Quantum Turing Machines Computations and Measurements

Contrary to the classical case, the relation between quantum programming languages and quantum Turing Machines (QTM) has not being fully investigated. In particular, there are features of QTMs that have not been exploited, a notable example being the intrinsic infinite nature of any quantum computation. In this paper we propose a definition of QTM, which extends and unifies the notions of Deutsch and Bernstein and Vazirani. In particular, we allow both arbitrary quantum input, and meaningful superpositions of computations, where some of them are "terminated" with an "output", while others are not. For some infinite computations an "output" is obtained as a limit of finite portions of the computation. We propose a natural and robust observation protocol for our QTMs, that does not modify the probability of the possible outcomes of the machines. Finally, we use QTMs to define a class of quantum computable functions---any such function is a mapping from a general quantum state to a probability distribution of natural numbers. We expect that our class of functions, when restricted to classical input-output, will be not different from the set of the recursive functions.Comment: arXiv admin note: substantial text overlap with arXiv:1504.02817 To appear on MDPI Applied Sciences, 202

Transformations of self: a phenomenological investigation into the lived experience of survivors of critical illness

Based on the hermeneutical, phenomenological perspective, this study explored the lived experience of individuals with a past hospitalization in an intensive care unit, with focus on their dreams. The purpose was to explore how it is to have been critically ill. Dreams are the language of the unconscious and can symbolically convey meanings. Eight participants recounted their experiences with critical illness through semi-structured phenomenological interviews and dream-telling. An interplay between the 'factual-external' world and the 'internal' world appeared to be the basis of their perception of the situation. Participants' narratives were immensely rich in symbols of transformation, transcendence and rebirth. Transformations in perception, in lived-body, and in lived time and space were some of the themes emerging as part of both conscious and dreaming experiences. Attitudes towards death were altered, and elements of heightened spirituality were evident in the aftermath of critical illness. Critical illness was conceptualized as a 'cocooning phase' leading to transformation of self, spiritual arousal and personal growth. Nurses may be able to alleviate suffering by supporting this process while in the ICU, as well as after discharg

Stress Tensor Correlators in the Schwinger-Keldysh Formalism

We express stress tensor correlators using the Schwinger-Keldysh formalism. The absence of off-diagonal counterterms in this formalism ensures that the +- and -+ correlators are free of primitive divergences. We use dimensional regularization in position space to explicitly check this at one loop order for a massless scalar on a flat space background. We use the same procedure to show that the ++ correlator contains the divergences first computed by `t Hooft and Veltman for the scalar contribution to the graviton self-energy.Comment: 14 pages, LaTeX 2epsilon, no figures, revised for publicatio

Updating the descriptive biopsychosocial approach to fit into a formal person-centered dynamic coherence model

Based on the Aristotelian dynamis-energeia-differentiation, a concept issuing dynamic coherence providers as the sub-level of individual realizations. This logical sub-level is given for any kind of realizations. Based on this two-level approach, to some degree similar to the two-level approach developed by Polanyi, model of biopsychosocial interaction is established. It is suggested as the theoretical basis for a person-centered approach in healthcare, integrating science and humanitite

A Praxical Solution of the Symbol Grounding Problem

Peer reviewe

Double-averaged velocity profiles over fixed dune shapes

Peer reviewedPublisher PD

The role of structural viscoelasticity in deformable porous media with incompressible constituents: applications in biomechanics

The main goal of this work is to clarify and quantify, by means of mathematical analysis, the role of structural viscoelasticity in the biomechanical response of deformable porous media with incompressible constituents to sudden changes in external applied loads. Models of deformable porous media with incompressible constituents are often utilized to describe the behavior of biological tissues, such as cartilages, bones and engineered tissue scaffolds, where viscoelastic properties may change with age, disease or by design. Here, for the first time, we show that the fluid velocity within the medium could increase tremendously, even up to infinity, should the external applied load experience sudden changes in time and the structural viscoelasticity be too small. In particular, we consider a one-dimensional poro-visco-elastic model for which we derive explicit solutions in the cases where the external applied load is characterized by a step pulse or a trapezoidal pulse in time. By means of dimensional analysis, we identify some dimensionless parameters that can aid the design of structural properties and/or experimental conditions as to ensure that the fluid velocity within the medium remains bounded below a certain given threshold, thereby preventing potential tissue damage. The application to confined compression tests for biological tissues is discussed in detail. Interestingly, the loss of viscoelastic tissue properties has been associated with various disease conditions, such as atherosclerosis, Alzheimer's disease and glaucoma. Thus, the findings of this work may be relevant to many applications in biology and medicine