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81.
Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV‐3) and possible latency of CyHV‐3 by temperature shift in the cells 下载免费PDF全文
M Imajoh H Fujioka K Furusawa K Tamura K Yamasaki S Kurihara J Yamane K Kawai S Oshima 《Journal of fish diseases》2015,38(6):507-514
A new cell line named CCF‐K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV‐3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV‐3‐infected CCF‐K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV‐3 was produced stably in CCF‐K104 cells over 30 viral passages. Our findings showed that CCF‐K104 is a useful cell line for isolation and productive replication of CyHV‐3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real‐time PCR showed that CyHV‐3 was present with low viral DNA loads, suggesting that CyHV‐3 may establish latent infection in CCF‐K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV‐3 genome arranged in a head‐to‐tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV‐3. 相似文献
82.
Natural non-allophanic Andosols often show aluminum (Al) toxicity to Al-sensitive plant roots. The significance of Al–humus complexes to Al toxicity has been emphasized. Allophanic Andosols also possess Al–humus complexes, but they rarely show any toxicity. In the present study, using model substances, we tested the toxicity of Al–humus complexes and its amelioration with allophanic materials. We extracted humic substances from the A horizons of a non-allophanic Andosol and an allophanic Andosol using a NaOH solution, and reacted the humic substances and partially neutralized AlCl3 solution at pH 4. Allophanic material was purified from commercial Kanuma pumice. Plant growth tests were conducted using a medium containing the Al–humus complexes (50 g kg−1 ), the allophanic material (0, 90, 180 and 360 g kg−1 ) and perlite. The root growth of barley ( Hordeum vulgare L.) and burdock ( Arctium lappa ) was reduced in the media containing the Al–humus complexes derived from both the non-allophanic and allophanic Andosols when the allophanic material was not added. With the addition of the allophanic materials, particularly in the 360 g kg−1 treatment, the growth of the barley roots was improved markedly. Although the root growth of the burdock tended to improve with allophanic materials, the effect was weaker than that for barley. Monomeric Al in a solution of the medium was not detected (< 0.05 mg L−1 ) following the addition of 360 g kg−1 of allophanic materials, whereas 0.8–1.7 mg L−1 Al was recorded without the allophanic material. 相似文献
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Fanomezantsoa Randriarilala Toshihide Kitakado Daisuke Shiode Masayuki Sakaguchi Toshifumi Hayashi Tadashi Tokai 《Fisheries Science》2014,80(2):261-271
Information on the distribution and bloom scale of the giant jellyfish Nemopilema nomurai is necessary to understand the impact on fisheries. In October 2009, we had an opportunity for visual counting of N. nomurai around Japan from a research/training vessel. To take into account possibly severe missed detection of N. nomurai in the close vicinity of the vessel, detection functions were modified by introducing an additional parameter δ expressing the proportion of detectable N. nomurai within a threshold perpendicular distance. Some covariate effects in the detection process were also investigated. The δ-modified hazard-rate detection function with δ variation parameter of jellyfish body size was chosen as the best-fit one by AIC model selection. The results suggested that a higher proportion (>30 % or more) of N. nomurai were undetected in the vicinity of vessel. The δ-modified model had an advantage of no loss of left-truncated data and provided better estimation of density with the smaller coefficient of variation than the conventional left truncation approach. It is applicable to other line transect surveys, e.g. aerial surveys. High densities of N. nomurai were found in the central part of the Sea of Japan and off Iwate Prefecture. 相似文献
86.
ABSTRACT We reviewed the role of the soil function of urban green space in mitigating the heat island phenomenon and urban flood damage, which are important issues in the modern urban environment. Urban sprawl has progressed remarkably in the southern part of the Kanto District of Japan, especially since the 1960s. The grassland/bare land area ratio in the center of Tokyo was more than 70% in the 1930s but less than 40% in 1990. On the other hand, the paving area ratio was ~2% in the 1930s but more than 10 times that amount in 1990. Thus, cities, such as Tokyo, in the southern part of the Kanto District have been significantly sealed soil throughout time, and the heat island phenomenon has intensified. Urban green space helps to mitigate the heat island phenomenon based on the water retention and heat dissipation function of plants and unsealed soil. A cool island effect was reported during summer days in urban green spaces in Tokyo. The mitigation of the heat island effect seems to be large, even when conditions, such as the park area, land use, afforestation area ratio, and soil type, differ. Soil sealing and compaction affect urban flooding by hindering the penetration of rainwater and increasing surface runoff. According to a survey in the hilly basin (1 km2) of the western part of Tokyo, the proportion of farm- and forestland decreased due to development. The urban area increased from ~10% in the 1970s to ~60% in the 1980s. As a result, the flood arrival time shortened. Green spaces have a high rainwater permeability. The forest soil structure and presence of O horizons further increase the permeability. By promoting permeability to the underground, it is possible to reduce and delay the water runoff on the land surface. To develop urban green space as green infrastructure, it is necessary to accumulate more information on the current situation and agenda for the future of urban green space. 相似文献
87.
Milking performance evaluation and factors affecting milking claw vacuum levels with flow simulator 下载免费PDF全文
Masafumi Enokidani Kazuhiro Kawai Yasunori Shinozuka Aiko Watanabe 《Animal Science Journal》2017,88(8):1134-1140
Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high‐producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk‐meter and vacuum shut‐off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum. 相似文献
88.
Understanding organic matter characteristics(e.g., amount and state) of sediments is necessary for evaluating both the sediment and water environments; however, methods that have been proposed to investigate these characteristics are relatively expensive. This study attempted to evaluate the organic matter characteristics of littoral sediments by employing solely the loss on ignition(LOI)method, which is the most economical and accessible method in developing countries. Different types of sediments were first oven dried at 100℃ and then continuously burned at 200, 300, 400, 500, and 600℃ for 4 h at each temperature. The mass LOI at each temperature was calculated and compared with the 100℃ oven-dried weight. Our results suggested that the mass LOI across the temperature range of 200–300℃(LOI_(200-300)):mass LOI at 600℃(LOI_(600)) ratio(LOI_(200-300)/LOI_(600)) could represent different types of sediments as well as the organic matter:organic C ratio. Compared with the sediments unaffected by wastewater, the sediments that were more influenced by the inflow of domestic wastewater had a higher LOI_(200-300)/LOI_(600). Interestingly, LOI_(200-300)/LOI_(600) could also represent changes in the organic matter characteristics as a function of organic matter decomposition in sediments. In conclusion, the organic matter characteristics of littoral sediments could be evaluated using solely the LOI method, particularly with LOI_(200-300)/LOI_(600). 相似文献
89.
Effectiveness of iron (Fe3+)-citrate and Fe3+-EDTA (ethylenediaminetetraacetic acid) in reducing arsenic (As)-toxicity in rice was evaluated. The treatments: 1) 0 µM As + 10 µM Fe3+-citrate (control), 2) 13.4 µM As + 10 µM Fe3+-citrate (As-treated), 3) 13.4 µM As + 10 µM Fe3+-citrate + 40 µM Fe3+-citrate (additional Fe3+-citrate), and 4) 13.4 µM As + 10 µM Fe3+-citrate + 40 µM Fe3+-EDTA (additional Fe3+-EDTA) were studied for 14 days. Chlorosis was found in the young leaves of the As-treated plants. Additional Fe3+-citrate failed to remediate the chlorosis, however, additional Fe3+-EDTA removed the chlorosis almost completely, indicating that the effectiveness of Fe3+-EDTA was much higher than Fe3+-citrate. The Fe3+-EDTA treated plants were greener than the additional Fe3+-citrate treated plants. Iron concentration in the shoots of additional Fe3+-EDTA plants was much higher than that of additional Fe3+-citrate plants, indicating that Fe3+-EDTA might have been more readily available to the plants roots than Fe3+-citrate. 相似文献
90.
Growth variability of Pacific saury Cololabis saira larvae under contrasting environments across the Kuroshio axis: survival potential of minority versus majority 下载免费PDF全文
Akinori Takasuka Kirara Nishikawa Hiroshi Kuroda Takeshi Okunishi Yugo Shimizu Hideo Sakaji Shin‐Ichi Ito Tadashi Tokai Yoshioki Oozeki 《Fisheries Oceanography》2016,25(4):390-406
Growth variability was examined for Pacific saury Cololabis saira larvae under contrasting environments across the Kuroshio axis, based on samples collected during the winter spawning season in 2013 and 2014. The growth rate index (residual of the otolith marginal 3‐day mean increment width from the linear regression on knob length) of larvae was compared among three areas: the inshore side of the Kuroshio axis, the Kuroshio axis, and the offshore side of the Kuroshio axis in relation to sea surface temperature (SST), salinity (SSS) and chlorophyll‐a (CHL) concentration. The larvae were more densely distributed in the Kuroshio axis and offshore areas of higher temperature and salinity and lower chlorophyll‐a concentration than in the inshore areas of lower temperature and salinity and higher chlorophyll‐a concentration. No marked differences in the growth rate index were found among the three areas, even though the larvae in the inshore areas showed slightly higher growth rates in 2013. Despite the broad ranges of environmental factors, no clear relationship between the growth rate index and any environmental factor was detected. The survival potential of Pacific saury larvae was considered to be at least comparable under contrasting environments across the Kuroshio axis. Such a geographical homogeneity is concluded to be attributable to compensable effects of physical and biological factors. We hypothesize that the minority under physically‐unfavorable but biologically‐favorable conditions on the inshore side of the Kuroshio axis could survive equally well as the majority under physically‐favorable but biologically‐unfavorable conditions around the Kuroshio axis and on the offshore side of the Kuroshio axis. 相似文献