Natural 15N and 13C abundance in Andisols influenced by long-term fertilization management in Japan     

Bingzi Zhao  Morihiro Maeda  Yasuo Ozaki 《Soil Science and Plant Nutrition》2013,59(4):555-562

Two field experiments were conducted on Andisols in Japan to evaluate the changes in the natural ¹⁵N and ¹³C abundance in the soil profile and to determine whether the values of δ¹⁵N could be used as an indicator of fertilizer sources or fertilizer fate. The 6-year experiment conducted at the National Agricultural Research Center (NARC) consisted of the following treatments: application of swine compost (COMPOST), slow-release nitrogen fertilizer (SRNF), readily available nitrogen fertilizer (RANF), and absence of fertilization (CONTROL). Experimental plots located at the Nippon Agricultural Research Institute (NARI) received cattle compost at different rates for 12 years; a forest soil at this site was sampled for comparison. Swine compost application led to a considerable change in the δ¹⁵N distribution pattern in the soil profile, with the highest δ¹⁵N values recorded in the top 20 cm layers of the COMPOST plot, decreasing in the sequence of CONTROL >- RANF > SRNF, mainly due to the relatively high δ¹⁵N value of swine compost and its subsequent decomposition. In contrast, SRNF application resulted in the lowest δ¹⁵N values in soil, indicating the presence of negligible nitrogen losses relative to input and low nitrogen cycling rates. Values of δ¹⁵N increased with compost application rates at NARI. In the leachate collected at 1-m depth, the δ¹⁵N values decreased in the sequence of COMPOST > RANF ≥ CONTROL > SRNF. The δ¹³C values in soil peaked in the 40–60 cm layers for all the fertilizers. The δ¹³C value was lowest in forest soil due to the presence of plant residues in soil organic matter. These results indicated that the δ¹⁵N values in the upper soil layers or leachate may enable to detect pollution sources of organic or inorganic nitrogen qualitatively in Andisols.  相似文献   

Molecular epidemiology of avian influenza viruses circulating among healthy poultry flocks in farms in northern Vietnam     

Takakuwa H  Yamashiro T  Le MQ  Phuong LS  Ozaki H  Tsunekuni R  Usui T  Ito H  Morimatsu M  Tomioka Y  Yamaguchi T  Ito T  Murase T  Ono E  Otsuki K 《Preventive veterinary medicine》2012,103(2-3):192-200

Repeated epizootics of highly pathogenic avian influenza (HPAI) virus subtype H5N1 were reported from 2003 to 2005 among poultry in Vietnam. More than 200 million birds were killed to control the spread of the disease. Human cases of H5N1 infection have been sporadically reported in an area where repeated H5N1 outbreaks among birds had occurred. Subtype H5N1 strains are established as endemic among poultry in Vietnam, however, insights into how avian influenza viruses including the H5N1 subtype are maintained in endemic areas is not clear. In order to determine the prevalence of different avian influenza viruses (AIVs), including H5N1 circulating among poultry in northern Vietnam, surveillance was conducted during the years 2006-2009. A subtype H5N1 strain was isolated from an apparently healthy duck reared on a farm in northern Vietnam in 2008 and was identified as an HPAI. Although only one H5N1 virus was isolated, it supports the view that healthy domestic ducks play a pivotal role in maintaining and transmitting H5N1 viruses which cause disease outbreaks in northern Vietnam. In addition, a total of 26 AIVs with low pathogenicity were isolated from poultry and phylogenetic analysis of all the eight gene segments revealed their diverse genetical backgrounds, implying that reassortments have occurred frequently among strains in northern Vietnam. It is, therefore, important to monitor the prevalence of influenza viruses among healthy poultry between epidemics in an area where AIVs are endemic.  相似文献   

Discovery of single-nucleotide mutations in acetolactate synthase genes by Ecotilling     

Guang-Xi Wang  Mui-Keng Tan  Hiromasa Saitoh  Toshiyuki Imaizumi  Tohru Tominaga 《Pesticide biochemistry and physiology》2007,88(2):143-148

TILLING (Targeting Induced Local Lesions IN Genomes) is a powerful reverse genetic technique that employs a mismatch-specific endonuclease to discover induced point mutations in genes of interest. The use of the TILLING technique to survey natural variation in genes is called Ecotilling. We report an adaptation of Ecotilling for rapid detection of single-nucleotide mutations in the acetolactate synthase (ALS) genes of sulfonylurea (SU)-resistant (R) Monochoria vaginalis (Pontederiaceae), a paddy weed, in Japan. Genomic DNA of a SU-R plant (target DNA) was mixed with the DNA of a SU-susceptible (S) plant (reference DNA). Ecotilling detected two nucleotide mutations in the ALS gene of SU-R M. vaginalis. These 2 mutations were confirmed by DNA sequencing. A single nucleotide mutation (C to A), in the codon CCT to CAT and another mutation (C to T), in the codon CCT to TCT were identified by sequencing. Both mutations result in the disruption of a Pro codon in the conserved Domain A region with the consequent substitution of a His residue in the first mutation and a Ser residue in the second. Substitution of the Pro residue in Domain A of the ALS gene has been reported to result in insensitivity to SUs in many weed biotypes. This study demonstrates that Ecotilling is a fast, reliable, economical method for detecting single-nucleotide mutations in genes arising from herbicide selection.  相似文献   

Trace toxic elements in agricultural soil and sediment in the biggest estuarine area,northern Vietnam     

Van Thinh  Nguyen  Ozaki  Akinori  Osanai  Yasuhito  Kurosawa  Kiyoshi 《Paddy and Water Environment》2019,17(2):63-68

Paddy and Water Environment - Soil quality, especially its toxic elements content, plays an important part in clarifying the sustainability of an estuarine ecosystem. In this study, six toxic...  相似文献   

Effect of swaying motion of floating vegetation on wind-induced entrainment phenomenon in closed water body     

Akinori Ozaki  Ken Mori 《Paddy and Water Environment》2008,6(2):171-180

When floating vegetation grows on the water surface in a closed water body, the vegetation counteracts the magnitude of the wind acting on the water surface, and affects the fluid flow and the water quality variation in it. In this study, in order to investigate the counteraction effect of the luxuriant growth of floating vegetation on the fluid flow and water quality in the closed water body, we conducted hydraulic experiments on wind-induced flow with density stratification using a wind tunnel test tank and imitated vegetation. We used imitated vegetation made from polystyrene foam plates instead of using real floating vegetation. And we experimentally considered the effect of the vegetation using the concept of the wind-induced entrainment phenomenon. In particular, we focused the effect of the occupation rate and the swaying motion of vegetation. The results indicated that the swaying motion of imitated floating vegetation had an effect on the scale of entrainment. In addition the results had the same tendency as the previous study on the wind-induced entrainment phenomenon.  相似文献   

Identification of a novel gene (Apq1) from the indica rice cultivar ‘Habataki’ that improves the quality of grains produced under high temperature stress     

Kazumasa Murata  Yukihide Iyama  Takuya Yamaguchi  Hidenobu Ozaki  Yoshinori Kidani  Takeshi Ebitani 《Breeding Science》2014,64(4):273-281

The appearance of brown rice grown under high temperature conditions is an important characteristic for improvement in Japanese rice breeding programs. We performed a QTL analysis of the appearance quality of brown rice using chromosome segment substitution lines of the indica cultivar ‘Habataki’ in the ‘Koshihikari’ genetic background. A line carrying a ‘Habataki’ segment on chromosome 7 showed a high percentage of perfect grains produced under high temperature conditions during the ripening period. To verify the role of this segment, and to narrow down the region containing the useful allele, substitution mapping was performed using multiple paired lines. As a result, the chromosomal location of a gene that we named Appearance quality of brown rice 1 (Apq1) was delimited to a 48-kb region. In addition, we developed an Apq1-near isogenic line (NIL) to evaluate the effect of Apq1 on various agronomic traits. Under high temperature conditions during the ripening period, the Apq1-NIL produced significantly higher percentages of perfect grains than ‘Koshihikari’. Other agronomic traits, including yield and palatability, were similar between the Apq1-NIL and ‘Koshihikari’. Therefore, the ‘Habataki’ allele of Apq1 will be useful in breeding programs aimed at improving the quality of grains ripened under high temperature conditions.  相似文献   

Increased locomotor activity,increased food and water intake and decreased PVN neurons in H1 calponin gene-deficient mice     

Bannai M  Yoshimoto R  MiTSUI-SAITO M  Hori M  Nishihara M  Takahashi K  Yamamura H  Taniguchi S  Katsuki M  Ozaki H  Karaki H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(1):153-155

Calponin (h1 or basic) is an actin-binding protein that is expressed abundantly in smooth muscle. Our previous study using h1 calponin-null mutant mice demonstrated that h1 calponin inhibits the shortening velocity of smooth muscle contraction without significantly affecting the amplitude of force production. Furthermore, early onset of osteogenesis and increased bone formation have been reported in mutated mice. In the present study, we examined the effect of h1 calponin depletion on the metabolism and behavior of mice and found that the mutated mice showed increased locomotor activity, as well as increased intake of food and water, associated with the decreased number of neurons in the paraventricular nucleus of the hypothalamus (PVN).  相似文献   

Secondary erythrocytosis associated with high plasma erythropoietin concentrations in a dog with cecal leiomyosarcoma     

Sato K  Hikasa Y  Morita T  Shimada A  Ozaki K  Kagota K 《Journal of the American Veterinary Medical Association》2002,220(4):486-90, 464

  相似文献   

Genetic effects on fatty acid composition of carcass fat of Japanese Black Wagyu steers     

Oka A  Iwaki F  Dohgo T  Ohtagaki S  Noda M  Shiozaki T  Endoh O  Ozaki M 《Journal of animal science》2002,80(4):1005-1011

Two hundred ninety-three Japanese Black Wagyu steers derived from 34 sires were used to investigate genetic effects on the fatty acid composition of carcass fat. All steers were fed identical diets for 365 d and slaughtered at similar ages. If the percentage of genetic contribution of sire A, B, or C was not lower than 25%, steers were classified into groups A, B, and C, respectively. Fatty acid compositions differed depending on deposit sites. Mean percentage of monounsaturated fatty acids (MUFA) tended to be higher in the outer parts than in the inner parts of the body. Percentage of MUFA in carcass fat was negatively correlated with withers height and BW and positively correlated with meat quality score and marbling score. Fatty acid compositions of the 34 sire groups varied, and mean percentages of MUFA in i.m. fat ranged from 47.71 to 54.77%. Steers in the C group grew larger than those in the A or B group. Mean percentages of MUFA for i.m. fat in the A, B, and C groups (52.83, 51.88, and 50.33%, respectively) differed (P < 0.05) from each other. Steers in the C group had higher (P < 0.05) percentages of saturated fatty acids than those in the A or B groups. Percentages of genetic contribution of sires B (P < 0.05) and C (P < 0.001) were negatively correlated with percentage of MUFA in i.m. fat. These results suggested that genetic factors affected fatty acid composition of carcass fat in Japanese Black Wagyu cattle and that some sires had potent genetic factors affecting this composition.  相似文献   

Effects of chemical ischemia on purine nucleotides,free radical generation,lipids peroxidation and intracellular calcium levels in C2C12 myotube derived from mouse myocytes     

Boffi FM  Ozaki J  Matsuki N  Inaba M  Desmaras E  Ono K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(6):483-488

To elucidate the mechanisms of ischemia-mediated myopathy using in vitro model, changes of purine nucleotides, membrane lipid peroxidation(TBARS), intracellular calcium ([Ca2+]i)levels, generation of free radicals, and deoxyribonucleic acid (DNA) fragmentation were examined in mouse-derived C2C12 myotubes under the condition with an inhibition of glycolytic and oxidative metabolism as the ischemic condition. In purine nucleotides, intracellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations rapidly and significantly decreased after the treatment with ischemia. No remarkable differences were observed in other purine nucleotides, with the exception of inosine monophosphate (IMP) and extracellular hypoxanthine levels, both of which increased significantly during the ischemia. The lactate dehydrogenase activity in culture supernatant of C2C12 myotubes increased significantly from 2 to 4 hr after the ischemia. On the generation of free radicals, no spectrum was detected in supernatants throughout the observation period, whereas supernatant TBARS concentration increased rapidly and significantly after the ischemia. The relative intensity of [Ca2+]i significantly increased after the ischemia. On the fragmented deoxyribonucleic acid(DNA), no TUNEL positive cells was detected in C2C12 myotubes after 1 hr of the ischemia, however the positive cell percentage subsequently increased. From these results, it was suggested that the ischemic condition induced changes of membrane permeability and increase of [Ca2+]i, both of which lead to cell membrane damage, although a free radical generation was not detected. The ischemic condition also induced the release of substrate hypoxanthine for free radical generation and might initiate the apoptotic pathway in C2C12 myotubes.  相似文献