People and their ideas are moving more freely back and forth across borders globally than ever before. This ebb and flow, through easy travel and growing communications technology, may be reshaping the traditional concept of a nation, say researchers. In fact, some people with homes in two countries are showing an amazing capacity to maintain dual identities -- with strong cultural ties and contributions to both places. "The nation is becoming something less territorial and more of a cultural collective," says UC Davis human and community development professor Michael P. Smith, co-organizer of a conference on campus this week, April 24-25, that explores the impacts of movements of people, ideas, culture and politics across borders. The two-day program, "Nationalism, Transnationalism and the Crisis of Citizenship," features more than 30 social scientists, community development researchers and activists, and ethnic studies scholars. Topics include transnational indigenous movements, borders and diasporas, and transnationalism in the Americas and in the Pacific Rim. Paradoxically, "transnationalism encourages nationalism both in the United States and in other countries" as both "sending" and "receiving" countries react to globalization by promoting preservation of their own national cultures, according to Smith. He is co-author, with UC Davis assistant professor of sociology Luis Eduardo Guarnizo, of the newly published book "Transnationalism From Below" (1998, Transactions Publishers).