THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

This project was supported by the Alfred P. Sloan Foundation under Award 2009-12-14, Chinese Academy of Sciences, IAP—the Global Network of Science Academies, U.K. Global Partnership Programme under Award 2010072600092647, U.S. Defense Threat Reduction Agency through TASC under Award 7500080708, U.S. Department of State under Award SAQMMA10M2776, U.S. National Institutes of Health under Award N01-OD-4-2139 (Task Order 236), and U.S. National Academies. The views expressed herein are those of the authors, and the content of this publication does not necessarily reflect the views or policies of the organizations or agencies that provided support for the project, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government.

International Standard Book Number-13: 978-0-309-21071-3
International Standard Book Number-10: 0-309-21071-2

Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055, (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet,

Copyright 2011 by the National Academy of Sciences. All rights reserved.

Printed in the United States of America

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement