National Academies Press: OpenBook

Animal Biotechnology: Science-Based Concerns (2002)

Chapter: Front Matter

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

ANIMAL BIOTECHNOLOGY: SCIENCE-BASED CONCERNS

Committee on Defining Science-based Concerns Associated with Products of Animal Biotechnology

Committee on Agricultural Biotechnology, Health, and the Environment

Board on Agriculture and Natural Resources

Board on Life Sciences

Division on Earth and Life Studies

NATIONAL RESEARCH COUNCIL OF THE NATIONAL ACADEMIES

THE NATIONAL ACADEMIES PRESS
Washington, D.C.
www.nap.edu

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

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 study was supported by Contract No. 223-93-1025 between the National Academy of Sciences and the U.S. Food and Drug Administration, and funds by the National Research Council. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.

Library of Congress Cataloging-in-Publication Data

Animal biotechnology: science-based concerns / Committee on Defining Science-based Concerns Associated with Products of Animal Biotechnology, Committee on Agricultural Biotechnology, Health, and the Environment, Board on Agriculture and Natural Resources, Board on Life Sciences, Division on Earth and Life Studies.

p. cm.

Includes bibliographical references and index.

ISBN 0-309-08439-3 (pbk.)

1. Animal biotechnology. I. National Research Council (U.S.). Committee on Defining Science-based Concerns Associated with Products of Animal Biotechnology.

SF140.B54 A58 2002

660'.65—dc21

2002151075

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, http://www.nap.edu.

Copyright 2002 by the National Academy of Sciences. All rights reserved.

Printed in the United States of America

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

THE NATIONAL ACADEMIES

Advisers to the Nation on Science, Engineering, and Medicine

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. A. Wulf is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. Wm. A. Wulf are chair and vice chair, respectively, of the National Research Council.

www.national-academies.org

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
This page in the original is blank.
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Committee on Defining Science-Based Concerns Associated with Products of Animal Biotechnology

JOHN G. VANDENBERGH, Chair,

North Carolina State University, Raleigh

ALWYNELLE (NELL) SELF AHL,

Tuskegee University

JOHN M. COFFIN,

Tufts University School of Medicine

WILLARD H. EYESTONE,

Virginia-Maryland Regional College of Veterinary Medicine

ERIC M. HALLERMAN,

Virginia Polytechnic and State University, Blacksburg

TUNG-CHING LEE,

Rutgers University

JOY A. MENCH,

University of California, Davis

WILLIAM M. MUIR,

Purdue University

R. MICHAEL ROBERTS,

University of Missouri, Columbia

THEODORE H. SCHETTLER,

Science and Environmental Health Network

LAWRENCE B. SCHOOK,

University of Illinois, Urbana

MICHAEL R. TAYLOR,

Resources for the Future

Staff

KIM WADDELL, Study Director

DEBRA DAVIS, Editor

MICHAEL R. KISIELEWSKI, Research Assistant

CINDY LOCHHEAD, Project Assistant

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Committee on Agricultural Biotechnology, Health, and the Environment

BARBARA A. SCHAAL, Chair,

Washington University, St. Louis, MO

DAVID A. ANDOW,

University of Minnesota, St. Paul

NEAL L. FIRST,

University of Wisconsin, Madison

LYNN J. FREWER,

Institute of Food Research, Norwich, UK

HENRY L. GHOLZ,

National Science Foundation, Arlington, VA

EDWARD GROTH III,

Consumers Union, Yonkers, NY

ERIC M. HALLERMAN,

Virginia Polytechnic Institute and State University, Blacksburg

RICHARD R. HARWOOD,

Michigan State University, East Lansing

CALESTOUS JUMA,

Harvard University, Cambridge, MA

SAMUEL B. LEHRER,

Tulane University School of Medicine, New Orleans, LA

SANFORD A. MILLER,

Georgetown University, Washington, DC

PHILIP G. PARDEY,

University of Minnesota, St. Paul

PER PINSTRUP-ANDERSEN,

International Food Policy Research Institute, Washington, DC

ELLEN K. SILBERGELD,

Johns Hopkins University, Baltimore, MD

ROBERT E. SMITH,

R. E. Smith Consulting, Inc., Newport, VT

ALLISON A. SNOW,

Ohio State University, Columbus

PAUL B. THOMPSON,

Purdue University, West Lafayette, IN

DIANA H. WALL,

Colorado State University, Fort Collins

Staff

JENNIFER KUZMA, Program Director

SETH STRONGIN, Project Assistant

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Board on Agriculture and Natural Resources

HARLEY W. MOON, Chair,

Iowa State University

SANDRA BARTHOLMEY,

Quaker Oats Company

DEBORAH BLUM,

University of Wisconsin, Madison

ROBERT B. FRIDLEY,

University of California

BARBARA P. GLENN,

Federation of Animal Science Societies

LINDA F. GOLODNER,

National Consumers League

W.R. (REG) GOMES,

University of California

PERRY R. HAGENSTEIN,

Institute for Forest Analysis, Planning, and Policy

CALESTOUS JUMA,

Harvard University

JANET C. KING,

University of California, Davis

WHITNEY MACMILLAN,

Cargill, Inc.

PAMELA A. MATSON,

Stanford University

TERRY L. MEDLEY,

DuPont Biosolutions Enterprise

JAMES A. MERCHANT,

University of Iowa

ALICE N. PELL,

Cornell University

SHARRON S. QUISENBERRY,

Montana State University

NANCY J. RACHMAN,

Exponent, Inc.

SONYA B. SALAMON,

University of Illinois

G. EDWARD SCHUH,

University of Minnesota

BRIAN J. STASKAWICZ,

University of California, Berkeley

JACK WARD THOMAS,

University of Montana

JAMES H. TUMLINSON,

USDA/ARS

B.L. TURNER,

Clark University

Staff

CHARLOTTE KIRK BAER, Director

STEPHANIE PADGHAM, Project Assistant

Page viii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Board on Life Sciences

COREY S. GOODMAN, Chair,

University of California, Berkeley

R. ALTA CHARO,

University of Wisconsin, Madison

JOANNE CHORY,

The Salk Institute for Biological Studies

DAVID J. GALAS,

Keck Graduate Institute of Applied Life Sciences

BARBARA GASTEL,

Texas A&M University, College Station

JAMES M. GENTILE,

Hope College

LINDA E. GREER,

Natural Resources Defense Council

ED HARLOW,

Harvard Medical School

ELLIOT M. MEYEROWITZ,

California Institute of Technology, Pasedena

ROBERT T. PAINE,

University of Washington, Seattle

GREGORY A. PETSKO,

Brandeis University

STUART L. PIMM,

Columbia University

JOAN B. ROSE,

University of South Florida, St. Petersburg

GERALD M. RUBIN,

Howard Hughes Medical Institute

BARBARA A. SCHAAL,

Washington University

RAYMOND L. WHITE,

University of Utah, Salt Lake City

Staff

FRANCES SHARPLES, Director

BRIDGET AVILA, Senior Project Assistant

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Preface

What we have before us are some breathtaking opportunities disguised as insoluble problems.

—John W. Gardner, 1965, upon appointment as the Secretary of the Department of Health, Education, and Welfare

Rarely in the modern history of humans has biology played such an important role in human affairs as it does today. In the eighteenth and nineteenth centuries, explorers stimulated the first major advance in biology by bringing back countless new species that Darwin, and others, put into a logical order based on the theory of natural selection. The development of evolutionary thinking and the clarification of the rules of genetic inheritance resulted in the theoretical base for targeted artificial selection—an essential component of progress in biology and agriculture.

A second major advance currently is underway. Due to the basic understanding of inheritance at the molecular level and the tools this has made available to biologists, it no longer is necessary to depend upon natural or artificial selection and breeding of progeny to produce new and improved individuals. Genes from the same or other species can be inserted into a genome, or the activity of a specific gene can be blocked. Further, once the genome has been altered artificially, large numbers of new plants and animals

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

carrying the modified genome can be made using cloning techniques. Producing animal models of human diseases for research, improving medical procedures, and increasing food production are but three modern advances that already have come to pass. More advances are predicted for the future. The committee— early in its discussions—recognized that not everything that bloomed from the biotechnology garden was a flower ready to be picked for the human bouquet. As was true for other technologic advances in the past, advances do not come without expected and unexpected risks. The committee also recognized that the technology it was studying is in its infancy. Many of the problems, such as inefficient reproduction and production of abnormal offspring, are receding as the technology advances. Therefore, the committee presents a “snapshot” of biotechnology and of potential concerns about that technology at present.

In view of the rapidly-changing biotechnologic landscape, federal agencies with responsibility for ensuring food safety, maintaining modern medical treatment standards, minimizing environmental impacts, and ensuring the welfare of animals requested that a committee formed by the National Research Council (NRC) of the National Academies explore concerns related to animal biotechnology. A committee of 12 scientists, physicians, and experts in regulatory issues accepted the task of defining science-based concerns associated with products of animal biotechnology. The committee’s report presents science-based concerns it identified but it does not contain specific recommendations. Identification of the concerns will allow others to develop regulatory policy where appropriate. While the focus of the committee was on the scientific information that could clarify the issues, it remained aware of the social and other policy issues involved in moving biotechnologic advances from the laboratory to the “real world.” Thus, assuming a bit of flexibility in our charge, our report addresses some of the policy issues involved as well.

In a sense, almost any issue related to a technologic advance can be a concern. The committee attempted to place concerns in relative priority order within sections of the report (i.e., hazards associated with the techniques themselves, food safety, environmental impacts, and animal welfare). In only a few cases was it possible to state that an issue brought to our table was not of concern. Much of the basic biology underlying the techniques remains to be discovered, and we have only partial information on the consequences of using biotechnologic techniques. This is true especially in terms of the environmental concerns raised. It became quickly apparent that more information was needed to assess the priority of concerns raised. Only more research will resolve this problem.

The committee relied heavily on published information, on presentations made by experts at an NRC-sponsored workshop, and on previous NRC reports. The NRC report, Environmental Effects of Transgenic Plants: The Scope and Adequacy of Regulation—recently completed by experts from the botanical half of the biologic world—was a valuable source of information.

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

This is an especially opportune time to explore the concerns related to animal biotechnology. The field has progressed to the point where we already have seen applications of this science to our daily lives, and might see many more. The committee hopes that our discussions, as reflected in this report, will inform government agencies and the public of the major scientific issues involved so that this technology can be applied as safely as possible without denying the public its benefits.

This study and the resulting report would not have been possible without the dedication, skill, and hard work of the study director, Dr. Kim Waddell, and research assistant, Michael Kisielewski, of the Board on Agriculture and Natural Resources of the National Academies.

JOHN G. VANDENBERGH, Chair

Committee on Defining Science-based Concerns Associated with Products of Animal Biotechnology

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
This page in the original is blank.
Page xiii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Acknowledgments

This study was enhanced by the contributions of many individuals who graciously offered their time, expertise, and knowledge. The committee thanks all who attended and/or participated in its public workshop:

MICHAEL D. BISHOP, Infigen, Inc., DeForest, WI

KEITH H. S. CAMPBELL, University of Nottingham, Loughborough, UK

JOSÉ B. CIBELLI, Advanced Cell Technology, Worcester, MA

JEAN FRUCI, The Pew Initiative on Food and Biotechnology, Washington, DC

PERRY B. HACKETT, Discovery Genomics, Inc., Minneapolis, MN

MICHAEL K. HANSEN, Consumer Policy Institute, Yonkers, NY

MARJORIE A. HOY, University of Florida, Gainesville

SAMUEL B. LEHRER, Tulane University Medical Center, New Orleans, LA

LARISA RUDENKO, Integrative Biostrategies, LLC, Washington, DC

PAUL B. THOMPSON, Purdue University, West Lafayette, IN

ROBERT J. WALL, United States Department of Agriculture Research Center, Beltsville, MD

The committee extends its appreciation to the staff members of the National Research Council’s (NRC) Division on Earth and Life Studies, Board on Agriculture and Natural Resources, and Board on Life Sciences for their commitment to the study process and their efforts in preparing this report.

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report:

ROY CURTISS III, Washington University, St. Louis, MO

REBECCA GOLDBURG, Environmental Defense, New York, NY

THOMAS J. HOBAN IV, North Carolina State University, Raleigh

ANNE R. KAPUSCINSKI, University of Minnesota, St. Paul

SANFORD A. MILLER, Center for Food and Nutrition Policy, Washington, DC

JAMES D. MURRAY, University of California, Davis

LARISA RUDENKO, Integrative Biostrategies, LLC, Washington, DC

PAUL B. THOMPSON, Purdue University, West Lafayette, IN

MARK E. WESTHUSIN, Texas A&M University, College Station

Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations nor did they see the final draft of the report before its release. The review of this report was overseen by Donald D. Brown, Carnegie Institution of Washington, Baltimore, MD, and George E. Seidel, Jr., Colorado State University, Fort Collins. Appointed by the National Research Council, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page xvii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page xviii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×

Tables and Boxes

TABLES

2.1

 

State of the Art of Transgenic Technology for Selected Organisms

 

39

3.1

 

Potential Uses of Transgenic Animals for Pharmaceutical Production

 

53

3.2

 

Applications of Xenotransplantation

 

55

3.3

 

Exogenous Pig Viruses of Concern in Xenotransplantation

 

57

3.4

 

Theoretical Scale of Risks Associated With PERV Transmission From Xenotransplants

 

60

5.1

 

Factors Contributing to Level of Concern for Species Transformed

 

83

BOXES

1.1

 

A Definition of Cloning

 

18

1.2

 

Progression of Technologies Incorporated into Modern Animal Agriculture

 

19

1.3

 

Examples of Technologies that are Experimentally Established but not Yet in Widespread Use in Animal Agriculture

 

22

1.4

 

Harms, Hazards, and Risks

 

33

2.1

 

Knockout and Knockin Technology

 

38

7.1

 

Error Bias

 

110

7.2

 

Labeling

 

118

Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R1
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R2
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R3
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R4
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R5
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R6
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R7
Page viii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R8
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R9
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R10
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R11
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R12
Page xiii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R13
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R14
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R15
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R16
Page xvii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R17
Page xviii Cite
Suggested Citation:"Front Matter." National Research Council. 2002. Animal Biotechnology: Science-Based Concerns. Washington, DC: The National Academies Press. doi: 10.17226/10418.
×
Page R18
Next: Executive Summary »
Animal Biotechnology: Science-Based Concerns Get This Book
×
Buy Paperback | $48.00 Buy Ebook | $38.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Genetic-based animal biotechnology has produced new food and pharmaceutical products and promises many more advances to benefit humankind. These exciting prospects are accompanied by considerable unease, however, about matters such as safety and ethics. This book identifies science-based and policy-related concerns about animal biotechnology—key issues that must be resolved before the new breakthroughs can reach their potential.

The book includes a short history of the field and provides understandable definitions of terms like cloning. Looking at technologies on the near horizon, the authors discuss what we know and what we fear about their effects—the inadvertent release of dangerous microorganisms, the safety of products derived from biotechnology, the impact of genetically engineered animals on their environment. In addition to these concerns, the book explores animal welfare concerns, and our societal and institutional capacity to manage and regulate the technology and its products. This accessible volume will be important to everyone interested in the implications of the use of animal biotechnology.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!