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31.
We investigated the profiles of circulating levels of inhibin A and total inhibin in beef cows with follicular cysts in relation to the patterns of follicular development and circulating gonadotropins and steroid hormones. Turnover of follicular waves was monitored in five cows every 2 days for 70 days from 10 days after detection of estrus without ovulation. The mean interwave intervals were 19.6 ± 1.0 days (n = 18 waves with cysts from the five cows). Circulating levels of inhibin A were approximately 170 pg/ml before emergence of follicular waves with cysts and increased (P < 0.05) concomitantly with follicle emergence. High concentrations of inhibin A (greater than 300 pg/ml) were noted for 7 days during the growth phase of cystic follicles, but inhibin A levels decreased gradually when development of the cysts reached a plateau. This profile of inhibin A was similar to those of total inhibin and estradiol, but was inversely related to the changes in plasma FSH concentrations. LH pulse frequency and mean concentrations of LH in cows with cysts were higher than those observed in the luteal phase of normal cyclic cows. These results indicate that the capacity to secrete inhibin, as well as estradiol, is maintained in cystic follicles, the growth of which is extended by LH secretion at levels greater than those seen in the normal luteal phase. Inhibin A plays an important role in the extension of interwave intervals by suppressing recruitment of a new cohort of follicles.  相似文献   
32.
Light elements such as oxygen in Earth's core influence the physical properties of the iron alloys that exist in this region. Describing the high-pressure behavior of these materials at core conditions constrains models of core structure and dynamics. From x-ray diffraction measurements of iron monoxide (FeO) at high pressure and temperature, we show that sodium chloride (NaCl)-type (B1) FeO transforms to a cesium chloride (CsCl)-type (B2) phase above 240 gigapascals at 4000 kelvin with 2% density increase. The oxygen-bearing liquid in the middle of the outer core therefore has a modified Fe-O bonding environment that, according to our numerical simulations, suppresses convection. The phase-induced stratification is seismologically invisible but strongly affects the geodynamo.  相似文献   
33.
The contribution of oceanic gabbros, representative rocks for layer 3 of the oceanic crust, to sea-floor spreading magnetic anomalies has been controversial because of the large variation in magnetic properties. Ocean Drilling Program (ODP) Leg 118 contains a continuous 500.7-meter section of oceanic gabbro that allows the relations between magnetization and petrologic characteristics, such as the degree of metamorphism and the magmatic evolution, to be clarified. The data suggest that oceanic gabbros, together with the effects of metamorphism and of magmatic evolution, account for a significant part of the marine magnetic anomalies.  相似文献   
34.
35.
Barley can be used as an extender of rice to increase the nutritive value of the end-product. Specific quality barley is required if the processed barley is to resemble cooked white rice in colour and shape. The barley must pearl and split without the production of broken kernels or fines and yet produce desired end use quality. Barley endosperm texture and colour are key to determining these processing characteristics. Testing of Canadian barley types indicated the waxy type was most appropriate for pearling and processing as rice extender. It had a firm endosperm texture that was not steely and yet processed into a white product with few broken grains. Covered barley was of better quality than hull-less, as the former generally had fewer steely kernels as well as firmer endosperm texture. Differences observed between two- and six-rowed type were related to grain size and could be overcome by proper adjustments to processing conditions. Growing conditions affected kernel size and barley protein contents but to a lesser extent than barley type. L* brightness values, Particle Size Index and kernel size were found to be important predictors of barley quality for pearling and as rice extender.  相似文献   
36.
Absorption of radiocesium (137Cs and 134Cs) through bark, and its subsequent translocation into wood and needles, has been suggested as a potential source of tree contamination, but the process is not well understood. Field experiments were conducted to confirm whether Cs could enter a Japanese cedar tree through the bark and how Cs moves within a tree. Stable Cs (133Cs) was applied to the bark at 1.2-m height on 10- and 26-year-old Japanese cedars. The 133Cs concentrations were determined in the bark, sapwood, and heartwood (for 26-year-old cedar only) of stem disks from several heights, as well as in current-year needles from the canopy. The 133Cs concentrations were considerably higher in the sapwood and heartwood of stem disks from 1.2-m height in treated trees than in untreated trees, suggesting that 133Cs penetrated the bark to enter the wood. The average 133Cs concentrations were higher in the heartwood than the sapwood, indicating 133Cs accumulation in the heartwood. High 133Cs concentrations in the needles of treated trees implied acropetal movement of 133Cs to actively growing organs. Our results demonstrate that Cs can enter Japanese cedar trees through the bark and that Cs is transported radially to the heartwood and vertically to the apex.  相似文献   
37.
The number of growth rings was counted on broken and burnt otoliths of eight Lethrinus spp. from two local populations: Lethrinus atkinsoni, L. harak, L. miniatus, L. nebulosus, L. obsoletus, L. ornatus, L. ravus, and L. rubrioperculatus, collected from 1985 to 1996 in waters off the Ryukyu Islands. Growth rings were revealed to be formed annually from about October to June by marginal analysis. In addition to obtaining the three parameters in von Bertalanffy growth equation and the maximum age in specimens, the relationship between age and both ovarian maturity rate and sex ratio (percentage female) was analyzed. The age at 50% of ovarian maturity was the lowest at 1–2 years old in L. harak, L. ravus, and L. rubrioperculatus and was the highest at approximately 4 years old in L. nebulosus. The age at which the sex ratio decreased to 50% due to sexual transition from female in protogynous hermaphrodite species was the lowest at 3–4 years old in the L. atkinsoni Okinawa population and was the highest at 7–8 years old in L. miniatus. The oldest maximum age for specimens was 26 years in L. nebulosus and the youngest maximum age was 12 years in L. ornatus.  相似文献   
38.
39.
In total, 83 avian pathogenic Escherichia coli (APEC) isolates from avian colibacillosis during a period from 2001 to 2006 in Japan were investigated for serogroups, typical virulence factors, antimicrobial susceptibility, and genetic relatedness. The most common serogroup was O78 (30.1%); 80.7% of isolates harbored the iss gene and 55.4% of isolates harbored the tsh gene. Antimicrobial resistance of the isolates was found for ampicillin (77.1%), oxytetracycline (75.9%), kanamycin (36.1%), fradiomycin (33.7%), trimethoprim (25.3%), enrofloxacin (21.7%), and florfenicol (6.0%). Although multiple antimicrobial-resistant phenotypes (three or more antimicrobials) accounted for 54.2% of isolates, no isolate exhibited resistance to all agents tested. The fluoroquinolone-resistant isolates had point mutations in GyrA (Ser83 --> Leu, Asp87 --> Asn) and ParC (Ser80 --> Ile, Glu84 --> Gly). Of 18 enrofloxacin-resistant E. coli isolates, nine isolates belonged to serotype O78. In PFGE analysis, eight of the nine enrofloxacin-resistant O78 isolates were classified into an identical cluster. This suggests that a specific genotype of fluoroquinolone-resistant O78 APEC may be widely distributed in Japan.  相似文献   
40.
The right testis and epididymis were excised from a Beagle dog that ejaculated high percentages of sperm with detached tails and with coiled tails. Cross sections of the organs were stamped on glass slides and histological examination of the organs was performed to find the portion where sperm with the abnormal tails appear. Many sperm with tails whose axoneme was exposed near the neck region were observed in the testis and they decreased in order from the caput, to the corpus, and the cauda epididymis. Sperm with detached tails and sperm with coiled tails gradually increased in the epididymis. These findings indicate that the tails of sperm with an exposed axoneme detached in the epididymis.  相似文献   
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