123,637 research outputs found

    Quantum mechanics in finite dimensional Hilbert space

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    The quantum mechanical formalism for position and momentum of a particle in a one dimensional cyclic lattice is constructively developed. Some mathematical features characteristic of the finite dimensional Hilbert space are compared with the infinite dimensional case. The construction of an unbiased basis for state determination is discussed.Comment: 14 pages, no figure

    Reliability of shoulder rotators isometric strength test using a novel pulley electromechanical dynamometer. Influence of the assessment position

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    Indexación: Scopus.Background: The shoulder complex, because of its relatively extensive freedom of motion, offers a great variety of testing positions and articular planes for strength examination. Despite this, reliability of results are not clearly addressed. A novel pulley electromechanical dynamometer (FED) (functional electronic dynamometer) could be an alternative in strength assessment, however, the relative and absolute reliability have not been reported in the literature. Objectives: To report the results of shoulder internal (IR) and rotators (ER) peak torque reliability in two assessment positions by FED in asymptomatic subjects. Methods: Fifty-two healthy college students were included and tested twice within a two week period. In a supine position, the subjects randomly performed four isometric strength tests (i.e. IR at 40°, IR at 90°, ER at 40°, and ER at 90° of shoulder abduction). Results: The intra-class correlation coefficients (ICC) for relative reliability at 90° were 0.96 (0.94-0.98) for IR and 0.94 (0.90-0.96) for ER. ICC at 40° were 0.89 (0.80-0.94) for IR and 0.97 (0.94-0.98) for ER. Absolute reliability expressed as standard error of measurement compared to the mean (SEM%) and 95% confidence interval (CI) of minimal detectable change percentage (MDC%) at 90° were 8.8% (-20.8, 28.4%) and 11.4% (-28.0, 35.2%) for ER. MDC% at 40° were 12.6% (-35.5, 34.8%) for IR and 18.1% (-28.1, 35, 2%) for ER. Conclusions: Isometric strength testing protocol using FED showed an excellent reproducibility and can be safely used in clinical settings to monitor the strength changes in a group of individuals or in a single individual. © 2018, Asian Journal of Sports Medicine.http://asjsm.com/en/articles/60406.htm

    Borderline personality in patients with poly-diagnoses treated for a Bipolar Disorder

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    Some patients with dysphoria, explosive behaviour, or suicidal ideation, may receive a diagnosis of, and treatment for Bipolar Disorder (BD) and, not infrequently. The coexistence of these two diagnoses has been explained in different ways. Some authors include the BPD in the bipolar spectrum; others are sceptical about the existence of real comorbidity, suggesting a misdiagnosis. This study aimed to assess the personality of this group of poly-diagnosed patients (PolyD) and hypothesised they had a pathological borderline organisation. Via the administration of the Schedler Westen Assessment Procedure (SWAP-200), we compared PolyD patients with those suffering from BPD or BD only. We performed two different MANCOVAs to test PolyD, BPD and BD patients' differences in PD-factors, Q-traits and age. The sample comprised 45 patients (Mean age=43.3, SD=15.7; Females 57.7%, N=26). BD patients (N=15) did not present any personality disorder, they had a higher functioning and Obsessive Q-traits, and a lower Histrionic PD-factor than both PolyD (N=20) and BPD (N=10) patients. Compared to PolyD patients, BD had inferior PD-Borderline, PD-Antisocial factor and Dependent-Masochistic Q-traits, but there were no other differences with BPD patients. PolyD did not differ from BPD patients in any of the PD-factors and Q-traits. Our results suggest that PolyD patients are different from BD patients and propose to consider the pathological borderline personality as a central core of their disease

    Quantum mechanical study of molecules - Eigenvalues and eigenvectors of real symmetric matrices

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    Computer methods for calculating eigenvalue and eigenvectors of real symmetric matrices arising in problems of molecular quantum mechanic

    The effect of an isothermal atmosphere on the propagation of three-dimensional waves in a thermally stratified accretion disk

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    We extend our analysis of the three-dimensional response of a vertically polytropic disk to tidal forcing at Lindblad resonances by including the effects of a disk atmosphere. The atmosphere is modeled as an isothermal layer that joins smoothly on to an underlying polytropic layer. The launched wave progressively enters the atmosphere as it propagates away from the resonance. The wave never propagates vertically, however, and the wave energy rises to a (finite) characteristic height in the atmosphere. The increase of wave amplitude associated with this process of wave channeling is reduced by the effect of the atmosphere. For waves of large azimuthal mode number m generated by giant planets embedded in a disk, the increase in wave amplitude is still substantial enough to be likely to dissipate the wave energy by shocks for even modest optical depths (tau greater than about 10) over a radial distance of a few times the disk thickness. For low-m waves generated in circumstellar disks in binary stars, the effects of wave channeling are less important and the level of wave nonlinearity increases by less than a factor of 10 in going from the disk edge to the disk center. For circumbinary disks, the effects of wave channeling remain important, even for modest values of optical depth.Comment: 11 pages, 4 figures, submitted to the Astrophysical Journa
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