70 resultados para 14-140


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Comparison between past changes in pollen assemblages and stable isotope ratios (deuterium and carbon) analyzed in the same peat core from Tierra del Fuego at latitude 55°S permitted identification of the relative contribution of precipitation versus temperature responsible for the respective change. Major steps in the sequence of paleoenvironmental changes, such as at 12700, 9000, 5000, and 4000 years ago are apparently related only to increase in precipitation, reflecting the latitudinal location and intensity of the westerly storm tracks. On the other hand, high paleoenvironmental variability, which is characteristic for the late-glacial and the latest Holocene, is related to temperature variability, which affects the relative moisture content. Comparison with other paleoenvironmental records suggests that the late-glacial temperature variability is probably related to variability in the extent of Antarctic sea-ice, which in turn appears to be related to the intensity of Atlantic deep-water circulation. Temperature variability during the latest Holocene, on the other hand, is probably related to the dynamics of the El Niño/Southern Oscillation.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two driving parameters to bound terrestrial carbon sequestration associated with an increase in carbon dioxide concentration.

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Abstracts of 24 oral presentations and 25 poster presentations.

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The appendices include the workshop agenda, a list of poster presentations, and a list of attendees.

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Four feeds having different protein levels were separately tested on Tor khudree fry having an average length of 23.5 mm and weight 55 mg. The best average growth of 15.66 mg and 0.456 mm/day was obtained with Feed IV which comprised rice bran, ground nut oil cake, Acetes, wheat flour and mineral mix at the ratio of 1:1:1:0.7143:0.01428. These constitute 35.29% of proteins. The Feed II which comprised R.B + G.O.C. + prawn shell + wheat flour and mineral mix at a ratio of 1:1:1:0.7143:0.01428 contained 32.61% crude proteins. It provided a growth rate of 14.83 mg and 0.440 mm per day. The conversion rates were 38.258 and 37.776 for feeds IV and II respectively. Since Feed II is cheaper than Feed IV and provides almost equal growth rate, it can be used in the nurseries for intensive rearing of T. khudree fry.