Biology Sranch Human Genetics - Following discussion by the Advisery Committees for Biology and Hedicine, a reagarch proposal submitted by br. James ¥. Neel of the University of Hichican hag been approved and a contract is being negotiated. This is the first contract dealing with human genetics, [r. Kee]. wiliconfirm estimates of spontaneous mutation rates for certain cenes which have been studied in the past md will obtain data necessary to estinate spontanecus autation rates for soveral characteris which have so far never heen studied. The information on human rates of mutation are iaportant not enly te a basic underatanding of human genetics, but also a better understand~ ing and estimation of the human genctie risks associated with atemic enerzy. The final report ef the Ad Hoc Committee for evaluation of the human genetic risks asacci:ted with nuclear energy has been formally signed nd submitted to the Director of the Division of ioelegy and Medicine. In this report, the Comaittee recomands that a conservative attitude be mal ntained, that exposures of ftsonnel be minimiadd, and that rescarch designed to supply data for more accurate estimation of the genetio riska be continued and expande. 3 Isotopic Expirinents in Plants = At the State Collage of Washington isotopic expurinents on the am:chanics of mineral translhecation in plants has in the past year been studying the conditions under which movement did or did not take place. 14 was deteruined that precipitation reactions occurred on the surfaces cf roots and in the veins of leaves which were sevore anough to constitute effective blocks to the utilisation of cartain mineral nutrients, especially iron, In the case of the leaf rein reaction, it was found to ve of sufficient magnitude to retard tha re-e:port fram the Isaf of calcium and iron under usual growth conditions, However, it was shown that (1) growth in an acid sedium and (2) growth at lowphoephorus levels caused these elements to beceme mobile and essily re-exported from leaves. Another, and perhaps the determining factor in rendering caleium and iren mobile, waa their respective tissue concentrations, Soth moved much more readily when their respective tissue concentrations were low. Phosphorus and perhaps sulfur (final results ere not yet avsilable) were freoly mobile under a wariety ef conditions which were found to inhibit sovement of calcium and iron. Medical Branch The winter mee@ing of Hio-medical Program Directors was held in New York on February 20-21, 1951. The NYOO Health and Safety Division arranged an excellent program which included papers on 4 wide range of subjects with Special emphasis on radiation and chemical hasards of prime inpertance to the Commission, The spezskers were largely from the NYOU wrsonnel and acientista representing major biology and madicine projecte uncer the WYOO, Of particuler eurrent intercet were reports by dr. 0, £. Lynch, dr. of WYOO ond Dr. J, BH Kuper of Brookhaven National Laboratory of studiea of the fallout fron the Nevaca testis. Bervilium Advisory Committee ~ The Division's Berylidun Advisory Comittea mat at the NYCO on February 7, 1951 and reviewed the recent data on beryllium poisoning, The recommended in-plant and neighberheed maximal allowsble concentrations were not changed from those of last year, i.e. OFFICE >» Geo 16—55741-

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