Duality theory emerged from the work by Marshall Stone [18] on Boolean algebras and distributive lattices in the 1930s. Later in the early 1970s Larisa Maksimova [10, 11] and Hilary Priestley [15, 16] developed analogous results for Heyting algebras, topological Boolean algebras, and distributive lattices. Duality for bounded, not necessarily distributive lattices, was developed by Alstir Urquh...

The Clinton Administration has implied that short-run failures to control health care costs may cause a reexamination of wage and price controls as elements of comprehensive health care reform. The most recent imposition of mandatory wage and price controls was the Economic Stabilization Program (ESP) of the early 1970s. We analyze trends in hospitals' economic behavior and utilization before, ...

The literature on political participation asserts that protest has increased over the last four decades, all over the world. This trend is derived from surveys asking questions about participation in various forms of protest, including demonstrations, boycotts, and unofficial strikes. The latter question made sense in the context in which it was formulated, Britain in the early 1970s, and with ...

www.aafp.org/afp AMERICAN FAMILY PHYSICIAN 2517 has changed dramatically since the early 1970s, largely because of the problems with thalidomide and diethylstilbestrol. Consequently, extensive testing is required before a drug can be labeled for use during pregnancy. Since 1975, the U.S. Food and Drug Administration (FDA) has assigned pregnancy risk factors to all drugs used in the United State...

Since the early 1970s, various authors have made steady progress toward resolutions of the algebraic cancellation problem, an easily-stated yet compellingly-elusive question whose difficulty emphasizes the limitations of our understanding of the geometry of objects as fundamental to algebraists as complex affine n-space. We survey these partial resolutions and examine the first known counterexa...

structure and function of socio – economic systems present different spatial effects in different countries of the world. in this study, structure and function of social and economical systems is analyzed to identify of changes within urban spatial structure. in tehran, effects of political and economic factor is analyzed for identification of changes of its spatial structure and its periphery ...

Archaeological evidence indicates that fishing was one of the earliest human production activities. Early fishing seems to have been mainly hunting and gathering along shores and inlets with fish farming emerging somewhat later in time. Capture fisheries expanded rapidly in the 19 and 20 centuries AD reaching the peak annual production of over 90 million metric tonnes in the early 1990s. Since ...

For many years venereal diseases have been a major problem in Greenland. Since the early 1950s gonorrhoea has been widely prevalent; in the middle of the 1960s the incidence increased rapidly. Since the early 1970s syphilis has become widespread in the population, and in 1977 an epidemic of chancroid occurred. The high figures for venereal diseases are basically due to the social change towards...