347 research outputs found

    Theory and Simulation of the diffusion of kinks on dislocations in bcc metals

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    Isolated kinks on thermally fluctuating (1/2) screw, edge and (1/2) edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform stochastic motion in a potential landscape that depends on the dislocation character and geometry, and their motion provides fresh insight into the coupling of dislocations to a heat bath. The kink formation energy, migration barrier and friction parameter are deduced from the simulations. A discrete Frenkel-Kontorova-Langevin (FKL) model is able to reproduce the coarse grained data from MD at a fraction of the computational cost, without assuming an a priori temperature dependence beyond the fluctuation-dissipation theorem. Analytic results reveal that discreteness effects play an essential r\^ole in thermally activated dislocation glide, revealing the existence of a crucial intermediate length scale between molecular and dislocation dynamics. The model is used to investigate dislocation motion under the vanishingly small stress levels found in the evolution of dislocation microstructures in irradiated materials

    Imperfect identity

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    Questions of identity over time are often hard to answer. A long tradition has it that such questions are somehow soft: they have no unique, determinate answer, and disagreements about them are merely verbal. I argue that this claim is not the truism it is taken to be. Depending on how it is understood, it turns out either to be false or to presuppose a highly contentious metaphysical claim

    An international survey of health literacy education within schools of pharmacy

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    Background: Health literacy (HL) influences patients’ health status, use of the healthcare system and medication-relatedbehaviours. However, the concept is relatively new to pharmacy and its incorporation in academic curricula has notbeen examined.Aims: To explore HL training in pharmacy schools internationally, and academics’ opinions in regards to how it shouldbe taught and assessed.Methods: An anonymous, online survey was administered to academics who teach within pharmacy degree coursesfrom countries where English is the main language.Results: Responses were received from 21 pharmacy schools in seven countries; 20 stated that HL was taught withintheir pharmacy degree, in four as a stand-alone topic. Small-group tutorials were thought to be the most beneficial formof teaching health literacy, best assessed using oral and objective structured clinical examinations.Conclusion: The majority of pharmacy schools taught health literacy and had similar opinions regarding best practiceteaching and assessment

    The Ontology of Intentional Agency in Light of Neurobiological Determinism: Philosophy Meets Folk Psychology

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    The moot point of the Western philosophical rhetoric about free will consists in examining whether the claim of authorship to intentional, deliberative actions fits into or is undermined by a one-way causal framework of determinism. Philosophers who think that reconciliation between the two is possible are known as metaphysical compatibilists. However, there are philosophers populating the other end of the spectrum, known as the metaphysical libertarians, who maintain that claim to intentional agency cannot be sustained unless it is assumed that indeterministic causal processes pervade the action-implementation apparatus employed by the agent. The metaphysical libertarians differ among themselves on the question of whether the indeterministic causal relation exists between the series of intentional states and processes, both conscious and unconscious, and the action, making claim for what has come to be known as the event-causal view, or between the agent and the action, arguing that a sort of agent causation is at work. In this paper, I have tried to propose that certain features of both event-causal and agent-causal libertarian views need to be combined in order to provide a more defendable compatibilist account accommodating deliberative actions with deterministic causation. The ‘‘agent-executed-eventcausal libertarianism’’, the account of agency I have tried to develop here, integrates certain plausible features of the two competing accounts of libertarianism turning them into a consistent whole. I hope to show in the process that the integration of these two variants of libertarianism does not challenge what some accounts of metaphysical compatibilism propose—that there exists a broader deterministic relation between the web of mental and extra-mental components constituting the agent’s dispositional system—the agent’s beliefs, desires, short-term and long-term goals based on them, the acquired social, cultural and religious beliefs, the general and immediate and situational environment in which the agent is placed, etc. on the one hand and the decisions she makes over her lifetime on the basis of these factors. While in the ‘‘Introduction’’ the philosophically assumed anomaly between deterministic causation and the intentional act of deciding has been briefly surveyed, the second section is devoted to the task of bridging the gap between compatibilism and libertarianism. The next section of the paper turns to an analysis of folk-psychological concepts and intuitions about the effects of neurochemical processes and prior mental events on the freedom of making choices. How philosophical insights can be beneficially informed by taking into consideration folk-psychological intuitions has also been discussed, thus setting up the background for such analysis. It has been suggested in the end that support for the proposed theory of intentional agency can be found in the folk-psychological intuitions, when they are taken in the right perspective

    Can discrete time make continuous space look discrete?

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    Van Bendegem has recently offered an argument to the effect that, if time is discrete, then there should exist a correspondence between the motions of massive bodies and a discrete geometry. On this basis, he concludes that, even if space is continuous, it should nonetheless appear discrete. This paper examines the two possible ways of making sense of that correspondence, and shows that in neither case van Bendegem's conclusion logically follows
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