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A controlled laboratory experiment is described, in principle and practice, which can be used for the of determination the rate of tissue decomposition in soil. By way of example, an experiment was conducted to determine the effect of temperature (12 degrees, 22 degrees C) on the aerobic decomposition of skeletal muscle tissue (Organic Texel x Suffolk lamb (Ovis aries)) in a sandy loam soil. Measurements of decomposition processes included muscle tissue mass loss, microbial CO2 respiration, and muscle tissue carbon (C) and nitrogen (N). Muscle tissue mass loss at 22 degrees C always was greater than at 12 degrees C (p < 0.001). Microbial respiration was greater in samples incubated at 22 degrees C for the initial 21 days of burial (p < 0.01). All buried muscle tissue samples demonstrated changes in C and N content at the end of the experiment. A significant correlation (p < 0.001) was demonstrated between the loss of muscle tissue-derived C (Ct) and microbially-respired C (Cm) demonstrating CO2 respiration may be used to predict mass loss and hence biodegradation. In this experiment Q10 (12 degrees C-22 degrees C) = 2.0. This method is recommended as a useful tool in determing the effect of environmental variables on the rate of decomposition of various tissues and associated materials. 相似文献
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Policy Considerations for States Supporting Stem Cell Research: Evidence from a Survey of Stem Cell Scientists 总被引:1,自引:0,他引:1
Aaron D. Levine 《Public administration review》2008,68(4):681-694
Five states now provide funding for stem cell research, and many states are developing or debating stem cell research policies. Despite this interest, little data exist to help policy makers design policies or forecast the impact of new legislation. This article reports novel data from two surveys: one directed at those most affected by these policies—stem cell scientists—and one at a group of biomedical researchers working in less contentious fields. These data identified relatively high mobility among stem cell scientists, particularly in states with restrictive policies, and a strong preference for states with permissive policies. These findings suggest that state-specific policies may prove to be effective recruiting tools. They also suggest specific recruitment strategies and highlight the importance of first-mover advantage as states compete for the same limited pool of mobile scientists. This research aims to provide a factual basis to support ongoing policy formulation in the area. 相似文献
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Chalfin Aaron Hansen Benjamin Lerner Jason Parker Lucie 《Journal of Quantitative Criminology》2022,38(1):127-157
Journal of Quantitative Criminology - This paper offers novel experimental evidence that violent crimes can be successfully reduced by changing the situational environment that potential victims... 相似文献
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Aaron James 《Ratio juris》2017,30(3):239-258
This paper suggests that “systemic risk” (e.g., of financial market collapse, or of ecological calamity) has a distinctive kind of moral significance. Two intuitive data points need to be explained. The first is that the systematic imposition of risk can be wrongful or unjust in and of itself, even if harm never ensues. The second is that, even so, there may be no one in particular to blame. We can explain both ideas in terms of what I call responsibilities of “Collective Due Care.” Collective Due Care arguably precludes purely aggregative cost‐benefit decision‐making and requires one kind of “precautionary” attitude in public choice. 相似文献
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