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A. I. Antoshkina 《Paleontological Journal》2014,48(4):353-368
Remains of Palaeomicrocodium from the Silurian and Devonian carbonate and clay deposits from the Timan-Northern Ural region, Salair, and Western Siberia are studied using various lithological and geochemical techniques. Characters suggesting their paleoecological and geochemical specialization are discussed. It is suggested that Palaeomicrocodium structures belong to ancient lichens or actinolichens. This hypothesis is based on a number of features of Palaeomicrocodium, including the presence of typical biologically fixed microelements of soil, such as Co, Cu, Zn, Ni, and Cd, sourced from the atmosphere; presence of kerogen carbonaceous matter in prismatic calcite monocrystals of Palaeomicrocodium; identification in their structure of probable hypha-like and rhizoid-like structures; morphological similarity to extant encrusting lichens. Like lichens, Palaeomicrocodium significantly contributed to chemical weathering of rocks by excreting various organic acids, which could effectively dissolve minerals and chelate metallic cations. As a result of the weathering induced by vital function of Palaeomicrocodium, rock-forming minerals exhibit surface corrosion. 相似文献
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Weaponizing Principles: Clinical Ethics Consultations & the Plight of the Morally Vulnerable 下载免费PDF全文
Autumn M. Fiester 《Bioethics》2015,29(5):309-315
Internationally, there is an on‐going dialogue about how to professionalize ethics consultation services (ECSs). Despite these efforts, one aspect of ECS‐competence that has received scant attention is the liability of failing to adequately capture all of the relevant moral considerations in an ethics conflict. This failure carries a high price for the least powerful stakeholders in the dispute. When an ECS does not possess a sophisticated dexterity at translating what stakeholders say in a conflict into ethical concepts or principles, it runs the risk of naming one side's claims as morally legitimate and decrying the other's as merely self‐serving. The result of this failure is that one side in a dispute is granted significantly more moral weight and authority than the other. The remedy to this problem is that ECSs learn how to expand the diagnostic moral lens they employ in clinical ethics conflicts. 相似文献
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