9,431 research outputs found

    Computerized Response Inhibition Training For Children With Trichotillomania

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    Evidence suggests that trichotillomania is characterized by impairment in response inhibition, which is the ability to suppress pre-potent/dominant but inappropriate responses. This study sought to test the feasibility of computerized response inhibition training for children with trichotillomania. Twenty-two children were randomized to the 8-session response inhibition training (RIT; n = 12) or a waitlisted control (WLT; n = 10). Primary outcomes were assessed by an independent evaluator, using the Clinical Global Impression-Improvement (CGI-I), and the NIMH Trichotillomania Severity (NIMH-TSS) and Impairment scales (NIMH-TIS) at pre, post-training/waiting, and 1-month follow-up. Relative to the WLT group, the RIT group showed a higher response rate (55% vs. 11%) on the CGI-I and a lower level of impairment on the NIMH-TIS, at post-training. Overall symptom reductions rates on the NIMH-TSS were 34% (RIT) vs. 21% (WLT) at post-training. The RIT\u27s therapeutic gains were maintained at 1-month follow-up, as indicated by the CGI-I responder status (= 66%), and a continuing reduction in symptom on the NIMH-TSS. This pattern of findings was also replicated by the 6 waitlisted children who received the same RIT intervention after post-waiting assessment. Results suggest that computerized RIT may be a potentially useful intervention for trichotillomania

    Agility of vortex-based nanocontact spin torque oscillators

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    We study the agility of current-tunable oscillators based on a magnetic vortex orbiting around a point contact in spin-valves. Theory predicts frequency-tuning by currents occurs at constant orbital radius, so an exceptional agility is anticipated. To test this, we have inserted an oscillator in a microwave interferometer to apply abrupt current variations while time resolving its emission. Using frequency shift keying, we show that the oscillator can switch between two stabilized frequencies differing by 25% in less than ten periods. With a wide frequency tunability and a good agility, such oscillators possess desirable figures of merit for modulation-based rf applications.Comment: 3 pages, 3 figure

    Frequency shift keying in vortex-based spin torque oscillators

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    Vortex-based spin-torque oscillators can be made from extended spin valves connected to an electrical nanocontact. We study the implementation of frequency shift keying modulation in these oscillators. Upon a square modulation of the current in the 10 MHz range, the vortex frequency follows the current command, with easy identification of the two swapping frequencies in the spectral measurements. The frequency distribution of the output power can be accounted for by convolution transformations of the dc current vortex waveform, and the current modulation. Modeling indicates that the frequency transitions are phase coherent and last less than 25 ns. Complementing the multi-octave tunability and first-class agility, the capability of frequency shift keying modulation is an additional milestone for the implementation of vortex-based oscillators in RF circuit.Comment: 6 pages, 5 figure

    Current-driven vortex oscillations in metallic nanocontacts

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    We present experimental evidence of sub-GHz spin-transfer oscillations in metallic nano-contacts that are due to the translational motion of a magnetic vortex. The vortex is shown to execute large-amplitude orbital motion outside the contact region. Good agreement with analytical theory and micromagnetics simulations is found.Comment: 4 pages, 3 figure

    Antibodies to combat viral infections: development strategies and progress.

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    Monoclonal antibodies (mAbs) are appealing as potential therapeutics and prophylactics for viral infections owing to characteristics such as their high specificity and their ability to enhance immune responses. Furthermore, antibody engineering can be used to strengthen effector function and prolong mAb half-life, and advances in structural biology have enabled the selection and optimization of potent neutralizing mAbs through identification of vulnerable regions in viral proteins, which can also be relevant for vaccine design. The COVID-19 pandemic has stimulated extensive efforts to develop neutralizing mAbs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with several mAbs now having received authorization for emergency use, providing not just an important component of strategies to combat COVID-19 but also a boost to efforts to harness mAbs in therapeutic and preventive settings for other infectious diseases. Here, we describe advances in antibody discovery and engineering that have led to the development of mAbs for use against infections caused by viruses including SARS-CoV-2, respiratory syncytial virus (RSV), Ebola virus (EBOV), human cytomegalovirus (HCMV) and influenza. We also discuss the rationale for moving from empirical to structure-guided strategies in vaccine development, based on identifying optimal candidate antigens and vulnerable regions within them that can be targeted by antibodies to result in a strong protective immune response

    Auto-oscillation threshold and line narrowing in MgO-based spin-torque oscillators

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    We present an experimental study of the power spectrum of current-driven magnetization oscillations in MgO tunnel junctions under low bias. We find the existence of narrow spectral lines, down to 8 MHz in width at a frequency of 10.7 GHz, for small applied fields with clear evidence of an auto-oscillation threshold. Micromagnetics simulations indicate that the excited mode corresponds to an edge mode of the synthetic antiferromagnet

    Cross-talk compensation of hyperfine control in donor qubit architectures

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    We theoretically investigate cross-talk in hyperfine gate control of donor-qubit quantum computer architectures, in particular the Kane proposal. By numerically solving the Poisson and Schr\"{o}dinger equations for the gated donor system, we calculate the change in hyperfine coupling and thus the error in spin-rotation for the donor nuclear-electron spin system, as the gate-donor distance is varied. We thus determine the effect of cross-talk - the inadvertent effect on non-target neighbouring qubits - which occurs due to closeness of the control gates (20-30nm). The use of compensation protocols is investigated, whereby the extent of crosstalk is limited by the application of compensation bias to a series of gates. In light of these factors the architectural implications are then considered.Comment: 15 pages, 22 figures, submitted to Nanotechnolog

    The strong coupling constant from lattice QCD with N_f=2 dynamical quarks

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    We compute ΛMSˉ\Lambda_{\bar{MS}} for two flavors of light dynamical quarks using non-perturbatively O(a)O(a) improved Wilson fermions. We improve on a recent calculation by employing Pad\'e-improved two-loop and three-loop perturbation theory to convert the lattice numbers to the MSˉ\bar{MS} scheme.Comment: Contribution to Lattice 2001 (matrix elements), typo correcte
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