Teaching Professional Formation in Response to the COVID-19 Pandemic.

In response to the COVID-19 pandemic, the Association of American Medical Colleges has called for a temporary suspension of clinical teaching activities for medical students. Planning for the continued involvement of learners in patient care during this pandemic should include teaching learners professional formation. The authors provide an ethical framework to guide such teaching, based on the ethical principle of beneficence and the professional virtues of courage and self-sacrifice from professional ethics in medicine. The authors show that these concepts support the conclusion that learners are ethically obligated to accept reasonable, but not unreasonable, risk. Based on this ethical framework, the authors provide an account of the process of teaching professional formation that medical educators and academic leaders should implement. Medical educators and academic leaders should embrace the opportunity that the COVID-19 pandemic presents for teaching professional formation. Learners should acquire the conceptual vocabulary of professional formation. Learners should recognize that risk of infection from patients is unavoidable. Learners should become aware of established ethical standards for professional responsibility during epidemics from the history of medicine. Learners should master understandable fear. Medical educators and academic leaders should ensure that didactic teaching of professional formation continues when it becomes justified to end learners\u27 participation in the processes of patient care; topics should include the professionally responsible management of scarce medical resources. The COVID-19 pandemic will not be the last major infectious disease that puts learners at risk. Professional ethics in medicine provides powerful conceptual tools that can be used as an ethical framework to guide medical educators to teach learners, who will bear leadership responsibilities in responses to future pandemics, professional formation

Second Preliminary Report on X-ray Yields from OMEGA II Targets

We present details about X-ray yields measured with LLNL and SNL diagnostics in soft and moderately hard X-ray bands from laser-driven, doped-aerogel targets shot on 07/14/06 during the OMEGA II test series. Yields accurate to {+-}25% in the 5-15 keV band are measured with Livermore's HENWAY spectrometer. Yields in the sub-keV to 3.2 keV band are measured with LLNL's DANTE diagnostic, the DANTE yields may be 35-40% too large. SNL ran a PCD-based diagnostic that also measured X-ray yields in the spectral region above 4 keV, and also down to the nearly sub-keV range. The PCD and HENWAY and DANTE numbers are compared. The time histories of the X-ray signals are measured with LLNL's H11 PCD, and from two SNL PCDs with comparable filtering. There is a persistent disagreement between the H11 PCD and SNL PCD measured FWHM, which is shown not to be due to analysis techniques. The recommended X-ray waveform is that from the SNL PCD p66k10, which was recorded on a fast, high-bandwidth TDS 6804 oscilloscope, and which are not plotted here

Final Report on X-ray Yields from OMEGA II Targets

We present details about X-ray yields measured with Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL) diagnostics in soft and moderately hard X-ray bands from laser-driven, doped-aerogel targets shot on 07/14/06 during the OMEGA II test series. Yields accurate to {+-}25% in the 5-15 keV band are measured with Livermore's HENWAY spectrometer. Yields in the sub-keV to 3.2 keV band are measured with LLNL's DANTE diagnostic, the DANTE yields are accurate to 10-15%. SNL ran a PCD-based diagnostic that also measured X-ray yields in the spectral region above 4 keV, and also down to the sub-keV range. The PCD and HENWAY and DANTE numbers are compared. The time histories of the moderately hard (h{nu} > 4 keV) X-ray signals are measured with LLNL's H11 PCD, and from two SNL PCDs with comparable filtration. There is general agreement between the H11 PCD and SNL PCD measured FWHM except for two of the shorter-laser-pulse shots, which is shown not to be due to analysis techniques. The recommended X-ray waveform is that from the SNL PCD p66k10, which was recorded on a fast, high-bandwidth TDS 6804 oscilloscope. X-ray waveforms from target emission in two softer spectral bands are also shown; the X-ray emissions have increasing duration as the spectral content gets softer

OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS

We report on recent progress for the development of a new cold X-ray optical test capability using the Omega Facility located at the Laboratory for Laser Energetics (LLE) at the University of Rochester. These tests were done on the 30 kJ OMEGA laser at the Laboratory for Laser Energetics (LLE) at the University of Rochester, Rochester, NY. We conducted a six-shot series called OMEGA II on 14 July 2006 in one eight-hour day (supported by the Defense Threat Reduction Agency). The initial testing was performed using simple protected gold optical coatings on fused silica substrates. PUFFTFT analyses were completed and the specimen's thermal lateral stress and transverse stress conditions were calculated and interpreted. No major anomalies were detected. Comparison of the pre- and posttest reflective measurements coupled with the TFCALC analyses proved invaluable in guiding the analyses and interpreting the observed damage. The Omega facility is a high quality facility for performing evaluation of optical coatings and coupons and provides experience for the development of future National Ignition Facility (NIF) testing

X-ray harmonic comb from relativistic electron spikes

X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright ultrafast coherent X-ray source is highly desirable, for example, for the diffractive imaging of individual large molecules, viruses, or cells. Here we demonstrate experimentally a new compact X-ray source involving high-order harmonics produced by a relativistic-irradiance femtosecond laser in a gas target. In our first implementation using a 9 Terawatt laser, coherent soft X-rays are emitted with a comb-like spectrum reaching the 'water window' range. The generation mechanism is robust being based on phenomena inherent in relativistic laser plasmas: self-focusing, nonlinear wave generation accompanied by electron density singularities, and collective radiation by a compact electric charge. The formation of singularities (electron density spikes) is described by the elegant mathematical catastrophe theory, which explains sudden changes in various complex systems, from physics to social sciences. The new X-ray source has advantageous scalings, as the maximum harmonic order is proportional to the cube of the laser amplitude enhanced by relativistic self-focusing in plasma. This allows straightforward extension of the coherent X-ray generation to the keV and tens of keV spectral regions. The implemented X-ray source is remarkably easily accessible: the requirements for the laser can be met in a university-scale laboratory, the gas jet is a replenishable debris-free target, and the harmonics emanate directly from the gas jet without additional devices. Our results open the way to a compact coherent ultrashort brilliant X-ray source with single shot and high-repetition rate capabilities, suitable for numerous applications and diagnostics in many research fields

Reconstruction of a cold atom cloud by magnetic focusing

No description supplie

Radiative properties of high wire number tungsten arrays with implosion times up to 250 ns

High wire number, 25-mm diameter tungsten wire arrays have been imploded on the 8-MA Saturn generator, operating in a long-pulse mode. By varying the mass load from 710 to 6140 ps/cm, implosion times of 130 to 250 ns have been obtained with implosion velocities of 50 to 25 cn-dys, respectively. These z-pinch implosions produced plasmas with millimeter diameters that radiated 600 to 800 kJ of x-rays, with powers of 20 to 49 TW; the corresponding pulse widths were 19 to 7.5 ns, with risetimes ranging from 6.5 to 4.0 ns. These powers and pulse widths are similar to those achieved with 50 ns implosion times on Saturn. Two-dimensional, radiation- magnetohydrodynamic calculations indicate that the imploding shells in these long implosion time experiments are comparable in width to those in the short pulse cases. This can only be due to lower initial perturbations. A heuristic wire array model suggests that the reduced perturbations, in the long pulse cases, may be due to the individual wire merger occurring well before the acceleration of the shell. The experiments and modeling suggest that 150 to 200 ns implosion time z-pinches could be employed for high-power, x-ray source applications

Radiative Properties of High Wire Number Tungsten Arrays with Implosion Times up to 250 ns

High wire number, 25-mm diameter tungsten wire arrays have been imploded on the 8-MA Saturn generator, operating in a long-pulse mode. By varying the mass load from 710 to 6140 ps/cm, implosion times of 130 to 250 ns have been obtained with implosion velocities of 50 to 25 cn-dys, respectively. These z-pinch implosions produced plasmas with millimeter diameters that radiated 600 to 800 kJ of x-rays, with powers of 20 to 49 TW; the corresponding pulse widths were 19 to 7.5 ns, with risetimes ranging from 6.5 to 4.0 ns. These powers and pulse widths are similar to those achieved with 50 ns implosion times on Saturn. Two-dimensional, radiation- magnetohydrodynamic calculations indicate that the imploding shells in these long implosion time experiments are comparable in width to those in the short pulse cases. This can only be due to lower initial perturbations. A heuristic wire array model suggests that the reduced perturbations, in the long pulse cases, may be due to the individual wire merger occurring well before the acceleration of the shell. The experiments and modeling suggest that 150 to 200 ns implosion time z-pinches could be employed for high-power, x-ray source applications

Allergen specificity of early peanut consumption and effect on development of allergic disease in the Learning Early About Peanut Allergy study cohort

BACKGROUND: Early introduction of dietary peanut in high-risk infants with severe eczema, egg allergy, or both prevented peanut allergy at 5 years of age in the Learning Early About Peanut Allergy (LEAP) study. The protective effect persisted after 12 months of avoiding peanuts in the 12-month extension of the LEAP study (LEAP-On). It is unclear whether this benefit is allergen and allergic disease specific. Objective: We sought to assess the effect of early introduction of peanut on the development of allergic disease, food sensitization, and aeroallergen sensitization. METHODS: Asthma, eczema, and rhinoconjunctivitis were diagnosed based on clinical assessment. Reported allergic reactions and consumption of tree nuts and sesame were recorded by questionnaire. Sensitization to food allergens and aeroallergens was determined by means of skin prick testing and specific IgE measurement. RESULTS: A high and increasing burden of food allergen and aeroallergen sensitization and allergic disease was noted across study time points; 76% of LEAP participants had at least 1 allergic disease at 60 months of age. There were no differences in allergic disease between LEAP groups. There were small differences in sensitization and reported allergic reactions for select tree nuts, with levels being higher in the LEAP consumption group. Significant resolution of eczema and sensitization to egg and milk occurred in LEAP participants and was not affected by peanut consumption. CONCLUSION: Early consumption of peanut in infants at high risk of peanut allergy is allergen specific and does not prevent the development of other allergic disease, sensitization to other food allergens and aeroallergens, or reported allergic reactions to tree nuts and sesame. Furthermore, peanut consumption does not hasten the resolution of eczema or egg allergy