2,025 research outputs found

    The Problem of Confirmation in the Everett Interpretation

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    I argue that the Oxford school Everett interpretation is internally incoherent, because we cannot claim that in an Everettian universe the kinds of reasoning we have used to arrive at our beliefs about quantum mechanics would lead us to form true beliefs. I show that in an Everettian context, the experimental evidence that we have available could not provide empirical confirmation for quantum mechanics, and moreover that we would not even be able to establish reference to the theoretical entities of quantum mechanics. I then consider a range of existing Everettian approaches to the probability problem and show that they do not succeed in overcoming this incoherence

    Everettian quantum mechanics and physical probability: Against the principle of “State Supervenience”

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    Everettian quantum mechanics faces the challenge of how to make sense of probability and probabilistic reasoning in a setting where there is typically no unique outcome of measurements. Wallace has built on a proof by Deutsch to argue that a notion of probability can be recovered in the many worlds setting. In particular, Wallace argues that a rational agent has to assign probabilities in accordance with the Born rule. This argument relies on a rationality constraint that Wallace calls state supervenience. I argue that state supervenience is not defensible as a rationality constraint for Everettian agents unless we already invoke probabilistic notions

    An International Cross-Cultural Study of the Role of Chief Informational Officers in Healthcare

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    The introduction and utilization of Information Systems (IS) in the hospital environment has had a significant and lasting impact on the practice of medicine. The development of this dissertation will attempt to explore a widely overlooked area: The comparison of Chief Information Officers (CIOs) in the United States and the United Kingdom. Aspects of CIO experiences relating to assumed roles, CIO challenges, skills, frustrations, success, failure, leadership, management, involvement and perceptions about the role of Information Technology (IT) in healthcare are discussed with a comparative global model. This study investigates the managerial roles of the Chief Information Officer based on Mintzberg\u27s classical managerial role model. To be successful, CIOs need to have relation-building skills, managerial skills, a broad knowledge of technology, and management, technical and business degrees along with certain personal traits and backgrounds. While high technology has emerged as an important economic issue in all advanced industrial countries, there is much variation between countries in the success of their high technological industries, and in government efforts to encourage high technology in the healthcare sector. This research will attempt to demonstrate that CIOs as a whole believe IT to be indispensable in effective realization of the healthcare mission in a global, information-intensive civilization, and that IT can positively impact the quality, cost and medical issues of healthcare. The overall objective of this study is to examine the following: (1) will an increase in global information technology expand awareness of appropriate differing styles? (2) does global information technology have a positive and significant relationship within the international community? Finally, this study calls for more interdisciplinary research integrating insight from organizational behavior, international business and information technology

    Can Everett be Interpreted Without Extravaganza?

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    Everett's relative states interpretation of quantum mechanics has met with problems related to probability, the preferred basis, and multiplicity. The third theme, I argue, is the most important one. It has led to developments of the original approach into many-worlds, many-minds, and decoherence-based approaches. The latter especially have been advocated in recent years, in an effort to understand multiplicity without resorting to what is often perceived as extravagant constructions. Drawing from and adding to arguments of others, I show that proponents of decoherence-based approaches have not yet succeeded in making their ontology clear.Comment: Succinct analysis forthcoming in Found. Phy

    QFT, Antimatter, and Symmetry

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    A systematic analysis is made of the relations between the symmetries of a classical field and the symmetries of the one-particle quantum system that results from quantizing that field in regimes where interactions are weak. The results are applied to gain a greater insight into the phenomenon of antimatter.Comment: LaTeX; 34 pages; revision corrects a few typos and makes some minor changes for clarity. Forthcoming in Studies in the History and Philosophy of Modern Physic

    On the attributes of a critical literature review

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    Exploring and evaluating findings from previous research is an essential aspect of all research projects enabling the work to be set in the context of what is known and what is not known. This necessitates a critical review of the literature in which existing research is discussed and evaluated, thereby contextualising and justifying the project. In this research note we consider what is understood by being critical when reviewing prior to outlining the key attributes of a critical literature review. We conclude with a summary checklist to help ensure a literature review is critical

    Evaluation of the angiotensin II receptor blocker azilsartan medoxomil in African-American patients with hypertension

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    The efficacy and safety of azilsartan medoxomil (AZL-M) were evaluated in African-American patients with hypertension in a 6-week, double-blind, randomized, placebo-controlled trial, for which the primary end point was change from baseline in 24-hour mean systolic blood pressure (BP). There were 413 patients, with a mean age of 52years, 57% women, and baseline 24-hour BP of 146/91mmHg. Treatment differences in 24-hour systolic BP between AZL-M 40mg and placebo (-5.0mmHg; 95% confidence interval, -8.0 to -2.0) and AZL-M 80mg and placebo (-7.8mmHg; 95% confidence interval, -10.7 to -4.9) were significant (P.001 vs placebo for both comparisons). Changes in the clinic BPs were similar to the ambulatory BP results. Incidence rates of adverse events were comparable among the treatment groups, including those of a serious nature. In African-American patients with hypertension, AZL-M significantly reduced ambulatory and clinic BPs in a dose-dependent manner and was well tolerated

    Real World Interpretations of Quantum Theory

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    I propose a new class of interpretations, {\it real world interpretations}, of the quantum theory of closed systems. These interpretations postulate a preferred factorization of Hilbert space and preferred projective measurements on one factor. They give a mathematical characterisation of the different possible worlds arising in an evolving closed quantum system, in which each possible world corresponds to a (generally mixed) evolving quantum state. In a realistic model, the states corresponding to different worlds should be expected to tend towards orthogonality as different possible quasiclassical structures emerge or as measurement-like interactions produce different classical outcomes. However, as the worlds have a precise mathematical definition, real world interpretations need no definition of quasiclassicality, measurement, or other concepts whose imprecision is problematic in other interpretational approaches. It is natural to postulate that precisely one world is chosen randomly, using the natural probability distribution, as the world realised in Nature, and that this world's mathematical characterisation is a complete description of reality.Comment: Minor revisions. To appear in Foundations of Physic

    Elasticity of Diamond at High Pressures and Temperatures

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    We combine density functional theory within the local density approximation, the quasiharmonic approximation, and vibrational density of states to calculate single crystal elastic constants, and bulk and shear moduli of diamond at simultaneous high pressures and temperatures in the ranges of 0-500 GPa and 0-4800 K. Comparison with experimental values at ambient pressure and high temperature shows an excellent agreement for the first time with our first-principles results validating our method. We show that the anisotropy factor of diamond increases to 40% at high pressures and becomes temperature independent.Comment: 10 pages, 3 figures, 1 tabl
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