825 research outputs found

    Is Touch in Romantic Relationships Universally Beneficial for Psychological Well-Being? The Role of Attachment Avoidance.

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    Affectionate touch is crucial for well-being. However, attachment avoidance is associated with negative attitudes toward touch. We tested two preregistered hypotheses about how attachment avoidance influences the association between touch in romantic couples and psychological well-being. We examined whether greater attachment avoidance is associated with a reduced link between touch and well-being, and/or whether reduced touch mediates the relationship between attachment avoidance and lower well-being. Across three studies, including two dyadic ones, we measured retrospective self-reports (Studies 1 and 2), laboratory observations (Study 2), and daily experiences (Study 3) of touch. Touch and well-being were positively associated, and attachment avoidance was associated with lower well-being and less frequent touch. Touch was associated with greater well-being regardless of level of attachment avoidance, and less frequent touch mediated the negative association between attachment avoidance and well-being in most analyses. This underscores the importance of touch, even for those valuing distance and autonomy

    An integrated approach for analysing and assessing the performance of virtual learning groups

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    Collaborative distance learning involves a variety of elements and factors that have to be considered and measured in order to analyse and assess group and individual performance more effectively and objectively. This paper presents an approach that integrates qualitative, social network analysis (SNA) and quantitative techniques for evaluating online collaborative learning interactions. Integration of various different data sources, tools and techniques provides a more complete and robust framework for group modelling and guarantees a more efficient evaluation of group effectiveness and individual competence. Our research relies on the analysis of a real, long-term, complex collaborative experience, which is initially evaluated in terms of principled criteria and a basic qualitative process. At the end of the experience, the coded student interactions are further analysed through the SNA technique to assess participatory aspects, identify the most effective groups and the most prominent actors. Finally, the approach is contrasted and completed through a statistical technique which sheds more light on the results obtained that far. The proposal draws a well-founded line toward the development of a principled framework for the monitoring and analysis of group interaction and group scaffolding which can be considered a major issue towards the actual application of the CSCL proposals to real classrooms.Peer ReviewedPostprint (author's final draft

    Diagonalization of an Integrable Discretization of the Repulsive Delta Bose Gas on the Circle

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    We introduce an integrable lattice discretization of the quantum system of n bosonic particles on a ring interacting pairwise via repulsive delta potentials. The corresponding (finite-dimensional) spectral problem of the integrable lattice model is solved by means of the Bethe Ansatz method. The resulting eigenfunctions turn out to be given by specializations of the Hall-Littlewood polynomials. In the continuum limit the solution of the repulsive delta Bose gas due to Lieb and Liniger is recovered, including the orthogonality of the Bethe wave functions first proved by Dorlas (extending previous work of C.N. Yang and C.P. Yang).Comment: 25 pages, LaTe

    Absence of Persistent Magnetic Oscillations in Type-II Superconductors

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    We report on a numerical study intended to examine the possibility that magnetic oscillations persist in type II superconductors beyond the point where the pairing self-energy exceeds the normal state Landau level separation. Our work is based on the self-consistent numerical solution for model superconductors of the Bogoliubov-deGennes equations for the vortex lattice state. In the regime where the pairing self-energy is smaller than the cyclotron energy, magnetic oscillations resulting from Landau level quantization are suppressed by the broadening of quasiparticle Landau levels due to the non-uniform order parameter of the vortex lattice state, and by splittings of the quasiparticle bands. Plausible arguments that the latter effect can lead to a sign change of the fundamental harmonic of the magnetic oscillations when the pairing self-energy is comparable to the cyclotron energy are shown to be flawed. Our calculations indicate that magnetic oscillations are strongly suppressed once the pairing self-energy exceeds the Landau level separation.Comment: 7 pages, revtex, 7 postscript figure

    Electrode Polarization Effects in Broadband Dielectric Spectroscopy

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    In the present work, we provide broadband dielectric spectra showing strong electrode polarization effects for various materials, belonging to very different material classes. This includes both ionic and electronic conductors as, e.g., salt solutions, ionic liquids, human blood, and colossal-dielectric-constant materials. These data are intended to provide a broad data base enabling a critical test of the validity of phenomenological and microscopic models for electrode polarization. In the present work, the results are analyzed using a simple phenomenological equivalent-circuit description, involving a distributed parallel RC circuit element for the modeling of the weakly conducting regions close to the electrodes. Excellent fits of the experimental data are achieved in this way, demonstrating the universal applicability of this approach. In the investigated ionically conducting materials, we find the universal appearance of a second dispersion region due to electrode polarization, which is only revealed if measuring down to sufficiently low frequencies. This indicates the presence of a second charge-transport process in ionic conductors with blocking electrodes.Comment: 9 pages, 6 figures, experimental data are provided in electronic form (see "Data Conservancy"

    Factors associated with failed ‘test of cure’ in the NHS cervical screening programme: a retrospective cohort study

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    Objective: To determine predictive factors associated with failed ‘test of cure’ (TOC) in the NHS Cervical Screening Programme (NHSCSP). Methods: Retrospective cohort study of all patients treated by large loop excision of transformation zone (LLETZ) between 1st April 2014 and 1st April 2019. Those with no documented HPV genotype on referral, no TOC outcome, those having a hysterectomy, chemotherapy and/or radiotherapy were excluded from final analysis. Results: Patients referred with a singular HPV genotype of HPV 16, HPV 18, or HPV Other types (HPV O) were significantly more likely to pass TOC than those referred with multiple HPV genotypes (p 51 yrs. and infection with multiple hr-HPV types were predictors of post treatment hr-HPV persistence. Knowledge of HPV genotype both at referral, and following treatment, could allow a more individualised, and patient-centred, approach to both the management and follow up of CIN. HPV genotype should be reported as standard on all cervical screening sample results. The term HPV O should not be utilised and instead actual HPV genotype should be reported. This would enable us to optimise not only future research but would also allow future monitoring of the efficacy of vaccination programmes

    Charged hydrogenic problem in a magnetic field: Non-commutative translations, unitary transformations, and coherent states

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    An operator formalism is developed for a description of charged electron-hole complexes in magnetic fields. A novel unitary transformation of the Hamiltonian that allows one to partially separate the center-of-mass and internal motions is proposed. We study the operator algebra that leads to the appearance of new effective particles, electrons and holes with modified interparticle interactions, and their coherent states in magnetic fields. The developed formalism is used for studying a two-dimensional negatively charged magnetoexciton XX^-. It is shown that Fano-resonances are present in the spectra of internal XX^- transitions, indicating the existence of three-particle quasi-bound states embedded in the continuum of higher Landau levels.Comment: 9 pages + 2 figures, accepted in PRB, a couple of typos correcte

    Lattice Pseudospin Model for ν=1\nu=1 Quantum Hall Bilayers

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    We present a new theoretical approach to the study of ν=1\nu=1 quantum Hall bilayer that is based on a systematic mapping of the microscopic Hamiltonian to an anisotropic SU(4) spin model on a lattice. To study the properties of this model we generalize the Heisenberg model Schwinger boson mean field theory (SBMFT) of Arovas and Auerbach to spin models with anisotropy. We calculate the temperature dependence of experimentally observable quantities, including the spin magnetization, and the differential interlayer capacitance. Our theory represents a substantial improvement over the conventional Hartree-Fock picture which neglects quantum and thermal fluctuations, and has advantages over long-wavelength effective models that fail to capture important microscopic physics at all realistic layer separations. The formalism we develop can be generalized to treat quantum Hall bilayers at filling factor ν=2\nu=2.Comment: 26 pages, 10 figures. The final version, to appear in PR
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