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This paper reports the outcome of an exercise in curve fitting to annual sets of Danish age-specific fertility rates for the years 1962 to 1971 by means of least squares. Functions fitted were a cubic spline, the Hadwiger and Coale-Trussell functions, the gamma and beta densities, two versions of a polynomial, and two of Brass's relational procedures, as(More)
  • Ed-Ited, R Bonnichsen, M H Sorg Orono, Maine Center, Brantingham, A P Der-Evianko +11 others
  • 2001
s t ro n g. 1989. " Studies of bone technology and taphonomy, Old Crow Basin, Yukon Territory, " in Bone modification. and spread of agriculture: A new model. current anthropology 21:751–72. The period between roughly 45,000 and 30,000 years ago witnessed several critical events in human evolutionary history, among them the appearance and elaboration of(More)
Hunter-gatherer populations in greater northeast Asia experienced dramatic range expansions during the early Upper Paleolithic (45ü22 ka) and the late Upper Pa-leolithic (18ü10 ka), both of which led to intensive occupations of cold desert environments including the Mongolian Gobi and northwest China. Range contractions under the cold, arid extremes of the(More)
The use of latest Pleistocene-Holocene paleosols in defining Chinese climatic sequences is plagued by poor chronological controls caused primarily by the use of radiocarbon dates derived from bulk soil carbon. Dating of a post-glacial aeolian/paleosol sequence in the Pigeon Mountain basin of north-central China, using culturally deposited charcoal, support(More)
Where did the first Americans come from and when did they get here? That basic question of American archaeology, long thought to have been solved, is re-emerging as a critical issue as the number of well-excavated sites dating to pre-Clovis times increases. It now seems possible that small populations of human foragers entered the Americas prior to the(More)
Archeological research over the past several years has started to provide evidence relevant to understanding both the timing of and processes responsible for human colonization of the Tibetan Plateau. This harsh, high-elevation environment is known to exact a heavy demographic toll on recent migrants, and such costs likely erected a substantial(More)
The area along the eastern and southeastern margins of the Tengger Desert, NW China, which is sensitive to the summer monsoon variations, was selected for studying the environmental conditions surrounding the transition between Paleolithic foragers and Neolithic farmer/pastoral-ists. Short cores were obtained from four lake basins in the southwestern(More)
BACKGROUND Triple-reassortant (tr) viruses of human, avian, and swine origin, including H1N1, H1N2, and H3N2 subtypes, emerged in North American swine herds in 1998 and have become predominant. While sporadic human infections with classical influenza A (H1N1) and with tr-swine influenza viruses have been reported, relatively few have been documented in(More)
The pre-Neolithic history of the Tibetan Plateau is virtually unknown. Test excavations of Late Paleolithic sites, described here, provide preliminary evidence that the initial occupation of the plateau's extreme environments was by small groups of foragers probably traveling from lower elevation plateau margins. These foragers occupied very short-term(More)