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161.
Sung-Sik KANG Keisuke KOYAMA Weiping HUANG Yinghua YANG Yojiro YANAGAWA Yoshiyuki TAKAHASHI Masashi NAGANO 《The Journal of reproduction and development》2015,61(2):99-105
The present study aimed to establish an efficient system for bovine embryo production by in vitro fertilization (IVF) that can achieve stable normal fertilization and blastocyst developmental rates in any bull without optimization of the sperm concentration in IVF medium. We examined the effects of a PHE mixture (20 μM D-penicillamine, 10 μM hypotaurine and 1 μM epinephrine), theophylline (2.5 mM), and sperm concentration (1, 2 or 5 × 106 cells/ml) on fertilization and blastocyst developmental rates. High cleavage rates (78.3 to 92.4%) and blastocyst developmental rates (31.9 to 62.0%) at day 7 were obtained in the presence of PHE and theophylline in IVF medium with a sperm concentration of 2 × 106 cells/ml using sperm from 9 bulls. In addition, the synergistic effect of PHE and theophylline on normal fertilization (2 pronuclei) was clarified at 12 h after IVF with a sperm concentration of 1 × 106 cells/ml. Moreover, high
linearity, high flagellar beat cross frequency, and low amplitude of lateral head of motile sperm were found by computer-assisted sperm analysis. In conclusion, the combination of the PHE mixture and theophylline synergistically accelerates sperm motility and sperm penetration of bovine oocytes. Theophylline activates sperm motility with increasing intracellular cAMP. However, PHE prevents an excessive increase of cAMP and maintains sperm motility without hyperactivation. When the combination of PHE and theophylline is added to IVF medium at a sperm concentration of 2 × 106 cells/ml, we can achieve stable normal fertilization and blastocyst development in any bull. 相似文献
162.
Yoshiyuki Yanase Yoshihisa Fujii Shogo Okumura Yuji Imamura Tsuyoshi Yoshimura 《Journal of Wood Science》2000,46(3):243-247
To examine the feasibility of using plate-type waveguides for effective detection of acoustic emissions (AEs) from termite attacks in wood, AEs generated by breaking pencil leads or by termite attacks were detected using an AE sensor with a resonant frequency of 140kHz with steel plates of four different sizes and thickness and three AE sensors without them. The larger plates were associated with larger amplitudes of the artificial AEs. The amplitudes of AEs detected by an AE sensor with a steel plate larger than 30×30mm were greater than the average amplitude of the artificial AEs detected by three AE sensors. When detecting AEs generated by the feeding activity of workers,Coptotermes formosanus Shiraki, the cumulative AE events detected by the sensor with a steel plate were much larger than those of the three AE sensors without a plate. Because AE waves are attenuated much less in a steel plate than in wood, it is more effective to attach the AE sensor to wood with a steel plate rather than directly to the wood. These findings suggest that it is feasible to use an AE sensor with a plate-type waveguide for the nondestructive detection of termite attacks in wood. 相似文献
163.
We investigated the sapling leaf display in the shade among trees of various leaf lifespans co-occurring under the canopy
of a warm-temperate conifer plantation. We measured leaf-area ratio (aLAR) and morphological traits of saplings of evergreen
broadleaved tree species and a deciduous tree species. Although we found large interspecific and intraspecific differences
in aLAR even among saplings of similar size in the homogeneous light environment, we did not find a consistent trend in aLAR
with leaf lifespan among the species. While deciduous trees annually produced a large leaf area, some evergreen broadleaved
trees retained their leaves across years and had aLAR values as high as those of deciduous trees. Among leaf-level, shoot-level,
and individual-level morphological traits, aLAR was positively correlated with current-year shoots mass per aboveground biomass
in deciduous trees, and with the area of old leaves per aboveground mass in evergreen broadleaved trees. Thus, tree-to-tree
variation in the degrees of annual shoot production and the accumulation of old leaves were responsible for the interspecific
and intraspecific variations in aLAR. 相似文献
164.
165.
166.
The objective of this study was to investigate the effects of the application of rice husk biochar on selected soil physical properties, rice growth, including root extension, and methane (CH4) emissions from paddy field soil. Three replication experiments were conducted using outdoor pot experiments utilizing commercial rice husk biochar mixed with paddy soil at a rate of 0 (control), 2, and 4 % (weight biochar/weight soil) in which the rice was cultivated for 100 days under a continuously flooded condition. The physical properties of soils were analyzed before and after the growing periods. Some parameters of rice growth and CH4 emissions of paddy soils were monitored weekly during the experiment. Root extension was also analyzed after harvesting. The experiments showed that the application of rice husk biochar improved the physical properties of paddy soils. It led to a decrease in bulk density and an increase in saturated hydraulic conductivity, including the total pore volume as well as the available soil water content. The shoot height of rice plants was significantly higher in soil amended with 4 % biochar than that in the control soil. However, other plant growth parameters and root extension were only slightly affected by the application. It was also found that amending soil with biochar led to a reduction of the total CH4 emissions by 45.2 and 54.9 % for an application rate of 2 and 4 %, respectively, compared with the control. Our results showed that the higher the application rate, the stronger the effect of biochar was observed. More research is still necessary for a better understanding of the underlying mechanisms. 相似文献
167.
Ampaabeng Gyedu KYEREMEH Toshio KIKUMOTO Duen-yau CHUANG Yuichi GUNJI Yoshiyuki TAKAHARA Yoshio EHARA 《Journal of General Plant Pathology》2000,66(3):264-268
Two pathogenic strains of E. carotovora subsp. carotovora 2T-2 and TT-4 with high bacteriocin activity but low sensitivity to the bacteriocins of other strains were treated with ethyl
methane sulphonate (EMS). Two avirulent mutants A-f-39 and B-e-19 developed from 2T-2 and TT-4, respectively, by this treatment
had the same bacteriocin activity as their respective parents and inhibited the in vitro growth of pathogenic strains of this species. The disease control of these two mutant strains were compared in the field in
1995 and 1997 to the control by CGE234M403 (M403) (a commercialized biocontrol agent), a mixture of A-f-39 and M403, and an
agrochemical (basic dithianon-copper chloride). The protection obtained with A-f-39 was comparable to M403 and was better
than that with the chemical. The mixture of A-f-39 and M403 consistently gave the best results in all the field trials.
Received 17 September 1999/ Accepted in revised form 22 February 2000 相似文献
168.
Yoshiyuki IMURA Satoko IGUCHI Kazuhiro TOYODA Yuki ICHINOSE Tomonori SHIRAISHI Tetsuji YAMADA 《Journal of General Plant Pathology》2000,66(2):123-127
Regulatory elements in the promoter of phenylalanine ammonia-lyase gene 1 of pea (PSPAL1) in response to nonpathogenic attack were identified by in vivo footprinting analysis. The footprints determined AC-rich sequences, Box-I and Box-II, that were conserved at similar positions
in the phenylpropanoid gene promoters from several plants. To reveal the functions of the AC-rich sequence in nonpathogen-responsiveness,
we constructed Box-I-deletion PSPAL1 promoter (dB-1) with GUS reporter gene and transformed it into tobacco plant. The dB-1 had reduced basal expression and a complete loss of nonpathogen-responsiveness. These results indicate the essentiality of
Box-I for PSPAL1 activation induced by nonpathogenic attack.
Received 27 October 1999/ Accepted in revised form 25 November 1999 相似文献
169.
The spread of tea drinking to the common people began in the 18th century in the middle of the Edo period. At the beginning of the Meiji era (1868-1912), tea was one of the most important agricultural prod ucts, ranking with silk, and was mainly exported, especially to North America. 相似文献
170.