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491.
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Toshiaki SUMIYOSHI Tomomi TANAKA Hideo KAMOMAE 《The Journal of reproduction and development》2014,60(2):106-114
Lactating Holstein-Friesian cows kept in tie-stall barn were used as subjects in this
study. Rectal examination, ultrasonography and blood sampling were conducted every other
day and then daily after the day on which diameter of the corpus luteum decreased. After
the luteal diameter decreased for 2 consecutive days, rectal and ultrasound examinations,
blood sampling, and observation of estrous signs were conducted at 6-h intervals. Most of
the estrous signs became obvious with the increase in estradiol-17β (E2) and
became most remarkable 24 to 30 hours before ovulation, at which point the E2
peak and luteinizing hormone (LH) surge were achieved, and then weakened which progression
to ovulation. The correlation between the intensity of four estrous signs (hyperemia and
swelling of the intravaginal part of the uterus, opening of the external uterine orifice
and viscosity of the cervical mucus) and the plasma E2 concentration was higher
than that of three estrous signs (swelling of the vulva, contraction of the uterus,
diameter of uterine horn) and the plasma E2 concentration. The relaxation of
the intravaginal part of the uterus showed a unique change compared with the other estrous
signs, and it became most obvious 6, 12 and 18 h before ovulation; this obviously relaxed
period was consistent with the generally accepted theoretical optimal time for artificial
insemination (AI), i.e., 6 to 24 h after initiation of estrus. These results suggest that
observation of estrous signs by vaginoscopic examination gave useful information for
detection of the optimal timing of AI in the periovulatory period in lactating dairy cows
kept in a tie-stall barn. 相似文献
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Colonization patterns of representative rumen bacteria were compared between untreated rice straw (UTS) and sodium hydroxide‐treated rice straw (SHTS). UTS and SHTS were incubated in the rumen of sheep for 10 min, 1, 2, 6, 12, 24, 48 and 96 h using the nylon bag method. The population sizes of 13 representative bacterial species or groups were quantified by real‐time PCR. The total bacterial population size (abundance) was similar in both UTS and SHTS. Fibrobacter succinogenes showed a higher population size compared to other fibrolytic species and was detected at a higher level in SHTS (3.7%) than in UTS (2.6%). Ruminococcus albus and Ruminococcus flavefaciens were also detected at higher levels in SHTS (0.15% and 0.29%) than in UTS (0.03% and 0.18%). Population sizes of non‐fibrolytic species, such as Selenomonas ruminantium, Anaerovibrio lipolytica and Succinivibrio dextrinosolvens were higher in UTS than in SHTS. Coefficient of determination (r2) on population changes between bacterial species or groups were higher in UTS than in SHTS, suggesting the necessity of stronger bacterial interactions for UTS digestion. Therefore, not only colonization of fibrolytic species, but also synergistic interactions between different bacterial species may be key to the ruminal digestion of rice straw. 相似文献
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Asanoma M Tachibana N Hirotsuka M Kohno M Watanabe Y 《Journal of agricultural and food chemistry》2012,60(21):5367-5372
This study assessed the effects of soy protein isolate (SPI) on severe kidney damage in deoxycorticosterone acetate (DOCA) salt-treated obese Zucker rats. These rats underwent heminephrectomy and were fed either casein or SPI diet for 12 weeks. From weeks 8 to 10 of the experiment, kidney damage was induced by biweekly injection of 25 mg/kg DOCA and administration of 0.5% NaCl (w/v) ad libitum. Urinary protein and N-acetyl-β-d-glucosaminidase excretions of SPI rats were much lower than those of casein rats at weeks 1 (p < 0.01) and 2 (p < 0.05) after DOCA treatment. Abnormal mineral excretions induced by DOCA treatment in casein rats were hardly detected in SPI rats. Severe atrophy of tubular epithelium and some flattened/detached renal tubules were also observed in casein rats, but not in SPI rats. These results indicate that consecutive treatment of SPI protects against renal dysfunction, particularly tubulointerstitial nephritis, in DOCA salt-treated obese Zucker rats. 相似文献
499.
Post-perovskite phase transition in MgSiO3 总被引:2,自引:0,他引:2
In situ x-ray diffraction measurements of MgSiO3 were performed at high pressure and temperature similar to the conditions at Earth's core-mantle boundary. Results demonstrate that MgSiO3 perovskite transforms to a new high-pressure form with stacked SiO6-octahedral sheet structure above 125 gigapascals and 2500 kelvin (2700-kilometer depth near the base of the mantle) with an increase in density of 1.0 to 1.2%. The origin of the D" seismic discontinuity may be attributed to this post-perovskite phase transition. The new phase may have large elastic anisotropy and develop preferred orientation with platy crystal shape in the shear flow that can cause strong seismic anisotropy below the D" discontinuity. 相似文献
500.
Ohta K Onoda S Hirose K Sinmyo R Shimizu K Sata N Ohishi Y Yasuhara A 《Science (New York, N.Y.)》2008,320(5872):89-91
Recent discovery of a phase transition from perovskite to post-perovskite suggests that the physical properties of Earth's lowermost mantle, called the D' layer, may be different from those of the overlying mantle. We report that the electrical conductivity of (Mg0.9Fe0.1)SiO3 post-perovskite is >10(2) siemens per meter and does not vary greatly with temperature at the conditions of the D' layer. A post-perovskite layer above the core-mantle boundary would, by electromagnetic coupling, enhance the exchange of angular momentum between the fluid core and the solid mantle, which can explain the observed changes in the length of a day on decadal time scales. Heterogeneity in the conductivity of the lowermost mantle is likely to depend on changes in chemistry of the boundary region, not fluctuations in temperature. 相似文献