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221.
Seismic evidence for deep-water transportation in the mantle   总被引:2,自引:0,他引:2  
We report seismic evidence for the transportation of water into the deep mantle in the subduction zone beneath northeastern Japan. Our data indicate that water is released from the hydrated oceanic crust at shallow depths (< approximately 100 kilometers) and then forms a channel of hydrated mantle material on top of the subducting plate that is the pathway for water into the deep mantle. Our result provides direct evidence that shows how water is transported from the ocean to the deep mantle in a cold subduction zone environment.  相似文献   
222.
Four Holstein steers fitted with duodenal cannula were used in a 4 × 4 Latin square design to investigate the effect of the combination of corn silage (CS) and alfalfa hay (AH) in different ratios on the ruminal and intestinal digestion of carbohydrates and feed particle passage rate. Steers were fed mixed diets containing both CS and AH in ratios of 80:20, 60:40, 40:60 and 20:80 on a dry matter basis at 95% of ad libitum feed intake. The increase of AH proportion in diets increased dry matter intake and ruminal digestion of dry matter, non-fiber carbohydrate, neutral and acid detergent fiber linearly. Ruminal digestibility of neutral detergent fiber showed a quadratic response, and total digestibility increased linearly with increasing AH proportion. Digestibility of acid detergent fiber in the rumen was not affected by the dietary treatments, but the total tract digestibility increased as the AH proportion increased. Mean retention time of feed particles in total compartment increased when the AH proportion increased from 20% to 60%, but decreased with further increase of the AH proportion. These results indicate that moderate combinations of CS and AH have an associative effect on ruminal fiber digestion, modifying particle movement in the rumen.  相似文献   
223.
224.
Signals mediating phytoalexin (PA) production were analyzed in primary leaves of oats cv. Iowa X469 treated with an elicitor victorin. Production of the PA avenanthramide A was inhibited by DPI, an inhibitor of NADPH oxidase/nitric oxide synthase (NOS) and the NOS inhibitors l-NMMA and 1,3-PBIT. However, catalase and superoxide dismutase (SOD) hardly suppressed it. From the data, NO functions as a major reactive oxygen species in signal transduction leading to PA production in the defense response of oats. EGTA, verapamil and ruthenium red inhibited PA production, suggesting that Ca2+ influx into the cytoplasm and intracellular Ca2+ movement are involved in the defense response. Trifluoperazine, a calmodulin function inhibitor, and K-252a, a serine/threonine kinase inhibitor, also suppressed the accumulation, whereas okadaic acid, a serine/threonine phosphatase inhibitor, did not suppress it, suggesting the involvement of calmodulin and protein kinase, but not of phosphatase in PA production. Received 24 December 1999/ Accepted in revised form 4 February 2000  相似文献   
225.
Vertical movements related to the thermoregulation were investigated in 12 juvenile bigeye tuna (Thunnus obesus) in Japanese waters using archival tag data. Movements changed with time of day, season, and body size. During daytime, bigeye tuna descended to greater depths, presumably to feed in the deep scattering layer (DSL). Thereafter, they repeatedly ascended to shallower layers, suggesting attempts at behavioral thermoregulation, although the beginning of vertical thermoregulatory ascents might reflect a shift in DSL depth. By the end of such movement, the whole‐body heat‐transfer coefficient might decrease because, although the depth and ambient temperature of the upper layers did not change, the body temperature gradually decreased significantly just after ascent for thermoregulation. Seasonal patterns indicated that the vertical thermal structure of the ocean might influence this ascent behavior. For example, from January to May, bigeye tuna made fewer ascents to less shallow waters, suggesting that they respond to increasing depths of the mixed surface layer by reducing energy expenditure during vertical migration. In addition, as body size increased, fewer thermoregulatory ascents were required to maintain body temperature, and fish remained deeper for longer periods. Thus, vertical thermoregulatory movements might change with body size as bigeye tuna develop better endothermic and thermoregulatory abilities. We hypothesize that bigeye might also increase cold tolerance as they grow, possibly due to ontogenetic shifts in cardiac function.  相似文献   
226.
Kasai  Akihide  Takada  Shingo  Yamazaki  Aya  Masuda  Reiji  Yamanaka  Hiroki 《Fisheries Science》2020,86(3):465-471
Fisheries Science - The environmental DNA (eDNA) technique is a convenient and powerful tool to detect rare species. Knowledge of the degradation rate of eDNA in water is important for...  相似文献   
227.
To investigate the presence of non-native anguillid eels in Japanese waters, 141 eels were collected from seven sampling sites throughout the Tone River system. Genetic species identification showed an extraordinary dominance of the non-native European eel Anguilla anguilla in the uppermost site of the study area. Estimation of age from otoliths suggested that the European eels were introduced into the river in the 1990s, corresponding to previous reports from other Japanese water systems. Comparison of the von Bertalanffy growth curve parameters indicated that the European eels caught in the Tone River system appeared to have a similar or even higher growth rate than the same species in the original habitats in Europe. The long-term inhabitation and the normal development of European eels in Japanese waters suggest that regulations prohibiting the release of non-native eels and safeguards against accidental escape from culture ponds must be strictly maintained in order to ensure the conservation of the native Japanese eel.  相似文献   
228.
We examined the effectiveness of saline, Euro-Collins solution (EC), and ET-Kyoto solution (ET-K) as preservation media for the cold storage of feline ovaries. Ovaries were maintained in these media at 4°C for 24, 48, or 72 h until oocyte retrieval. The ET-K group exhibited a higher oocyte maturation rate than the saline group after 72 h of storage. Moreover, ET-K could sustain the competence of the feline oocytes to cleave after 48 h, and the morula formation rate of the ET-K group was higher than that of the other groups after 24 and 48 h. Furthermore, the ET-K group exhibited a higher blastocyst formation rate than the other groups after storage for 24 h, and only ET-K retained the developmental competence in blastocysts after 48 h of storage. In addition, regarding the cell numbers of the blastocysts, there was no significant difference among the tested groups. In conclusion, our results indicate that ET-K is a suitable preservation medium for feline ovaries.  相似文献   
229.
Measurements of the singlet oxygen ((1)O(2)) quenching rates (k(Q) (S)) and the relative singlet oxygen absortpion capacity (SOAC) values were performed for 16 phenolic antioxidants (tocopherol derivatives, ubiquinol-10, caffeic acids, and catechins) and vitamin C in ethanol/chloroform/D(2)O (50:50:1, v/v/v) solution at 35 °C. It has been clarified that the SOAC method is useful to evaluate the (1)O(2)-quenching activity of lipophilic and hydrophilic antioxidants having 5 orders of magnitude different rate constants from 1.38 × 10(10) M(-1) s(-1) for lycopene to 2.71 × 10(5) for ferulic acid. The logarithms of the k(Q) (S) and the SOAC values for phenolic antioxidants were found to correlate well with their peak oxidation potentials (E(p)); the antioxidants that have smaller E(p) values show higher reactivities. In previous works, measurements of the k(Q) (S) values for many phenolic antioxidants were performed in ethanol. Consequently, measurements of the k(Q) (S) and relative SOAC values were performed for eight carotenoids in ethanol to investigate the effect of solvent on the (1)O(2)-quenching rate. The k(Q) (S) values for phenolic antioxidants and carotenoids in ethanol were found to correlate linearly with the k(Q) (S) values in ethanol/chloroform/D(2)O solution with a gradient of 1.79, except for two catechins. As the relative rate constants (k(Q)(AO) (S)/k(Q)(α-Toc) (S)) of antioxidants (AO) are equal to the relative SOAC values, the SOAC values do not depend on the kinds of solvent used, if α-tocopherol is used as a standard compound. In fact, the SOAC values obtained for carotenoids in mixed solvent agreed well with the corresponding ones in ethanol.  相似文献   
230.
A 1-year-old domestic shorthair cat was evaluated for a chronic history of back pain, dysuria, and paraplegia. Radiographic and computed tomographic examinations showed circumferential widening of the vertebral canal at T13 and T14. A spinal epidural abscess (SEA) compressing the spinal cord from the level of T11 to L1 was suspected following intravenous contrast administration, and was confirmed by surgical exploration and histopathological analysis. The cat recovered its motor and bladder functions following surgical decompression and antibiotic therapy. SEA is a neurological emergency requiring prompt treatment. However, the present case had a prolonged disease course and pressure atrophy of the vertebrae was strongly suspected. To our knowledge, this imaging finding has not been reported in dogs or cats with SEA.  相似文献   
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