66 research outputs found

    Joint reality and Bell inequalities for consecutive measurements

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    Some new Bell inequalities for consecutive measurements are deduced under joint realism assumption, using some perfect correlation property. No locality condition is needed. When the measured system is a macroscopic system, joint realism assumption substitutes the non-invasive hypothesis advantageously, provided that the system satisfies the perfect correlation property. The new inequalities are violated quantically. This violation can be expected to be more severe than in the case of precedent temporal Bell inequalities. Some microscopic and mesoscopic situations, in which the new inequalities could be tested, are roughly considered.Comment: 7 pages, no figure

    Classical dilute relativistic plasma in equilibrium. Two-particle distribution function

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    We consider here a dilute hot plasma which is homogeneous and in equilibrium in the framework of classical relativistic statistical mechanics as formulated recently by the authors. No external fields are present. The two-particle distribution function of the plasma is calculated for any temperature. This distribution will be physically significant, as long as the creation of pairs can be neglected. Several limits which apply at low or high temperatures are discussed. Comparison with previous work from several authors is made

    Acquisition of competencies of nurses: improving the performance of the healthcare system

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    Perspectives of the core competencies of nurses are varied among postgraduate-year nurses, which makes it challenging to establish training programs and develop evaluation instruments. Particularly critical for nurses is the ongoing acquisition of competencies throughout life. Sometimes this acquisition is funded by the healthcare system, but the key question is how the system leverages this acquisition and ultimately how it translates into patient care. This study seeks to explore nurses’ key competencies acquired through continuing education from the perspective of two groups of postgraduate nurses with different levels of experience and with different objectives to be assessed. An NGT procedure was applied to the group discussion. The participants were recruited according to basic factors such as the number of years of professional experience, their level of education, and their preferred professional status. Thus, seventeen professionals participated in the study, representing two public hospitals in the city. Following the NGT procedure, the competencies identified from the thematic analysis were scored and ranked to achieve a consensus. Eight core issues were derived in the novel group concerning transferring the competencies to patient care quality: holism, care work, organizational barriers, specialization, no transfer, confidence, knowledge, and instrumental tools. Four core issues were derived when asked about the relationship between the resources invested and the organizational and professional development of the nursing staff: professional development, positive learning, negative learning, and recognition. In the more experienced group, seven issues were derived from the first issue raised: continuous learning, quality, confidence, holism, safe care, autonomy, and technical issues. Additionally, six issues arose from the second question: satisfaction, autonomy, creativity, productivity, professional development, and recognition. In conclusion, the perceptions of the two selected groups are negative when it comes to assessing the extent to which the competencies acquired in lifelong learning are transferred to the patient and the system evaluates and recognizes these competencies for improvement

    Quantum correlations in the temporal CHSH scenario

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    We consider a temporal version of the CHSH scenario using projective measurements on a single quantum system. It is known that quantum correlations in this scenario are fundamentally more general than correlations obtainable with the assumptions of macroscopic realism and non-invasive measurements. In this work, we also educe some fundamental limitations of these quantum correlations. One result is that a set of correlators can appear in the temporal CHSH scenario if and only if it can appear in the usual spatial CHSH scenario. In particular, we derive the validity of the Tsirelson bound and the impossibility of PR-box behavior. The strength of possible signaling also turns out to be surprisingly limited, giving a maximal communication capacity of approximately 0.32 bits. We also find a temporal version of Hardy's nonlocality paradox with a maximal quantum value of 1/4.Comment: corrected versio

    Gravitational radiation from the magnetic field of a strongly magnetized star

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    We consider the electromagnetic (e.m.) field of a compact strongly magnetized star. The star is idealized as a perfect conducting sphere, rigidly rotating in a vacuum, with a magnetic moment not aligned with its rotation axis. Then we use the exterior e.m. solution, obtained by Deutsch (1955) in his classic paper, to calculate the gravitational waves emitted by the e.m. field when its wavelength is much longer than the radius of the star. In some astrophysical situations, this gravitational radiation can overcome the quadrupole one emitted by the matter of the star, and, for some magnetars, would be detectable in the near future, once the present detectors, planned or under construction, become operative.Lapiedra Civera, Ramon, [email protected]

    Cosmic censorship conjecture in some matching spherical collapsing metrics

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    A physically plausible Lemaître-Tolman-Bondi collapse in the marginally bound case is considered. By 'physically plausible,' we mean that the corresponding metric is C1 matched at the collapsing star surface and further that its intrinsic energy is, as due, stationary and finite. It is proved for this Lemaître-Tolman-Bondi collapse, for some parameter values, that its intrinsic central singularity is globally naked, thus violating the cosmic censorship conjecture with, for each direction, one photon, or perhaps a pencil of photons, leaving the singularity and reaching the null infinity. Our result is discussed in relation to some other cases in the current literature on the subject in which some of the central singularities are globally naked, too

    Intrinsic energy of Lemaître-Tolman-Bondi models and cosmological implications

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    Recently, some Lemaître-Tolman-Bondi metrics have been considered as models alternative to the dark energy within the Friedmann-Lemaître-Robertson-Walker universes. The vanishing of the intrinsic energy of these metrics is examined since such a vanishing, in the present case and in general, could be interpreted as a necessary condition to consider the possibility of the quantum creation of a metric. More specifically, this vanishing is examined in the particular case where the Lemaître-Tolman-Bondi metrics behave asymptotically like a Friedmann-Lemaître-Robertson-Walker universe. Finally, we deal with a particular model ruled out after being confronted with cosmic observations. In a minimal agreement with this negative result, leaving aside an unstable case, the value of the intrinsic energy of this particular model does not vanish and becomes in fact minus infinite

    Direct Interactions in Relativistic Statistical Mechanics

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    Directly interacting particles are considered in the multitime formalism of predictive relativistic mechanics. When the equations of motion leave a phase-space volume invariant, it turns out that the phase average of any first integral, covariantly defined as a flux across a 7n7n-dimensional surface, is conserved. The Hamiltonian case is discussed, a class of simple models is exhibited, and a tentative definition of equilibrium is proposed.Comment: Plain Tex file, 26 page

    Proliferative multifocal leukoplakia better name that proliferative verrucous leukoplakia

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    In this letter I propose the name "Proliferative Multifocal Leukoplakia" with the goal of reducing under-diagnosis of this disease, improve the early diagnosis, try to make an early therapy and control, and prevent its malignant transformation

    Classical relativistic statistical mechanics: The case of a hot dilute plasma

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    Starting from predictive relativistic mechanics we develop a classical relativistic statistical mechanics. For a system of N particles, the basic distribution function depends, in addition to the 6N coordinates and velocities, on N times, instead of a single one as in the usual statistical mechanics. This generalized distribution function obeys N (instead of 1) continuity equations, which give rise to N Liouville equations in the case of a dilute plasma (i.e., to lowest, nonzero order in the charges). Hence, the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy for the reduced generalized distribution functions is derived. A relativistic Vlasov equation is obtained in this way. Thermal equilibrium is then considered for a dilute plasma. The calculation is explicitly worked out for a weakly relativistic plasma, up to order 1/c2, and known results are recovered
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