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81.
The contributions and relationships of erosion by splash and overland flow over a steep slope in a Japanese beech forest in plots with different percentages of ground cover were examined. Three erosion plots (2 m wide × 5 m long) with average understory coverage of 1%, 45%, and 94% were installed. Sediment transported by rain splash and by overland flow was sampled separately. For the plots with sparse, moderate, and high understory coverage, the average proportions of splash soil to total soil erosion during the monitoring period were 16%, 32%, and 18%, respectively. A significant correlation between the amount of splash soil and precipitation was found in the plots with 1% and 45% understory coverage, whereas no statistical relationship was identified for the plot with high understory coverage. At the sparse ground cover plot showing the largest sediment movement, the contribution of splash transport decreased with increasing precipitation. The amount of sheetwash erosion was significantly correlated with the amount of splash soil under the condition of sparse ground cover. This relationship was more pronounced during high precipitation events and the rainy season. Splash contribution to the sediment transport was in the range of 0.8%–76.7%, 2.8%–81% and 2.1%–60.8% for plot with high, moderate and low ground cover, respectively. The sparse ground cover showed the largest variation of splash and sheetwash contribution in soil erosion. This variability was due to variation in ground cover and soil surface wetness condition which led to a variation of detachment and non-linear relationship of sheetwash splash.  相似文献   
82.
83.
This study aimed to evaluate the clinical utility of ultrasonography in the diagnosis of a newborn calf presenting with extended swelling within its right flank, in addition to its therapeutic planning. Ultrasonograms of the bilateral flanks identified thinning of the external and internal oblique abdominal muscles in whole areas of the abdominal walls. A right lateral abdominal hernia associated with thin abdominal muscular structures was diagnosed ultrasonographically. The right flank abdominal hernia was successfully reconstructed through a modified Mayo mattress suture. This allowed the overlapping of the two very thin structures of the abdominal walls, resulting in the creation of a thicker structure of the right lateral abdominal walls. Reconstruction of the abdominal walls using this method could prevent re-protrusion of the viscera during calf growth.  相似文献   
84.
It is well known that tillage of soil produces greater aeration and incorporates crop residues and fertilizers into inner soil layers, thus stimulating the microbial activities and increasing the rate of decomposition of soil organic matter. Tillage operation has been, therefore, one of the important practices to increase soil productivity.  相似文献   
85.
Sterol ferulate, free sterol, and 5-alk(en)ylresorcinol constituents of wheat, rye, and corn bran oils were studied. Among the sterol ferulates, one novel compound, 24-methylenecholestanol ferulate (7), along with six known compounds, namely, 24-methylcholestanol ferulate (1), 24-methylcholesterol ferulate (2), 2-methyllathosterol ferulate (3), stigmastanol ferulate (4), sitosterol ferulate (5), and schottenol ferulate (6), were isolated and characterized. Five known free sterols, namely, 24-methylcholesterol (8), stigmastanol (9), sitosterol (10), schottenol (11), and stigmasterol (12), were isolated and identified. 5-Alk(en)ylresorcinols were found in wheat and rye bran oils but not in corn bran oil. Of these, one new compound, 5-n-(2'-oxo-14'-Z-heneicosenyl) resorcinol (19), and seven known compounds, namely, 5-n-heptadecyl- (13), 5-n-nonadecyl- (14), 5-n-heneicosyl- (15), 5-n-tricosyl- (16), 5-n-pentacosyl- (17), 5-n-(14'-Z-nonadecenyl)- (18), and 5-n-(2'-oxoheneicosyl)resorcinols (20), were isolated and characterized. These compounds were evaluated with respect to their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, which is known to be a primary screening test for antitumor promoters. Four compounds, 1, 2, 4, and 11, showed potent inhibitory effects on EBV-EA induction.  相似文献   
86.
An 8-year and 6-month-old female Maltese dog showed a stoop with rigidity of her cervix and back. Neurologic examination showed loss of proprioception, and deficiency of pain response. Postmortem examination revealed the neoplastic mass replacing the central area in the cervical spinal cord at the level from 4th to 5th segments. Histologically, the mass was composed of neoplastic ependymal cells. The neoplastic cells showed marked atypism, and occasionally formed ependymal rosettes. Based on the morphologic features, the tumor was diagnosed as anaplastic ependymoma. Immunohistochemistry showed that the neoplastic cells were negative for glial fibrillary acid protein, and slightly positive for vimentin and cytokeratin.  相似文献   
87.
A greenhouse experiment was conducted to determine the influence of the environmental factors such as low-temperature,drought stress,salt-alkali and flooding on the survival rate,propagation rate,fresh biomass and viability of the Alternanthera philoxeroides and its competitive ability against rice by using bioassay method.A high viability of 84%was found when the stems were treated at 4℃and then grew under normal conditions,while no viable plant was noted when the stems were treated at-20℃and grew under normal conditions.Compared to the fresh stem with water content of 93.5%,the survival rate,number of propagated stems and fresh biomass of A.philoxeroides derived from the stems with water content of 30.2%were reduced by 45%, 33%and 74%respectively.The treatments of 0.1%salt-alkaline solution led to loss of viability of A.philoxeroides.The stems of A. philoxeroides could grow in wet soil with different depths of water-layer.The A.philoxeroides at density of 23-180 plants/m2reduced the rice grain yield by 43-50%at the rice plant density of 100 plants/m 2 .  相似文献   
88.
Aged female snow crabs Chionoecetes opilio, 9 or so years old after their final molt, were collected sporadically from artificial reefs established off the coast of Wakasa Bay, Sea of Japan. In order to clarify the degenerative changes that occur in spent ovaries, the ovaries of these crabs were examined histologically. The ovaries were found to be reduced in both size and volume, with most showing significant oosorption by follicular epithelial cells. Reserve fund eggs and unspawned eggs were rarely detected, with the exception of some in atretic follicles. One to dozens of orange to black nodules scattered over the ovary consisted of masses of degenerative ova in various stages of oolysis. Since nodular formation was recognized in 26% of these aged individuals, it seems very likely that such crabs are unable to spawn healthy eggs.  相似文献   
89.
 为明确环境因子对水生生物型空心莲子草生活力的影响以及空心莲子草与水稻的竞争关系,采用生物测定方法,分析了低温、干燥、盐碱、水层等因子对空心莲子草茎的活棵率、繁殖茎数和植株生物量的影响,还研究了不同种群密度的空心莲子草对水稻产量性状的影响。 空心莲子草茎在4℃低温随后常温处理的活棵率达84%,而在-20℃随后常温处理后完全失去生活力;在含水量为30.2%时,空心莲子草茎的活棵率、繁殖茎数和植株鲜质量比鲜样(含水量93.5%)处理的分别下降了45%、33%和74%;0.1%盐碱水溶液处理就可使空心莲子草茎基本失去生活力;水生生物型空心莲子草茎在土壤湿润和不同水层条件下都能够成活和生长。在水稻100株/m2条件下,接种空心莲子草茎23~360株/m2使水稻减产43%~53%。  相似文献   
90.
The physiological and biochemical mechanisms of organogenesis in Equisetum arvense have not been clarified yet. However, high concentrations of nitrogen have been shown to exert an inhibitory effect on in vitro tuber formation in E. arvense. The aim of this study was to clarify the influence of the form of nitrogen in a medium on in vitro organogenesis in E. arvense. Single‐node segments of E. arvense rhizomes were cultured in the test medium. The NH4‐N and NO3‐N concentrations of the test medium, respectively, were adjusted by adding NH4H2PO4 and KNO3 to the basal medium. The basal medium was a nitrogen‐free, modified form of White's medium. Vegetative shoots were newly formed in the test tubes for concentrations of NO3‐N and NH4‐N that exceeded 56 mg L?1. However, no rhizome was formed at NH4‐N concentrations exceeding 28 mg L?1. The number of newly formed tubers decreased at an NH4‐N concentration of 28 mg L?1 and no tuber was formed at NH4‐N concentrations exceeding 56 mg L?1. In summary, although the presence of NO3‐N in the medium did not inhibit in vitro rhizome or tuber formation in E. arvense, the presence of NH4‐N in the medium exerted a strong inhibitory effect on the in vitro formation of both of these organs.  相似文献   
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