419 research outputs found

    A clinical-psychological perspective on somatization among immigrants: a systematic review

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    Background: Somatic and psychopathological conditions (e.g., anxiety, depression, post-traumatic stress disorder, and somatization) are frequent among immigrants belonging to various ethnic groups. Worldwide findings on the epidemiology regarding specific mental conditions still vary with respect to different migration samples and migration contexts. This inconsistency also holds true in the incidence of somatization among migrants. We carried out a systematic review analyzing the relationship between migration and somatization by providing a qualitative data synthesis of original research articles on the topic. Methods: According to PRISMA guidelines, we conducted a systematic search of the literature on PubMed, Scopus, ISI Web of Science, PsycINFO, Google Scholar, and ScienceDirect. The articles were selected using multiple combinations of relevant search terms (e.g., defined somatization and related disorders, and migration status). Each database was searched systematically from January 2000 to December 2017. Results: The initial search identified 338 records, of which 42 research reports met the predefined inclusion criteria and were analyzed. Most studies (n = 38; 90%) were cross-sectional. The main findings of this study are that migrants with somatization exhibited more psychological distress, had an increased perceived need for healthcare service utilization, and reported more post-migration living difficulties and/or post-traumatic stress disorder than those without somatization. It was also found that specific individual features mediate the association between somatization and migration. The prevalence and correlates of somatization were found to vary across the immigrant groups, depending on cultural variation in reasons for migration, stress exposure, explanatory models of illness, coping, and other individual variables. Conclusion: Somatization is a challenge for health professionals due to its vague nature. In this regard, clinical management of immigrant patients should include further efforts to address emotional distress, with special attention to social, cultural, and linguistic differences

    Mapping the spin-dependent electron reflectivity of Fe and Co ferromagnetic thin films

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    Spin Polarized Low Energy Electron Microscopy is used as a spin dependent spectroscopic probe to study the spin dependent specular reflection of a polarized electron beam from two different magnetic thin film systems: Fe/W(110) and Co/W(110). The reflectivity and spin-dependent exchange-scattering asymmetry are studied as a function of electron kinetic energy and film thickness, as well as the time dependence. The largest value of the figure of merit for spin polarimetry is observed for a 5 monolayer thick film of Co/W(110) at an electron kinetic energy of 2eV. This value is 2 orders of magnitude higher than previously obtained with state of the art Mini-Mott polarimeter. We discuss implications of our results for the development of an electron-spin-polarimeter using the exchange-interaction at low energy.Comment: 5 pages, 4 figure

    Tracking Cooper Pairs in a Cuprate Superconductor by Ultrafast Angle-Resolved Photoemission

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    In high-temperature superconductivity, the process that leads to the formation of Cooper pairs, the fundamental charge carriers in any superconductor, remains mysterious. We use a femtosecond laser pump pulse to perturb superconducting Bi2Sr2CaCu2O8+{\delta}, and study subsequent dynamics using time- and angle-resolved photoemission and infrared reflectivity probes. Gap and quasiparticle population dynamics reveal marked dependencies on both excitation density and crystal momentum. Close to the d-wave nodes, the superconducting gap is sensitive to the pump intensity and Cooper pairs recombine slowly. Far from the nodes pumping affects the gap only weakly and recombination processes are faster. These results demonstrate a new window into the dynamical processes that govern quasiparticle recombination and gap formation in cuprates.Comment: 22 pages, 9 figure

    Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene

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    We study the broadband optical conductivity and ultrafast carrier dynamics of epitaxial graphene in the few-layer limit. Equilibrium spectra of nominally buffer, monolayer, and multilayer graphene exhibit significant terahertz and near-infrared absorption, consistent with a model of intra- and interband transitions in a dense Dirac electron plasma. Non-equilibrium terahertz transmission changes after photoexcitation are shown to be dominated by excess hole carriers, with a 1.2-ps mono-exponential decay that reflects the minority-carrier recombination time.Comment: 4 pages, 3 figures, final versio

    Ultrafast Dynamics of Vibrational Symmetry Breaking in a Charge-ordered Nickelate

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    The ability to probe symmetry breaking transitions on their natural time scales is one of the key challenges in nonequilibrium physics. Stripe ordering represents an intriguing type of broken symmetry, where complex interactions result in atomic-scale lines of charge and spin density. Although phonon anomalies and periodic distortions attest the importance of electron-phonon coupling in the formation of stripe phases, a direct time-domain view of vibrational symmetry breaking is lacking. We report experiments that track the transient multi-THz response of the model stripe compound La1.75_{1.75}Sr0.25_{0.25}NiO4_{4}, yielding novel insight into its electronic and structural dynamics following an ultrafast optical quench. We find that although electronic carriers are immediately delocalized, the crystal symmetry remains initially frozen - as witnessed by time-delayed suppression of zone-folded Ni-O bending modes acting as a fingerprint of lattice symmetry. Longitudinal and transverse vibrations react with different speeds, indicating a strong directionality and an important role of polar interactions. The hidden complexity of electronic and structural coupling during stripe melting and formation, captured here within a single terahertz spectrum, opens new paths to understanding symmetry breaking dynamics in solids.Comment: 21 pages, 4 figures; updated version with journal re
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