Once patronized primarily by the counterculture and the health food establishment, the organic food industry today is a multi-billion-dollar business driven by ever-growing consumer demand for safe food and greater public awareness of ecological issues. Assumed by many to be a recent phenomenon, that industry owes much to agricultural innovations that go back to the Dust Bowl era.

This book explores the roots and branches of alternative agricultural ideas in twentieth-century America, showing how ecological thought has challenged and changed agricultural theory, practice, and policy from the 1930s to the present. It introduces us to the people and institutions who forged alternatives to industrialized agriculture through a deep concern for the enduring fertility of the soil, a passionate commitment to human health, and a strong advocacy of economic justice for farmers.

Randal Beeman and James Pritchard show that agricultural issues were central to the rise of the environmental movement in the United States. As family farms failed during the Depression, a new kind of agriculture was championed based on the holistic approach taught by the emerging science of ecology. Ecology influenced the "permanent agriculture" movement that advocated such radical concepts as long-term land use planning, comprehensive soil conservation, and organic farming. Then in the 1970s, "sustainable agriculture" combined many of these ideas with new concerns about misguided technology and an over-consumptive culture to preach a more sensible approach to farming.

In chronicling the overlooked history of alternative agriculture, A Green and Permanent Land records the significant contributions of individuals like Rex Tugwell, Hugh Bennett, Louis Bromfield, Edward Faulkner, Russell and Kate Lord, Scott and Helen Nearing, Robert Rodale, Wes Jackson, and groups like Friends of the Land and the Practical Farmers of Iowa. And by demonstrating how agriculture also remains central to the public interest--especially in the face of climatic crises, genetically altered crops, and questionable uses of pesticides--this book puts these issues in historical perspective and offers readers considerable food for thought.

Preserving Yellowstone's Natural Conditions describes in fascinating detail the historical origins and development of wildlife management in Yellowstone National Park, alongside shifting understandings of nature in science and culture. James A. Pritchard traces the idea of "natural conditions" through time, from the introduction of this concept by early ecologists in the 1930s. He tells several overlooked stories of Yellowstone wildlife, including a sensational scientific hunt for bears with bow and arrow, and the episode of the predator pelicans, which facilitated a fundamental shift toward protection of all wildlife in Yellowstone, and for the National Park Service as a whole. A prolonged debate regarding the elk herd on Yellowstone's northern range is addressed, along with the origins of the notion of natural regulation, and the reasons for ending direct reductions of elk. This story emphasizes how ecological science came to Yellowstone and to the National Park Service, subsequently developing over a period of decades. In the new afterword to this book Pritchard summarizes recent developments in wildlife science and management-such as the "ecology of fear" and trophic cascades-and discusses historical continuities in the role of the park as a wildlife refuge and the inestimable values of the park for wildlife conservation.

The Global War on Terror with specific emphasis on the recent military operation in Afghanistan has shown the invaluable contribution that heavy lift helicopters bring to the combatant commander. However, the flight range, altitudes and lift capability required to operate effectively in such an austere environment are pushing the limits of these helicopters. In an attempt to increase the operational capability of the CH-53E, this study will investigate methods for maximizing tail rotor effectiveness at high gross weights and high altitudes. This thesis records an analytical study designed to investigate the intricacies of tail rotor design and, by the computational simulation afforded through the Rotorcraft Comprehensive Analysis System (RCAS), define a tail rotor at high altitude that will reduce the tail rotor power required in hover by 10%. The versatility required of the tail rotor is seen due to the nature of the flow regime, which requires the tail rotor to effectively operate with inflow velocity from any direction, with a spanwise distribution of flow that produces Reynolds numbers up to 5.6e7 and with pilot commanded pitch changes from -10 to 24 degrees. With little to no assistance from the vertical fin, the tail rotor is most heavily relied on for antitorque response in hover; therefore, focus will be placed on hovering efficiencies tempered by solid forward flight and hover slide performance.

American ecologists seeking to influence the founders of the National Park Service had hoped that protection of the parks would create preserves where "natural conditions" could exist in an idealized presettlement state. These hopes, however, produced a bitter irony. In order to secure a naturally functioning park, officials had to provide intensive management to preserve "nature at work". For the better part of the twentieth century, the forms this management has taken have polarized public opinion.

James A. Pritchard's Preserving Yellowstone's Natural Conditions demonstrates that even the most up-to-date scientific policy could not reckon with public expectations and animal behavior. When Yellowstone stopped its bear feeding program in an attempt to restore naturally regulated bear populations, the public bemoaned the loss of the spectacle. The bears, meanwhile, had learned to associate humans with food, and the loss of reliable meals brought them into campsites. Park officials had to shoot bears that made a menace of themselves, leaving many people frustrated with the park's attempts to preserve Yellowstone as a natural ecosystem.

Pritchard believes that restoring natural conditions for bears and other animals is a sound idea. Yellowstone, he argues, represents an ecological anchor, a relatively untrammeled slice of nature. Despite decades of tampering, the park provides scientists and managers with an outdoor laboratory for examining natural processes that existed before extensive settlement.