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11.
12.
Eight glacial cycles from an Antarctic ice core 总被引:9,自引:0,他引:9
Augustin L Barbante C Barnes PR Barnola JM Bigler M Castellano E Cattani O Chappellaz J Dahl-Jensen D Delmonte B Dreyfus G Durand G Falourd S Fischer H Flückiger J Hansson ME Huybrechts P Jugie G Johnsen SJ Jouzel J Kaufmann P Kipfstuhl J Lambert F Lipenkov VY Littot GC Longinelli A Lorrain R Maggi V Masson-Delmotte V Miller H Mulvaney R Oerlemans J Oerter H Orombelli G Parrenin F Peel DA Petit JR Raynaud D Ritz C Ruth U Schwander J Siegenthaler U Souchez R Stauffer B Steffensen JP Stenni B 《Nature》2004,429(6992):623-628
The Antarctic Vostok ice core provided compelling evidence of the nature of climate, and of climate feedbacks, over the past 420,000 years. Marine records suggest that the amplitude of climate variability was smaller before that time, but such records are often poorly resolved. Moreover, it is not possible to infer the abundance of greenhouse gases in the atmosphere from marine records. Here we report the recovery of a deep ice core from Dome C, Antarctica, that provides a climate record for the past 740,000 years. For the four most recent glacial cycles, the data agree well with the record from Vostok. The earlier period, between 740,000 and 430,000 years ago, was characterized by less pronounced warmth in interglacial periods in Antarctica, but a higher proportion of each cycle was spent in the warm mode. The transition from glacial to interglacial conditions about 430,000 years ago (Termination V) resembles the transition into the present interglacial period in terms of the magnitude of change in temperatures and greenhouse gases, but there are significant differences in the patterns of change. The interglacial stage following Termination V was exceptionally long--28,000 years compared to, for example, the 12,000 years recorded so far in the present interglacial period. Given the similarities between this earlier warm period and today, our results may imply that without human intervention, a climate similar to the present one would extend well into the future. 相似文献
13.
Johansson ME Ambort D Pelaseyed T Schütte A Gustafsson JK Ermund A Subramani DB Holmén-Larsson JM Thomsson KA Bergström JH van der Post S Rodriguez-Piñeiro AM Sjövall H Bäckström M Hansson GC 《Cellular and molecular life sciences : CMLS》2011,68(22):3635-3641
In discussions on intestinal protection, the protective capacity of mucus has not been very much considered. The progress in the last years in understanding the molecular nature of mucins, the main building blocks of mucus, has, however, changed this. The intestinal enterocytes have their apical surfaces covered by transmembrane mucins and the whole intestinal surface is further covered by mucus, built around the gel-forming mucin MUC2. The mucus of the small intestine has only one layer, whereas the large intestine has a two-layered mucus where the inner, attached layer has a protective function for the intestine, as it is impermeable to the luminal bacteria. 相似文献
14.
Brown KM Macgregor S Montgomery GW Craig DW Zhao ZZ Iyadurai K Henders AK Homer N Campbell MJ Stark M Thomas S Schmid H Holland EA Gillanders EM Duffy DL Maskiell JA Jetann J Ferguson M Stephan DA Cust AE Whiteman D Green A Olsson H Puig S Ghiorzo P Hansson J Demenais F Goldstein AM Gruis NA Elder DE Bishop JN Kefford RF Giles GG Armstrong BK Aitken JF Hopper JL Martin NG Trent JM Mann GJ Hayward NK 《Nature genetics》2008,40(7):838-840
We conducted a genome-wide association pooling study for cutaneous melanoma and performed validation in samples totaling 2,019 cases and 2,105 controls. Using pooling, we identified a new melanoma risk locus on chromosome 20 (rs910873 and rs1885120), with replication in two further samples (combined P < 1 x 10(-15)). The per allele odds ratio was 1.75 (1.53, 2.01), with evidence for stronger association in early-onset cases. 相似文献
15.
A. J. Mordue A. Blackwell B. S. Hansson L. J. Wadhams J. A. Pickett 《Cellular and molecular life sciences : CMLS》1992,48(11-12):1109-1111
The attraction of gravidCulex quinquefasciatus by the oviposition pheromone,erythro-6-acetoxy-5-hexadecanolide, and by polluted water is described. Both materials increase oviposition and when combined the effect is additive. The oviposition behaviour is reflected by the antennal sensitivity to these compounds. 相似文献
16.
Falsificationism Falsified 总被引:1,自引:1,他引:0
Sven Ove Hansson 《Foundations of Science》2006,11(3):275-286
A conceptual analysis of falsificationism is performed, in which the central falsificationist thesis is divided into several
components. Furthermore, an empirical study of falsification in science is reported, based on the 70 scientific contributions
that were published as articles in Nature in 2000. Only one of these articles conformed to the falsificationist recipe for
successful science, namely the falsification of a hypothesis that is more accessible to falsification than to verification.
It is argued that falsificationism relies on an incorrect view of the nature of scientific inquiry and that it is, therefore,
not a tenable research methodology. 相似文献
17.
Zusammenfassung Trächtige Mäuse wurden zwei Tage vor dem erwarteten Werfen mit dem Antimetabolit des Methionins14C-DL-Aethionin intravenös behandelt. Aufnahme und Einbau des Antimetabolits wurden gleichzeitig autoradiographisch und chemisch untersucht. Die Plazentaschranke ist für Aethionin durchlässig; die Radioaktivität fand sich in den Foeten angehäuft, dabei war aber nur ein ganz geringer Teil des Aethionins in den Eiweisskörper derselben eingebaut. Der Einbau des Aethionins in den Organen (Leber und Pankreas) der Mutter war ebenfalls äusserst gering.Aus den Ergebnissen wird der Mechanismus der toxischen Wirkung des Aethionins erklärt.
This work was supported by grants from the Swedish Medical Research Council. 相似文献
This work was supported by grants from the Swedish Medical Research Council. 相似文献
18.
Elisabeth Hansson J. Jarlstedt Å. Sellström 《Cellular and molecular life sciences : CMLS》1980,36(5):576-577
Summary The exogenous release of glutamate has been successfully studied in the cochlear nucleus of guinea-pigs after physiological sound stimulation of the ear (frequency 2000–20,000 Hz at 100 dBA).Acknowledgments. This study was supported by grants from the Swedish Medical Research Council (B80-12X-05666-01) and Torsten Söderbergs och Ragnar Söderbergs stiftelser. 相似文献
19.
Toxicity of pyrazole and 4-methylpyrazole in mice and rats 总被引:2,自引:0,他引:2
20.