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排序方式: 共有119条查询结果,搜索用时 7 毫秒
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J. T. BONNER T. A. DAVIDOWSKI W.-L. HSU D. A. LAPEYROLERIE H. L. B. SUTHERS 《Differentiation; research in biological diversity》1982,21(1-3):123-126
A key environmental factor in inducing final fruiting body differentiation in the migrating slugs of cellular slime molds is loss of contact with a surface film of water. If the slug tip reaches above the water film, fruiting tends to occur, but if it stays in contact with the surface water, continued migration is favored. Light is effective in promoting fruiting only if the phototactic slugs orient away from surface (as with overhead light) and therefore, only indirectly affects differentiation. 相似文献
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在研究我国青鼬种下分化过程中,发现海南岛所产青鼬与大陆青鼬其它亚种有较大区别,经鉴定认为应是一新亚种,拟命名为:青鼬海南亚种Martes flavigulahainana,新亚种。 相似文献
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SUMMARY.
- 1 We evaluated survival, growth and time to maturation of the fairy shrimp, Streptocephalus seali Ryder, in the laboratory at various combinations of temperature and water hardness.
- 2 Both independent factors affected survival and growth of S. seali. Multiple regression analysis and response surface modelling predict that after 4 days, over 80% survival is obtained at temperatures from 14 to 28°C and water hardnesses from 60 to 130 mg CaCO3 1-?1.
- 3 Growth rates of larvae were often maximum at physicochemical conditions other than those which had promoted maximum rates of survival. For example, after 12 days mean total body length was almost 12 mm in larvae which had been maintained at 34°C (80 mg CaCO3 1-?1): the maximum survival rate had been obtained at 19°C. Total length was directly correlated with temperature at the lowest hardness tested, but not at the other two hardnesses (100 and 120 mg CaCO3 1-?1). At the latter water hardnesses, total length was significantly less at 34°C than at 32°C on all three sampling occasions (4, 8 and 12 days post-hatch).
- 4 Similarly, developmental stage of larvae correlated well with temperature but larvae reared at 34°C did not develop more quickly than those reared at 32°C. After 12 days, most larvae at the two highest temperature treatments had developed at least to Stage 14 and many were nearly mature; at 17°C most larvae were still at Stage 10.
- 5 During our study of maturation rate of females we noted that egg production was initiated after completion of fourteen or fifteen moults. Mean time to maturation at 27°C (17.3±2.8 days) exceeded that at 32°C (12.3±2.6days). The minimum time to maturation of a shrimp was 9 days at 32°C.
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(一)靜脈注射腎上腺素對組織胺引起的貓胃分泌不論在急性或慢性實驗,通常是双相的,開頭抑制分泌,接着增加分泌,兩相大小相似,有時第二相還稍為大些。在一次注射0.02—0.1毫克腎上腺素之後,整個效應過程歷時約10—15分钟。若用較長的間隔如每10—30分鐘收集一次胃分泌,則此双相效應就會被掩蓋,因而得出腎上腺素對貓胃分泌無明顯效應或有增加分泌的效應的結論,如Baxter等人所得到的一樣。 (二)在急性實驗中,刺激大内臟神經對组織胺引起的貓胃分泌有顯著的抑制效應。与腎上腺素的效應不同,刺激大內臟神經的效應通常是單相的。我們在工作中经常得到馮德培所长的指导。谨致谢意. 相似文献
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云毛虫属(Hoenimnema Lajonquiere 1973)在我国已知有6种及1亚种。我们在黄南藏族自治州麦秀林场采得1种,它的外部形态与已知者区别显著,兹定为新种。青海云毛虫Hoenimnema chinghaiensis Hsu新种(图1-2) 蛾体长约30毫米,翅展约86毫米。体翅棕褐色。触角主干赭褐色,杂生灰白色鳞片;羽枝黑 相似文献
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CHAO-KUANG HSU G. ROBERT CAMPBELL NORMAN D. LEVINE 《The Journal of eukaryotic microbiology》1973,20(2):195-203
SYNOPSIS. A list is given of 67 named species of Leucocytozoon considered valid at present. Another list is given of 1 reptilian and 146 avian hosts of named species of Leucocytozoon. A 3rd list is given of 34 synonyms. Leucocytozoon has been named from about 0.7% of the approximately 8600 species of birds that exist. The following new taxonomic names are included: L. danilewskyi var. hirundinis Sergent & Sergent, 1905 is emended to L. hirundinis; Saurocytozoon tupinambi Lainson & Shaw, 1969 is changed to Leucocytozoon (Saurocytozoon) tupinambi (Lainson & Shaw, 1969). 相似文献