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101.
Fisher AT Davis EE Hutnak M Spiess V Zühlsdorff L Cherkaoui A Christiansen L Edwards K Macdonald R Villinger H Mottl MJ Wheat CG Becker K 《Nature》2003,421(6923):618-621
Hydrothermal circulation within the sea floor, through lithosphere older than one million years (Myr), is responsible for 30% of the energy released from plate cooling, and for 70% of the global heat flow anomaly (the difference between observed thermal output and that predicted by conductive cooling models). Hydrothermal fluids remove significant amounts of heat from the oceanic lithosphere for plates typically up to about 65 Myr old. But in view of the relatively impermeable sediments that cover most ridge flanks, it has been difficult to explain how these fluids transport heat from the crust to the ocean. Here we present results of swath mapping, heat flow, geochemistry and seismic surveys from the young eastern flank of the Juan de Fuca ridge, which show that isolated basement outcrops penetrating through thick sediments guide hydrothermal discharge and recharge between sites separated by more than 50 km. Our analyses reveal distinct thermal patterns at the sea floor adjacent to recharging and discharging outcrops. We find that such a circulation through basement outcrops can be sustained in a setting of pressure differences and crustal properties as reported in independent observations and modelling studies. 相似文献
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Macroeconomic indicators are typically appraised in seasonally adjusted form, and forecasts are often presented in a similar way (as annual changes, for example). Moreover, the quarterly macroeconomic models used in forecasting are commonly estimated from seasonally adjusted data. Nevertheless, these models can generate forecasts with seasonal patterns, and this paper assesses the cause and cure of this phenomenon. It is found that forecast seasonality is induced by seasonality in the various inputs: exogenous variables, residual adjustments, the dynamic specification of certain equations, and annual changes in policy variables. Series changing annually but observed quarterly are termed ‘intercalated series’, and are simple examples of periodic processes. Forecast seasonality can be removed by appropriate adjustment of all these inputs. Models containing explicit future expectations variables solved in a model-consistent manner are also considered: numerical sensitivity to the terminal quarter may result from terminal conditions that require adjustment when seasonality is present. 相似文献
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Georgraphic differences in phytoplankton sensitivity to PCBs 总被引:1,自引:0,他引:1
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Y. Lass S. Akselrod B. Gavish S. Cohen A. Fisher 《Cellular and molecular life sciences : CMLS》1979,35(5):650-652
Summary Time course measurements of the action of muscarinic antagonists were performed in the spontaneously beating carp atrium. Several high affinity drugs, which embody the quinuclidine structure were examined. The structural flexibility of these molecules was reflected in the dissociation of the drugs from the muscarinic receptor. The dissociation of rigid drugs was very much prolonged as compared to flexible drugs of the same affinity.We thank Prof. S. Lifson for helpful discussion and Mrs M. Bendikovsky for technical assistance. This work was supported by a USA-Israel Binational Science Foundation (BSF-Jerusalem) grant to Y. Lass. 相似文献
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Mutations in the endosomal ESCRTIII-complex subunit CHMP2B in frontotemporal dementia 总被引:21,自引:0,他引:21
Skibinski G Parkinson NJ Brown JM Chakrabarti L Lloyd SL Hummerich H Nielsen JE Hodges JR Spillantini MG Thusgaard T Brandner S Brun A Rossor MN Gade A Johannsen P Sørensen SA Gydesen S Fisher EM Collinge J 《Nature genetics》2005,37(8):806-808
We have previously reported a large Danish pedigree with autosomal dominant frontotemporal dementia (FTD) linked to chromosome 3 (FTD3). Here we identify a mutation in CHMP2B, encoding a component of the endosomal ESCRTIII complex, and show that it results in aberrant mRNA splicing in tissue samples from affected members of this family. We also describe an additional missense mutation in an unrelated individual with FTD. Aberration in the endosomal ESCRTIII complex may result in FTD and neurodegenerative disease. 相似文献