12,499 research outputs found

    The Methodology of Political Theory

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    This article examines the methodology of a core branch of contemporary political theory or philosophy: “analytic” political theory. After distinguishing political theory from related fields, such as political science, moral philosophy, and legal theory, the article discusses the analysis of political concepts. It then turns to the notions of principles and theories, as distinct from concepts, and reviews the methods of assessing such principles and theories, for the purpose of justifying or criticizing them. Finally, it looks at a recent debate on how abstract and idealized political theory should be, and assesses the significance of disagreement in political theory. The discussion is carried out from an angle inspired by the philosophy of science

    What Normative Facts Should Political Theory Be About? Philosophy of Science meets Political Liberalism

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    Just as different sciences deal with different facts—say, physics versus biology—so we may ask a similar question about normative theories. Is normative political theory concerned with the same normative facts as moral theory or different ones? By developing an analogy with the sciences, we argue that the normative facts of political theory belong to a higher— more coarse-grained—level than those of moral theory. The latter are multiply realizable by the former: competing facts at the moral level can underpin the same facts at the political one. Consequently, some questions that moral theories answer are indeterminate at the political level. This proposal offers a novel interpretation of John Rawls’s idea that, in public reasoning, we should abstract away from comprehensive moral doctrines. We contrast our distinction between facts at different levels with the distinction between admissible and inadmissible evidence and discuss some implications for the practice of political theory

    Electroweak corrections in the 2HDM for neutral scalar Higgs-boson production through gluon fusion

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    We have computed the two-loop, electroweak corrections to the production of a light and a heavy neutral, scalar Higgs-boson through the important gluon fusion process in the Two-Higgs-Doublet Model. We provide our results in various renormalization schemes for different scenarios and benchmark points, which will be valuable for experimental studies at the LHC. We describe the technicalities of our two-loop calculation and augment it by a phenomenological discussion. Our results are also applicable to the gluonic neutral, scalar Higgs-boson decays.Comment: 36 pages, 11 figures, 8 tables, v2: version accepted for publication in the journa

    Ultrasensitivity and sharp threshold theorems for multisite systems

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    We study the ultrasensitivity of multisite binding processes where ligand molecules can bind to several binding sites, considering more particularly recent models involving complex chemical reactions in phosphorylation systems such as allosteric phosphorylation processes, or substrate-catalyst chain reactions and nucleosome mediated cooperativity. New statistics based formulas for the Hill coefficient and the effective Hill coefficient are provided and necessary conditions for a system to be ultrasensitive are exhibited. We then assume that the binding process is described by a density dependent birth and death process. We provide precise large deviation results for the steady state distribution of the process, and show that switch-like ultrasensitive responses are strongly related to the multi-stability of the associated dynamical system. Ultrasensitivity occurs if and only if the entropy of the dynamical system has more than one global minimum for some critical ligand concentration. In this case, the Hill coefficient is proportional to the number of binding sites, and the systems is highly ultrasensitive. We also discuss the interpretation of an extension IqI_q of the effective Hill coefficient I0.9I_{0.9} for which we recommend the computation of a broad range of values of qq instead of just the standard one corresponding to the 10% to 90% variation in the dose-response. It is shown that this single choice can sometimes mislead the conclusion by not detecting ultrasensitivity. This new approach allows a better understanding of multisite ultrasensitive systems and provides new tools for the design of such systems

    Timing is everything: the impact of wakeup schedule distribution on asynchronous power save protocols

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    Asynchronous power save protocols have been proposed for use in ad hoc networks. In many protocols, nodes independently follow a common periodic wakeup schedule, each with some unknown offset relative to its neighbors. The schedule is defined to ensure deterministic intervals of overlap between nodes, regardless of the distribution of the nodes' wakeup schedules. This paper studies the sensitivity of a simple asynchronous power save protocol to the actual distribution of the nodes' wakeup schedules. In practical terms: For given topology and traffic load, are there particularly "good" or "bad" distributions? We define a simplified model of network operation that allows us to study this question in simulation. The results show that the performance variation has a narrow probability distribution, but with long tails. The variation is shown to derive largely from timing dependencies rather than overall capacity of the system. The result suggests the feasibility of manipulating the wakeup schedule distribution to improve performance. Although the best wakeup distributions often mitigate the performance penalty imposed by the power save protocol, their relative rarity implies that randomized strategies will not be sufficient to obtain maximum advantage

    The impact of wakeup schedule distribution in synchronous power save protocols on the performance of multihop wireless networks

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    By definition, the operation of an asynchronous power save protocol permits an arbitrary distribution of nodes' wakeup schedules. This wakeup schedule distribution creates an uncoordinated pattern of times at which nodes will attempt to transmit. Intuitively, we would expect that some patterns will be more (or less) favorable than others for a given traffic pattern. We investigate the impact of this wakeup pattern on network capacity and present simulation data showing that the capacity associated with the best wakeup patterns is significantly larger than that of the worst. This result not only gives insight to the behavior of such protocols, but also acts as a feasibility study showing the potential benefit of mechanisms by which nodes adapt their wakeup schedules to obtain improved performance
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