137 research outputs found

    Longitudinal links between adolescent social anxiety and depressive symptoms: testing the mediational effects of cybervictimization

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    This study focuses on the temporal sequence between social anxiety and depressive symptoms, and whether cybervictimization might mediate these links. We used a longitudinal sample of 501 early adolescents (51.9% girls; Mage = 13.96) followed at three time points. Using a cross-lagged path model in MPlus, we found that social anxiety predicted depressive symptoms over time, but not the other way around. Time-1 depressive symptoms also predicted cybervictimization, but only for boys and not for girls. No mediating effects of cybervictimization emerged; however, Time-2 social anxiety was a significant mediator between Time-1 social anxiety and depressive symptoms, whereas Time-2 depressive symptoms significantly mediated the link between Time-1 social anxiety and Time-3 depressive symptoms. In sum, social anxiety was a strong predictor of depressive symptoms over time but not vice versa-irrespective of cybervictimization

    Conductance anisotropy and linear magnetoresistance in La2-xSrxCuO4 thin films

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    We have performed a detailed study of conductance anisotropy and magnetoresistance (MR) of La2-xSrxCuO4 (LSCO) thin films (0.10 < x < 0.25). These two observables are promising for the detection of stripes. Subtle features of the conductance anisotropy are revealed by measuring the transverse resistance Rxy in zero magnetic field. It is demonstrated that the sign of Rxy depends on the orientation of the LSCO Hall bar with respect to the terrace structure of the substrate. Unit-cell-high substrate step edges must therefore be a dominant nucleation source for antiphase boundaries during film growth. We show that the measurement of Rxy is sensitive enough to detect the cubic-tetragonal phase transition of the SrTiO3(100) (STO) substrate at 105 K. The MR of LSCO thin films shows for 0.10 < x < 0.25 a non-monotonic temperature dependence, resulting from the onset of a linear term in the MR above 90 K. We show that the linear MR scales with the absolute Hall resistivity, with the constant of proportionality independent of temperature. Such scaling suggests that the linear MR originates from current distortions induced by structural or electronic inhomogeneities. The possible role of stripes for both the MR and the conductance anisotropy is discussed throughout the paper

    Longitudinal links between adolescent social anxiety and depressive symptoms: stressful experiences at home, in school and with peers

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    Social anxiety and depressive symptoms often co-occur during early adolescence but contributing factors to this development are still a matter of debate. This study examined the role of daily stressors (peers, school and homelife) in the links between adolescent social anxiety and depressive symptoms. 7-8th graders at Time 1 (N = 2,752, Mage = 13.65; 47.5% girls) were followed across three time-points. Cross-lagged path models showed that depressive symptoms predicted later social anxiety, but not vice versa. Bidirectional links were identified between peer stress and social anxiety, and between school/homelife stress and depressive symptoms, respectively. Indirect effects of social anxiety, depressive symptoms, and daily stressors were found, though stressors did not mediate the links between social anxiety and depressive symptoms (or vice versa). Our findings indicate an intricate role of daily stressors in different domains on the links between social anxiety and depressive symptoms

    Evaluating immersive teleoperation interfaces: coordinating robot radiation monitoring tasks in nuclear facilities

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    We present a virtual reality (VR) teleoperation interface for a ground-based robot, featuring dense 3D environment reconstruction and a low latency video stream, with which operators can immersively explore remote environments. At the UK Atomic Energy Authority's (UKAEA) Remote Applications in Challenging Environments (RACE) facility, we applied the interface in a user study where trained robotics operators completed simulated nuclear monitoring and decommissioning style tasks to compare VR and traditional teleoperation interface designs. We found that operators in the VR condition took longer to complete the experiment, had reduced collisions, and rated the generated 3D map with higher importance when compared to non-VR operators. Additional physiological data suggested that VR operators had a lower objective cognitive workload during the experiment but also experienced increased physical demand. Overall the presented results show that VR interfaces may benefit work patterns in teleoperation tasks within the nuclear industry, but further work is needed to investigate how such interfaces can be integrated into real world decommissioning workflows

    Evaluating Immersive Teleoperation Interfaces: Coordinating Robot Radiation Monitoring Tasks in Nuclear Facilities

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    We present a virtual reality (VR) teleoperation interface for a ground-based robot, featuring dense 3D environment reconstruction and a low latency video stream, with which operators can immersively explore remote environments. At the UK Atomic Energy Authority's (UKAEA) Remote Applications in Challenging Environments (RACE) facility, we applied the interface in a user study where trained robotics operators completed simulated nuclear monitoring and decommissioning style tasks to compare VR and traditional teleoperation interface designs. We found that operators in the VR condition took longer to complete the experiment, had reduced collisions, and rated the generated 3D map with higher importance when compared to non-VR operators. Additional physiological data suggested that VR operators had a lower objective cognitive workload during the experiment but also experienced increased physical demand. Overall the presented results show that VR interfaces may benefit work patterns in teleoperation tasks within the nuclear industry, but further work is needed to investigate how such interfaces can be integrated into real world decommissioning workflows

    FLASHlight MRI in real time - a step towards Star Trek medicine

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    This work describes a dynamic magnetic resonance imaging (MRI) technique for local scanning of the human body with use of a handheld receive coil or coil array. Real-time MRI is based on highly undersampled radial gradient-echo sequences with joint reconstructions of serial images and coil sensitivity maps by regularized nonlinear inversion (NLINV). For this proof-of-concept study, a fixed slice position and field-of-view (FOV) were predefined from the operating console, while a local receive coil (array) is moved across the body—for the sake of simplicity by the subject itself. Experimental realizations with a conventional 3 T magnet comprise dynamic anatomic imaging of the head, thorax and abdomen of healthy volunteers. Typically, the image resolution was 0.75 to 1.5 mm with 3 to 6 mm section thickness and acquisition times of 33 to 100 ms per frame. However, spatiotemporal resolutions and contrasts are highly variable and may be adjusted to clinical needs. In summary, the proposed FLASHlight MRI method provides a robust acquisition and reconstruction basis for future diagnostic strategies that mimic the usage of ultrasound. Necessary extensions for this vision require remote control of all sequence parameters by a person at the scanner as well as the design of more flexible gradients and magnets
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