State of stress and intraplate earthquakes in the United States     

Zoback MD  Zoback ML 《Science (New York, N.Y.)》1981,213(4503):96-104

Recently compiled data on the state of stress have been used to define stress provinces in the conterminous United States in which the orientation and relative magnitude of the horizontal principal stresses are fairly uniform. The observed pattems of stress constrain mechanisms for generating intraplate lithospheric stresses. Coupled with new information on geologic structure and tectonism in seismically active areas of the Midcontinent and East, these data help to define some characteristics common to these areas and to identify key questions regarding why certain faults seem to be seismically active.  相似文献   

Echoes of toronto     

Bromley DA 《Science (New York, N.Y.)》1981,213(4512):1063

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A framework for systematics     

Straney DO 《Science (New York, N.Y.)》1981,214(4522):788-789

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Aspects of metabolism related to the occurrence of skin lesions in biotin‐deficient chicks     

C. C. Whitehead  D. W. Bannister 《British poultry science》1981,22(5):467-472

1. Chicks were fed on biotin‐deficient low‐ and high‐protein diets supplemented with increasing concentrations of biotin.

2. Biotin deficiency decreased hepatic activity of pyruvate carboxylase [EG 6.4.1.1] but activity of acetyl‐CoA carboxylase [EG 6.4.1.2] was comparatively unaffected.

3. Increasing dietary protein increased the severity of biotin deficiency as assessed by skin lesions and decreased plasma biotin concentrations.

4. The severity of the skin lesions over all the treatments was most closely related to plasma biotin concentration.  相似文献   

A biography of john cochrane smith 1885 - 1917          下载免费PDF全文

Richardson DJ  Nielsen NO 《The Canadian veterinary journal. La revue veterinaire canadienne》1981,22(5):114-120

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Evolutionary studies     

Russell-Hunter WD 《Science (New York, N.Y.)》1981,212(4492):281

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Charting a course for science     

Carey WD 《Science (New York, N.Y.)》1981,212(4502):1455

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Internationalism in denmark     

Cassidy DC 《Science (New York, N.Y.)》1981,211(4478):158-159

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The agriculture grants program     

Krogmann DW  Key J 《Science (New York, N.Y.)》1981,213(4504):178-182

The Competitive Research Grants Office was established in 1978 by the federal government to encourage and support basic research related to agriculture. The effort has been enfeebled by controversy and continues to teeter on the edge of congressional extinction. The origins of the Competitive Research Grants Office and its first 3 years of operation make an interesting portrait of the problems of science and government in these times.  相似文献   

Response ofSpodoptera littoralis (Boisd.) andEarias insulana (Boisd.) larvae to azadirachtin and salannin     

J. Meisner  K. R. S. Ascher  R. Aly  J. D. Warthen 《Phytoparasitica》1981,9(1):27-32

The effect of azadirachtin and salannin, two triterpenoids isolated from seeds of neem (Azadirachta indica A. Juss), on the feeding response ofSpodoptera littoralis (Boisd.) andEarias insulana (Boisd.) larvae, was investigated. Styropor (foamed polystyrene) lamellae were painted on both sides with a mixture of 5% sucrose with different concentrations of either azadirachtin or salannin dissoled in methanol-water (3∶7). Azadirachtin strongly suppressed feeding inS. littoralis larvae even at 0.001%, whereas salannin showed some antifeedant activity at 0.005% and above. Larvae ofE. insulana were deterred from feeding on azadirachtin-treated lamellae even at 0.005%, whereas salannin was effective only at 0.01% and above. Azadirachtin applied on cotton leaves deterred larvae ofS. littoralis from feeding at all concentrations ranging between 0.001 and 0.02%.  相似文献