements: boron (B), sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), strontium (Sr), molybdenum (Mo), cadmium (Cd) and cesium (Cs). Large amounts of B and Ca accumulated in plant leaves, while Fe, Na, Ni, As and Cd tended to mainly occur in the roots, and Mo was the only element to accumulate in the stems. The elemental compositions within plants were severely disturbed by treatment with toxic elements. Competition between element pairs in the same group (e.g. K and Cs; Ca and Sr) was not found. Iron, Cu and Zn accumulation were induced by Cd and Ni addition. When natural variants grew in a nutrition solution with subtoxic levels of As, Cd, Cs, Ni, Mo and Sr, intriguing relationships between the elements (such as Fe, As and K; Mg and Ni; Mn and Ca) were revealed using principal-component analysis. This study on the plant ionome offers detailed information of element interactions and indicates that chemically different elements might be closely linked in uptake or translocation systems.  相似文献   

T4-type bacteriophage communities estimated from the major capsid genes (g23) in manganese nodules in Japanese paddy fields     

Vita Ratri CAHYANI  Jun MURASE  Eiji ISHIBASHI  Susumu ASAKAWA  Makoto KIMURA 《Soil Science and Plant Nutrition》2009,55(2):264-270

The present study compared the capsid gene ( g23 ) of T4-type bacteriophages (phages) in Mn nodules with those in the plow layer soil and subsoils of two Japanese paddy fields by applying the primers MZIA1bis and MZIA6 to DNA extracts from the nodules and soils. The deduced amino acid sequences of the g23 genes in the Mn nodules were similar to those in the plow layer soil and in the subsoils. This result indicated that similar T4-type phage communities developed at these sites and that the diversity of T4-type phage communities was wide enough to cover those in the plow layer soil and in the subsoils. The majority of g23 clones formed several clusters with the clones and phages obtained from far-apart paddy fields, and the sequences of two clones were completely identical to a phage and a clone from other paddy fields at the nucleotide or amino acid level, indicating horizontal transfer of g23 genes between those paddy fields. A clone with a long nucleotide residue (686 bp) and a distribution remote from the other clones in the phylogenetic tree indicated that there were many uncharacterized, novel g23 genes in the paddy fields.  相似文献   

中国和日本农业活动对流域氮素收支的影响     

S. D. KIMURA  YAN Xiao-Yuan  R. HATANO  A. HAYAKAWA  K. KOHYAMA  TI Chao-Pu  DENG Mei-Hu  M. HOJITO  S. ITAHASHI  K. KURAMOCHI  CAI Zu-Cong  M. SAITO 《土壤圈》2012,22(2):137-151

To analyze the effect of agricultural activity on nitrogen(N) budget at the watershed scale,a comparative study was conducted at two Japanese watersheds,the Shibetsu River watershed(SRW) and Upper-Naka River watershed(UNRW),and one Chinese watershed,the Jurong Reservoir watershed(JRW).The total area and the proportion of agricultural area(in parentheses) of the watersheds were 685(51%),1 299(21%),and 46 km 2(55%) for SRW,UNRW,and JRW,respectively.The main agricultural land use in SRW was forage grassland,while paddy fields occupied the highest proportion of cropland in UNRW(11% of total area) and JRW(31% of total area).The farmland surplus N was 61,48,and 205 kg N ha 1 year 1 for SRW,UNRW,and JRW,respectively.The total input and output for the whole watershed were 89 and 76,83 and 61,and 353 and 176 kg N ha 1 year 1 for SRW,UNRW,and JRW,respectively.The proportion of discharged N to net anthropogenic N input was 31%,37%,and 1.7% for SRW,UNRW,and JRW,respectively.The two watersheds in Japan showed similar proportions of discharged N to those of previous reports,while the watershed in China(JRW) showed a totally different characteristic compared to previous studies.The high N input in JRW did not increase the amount of discharged N at the outlet of the watershed due to high proportions of paddy fields and water bodies,which was an underestimated N sink at the landscape scale.  相似文献   

Comparison of vascular endothelial growth factor/vascular endothelial growth factor receptor 2 expression and its relationship to tumor cell proliferation in canine epithelial and mesenchymal tumors     

Mayu KIMURA  Kaede MIYAHARA  Masahiro YAMASAKI  Naohiro UCHIDA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(1):133

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TMAOase, trimethylamine-N-oxide demethylase, isa thermostable and active enzyme at 80°C     

MEIKO  KIMURA  IKUO  KIMURA  NOBUO  SEKI 《Fisheries Science》2003,69(2):414-420

ABSTRACT:   Purified trimethylamine- N -oxide demethylase (TMAOase)from walleye pollack muscle is a thermostable protein that was notinactivated after heating at 80°C for 30 min.The heated enzyme was electrophoresed in the same manner as fornative enzyme. Circular dichroism (CD) spectra for purified enzymechanged reversibly in the temperature range of 10–80°C.As the enzyme was still active at 80°C, the CD spectralchange did not directly relate to enzyme activity. TMAOase activity inthe myofibrillar fraction decreased sharply above 30°C,but was extracted and recovered from the heated myofibrillar fraction,suggesting that the activity seemed to be interrupted and apparently inactivateddue to the thermal alteration of myofibrillar proteins or some unknownfactors. The complicated profile found in dimethylamine (DMA) formationfrom trimethylamine- N -oxide (TMAO) in walleye pollack muscleduring heating consisted of both enzymic and non-enzymic processes.Most DMA was produced enzymatically below 40°C and interruptedabove 40°C. Therefore, DMA and trimethylamine was formednon-enzymatically at high temperatures regardless of the presenceof native enzyme. A new, simple and easy purification method wasproposed based on the thermostable nature of the enzyme.  相似文献