Proceedings of the National Academy of Sciences of the United States of America, Volume 7

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National Academy of Sciences, 1921 - Electronic journals
The Proceedings of the National Academy of Sciences (PNAS) publishes research reports, commentaries, reviews, colloquium papers, and actions of the Academy. PNAS is a multidisciplinary journal that covers the biological, physical, and social sciences.


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Page 137 - Papers from the Department of Biometry and Vital Statistics, School of Hygiene and Public Health, Johns Hopkins University, No.
Page 360 - Washington, DC The Bulletin of the National Research Council presents contributions from the National Research Council, other than proceedings, for which hitherto no appropriate agencies of publication have existed. The "Bulletin" is published at irregular intervals.
Page 358 - Science and the Division of Chemistry and Chemical Technology of the National Research Council.
Page 44 - THE PROCEEDINGS is the official organ of the NATIONAL ACADEMY OF SCIENCES and of the NATIONAL RESEARCH COUNCIL for...
Page 141 - ... value by the 25th day. At first it looks as if the mean tends to rise even until the 32nd day. That this is not the case, however, is shown by the fact that the value on the 25th day does not vary appreciably from that of the 72nd day. The same type of result was obtained for all of the six distances shown in figure 1, namely, for the distances posterior end to parabasal body, parabasal body to nucleus, nucleus to anterior end, anterior end to end of T Lencjth PIG.
Page 361 - Number 12. Cooperative experiments upon the protein requirements for the growth of cattle. First report of the Subcommittee on Protein Metabolism in Animal Feeding. By HENRY PRENTISS ARMSBY, Chairman. June, 1921. Pages 70. Price $1.00. Number 13. The research activities of departments of the state government of California in relation to the movement for reorganization. By JAMES R. DOUGLAS. June, 1921. Pages 46. Price 60 cents.
Page 339 - On a method of precisely measuring the vibratory periods of tuning-forks, and the determination of the laws of the vibrations of forks; with special reference to these facts and laws to the action of a simple chronoscope.
Page 66 - The volume of many metals at 0 C. and 12,000 kg. [per cm.2] is less than the volume at atmospheric pressure at 0 Abs. The resistance of most metals tends towards zero at 0 Abs., but at 0 C. at the same volume the resistance is only a few per cent less than under normal conditions.
Page 41 - As a matter of record it seems advisable to bring up to date and summarize the chief results derived from the writer's main pedigree culture of Paramecium aurelia. This culture, designated Culture I, was started on May 1, 1907, by the isolation of a "wild" individual which was found in a laboratory aquarium.1 The original specimen was placed in about five drops of culture fluid on a glass slide having a central ground concavity, and when this animal had produced four individuals, each of these was...
Page 44 - However, at the formal termination of the experiments in 1915, I was reluctant to discard the race and was tempted to keep it under control but without such exacting daily observation and recording of the daily division rate. In this manner it has been maintained up to the present (December, 1920). But, from time to time, thirty-day tests have been made of the vitality of the race under the former rigid culture conditions, and in each case the same general average division rate has been revealed...

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