283 research outputs found

    Unsharp Quantum Reality

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    The positive operator (valued) measures (POMs) allow one to generalize the notion of observable beyond the traditional one based on projection valued measures (PVMs). Here, we argue that this generalized conception of observable enables a consistent notion of unsharp reality and with it an adequate concept of joint properties. A sharp or unsharp property manifests itself as an element of sharp or unsharp reality by its tendency to become actual or to actualize a specific measurement outcome. This actualization tendency-or potentiality-of a property is quantified by the associated quantum probability. The resulting single-case interpretation of probability as a degree of reality will be explained in detail and its role in addressing the tensions between quantum and classical accounts of the physical world will be elucidated. It will be shown that potentiality can be viewed as a causal agency that evolves in a well-defined way

    Sharp and fuzzy observables on effect algebras

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    Observables on effect algebras and their fuzzy versions obtained by means of confidence measures (Markov kernels) are studied. It is shown that, on effect algebras with the (E)-property, given an observable and a confidence measure, there exists a fuzzy version of the observable. Ordering of observables according to their fuzzy properties is introduced, and some minimality conditions with respect to this ordering are found. Applications of some results of classical theory of experiments are considered.Comment: 23 page

    Extending scientific computing system with structural quantum programming capabilities

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    We present a basic high-level structures used for developing quantum programming languages. The presented structures are commonly used in many existing quantum programming languages and we use quantum pseudo-code based on QCL quantum programming language to describe them. We also present the implementation of introduced structures in GNU Octave language for scientific computing. Procedures used in the implementation are available as a package quantum-octave, providing a library of functions, which facilitates the simulation of quantum computing. This package allows also to incorporate high-level programming concepts into the simulation in GNU Octave and Matlab. As such it connects features unique for high-level quantum programming languages, with the full palette of efficient computational routines commonly available in modern scientific computing systems. To present the major features of the described package we provide the implementation of selected quantum algorithms. We also show how quantum errors can be taken into account during the simulation of quantum algorithms using quantum-octave package. This is possible thanks to the ability to operate on density matrices

    BIOLOGICAL, BEHAVIORAL, AND PSYCHOSOCIAL ATTRIBUTES OF INDIVIDUALS WITH COPD

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    The purpose of this dissertation was to evaluate the biological, behavioral, and psychosocial attributes of individuals diagnosed with chronic obstructive pulmonary disease (COPD). Specific aims were to: 1) explore the predictive power of spirometry measures for event-free survival in patients with heart failure and suspected COPD, focusing on the differences in survival between those with and without airflow limitation; 2) examine the psychometric properties of the Multidimensional Scale of Perceived Social Support (MSPSS) in patients with concomitant COPD and heart failure; and 3) test the efficacy of a theory-based, multidimensional, self-care educational intervention using an eHealth platform on measures of symptom severity and variability, anxiety and depressive symptoms, perceived self-care ability, perceived self-care adherence, and selfcare information needs (knowledge) in a sample of adult patients with stable COPD. Specific aim one was addressed by evaluation of the predictive power of spirometry measures (forced expiratory volume/second [FEV1], forced vital capacity [FVC], and the ratio of FEV1/FVC) for event-free time to combined hospitalization/mortality after controlling for clinical and sociodemographic variables. This analysis revealed that those patients with airflow limitation were 2.2 times more likely to experience hospitalization/mortality compared to those without airflow limitation. The second specific aim was addressed with a psychometric evaluation of the Multidimensional Scale of Perceived Social support (MSPSS) which included determination of internal consistency reliability, the factor structure and construct validity by hypothesis testing in participants with comorbid COPD and heart failure. The MSPSS was a valid and reliable instrument to measure perceived social support in patients with comorbid COPD and heart failure. The third specific aim was addressed by a trial of an eHealth educational intervention in participants with COPD (N = 20). This intervention resulted in significant change in symptom severity evaluation in patients categorized as having medium symptom severity for the following symptoms: distress due to cough, chest tightness, dyspnea with activity and fatigue; these symptoms were perceived as more severe in the intervention period. Anxiety, depressive symptoms and perceived self-care ability were unchanged; however, perceived self-care adherence scores improved, and knowledge needs were significantly reduced after the intervention

    Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects

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    We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.Comment: Cent. Eur. J. Phys, in pres

    Complete positivity of nonlinear evolution: A case study

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    Simple Hartree-type equations lead to dynamics of a subsystem that is not completely positive in the sense accepted in mathematical literature. In the linear case this would imply that negative probabilities have to appear for some system that contains the subsystem in question. In the nonlinear case this does not happen because the mathematical definition is physically unfitting as shown on a concrete example.Comment: extended version, 3 appendices added (on mixed states, projection postulate, nonlocality), to be published in Phys. Rev.

    Nonlinear Quantum Mechanics at the Planck Scale

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    I argue that the linearity of quantum mechanics is an emergent feature at the Planck scale, along with the manifold structure of space-time. In this regime the usual causality violation objections to nonlinearity do not apply, and nonlinear effects can be of comparable magnitude to the linear ones and still be highly suppressed at low energies. This can offer alternative approaches to quantum gravity and to the evolution of the early universe.Comment: Talk given at the International Quantum Structures 2004 meeting, 16 pages LaTe

    Oral anticancer agents: Presenting new challenges for family caregivers of patients with cancer

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    Attendees will learn the current state of the science on the new challenges that family caregivers face when patients are prescribed oral anticancer agents (OAA). Strategies for clinicians to support these family caregivers will be discussed

    Patients with advanced-stage cancer: Caregivers perspective on patient symptoms, treatment sessions, and coping

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    Attendees will learn about perspectives on patient symptoms, difficulties during treatment, and coping needs in caregivers of advanced stage cancer survivors (ASCS). Strategies for interventions to support these caregivers will be discussed
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