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131.
Wille M Negretmaltese cross JA Hooghiemstra H 《Review of Palaeobotany and Palynology》2000,109(1):45-63
A pollen record from Timbio, located at an elevation of 1750m on the high plain of Popayán (2 degrees 24'N, 76 degrees 36'W) is presented. This forms the basis for reconstructing the vegetation and climate history for the periods from 27000 to 9200 radiocarbon years before the present (14Cyr BP) and 2100 14Cyr BP to sub-recent. The 5m sediment core has time control based on seven AMS radiocarbon dates. Four pollen assemblage zones (TIM-1 to TIM-4) are recognized. During the period of 27200 to 26000 14Cyr BP, an Andean forest was near the site. The vegetation consisted of forest and open herb-rich vegetation, climatic conditions were moist and temperatures some 6 degrees C lower than compared to those of today. During the period of 26000 to 16000 14Cyr BP forest was less open. The observed succession from a Podocarpus-Weinmannia dominated forest to a Hedyosmum dominated forest, and finally to a forest with Ilex, Myrica and ferns indicates a progressive decrease of temperature during this period, with a maximum temperature depression of ca. 5-7.5 degrees C compared to present-day conditions. During the period of 16000 to 9200 14Cyr BP, temperature decrease is estimated at ca. 7.5 degrees C and the climate was the driest. During the period of 2100 to 600 14C2600m altitude (ca. 8 degrees C) and those at sea-level (2.5-6 degrees C) and supports the observation that glacial lapse rates were higher than in modern times. 相似文献
132.
To evaluate breastfed infants' responses to scented objects, we videotaped
the facial and bodily reactions of sixty-three infants as they explored, in
succession, three toys that were identical in appearance but different in
their characteristic odor. Two of the toys were scented with odorants
previously shown to be transmitted to human milk, one with ethanol and the
other with vanilla, whereas the third toy was unscented. Each videotape was
subjected to frame-by-frame analysis to measure a variety of behaviors that
are considered either to be exploratory in nature in that they lead to
perceptual information about the object or to reflect the infants' hedonic
reaction. Analyses of these behaviors revealed that the infants looked more
and vocalized less in the presence of the vanilla-scented toy and spent
less time manipulating the ethanol-scented toy when compared with the
unscented toy. Moreover, differential exposure to the odors of ethanol and
vanilla, as indicated by differential consumption of alcohol by a parent or
use of vanilla-scented product by the mother, was related to differential
responses to these odors. These findings suggest that human infants are
able to detect and retain information about the chemical features of their
environment.
相似文献
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