Water for North America

Roadmap for sustainable water resources in southwestern North America.

The management of water resources in arid and semiarid areas has long been a challenge, from ancient Mesopotamia to the modern southwestern United States. As our understanding of the hydrological and climatological cycles has improved, and our ability to manipulate the hydrologic cycle has increased, so too have the challenges associated with managing a limited natural resource for a growing po...

Admixture in North America

The history of North America has been marked by the encounter of populations from different continents. The discovery of the New World began a period defined by human migrations at a much larger scale than in previous history. This movement of people, voluntary or forced, changed profoundly the human landscape. As populations came into contact, admixture followed in varying degrees depending on...

Medicine in North America

Outside North America

ions and first-class procedures We've seen two ways to express the square-root computation as an instance of a more general method, once as a fixed-point search and once using Newton's method. Since Newton's method was itself expressed as a fixed-point process, we actually saw two ways to compute square roots as fixed points. Each method begins with a function and finds a fixed point of some tr...

Travel in North America