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231.
232.
Lyons C Dowling V Tedengren M Gardeström J Hartl MG O'Brien N van Pelt FN O'Halloran J Sheehan D 《Marine environmental research》2003,56(5):585-597
Glutathione S-transferase (GST) and heat shock proteins (hsps) 40, 60, 70 and 90 were determined by immunoblotting using actin as an internal control in Mytilus edulis from one station outside (site1) and three stations within (sites 2-4) Cork Harbour, Ireland. Comparisons were made between gill and digestive gland and between sites. Gill shows generally higher hsp 60, 70 and 90 while digestive gland has higher hsp 40. Site 1 showed higher gill hsps 40 and 70 than sites 2-4 while gill GST was higher in sites 3 and 4 than 1 and 2. Comparison with sites in the North Sea (site 5: outside Tj?rn? in The Koster archipelago in the Skagerack) and Baltic Sea (site 6: Ask? island) also revealed lower hsps 40 and 70 in site 6 (low salinity) than site 5 (high salinity) although hsps 60, 70 and 90 were detectable in digestive gland unlike sites 1-4. Previously, only hsp 70 had been studied at these sites [Mar. Environ. Res. 39. (1995), 181]. At the mRNA level, gill hsp 70 is 80-fold higher at Tj?rn? than Ask?. These data suggest that, while salinity may slightly decrease hsp 40 and 70, both hsp 70 and GST are selectively up-regulated by approx. 10- and 3-fold, respectively, at Tj?rn? compared to the other sites which we attribute to exposure to more widely fluctuating pollution levels. 相似文献
233.
Simply supported or clamped boundary conditions are rather ideal situations difficult to satisfy from a physical viewpoint. This paper considers a more “moderate” restriction: the case of edges elastically restrained against rotation for which no exact solution appears in the open literature. Eigenvalues corresponding to a wide range of the intervening geometric and mechanical parameters are determined. Good agreement is obtained with frequency coefficients determined two decades ago by means of a variational method. Obviously the problem is of basic interest in many ocean engineering applications: from the design of certain underwater acoustic transducers to pump and compressor elements passing through the design of naval vehicles and ocean structures. 相似文献
234.
Michael Frenz Russell B. Wynn Aggeliki Georgiopoulou Vera B. Bender Gayle Hough Douglas G. Masson Peter J. Talling Bryan T. Cronin 《International Journal of Earth Sciences》2009,98(4):721-733
A series of individual turbidites, correlated over distances >100 km, are present in the recent fill of the Agadir Basin,
offshore northwest Africa. The aim here is to unravel multiple turbidite source areas and flow pathways, and show how turbidite
provenance studies contribute to interpretation of flow processes. Agadir Basin turbidites are sourced from four main areas,
with the majority originating from the siliciclastic Morocco Shelf; their sand-mud distribution is strongly controlled by
flow sediment volume, with relatively low-volume flows dying out within the Agadir Basin and large-volume flows bypassing
significant sediment volumes to basins further downslope. Two large-volume volcaniclastic turbidites are attributed to a Canary
Islands landslide source, while several small mud-dominated turbidites are interpreted to be locally sourced from hemipelagic-draped
seamounts (e.g. Turbidite AB10). Finally, Turbidite AB1 (∼1 ka) is only present in the western Agadir Basin, and is linked
to recent “re-activation” of the Sahara Slide headwall. The muddy suspension clouds of three large-volume flows, all linked
to large-scale landslides, have covered huge areas of seafloor and flowed along or even slightly upslope for long distances.
It is proposed that northeastwards-flowing bottom currents have aided transport of these dilute flow fractions into and across
the Agadir Basin. 相似文献
235.
236.
Ricardo A. Olea Vera Pawlowsky-Glahn 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(6):749-757
The Kolmogorov–Smirnov test is a convenient method for investigating whether two underlying univariate probability distributions
can be regarded as undistinguishable from each other or whether an underlying probability distribution differs from a hypothesized
distribution. Application of the test requires that the sample be unbiased and the outcomes be independent and identically
distributed, conditions that are violated in several degrees by spatially continuous attributes, such as topographical elevation.
A generalized form of the bootstrap method is used here for the purpose of modeling the distribution of the statistic D of the Kolmogorov–Smirnov test. The innovation is in the resampling, which in the traditional formulation of bootstrap is
done by drawing from the empirical sample with replacement presuming independence. The generalization consists of preparing
resamplings with the same spatial correlation as the empirical sample. This is accomplished by reading the value of unconditional
stochastic realizations at the sampling locations, realizations that are generated by simulated annealing. The new approach
was tested by two empirical samples taken from an exhaustive sample closely following a lognormal distribution. One sample
was a regular, unbiased sample while the other one was a clustered, preferential sample that had to be preprocessed. Our results
show that the p-value for the spatially correlated case is always larger that the p-value of the statistic in the absence of spatial correlation, which is in agreement with the fact that the information content
of an uncorrelated sample is larger than the one for a spatially correlated sample of the same size. 相似文献
237.
A steep‐margined carbonate platform is developed in the Carboniferous synorogenic foreland basin of northern Spain. Dips of 60–90° produced during Late Carboniferous thrusting enable cross‐sections of a 4‐km‐wide portion of the marginal area of this platform (Las Llacerias outcrop) to be studied in aerial photographs at a seismic scale. Three stratal domains are observed: (1) a horizontal‐bedded platform; (2) a clinoformal‐bedded margin with a relief of up to 500 m; and (3) a low‐angle toe‐of‐slope, where slope beds interfinger with basin sediments. The slope shows well‐bedded sigmoidal clinoforms with depositional dips ranging from 15° to 32°. Based on lithology and stratal patterns, four facies groups have been recognized: (1) a flat‐topped platform, in which thick algal boundstone, skeletal packstone–grainstone and peloidal micrite wackestone with a poorly rhythmic character prevail; (2) the platform margin and upper slope, characterized by microbial boundstone spanning a bathymetric range of ≈150 m measured from the break of slope; (3) a slope, predominantly composed of margin‐derived rudstones and breccias; and (4) a toe‐of‐slope to basin zone, where a cyclic alternation of spiculitic siltstones, packstone to grainstone calciturbidites and rudstone/breccia is visible. Five successive stages of platform development are deduced: (1) Bashkirian: flooding of the pre‐existing Serpukhovian platform giving rise to the nucleation of a low‐angle ramp to the south‐east of the study area with microbial mud‐mound accumulations, and breccias and calciturbidites on the margins; (2) Early Moscovian: an influx of siliciclastic sediment buried part of the platform and reduced the area of carbonate sedimentation; (3) Moscovian: aggradation and progradation of the carbonate system produced an extensive steep‐margined and flat‐topped shallow‐water platform (shelf system); (4) Latest Moscovian–earliest Kasimovian: drowning of the platform; and (5) Kasimovian: covering of the platform by marly calcareous ramp sediments. 相似文献
238.
239.
Adrian Gilli Flavio S. Anselmetti Daniel Ariztegui J. Platt Bradbury Kerry R. Kelts Vera Markgraf & Judith A. McKenzie 《地学学报》2001,13(6):443-448
Lake sediments from a closed basin in southern Patagonia (Argentina) provide a continental archive with which to reconstruct climate change and to test the interhemispheric synchroneity of abrupt events. High-resolution sub-bottom seismic profiles of Lago Cardiel indicate substantial lake-level changes since the late Pleistocene, which were identified and dated in a series of long piston cores. These data allow the reconstruction of the regional water balance at 49=" PSFT − BC "202S since the late glacial. The seismic stratigraphy reveals a dry late glacial climate with a desiccation of the basin around 11 220 yr BP (14 C). Lake level rapidly increased by 135 m at the Holocene transition. Following the early Holocene highstand at + 55 m, lake level never dropped significantly below modern level. The palaeoclimate changes implied by the Lago Cardiel record are out-of-phase with those implied by records from tropical South America and demonstrate considerable latitudinal asynchroneity in the climate evolution of this continent. 相似文献
240.
The laser 40Ar/39Ar dating technique has been applied to five Luna 16 basalt fragments and one impact glass, and nine Luna 24 basalt fragments and one breccia. The textures of these basalts are fine-grained ophitic and coarse-grained basalts. The samples contain high levels of solar and lunar atmospheric argon acquired during their residence on the lunar surface. These trapped argon components are predominantly released at low temperature steps and can be distinguished from radiogenic and cosmogenic released at intermediate and high temperature steps. The apparent ages obtained for Luna 16 samples span a narrow range of 3.29 to 3.38 Ga. A young age of 0.988 Ga was obtained for a basaltic impact glass indicating the age of an impact event in the vicinity of Luna 16 landing site. The ages obtained for Luna 24 samples suggest the existence of at least three periods of volcanism occurring over a protracted interval of between 3.45 and 2.52 Ga. The long period of volcanism suggested for the Mare Crisium was likely due to a combination of geophysical and geochemical features in the surrounding and underlying areas of the Crisium Basin. Attempts at dating three Luna 20 samples were inconclusive due to their high trapped argon contents. 相似文献