943 research outputs found

    Geoengineering and Non-Ideal Theory

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    The strongest arguments for the permissibility of geoengineering (also known as climate engineering) rely implicitly on non-ideal theory—roughly, the theory of justice as applied to situations of partial compliance with principles of ideal justice. In an ideally just world, such arguments acknowledge, humanity should not deploy geoengineering; but in our imperfect world, society may need to complement mitigation and adaptation with geoengineering to reduce injustices associated with anthropogenic climate change. We interpret research proponents’ arguments as an application of a particular branch of non-ideal theory known as “clinical theory.” Clinical theory aims to identify politically feasible institutions or policies that would address existing (or impending) injustice without violating certain kinds of moral permissibility constraints. We argue for three implications of clinical theory: First, conditional on falling costs and feasibility, clinical theory provides strong support for some geoengineering techniques that aim to remove carbon dioxide from the atmosphere. Second, if some kinds of carbon dioxide removal technologies are supported by clinical theory, then clinical theory further supports using those technologies to enable “overshoot” scenarios in which developing countries exceed the cumulative emissions caps that would apply in ideal circumstances. Third, because of tensions between political feasibility and moral permissibility, clinical theory provides only weak support for geoengineering techniques that aim to manage incoming solar radiation

    Political legitimacy in decisions about experiments in solar radiation management

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    Some types of solar radiation management (SRM) research are ethically problematic because they expose persons, animals, and ecosystems to significant risks. In our earlier work, we argued for ethical norms for SRM research based on norms for biomedical research. Biomedical researchers may not conduct research on persons without their consent, but universal consent is impractical for SRM research. We argue that instead of requiring universal consent, ethical norms for SRM research require only political legitimacy in decision-making about global SRM trials. Using Allen Buchanan & Robert Keohane's model of global political legitimacy, we examine several existing global institutions as possible analogues for a politically legitimate SRM decision-making body

    Defense communications : the future directions

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    Characterization of body weight and composition changes during the sophomore year of college

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    <p>Abstract</p> <p>Background</p> <p>Years spent in college represents a critical time for obesity development though little information is known regarding how body weight and composition changes beyond the first year of college. The aim of this study was to investigate changes in body weight and composition and the factors influencing those changes among sophomore females.</p> <p>Methods</p> <p>Body composition by dual energy X-ray absorptiometry was obtained in participants beginning during their freshman year and continued through their sophomore year.</p> <p>Results</p> <p>No difference was observed between sophomore year fall and spring visits for body weight (60.4 versus 60.6 kg) or fat mass (19.3 versus 18.7 kg). However, a significant (<it>P </it>≤ 0.05) decrease was observed for body fat (31.9 versus 30.9 %fat) and a significant increase was observed for fat-free mass (37.7 versus 38.4 kg). Participants living off campus significantly (<it>P </it>≤ 0.05) declined in body fat (33.0 versus 31.0 %fat) and fat mass (19.4 versus 18.2 kg) and increased in fat-free mass (36.1 versus 37.2 kg) with no differences in those living on campus.</p> <p>Conclusion</p> <p>No change in body weight was observed in females during their sophomore year. However, an increase in fat-free mass accompanied with a decrease in fat mass resulted in a decrease in body fat. Participants living off campus had favorable changes in their body composition by means of decreasing %fat and fat mass while increasing fat-free mass. Participants living on campus did not demonstrate these favorable changes.</p

    Understanding defects in amorphous silicon with million-atom simulations and machine learning

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    The structure of amorphous silicon is widely thought of as a fourfold-connected random network, and yet it is defective atoms, with fewer or more than four bonds, that make it particularly interesting. Despite many attempts to explain such "dangling-bond" and "floating-bond" defects, respectively, a unified understanding is still missing. Here, we show that atomistic machine-learning methods can reveal the complex structural and energetic landscape of defects in amorphous silicon. We study an ultra-large-scale, quantum-accurate structural model containing a million atoms, and more than ten thousand defects, allowing reliable defect-related statistics to be obtained. We combine structural descriptors and machine-learned local atomic energies to develop a universal classification of the different types of defects in amorphous silicon. The results suggest a revision of the established floating-bond model by showing that fivefold-coordinated atoms in amorphous silicon exhibit a wide range of local environments, and it is shown that fivefold (but not threefold) coordination defects tend to cluster together. Our study provides new insights into one of the most widely studied amorphous solids, and has general implications for modelling and understanding defects in disordered materials beyond silicon alone

    Petition for a Writ of Certiorari. Sandifer v. United States Steel Corp., 134 S. Ct. 870 (2014) (No. 12-417), 2012 U.S. S. Ct. Briefs LEXIS 4304

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    QUESTIONS PRESENTED Under the Fair Labor Standards Act, the period of time during which a covered employee must be paid begins when the worker engages in a principal activity. Donning and doffing safety gear (including protective clothing) required by the employer is a principal activity when it is an integral and indispensable part of the activities for which the worker is employed. Such requirements are common in manufacturing firms. However, under section 203(o) of the Act an employer need not compensate a worker for time spent in “changing clothes” (even if it is a principal activity) if that time is expressly excluded from compensable time under a bona fide collective bargaining agreement applicable to that worker. The interrelated questions presented are: (1) What constitutes “changing clothes” within the meaning of section 203(o)? (2) If a worker’s actions are a principal activity but fall within the scope of the section 203(o) exemption, do those actions nonetheless commence the period of time during which (aside from the clothes-changing time) the worker must be compensated? (3) If a worker engages in a principal activity which is not exempted by section 203(o), but which involves only a de minimis amount of time, does the activity nonetheless commence the period of time during which the worker must be compensated
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