Dellarco V.,U.S. Environmental Protection Agency |
Journal of Nutrition | Year: 2012
To advance the utility and predictability of safety evaluation, an integrated approach that relies on all existing knowledge to understand how agents perturb normal biological function or structure is needed to progress more focused evaluation strategies. The mode of action (MOA)-human relevance framework developed by the International Program for Chemical Safety and The International Life Sciences Institute provides a useful analytical approach where different lines of evidence (e.g., in vitro, in vivo) can be organized, linked, and integrated at different levels of biological organization into a more efficient, hypothesis-driven approach to safety evaluation. This framework provides a weight-of-evidence approach based on considerations for causality (as originally articulated by Bradford Hill), including dose response and temporal concordance, consistency, specificity, and biological plausibility and coherence. Once an animal MOA and its key events are established, qualitative and quantitative comparisons between experimental animals and humans are made based on the key events. This comparison enables a conclusion as to whether the MOA is likely operative in humans and, if so, whether it can result in a more refined hazard and dose-response assessment. This framework provides an important tool to promote and formalize the use of MOA data in safety evaluation regardless of whether the information comes from traditional or novel approaches, such as those recommended by the NRC in its 2007 report "Toxicity Testing in the 21st Century," which recommends moving away from traditional approaches of measuring adverse endpoints by using newer technologies to identify ways agents may considerably perturb cellular pathways to produce their toxicity. © 2012 American Society for Nutrition.
Antipode | Year: 2011
This article traces the creation of a market for carbon sequestration by trees under the Kyoto Protocol on climate change, describing the problems encountered by UN negotiators as they attempted to abstract, isolate, quantify and commodify a process akin to breathing, which takes place naturally everywhere, anyway. It starts with an overview of the history of the negotiations that defined the commodity and the rules to govern its trade, creating the scarcity conditions for the market to work. It then goes over the key problems encountered and how they were solved. The analysis draws attention to time and risk as critical elements in reproducing uneven development, and suggests that this new market can be understood as an instance of capital involution-that is, an instance where a narrow pattern persistently repeated leads to ever increasing complexity but, instead of evolving into something new, it generates further entrapment. © 2011 The Author Antipode © 2011 Editorial Board of Antipode.
Applied Optics | Year: 2010
In this paper, the sensitivity control for manufacturing errors is treated from three aspects. A wavefrontbased sensitivity function is proposed, the effect of which is verified with the modulation transfer function (MTF)-based Monte Carlo simulation. Then, the direct optimization of the MTF-based Monte Carlo simulation result is proposed. Finally, the effect of the sensitivity control function to get better lens types is shown. © 2010 Optical Society of America.
Solvent Extraction and Ion Exchange | Year: 2013
Applicability of room temperature liquids (RTILs) as diluents in the solvent extraction of f-elements is reviewed. Characteristics of selected RTILs, important for such an application, are gathered. Properties tabulated are the melting and freezing points, density, mutual solubility with water, viscosity, surface tension, specific conductivity, and radiation stability. Properties such as environmental compatibility, toxicity, chemical and thermal stability, biodegradability, and chemical degradability imply that RTILs are not harmless to the environment or to work safety. The extraction efficiency and mechanism in systems involving RTILs is described, discussed, and compared with systems involving molecular diluents. Particularly assessed is the extraction of nitric acid by RTILs alone and TBP, the extraction of U(VI), Ce(IV), Pu(IV), Am(III), and lanthanides(III) by RTILs alone, the extraction of U(VI), Ce(IV), actinides(III,IV), and lanthanides(III) by solvating O-donors, the extraction of Eu(III) by a solvating N-donor, the extraction of lanthanides(III) and Am(III) by acidic extractants, and the extraction of actinides(III,IV) and lanthanides(III) by task specific ionic liquids. © 2013 Copyright Taylor & Francis Group, LLC.
Applied Optics | Year: 2012
In this paper, a rapid optimization method of cost-based tolerancing is proposed. An example shows that only a few cases of the Monte Carlo simulation are necessary to find the best balance of the yield and the tolerance cost for the practical tolerancing problem. © 2012 Optical Society of America.