800 resultados para APENDICULAR SKELETON
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Mode of access: Internet.
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"The product of collaboration between Edith Roper, who brought to America her own records, set down while she was newspaper correspondent for several years in the Nazi courts, and Clara Leiser, who rendered into English and helped arrange these records for the American reader, including occasional comments of her own."--p. [2]
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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"This skeleton form of report was framed to assist practical Miners and Mine Owners ... in making a comprehensive report"--T.p.
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Certain 3-azabicyclo[3.3.1] nonane derivatives undergo unprecedented stereospecific skeletal cleavage when subjected to light affording a novel heterotricyclic skeleton.
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This paper presents a novel algorithm for medial surfaces extraction that is based on the density-corrected Hamiltonian analysis of Torsello and Hancock [1]. In order to cope with the exponential growth of the number of voxels, we compute a first coarse discretization of the mesh which is iteratively refined until a desired resolution is achieved. The refinement criterion relies on the analysis of the momentum field, where only the voxels with a suitable value of the divergence are exploded to a lower level of the hierarchy. In order to compensate for the discretization errors incurred at the coarser levels, a dilation procedure is added at the end of each iteration. Finally we design a simple alignment procedure to correct the displacement of the extracted skeleton with respect to the true underlying medial surface. We evaluate the proposed approach with an extensive series of qualitative and quantitative experiments. © 2013 Elsevier Inc. All rights reserved.
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Insight into the response of reef corals and other major marine calcifiers to ocean acidification is limited by a lack of knowledge about how seawater pH and carbonate chemistry impact the physiological processes that drive biomineralization. Ocean acidification is proposed to reduce calcification rates in corals by causing declines in internal pH at the calcifying tissue-skeleton interface where biomineralization takes place. Here, we performed an in vivo study on how partial-pressure CO(2)-driven seawater acidification impacts intracellular pH in coral calcifying cells and extracellular pH in the fluid at the tissue-skeleton interface [subcalicoblastic medium (SCM)] in the coral Stylophora pistillata. We also measured calcification in corals grown under the same conditions of seawater acidification by measuring lateral growth of colonies and growth of aragonite crystals under the calcifying tissue. Our findings confirm that seawater acidification decreases pH of the SCM, but this decrease is gradual relative to the surrounding seawater, leading to an increasing pH gradient between the SCM and seawater. Reductions in calcification rate, both at the level of crystals and whole colonies, were only observed in our lowest pH treatment when pH was significantly depressed in the calcifying cells in addition to the SCM. Overall, our findings suggest that reef corals may mitigate the effects of seawater acidification by regulating pH in the SCM, but they also highlight the role of calcifying cell pH homeostasis in determining the response of reef corals to changes in external seawater pH and carbonate chemistry.