Aspects of crinoid palaeontology of the North Esk Inlier,Scotland (Silurian,Llandovery, Telychian)

Abstract: The described fauna of well‐preserved Llandovery (Telychian) echinoderms from the North Esk Inlier, including six crinoids, one echinoid and seven starfish species, is mainly allochthonous. Most of these taxa are known only from starfish beds, channel fill deposits probably representing submarine mass flows and preserving a biota probably derived from elsewhere, presumably shallower water. Only one crinoid species, Pisocrinus cf. campana Miller, is recognized as a common fossil away from the starfish beds and is a biostratigraphic marker for the base of the Wether Law Linn Formation, forming part of the Skenidioides‐Cyrtia Association. Crinoid columnals preserved perpendicular to bedding (that is, in putative life position) in Lamont’s bivalve bed, Deerhope Formation, are tentatively interpreted as being in situ by comparison with a similar occurrence in the Silurian of Arisaig, Nova Scotia. Two new species of crinoid are described, the cladid Dendrocrinus? sp. and the columnal morphospecies Pentagonocyclicus (col.) lamonti sp. nov.     

Scale and uncertainty in modeled soil organic carbon stock changes for US croplands using a process‐based model

Process‐based model analyses are often used to estimate changes in soil organic carbon (SOC), particularly at regional to continental scales. However, uncertainties are rarely evaluated, and so it is difficult to determine how much confidence can be placed in the results. Our objective was to quantify uncertainties across multiple scales in a process‐based model analysis, and provide 95% confidence intervals for the estimates. Specifically, we used the Century ecosystem model to estimate changes in SOC stocks for US croplands during the 1990s, addressing uncertainties in model inputs, structure and scaling of results from point locations to regions and the entire country. Overall, SOC stocks increased in US croplands by 14.6 Tg C yr^?1 from 1990 to 1995 and 17.5 Tg C yr^?1 during 1995 to 2000, and uncertainties were ±22% and ±16% for the two time periods, respectively. Uncertainties were inversely related to spatial scale, with median uncertainties at the regional scale estimated at ±118% and ±114% during the early and latter part of 1990s, and even higher at the site scale with estimates at ±739% and ±674% for the time periods, respectively. This relationship appeared to be driven by the amount of the SOC stock change; changes in stocks that exceeded 200 Gg C yr^?1 represented a threshold where uncertainties were always lower than ±100%. Consequently, the amount of uncertainty in estimates derived from process‐based models will partly depend on the level of SOC accumulation or loss. In general, the majority of uncertainty was associated with model structure in this application, and so attaining higher levels of precision in the estimates will largely depend on improving the model algorithms and parameterization, as well as increasing the number of measurement sites used to evaluate the structural uncertainty.     

NO ETHICAL BYPASS OF MORAL STATUS IN STEM CELL RESEARCH

Recent advances in reprogramming technology do not bypass the ethical challenge of embryo sacrifice. Induced pluripotent stem cell (iPS) research has been and almost certainly will continue to be conducted within the context of embryo sacrifice. If human embryos have moral status as human beings, then participation in iPS research renders one morally complicit in their destruction; if human embryos have moral status as mere precursors of human beings, then advocacy of iPS research policy that is inhibited by embryo sacrifice concerns renders one morally complicit in avoidable harms to persons. Steps may be taken to address these complicity concerns, but in the final analysis there is no alternative to achieving clarity with respect to the moral status of the human embryo.