Evidence for competition between the superconducting and the pseudogap state in (BiPb)_2(SrLa)_2CuO_{6+\delta} from muon-spin rotation experiments

The in-plane magnetic penetration depth \lambda_{ab} in optimally doped (BiPb)_2(SrLa)_2CuO_{6+\delta} (OP Bi2201) was studied by means of muon-spin rotation. The measurements of \lambda_{ab}^{-2}(T) are inconsistent with a simple model of a d-wave order parameter and a uniform quasiparticle weight around the Fermi surface. The data are well described assuming the angular gap symmetry obtained in ARPES experiments [Phys. Rev. Lett {\bf 98}, 267004 (2007)], where it was shown that the superconducting gap in OP Bi2201 exists only in segments of the Fermi surface near the nodes. We find that the remaining parts of the Fermi surface, which are strongly affected by the pseudogap state, do not contribute significantly to the superconducting condensate. Our data provide evidence that high temperature superconductivity and pseudogap behavior in cuprates are competing phenomena.Comment: 5 pages, 3 figure

Zero-field superfluid density in d-wave superconductor evaluated from the results of muon-spin-rotation experiments in the mixed state

We report on measurements of the in-plane magnetic penetration \lambda_{ab} in the optimally doped cuprate superconductor (BiPb)_2(SrLa)_2CuO_6+\delta (OP Bi2201) by means of muon-spin rotation (\muSR). We show that in unconventional $d-$wave superconductors (like OP Bi2201), \muSR experiments conducted in various magnetic fields allow to evaluate the zero-field magnetic penetration depth \lambda_0, which relates to the zero-field superfluid density in terms of \rho_s\propto\lambda_0^-2.Comment: 4 pages, 5 figure

A global simulation for laser driven MeV electrons in 50μm50\mu m-diameter fast ignition targets

The results from 2.5-dimensional Particle-in-Cell simulations for the interaction of a picosecond-long ignition laser pulse with a plasma pellet of 50-$\mu m$ diameter and 40 critical density are presented. The high density pellet is surrounded by an underdense corona and is isolated by a vacuum region from the simulation box boundary. The laser pulse is shown to filament and create density channels on the laser-plasma interface. The density channels increase the laser absorption efficiency and help generate an energetic electron distribution with a large angular spread. The combined distribution of the forward-going energetic electrons and the induced return electrons is marginally unstable to the current filament instability. The ions play an important role in neutralizing the space charges induced by the the temperature disparity between different electron groups. No global coalescing of the current filaments resulted from the instability is observed, consistent with the observed large angular spread of the energetic electrons.Comment: 9 pages, 6 figures, to appear in Physics of Plasmas (May 2006

Audio mixing in a tri-port nano-electro-mechanical device

We report on experiments performed on a cantilever-based tri-port nano-electro-mechanical (NEMS) device. Two ports are used for actuation and detection through the magnetomotive scheme, while the third port is a capacitively coupled gate electrode. By applying a low frequency voltage signal on the gate, we demonstrate mixing in the mechanical response of the device, even for {\it low magnetomotive drives, without resorting to conduction measurements through the NEMS}. The technique can thus be used in particular in the linear regime, as an alternative to nonlinear mixing, for normal conducting devices. An analytic theory is presented reproducing the data without free parameter

Evidence of resonant surface wave excitation in the relativistic regime through measurements of proton acceleration from grating targets

The interaction of laser pulses with thin grating targets, having a periodic groove at the irradiated surface, has been experimentally investigated. Ultrahigh contrast ($\sim 10^{12}$) pulses allowed to demonstrate an enhanced laser-target coupling for the first time in the relativistic regime of ultra-high intensity >10^{19} \mbox{W/cm}^{2}. A maximum increase by a factor of 2.5 of the cut-off energy of protons produced by Target Normal Sheath Acceleration has been observed with respect to plane targets, around the incidence angle expected for resonant excitation of surface waves. A significant enhancement is also observed for small angles of incidence, out of resonance.Comment: 5 pages, 5 figures, 2nd version implements final correction

Utilization of Wellness Practices For Burnout and Stress During COVID-19 Among an Interdisciplinary Cohort of Emergency Healthcare Workers

Introduction: The Coronavirus Disease (COVID-19) introduced additional stress to the baseline occupational stressors of emergency care workers. The objectives of this study were to evaluate perceived stress and burnout and the utilization and perceived benefit of wellness practices among emergency healthcare workers (EHCWs), including: emergency physicians, advanced practice providers (APPs), nurses, and departmental administrative staff during the COVID-19 pandemic. Methods: A cross-sectional 28-item electronic survey of EHCWs at three hospitals in a major United States city was used to measure participants’ utilization and perceived benefit of wellness practices, burnout (2-item measure), overall stress (perceived stress scale), and stress related to COVID-19. Results: The sample consisted of 260 respondents (response rate 44.6%, 583 eligible). Over one-half (56.5%) reported burnout from their job and a majority (58.5%) reported moderate to high stress. Wellness activities including regular exercise and engaging in hobbies were associated with lower reports of burnout. Higher stress levels were reported by participants who had tested positive for COVID-19. Nurses reported the highest rates of burnout overall (80.6%). Females reported higher rates of burnout than males across the cohort (64.5 vs 41.9%, p = 0.001), and female APPs reported significantly higher burnout than did male APPs (69.2 vs 38.5%, p = 0.048). Participants reported donated personal protective equipment (PPE) and meals on shift were extremely helpful. Conclusion: The COVID-19 pandemic was a significant contributor to the stress of EHCWs. Regular engagement in wellness activities was associated with lower rates of burnout. The benefit of engagement in wellness practices, both individual practices and organizational interventions are paramount to mitigate stress and burnout in EHCWs

A Comprehensive Residency Wellness Curriculum

Introduction: Resident physician burnout is an epidemic in medical education. There are several wellness curricula published, but few describe a comprehensive program to address wellness. Our objectives were to develop and pilot a longitudinal resident wellness curriculum and assess for feasibility and sustainability. Methods: We surveyed emergency medicine (EM) residents from two residency programs in the United States to assess a baseline level of burnout using the Maslach Burnout Inventory. We developed a comprehensive and longitudinal wellness curriculum for EM residents that incorporated all domains identified by the American College of Emergency Physicians Wellness Wheel. Mindfulness practice was incorporated throughout the curriculum. Results: A convenience sample of 106 EM residents were sent the baseline survey. A response rate of 69% was achieved, the median age of the respondents was 29 years, and 44.5% were female. Overall, 67.5% (95% CI: 50.5; 80.8%) reported burnout in at least one of the three domains of the Maslach Burnout inventory. 34.8% reported burnout in the personal accomplishment domain, 40.8% reported depersonalization, and 44.3% reported emotional exhaustion. The wellness curriculum was successfully implemented at the Georgia-based residency program. The curriculum has proven to be sustainable since it began in 2016. Quantitative statistical testing for the post-intervention survey was not possible due to a low response rate. However, subjective receivability was high, with participants describing these sessions as high-yield, informative and practical. Conclusions: Burnout is highly prevalent among EM residents. We provide a curriculum developed for an EM residency program that is multifaceted and comprehensive, including basic wellness topics, mindfulness, financial and medicolegal issues, as well as topics that address the stresses specific to clinical emergency medicine. The curriculum has been in place in its current form since 2016 and has proven to be sustainable