589 research outputs found

    Serious interface design for dental health: Wiimote-based tangible interaction for school children

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    This paper describes a camera-based approach towards creating a tangible interface for serious games. We introduce our game for dental health targeted at school children which implements the Nintendo WiiMote as infrared camera. Paired with a gesture-recognition system, this combination allows us to apply real-world items as input devices. Thereby, the game tries to address different aspects of dental hygiene along with the improvement of children's motor skills. In our focus group test, we found that tangible interfaces offer great potential for educational purposes and can be used to engage kids in a playful learning process by addressing their childlike curiosity and fostering implicit learning

    Whose ethos? Whose ethics?: the contributions of Anabaptist theology and ethics to contemporary biomedical ethics

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    This dissertation argues for the inclusion of Radical Reformation Theology into the discussion of contemporary biomedical ethics. Historically, Anabaptist/Mennonite theology has not had a place in the development of biomedical ethics. Catholic moral theology and various definitions of Protestant theological ethics have shaped the field of biomedical ethics alongside several important philosophical theories. A combination of such theological and philosophical theories of biomedical ethics has been the result of the Belmont Report and has later been expanded into The Four Principles of Biomedical Ethics with its focus on autonomy, beneficence, maleficence, and justice.However, the empirical research among Anabaptist/Mennonite physicians shows that such theories do not make adequate reference to Anabaptist/Mennonite theology and ethics and its approach to agent-based virtue ethics. This theology emphasises servanthood as the model for the physician, peace and non-violent justice as the modus operandi for this servanthood model, and community as the sustaining and sending forum for such servanthood. If these perspectives were included in the contemporary discussion of biomedical ethics, the virtuous agent would be enabled to embody a reconciling relationship the physician with the patient and vice versa. In Anabaptist/Mennonite theology, agency formation has high priority and happens through the model of observation-participation embodiment. Theology is therefore observed, participated in, and embodied by the individual agent within the setting of community.Such an agent-focused approach that seeks consensus in biomedical ethics would help to balance a principled approach that seeks to find the lowest common denominator. This agent-based approach could also aid in the process of uncovering the blind spots of contemporary biomedical ethics such as injustices in health care access and resource allocation, discriminatory policy-making, and the favouring of a largely utilitarian-deontological pragmatism in biomedical ethics.The voice of Anabaptist/Mennonite theology is comparatively young, and barely experienced enough, to be heard loudly. However, the adolescent voice of this theology of embodiment may have broken, and a sustainable vision for an Anabaptist/Mennonite biomedical ethics might hopefully be found in the pages of this research

    Polarization Suppression and Nonmonotonic Local Two-Body Correlations in the Two-Component Bose Gas in One Dimension

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    We study the interplay of quantum statistics, strong interactions and finite temperatures in the two-component (spinor) Bose gas with repulsive delta-function interactions in one dimension. Using the Thermodynamic Bethe Ansatz, we obtain the equation of state, population densities and local density correlation numerically as a function of all physical parameters (interaction, temperature and chemical potentials), quantifying the full crossover between low-temperature ferromagnetic and high-temperature unpolarized regimes. In contrast to the single-component, Lieb-Liniger gas, nonmonotonic behaviour of the local density correlation as a function of temperature is observed.Comment: 4 pages, 6 figure

    Universal phase shift and non-exponential decay of driven single-spin oscillations

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    We study, both theoretically and experimentally, driven Rabi oscillations of a single electron spin coupled to a nuclear spin bath. Due to the long correlation time of the bath, two unusual features are observed in the oscillations. The decay follows a power law, and the oscillations are shifted in phase by a universal value of ~pi/4. These properties are well understood from a theoretical expression that we derive here in the static limit for the nuclear bath. This improved understanding of the coupled electron-nuclear system is important for future experiments using the electron spin as a qubit.Comment: Main text: 4 pages, 3 figures, Supplementary material: 2 pages, 3 figure

    Equilibrium thermodynamic properties of interacting two-component bosons in one dimension

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    The interplay of quantum statistics, interactions and temperature is studied within the framework of the bosonic two-component theory with repulsive delta-function interaction in one dimension. We numerically solve the thermodynamic Bethe Ansatz and obtain the equation of state as a function of temperature and of the interaction strength, the relative chemical potential and either the total chemical potential or a fixed number of particles, allowing to quantify the full crossover behaviour of the system between its low-temperature ferromagnetic and high-temperature unpolarized regime, and from the low coupling decoherent regime to the fermionization regime at high interaction.Comment: 17 pages, 8 figure

    Theory of excitons in cubic III-V semiconductor GaAs, InAs and GaN quantum dots: fine structure and spin relaxation

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    Exciton fine structures in cubic III-V semiconductor GaAs, InAs and GaN quantum dots are investigated systematically and the exciton spin relaxation in GaN quantum dots is calculated by first setting up the effective exciton Hamiltonian. The electron-hole exchange interaction Hamiltonian, which consists of the long- and short-range parts, is derived within the effective-mass approximation by taking into account the conduction, heavy- and light-hole bands, and especially the split-off band. The scheme applied in this work allows the description of excitons in both the strong and weak confinement regimes. The importance of treating the direct electron-hole Coulomb interaction unperturbatively is demonstrated. We show in our calculation that the light-hole and split-off bands are negligible when considering the exciton fine structure, even for GaN quantum dots, and the short-range exchange interaction is irrelevant when considering the optically active doublet splitting. We point out that the long-range exchange interaction, which is neglected in many previous works, contributes to the energy splitting between the bright and dark states, together with the short-range exchange interaction. Strong dependence of the optically active doublet splitting on the anisotropy of dot shape is reported. Large doublet splittings up to 600 μ\mueV, and even up to several meV for small dot size with large anisotropy, is shown in GaN quantum dots. The spin relaxation between the lowest two optically active exciton states in GaN quantum dots is calculated, showing a strong dependence on the dot anisotropy. Long exciton spin relaxation time is reported in GaN quantum dots. These findings are in good agreement with the experimental results.Comment: 22+ pages, 16 figures, several typos in the published paper are corrected in re

    SN 2013df, a double-peaked IIb supernova from a compact progenitor and an extended H envelope

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    Optical observations of the type IIb SN 2013df from a few days to about 250 days after explosion are presented. These observations are complemented with UV photometry taken by \textit{SWIFT} up to 60 days post-explosion. The double-peak optical light curve is similar to those of SNe 1993J and 2011fu although with different decline and rise rates. From the modelling of the bolometric light curve, we have estimated that the total mass of synthesised 56^{56}Ni in the explosion is 0.1\sim0.1 M_{\odot}, while the ejecta mass is 0.81.40.8-1.4 M_{\odot} and the explosion energy 0.41.2×10510.4-1.2 \times 10^{51}erg. In addition, we have estimated a lower limit to the progenitor radius ranging from 6416964-169 RR_{\odot}. The spectral evolution indicates that SN 2013df had a hydrogen envelope similar to SN 1993J (0.2\sim 0.2 M_{\odot}). The line profiles in nebular spectra suggest that the explosion was asymmetric with the presence of clumps in the ejecta, while the [O\,{\sc i}] λ\lambdaλ\lambda63006300, 63646364 luminosities, may indicate that the progenitor of SN 2013df was a relatively low mass star ( 1213\sim 12-13 M_{\odot}).Comment: 18 pages, 11 figures, 9 tables, accepted for publication in MNRA

    Sonoelastography of the Common Flexor Tendon of the Elbow with Histologic Agreement: A Cadaveric Study.

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    Purpose To determine the correlation of the results of conventional B-mode ultrasonography (US) and compression sonoelastography with histologic results in common flexor tendons of the elbow in human cadavers. Materials and Methods Twenty-five common flexor tendons were evaluated in 16 fresh, unembalmed cadavers of 11 women with a median age of 85 years (range, 71-101 years) and five men with a median age of 78 years (range, 70-88 years). Informed consent was provided according to the last will of the donors. B-mode US results were classified as grade 1, normal tendon with homogeneous fibrillar pattern; grade 2, tendon thickening or hypoechoic areas and/or calcifications in less than 30% of the tendon; or grade 3, hypoechoic areas and/or calcifications greater than 30% of the tendon. Sonoelastographic results were grade 1, blue (hardest) to green (hard); grade 2, yellow (soft); and grade 3, red (softest). The intraclass correlation coefficient was calculated to determine agreement with histologic findings for each B-mode US, sonoelastographic, and combined B-mode US and sonoelastographic examination. Histologic results were grade 1, normal, with parallel fibrillar pattern; grade 2, mild tendinopathy, with cellular infiltration, angiogenesis, or fatty vacuoles; or grade 3, severe tendinopathy, with loss of parallel collagen structure and necrosis. Results Histologic alterations were detected in 44% (11 of 25) of biopsy specimens. Intraclass correlation with histologic results was 0.57 for B-mode US, 0.68 for sonoelastography, and 0.84 for the combination of the two approaches. Conclusion The addition of sonoelastography to B-mode US provided statistically significant improvement in correlation with histologic results compared with the use of B-mode US alone (P \u3c .02). (©) RSNA, 2016 Online supplemental material is available for this article

    Timely N-Acetyl-Cysteine and Environmental Enrichment Rescue Oxidative Stress-Induced Parvalbumin Interneuron Impairments via MMP9/RAGE Pathway: A Translational Approach for Early Intervention in Psychosis.

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    Research in schizophrenia (SZ) emphasizes the need for new therapeutic approaches based on antioxidant/anti-inflammatory compounds and psycho-social therapy. A hallmark of SZ is a dysfunction of parvalbumin-expressing fast-spiking interneurons (PVI), which are essential for neuronal synchrony during sensory/cognitive processing. Oxidative stress and inflammation during early brain development, as observed in SZ, affect PVI maturation. We compared the efficacy of N-acetyl-cysteine (NAC) and/or environmental enrichment (EE) provided during juvenile and/or adolescent periods in rescuing PVI impairments induced by an additional oxidative insult during childhood in a transgenic mouse model with gluthation deficit (Gclm KO), relevant for SZ. We tested whether this rescue was promoted by the inhibition of MMP9/RAGE mechanism, both in the mouse model and in early psychosis (EP) patients, enrolled in a double-blind, randomized, placebo-controlled clinical trial of NAC supplementation for 6 months. We show that a sequential combination of NAC+EE applied after an early-life oxidative insult recovers integrity and function of PVI network in adult Gclm KO, via the inhibition of MMP9/RAGE. Six-month NAC treatment in EP patients reduces plasma sRAGE in association with increased prefrontal GABA, improvement of cognition and clinical symptoms, suggesting similar neuroprotective mechanisms. The sequential combination of NAC+EE reverses long-lasting effects of an early oxidative insult on PVI/perineuronal net (PNN) through the inhibition of MMP9/RAGE mechanism. In analogy, patients vulnerable to early-life insults could benefit from a combined pharmacological and psycho-social therapy
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