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21.
Tomohito Sano Takashi Hirano Naishen Liang Ryuichi Hirata Yasumi Fujinuma 《Forest Ecology and Management》2010
A typhoon event catastrophically destroyed a 45-year-old Japanese larch plantation in southern Hokkaido, northern Japan in September 2004, and about 90% of trees were blown down. Vegetation was measured to investigate its regeneration process and CO2 flux, or net ecosystem production (NEP), was measured in 2006–2008 using an automated chamber system to investigate the effects of typhoon disturbance on the ecosystem carbon balance. Annual maximum aboveground biomass (AGB) increased from 2.7 Mg ha−1 in 2006 to 4.0 Mg ha−1 in 2007, whereas no change occurred in annual maximum leaf area index (LAI), which was 3.7 m2 m−2 in 2006 and 3.9 m2 m−2 in 2007. Red raspberry (Rubus idaeus) had become dominant within 2 years after the typhoon disturbance, and came to account for about 60% and 50% of AGB and LAI, respectively. In comparison with CO2 fluxes measured by the eddy covariance technique in 2001–2003, for 4.5 months during the growing season, the sum of gross primary production (GPP) decreased on average by 739 gC m−2 (64%) after the disturbance, whereas ecosystem respiration (RE) decreased by 501 gC m−2 (51%). As a result, NEP decreased from 159 ± 57 gC m−2 to −80 ± 30 gC m−2, which shows that the ecosystem shifted from a carbon sink to a source. Seasonal variation in RE was strongly correlated to soil temperature. The interannual variation in the seasonal trend of RE was small. Light-saturated GPP (Pmax) decreased from 30–45 μmol m−2 s−1 to 8–12 μmol m−2 s−1 during the summer season through the disturbance because of large reduction in LAI. 相似文献
22.
Effects of mangrove deforestation on fish assemblage at Pak Phanang Bay,southern Thailand 总被引:2,自引:0,他引:2
Tatsuya Shinnaka Mitsuhiko Sano Kou Ikejima Prasert Tongnunui Masahiro Horinouchi Hisashi Kurokura 《Fisheries Science》2007,73(4):862-870
Daytime sampling using a seine net was conducted at Pak Phanang Bay (Nakhon Si Thammarat Province, Thailand) in February and
July 2006, to determine differences in fish assemblage structures between a mangrove site and an adjacent site completely
cleared of mangroves. The overall numbers of fish species and individuals were significantly higher at the mangrove site than
the cleared site in both months. Although benthic crustacean feeders showed more species and individual numbers at the mangrove
site in both months, the opposite was found for zooplankton feeders. A cluster analysis, based on the abundance of each species,
demonstrated that the fish assemblage structures were distinctly different between the two sites. In addition, significant
differences in length frequency distributions for each of the four most abundant species were found between the sites in February
and/or July. Small individuals of Scatophagus argus, Ambassis nalua, and Tetraodon nigroviridis were more common at the mangrove site, and of Chelon subviridis at the cleared site. These results suggest that mangrove deforestation exerts marked effects on fish assemblages. 相似文献
23.
The paddy field is being recognised as a biodiversity hotspot fostering a variety of organisms. However, there are few studies on the ecology of paddy field nematodes. We characterised nematode communities in rice paddy fields by comparing them with upland fields of rice or soybean. We examined nematode communities of the top (0-15 mm) and second (15-50 mm) soil layers before flooding (March or April), during flooding (June or July) and during the draining period (October) 2007-2009. We found that the nematode community in the paddy was different than that in the upland fields during all periods. Rhabdolaimus, Tobrilus, Mesodorylaims and Monhysteridae characterised the top of the paddy and Hirschmanniella characterised the second layer of the paddy. Total nematode density was generally lower in the paddy than in the upland field. However, the density in the paddy top layer increased with time from the flooding period to the draining period, during which time it was about the same as (or even greater than) the peak density in the upland fields. The density in the second layer of the paddy remained lower than that in the top layer of the paddy throughout the time course. Community diversity values were generally greater in the paddy top layer than in the paddy second layer across the six sampling periods, but periodic differences between the paddy and upland fields or between soil layers were not significant. During the flooding period, the F/(F + B) (13-37) and Enrichment Index (17-38) values were lower in the paddy than in the upland fields (32-47, 37-74, respectively) to reflect that bacteria dominate over fungi with slow decomposition due to anaerobic conditions in the flooded paddy field. In addition, particularly in the top layer, the Maturity (2.0-2.4) and Structure Index (23-72) values were greater in the paddy than in the upland fields (1.7-2.1, 9-15, respectively), indicating a well-developed ecosystem under water. These unique nematode communities persisted during the draining period, but there was a rapid increase in opportunistic bacterivores, which increased the EI values. We suggest that bactivorous nematodes in the families Cephalobidae and Chronogasteridae, herbivores in the genus Hirschmanniella, and fungivores in the genus Filenchus may be specific to paddy field soil rather than to pond and lake sediments. 相似文献
24.
Masaaki Katayama Yasuhiko Okamura Shunsuke Shimamura Rieko Katayama Hiroaki Kamishina Yuji Uzuka 《Research in veterinary science》2014
Graft perfusion with cold heparinized saline has known to induce ischemia and reperfusion injury in feline kidney transplantation. In this study, the effects of phosphate-buffered sucrose solution and heparinized saline solution on early kidney graft function were compared in feline kidney autotransplantation. Perfusion of grafts with or without hypothermic storage with chilled phosphate-buffered sucrose solution prevented ischemia and reperfusion injury despite a very short ischemic time. The results of our study suggest that phosphate-buffered sucrose perfusion and storage solution should be effective to reduce ischemia and reperfusion injury despite a very short ischemic time in feline kidney transplantation. 相似文献
25.
Tree-ring-width chronology of Larix gmelinii as an indicator of changes in early summer temperature in east-central Kamchatka 总被引:2,自引:0,他引:2
We developed a 378-year tree-ring-width chronology based on 110 core samples from 55 individual trees of Larix gmelinii (Rupr.) Rupr. growing in a wide open forest close to the tree line in the Kronotsky National Park. Reflecting strong climatic
control over tree growth not only within the study area but also more extensively over central Kamchatka, our chronology was
well correlated with those from other larch sites. Response analysis with 10-day mean temperature revealed that the ring width
was primarily controlled by the temperature of early summer, i.e., of late May through late June (40 days). While the regression
models for a formal reconstruction failed to pass stringent verification tests commonly used in dendroclimatology, the relationship
between tree growth and climate was statistically significant and credible. We therefore used our chronology as a proxy of
early summer temperature. The chronology shows a cool period from the 1660s until the 1680s, followed by gradual warming until
ca. 1800, then by a slight cooling trend extending to ca. 1910, and a warming trend continuing up to the present, with decadal
fluctuations throughout the chronology. The warming trend found in our chronology over the twentieth century is generally
consistent with the ones commonly appearing in higher latitudes. 相似文献
26.
为研究鲤疱疹病毒Ⅱ型(Cy HV-2)体外感染复制特征以及异育银鲫抗病毒免疫应答反应。本实验采用组织块培养法建立了异育银鲫背鳍细胞的原代培养体系。结果显示,在10 d左右可观察到组织块迁移分离出新的单层细胞,3周左右细胞可覆盖底部面积为25cm2培养瓶的底部;经Cy HV-2悬液感染离体培养的原代细胞,3 d后病毒滴度增殖至106拷贝/m L;在病毒感染6 d后出现典型的细胞病变效应;Cy HV-2感染原代细胞后,分析前期通过鱼体水平实验鉴定出的与该病毒感染相关的免疫基因:PNP5a、MPO、MHCⅠ、LYZ-C、IL-11、ITLN、PNP5a和DUSP,Real-time Rt-PCR结果显示大部分基因在细胞水平均有显著性的上调,与鱼体水平实验结果一致。本研究建立了原代培养的异育银鲫背鳍细胞,用于构建体外感染Cy HV-2病毒的细胞模型,为深入研究Cy HV-2的感染复制规律及其与宿主的相互作用关系,以及细胞水平筛选抗病毒药物实验奠定了基础。 相似文献
27.
Nishifuji K Ueda Y Sano A Kadoya M Kamei K Sekiguchi M Nishimura K Iwasaki T 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2005,52(9):478-480
A 5-year-old male Siberian husky bred outdoor in Tokyo had a swollen paw with interdigital granulomatous lesions in the left hindlimb. The dog had no apparent pulmonary or gastrointestinal involvement. Histopathological analysis of the skin lesions demonstrated yeast-like organisms predominantly within macrophages. Sequence analysis of fungal ribosome RNA gene isolated from a paraffin sample revealed a 100% homology with the teleomorph of Histoplasma capsulatum. The present case may support the concept of primary cutaneous canine histoplasmosis as an endemic phenotype recognized in Japan. 相似文献
28.
Masaharu Komatsu Naoki Ichiyama Takashi Kurimoto Shota Takumi Kazuhiro Shiozaki Yasumasa Sugiyama Tatsuhiko Furukawa Seiichi Ando Saki Itonori Hiroaki Saito 《Fisheries Science》2013,79(2):313-320
We have previously established the method for isolation of ceramide aminoethylphosphonate (CAEP) from jumbo flying squid Dosidicus gigas. In this study, we performed a MTT assay to evaluate the safety of CAEP to the cell lines for the application to health food and supplements. The CAEP did not show any cytotoxicity to various HEK293-transfectant cells. Next, we elucidated the positive function of CAEP to the somatic cells. Recently, we have reported that hepatotoxin microcystin-LR was taken up into the hepatocytes mediated by hepatocellular uptake transporters OATP1B1 and OATP1B3, and the cells were induced cytotoxicity subsequently. Cytotoxicity of microcystin-LR to permanently OATP1B3-expressing HEK293-OATP1B3 cells rather than to HEK293-OATP1B1 cells was preferentially attenuated by CAEP in a concentration-dependent manner. In addition, the enzyme activity of serine/threonine phosphatase, which was inhibited by microcystin-LR, was recuperated by co-exposure to CAEP. Furthermore, microcystin-LR-induced cellular protein phosphorylation were disrupted by CAEP exposure. These results suggested that CAEP is a promising remedy and/or preventive medicine for liver damage with microcystin-LR. 相似文献
29.