Pulse Morphology of the Galactic Center Magnetar PSR J1745-2900

We present results from observations of the Galactic Center magnetar, PSR J1745-2900, at 2.3 and 8.4 GHz with the NASA Deep Space Network 70 m antenna, DSS-43. We study the magnetar's radio profile shape, flux density, radio spectrum, and single pulse behavior over a ~1 year period between MJDs 57233 and 57621. In particular, the magnetar exhibits a significantly negative average spectral index of $\langle\alpha\rangle$ = -1.86 $\pm$ 0.02 when the 8.4 GHz profile is single-peaked, which flattens considerably when the profile is double-peaked. We have carried out an analysis of single pulses at 8.4 GHz on MJD 57479 and find that giant pulses and pulses with multiple emission components are emitted during a significant number of rotations. The resulting single pulse flux density distribution is incompatible with a log-normal distribution. The typical pulse width of the components is ~1.8 ms, and the prevailing delay time between successive components is ~7.7 ms. Many of the single pulse emission components show significant frequency structure over bandwidths of ~100 MHz, which we believe is the first observation of such behavior from a radio magnetar. We report a characteristic single pulse broadening timescale of $\langle\tau_{d}\rangle$ = 6.9 $\pm$ 0.2 ms at 8.4 GHz. We find that the pulse broadening is highly variable between emission components and cannot be explained by a thin scattering screen at distances $\gtrsim$ 1 kpc. We discuss possible intrinsic and extrinsic mechanisms for the magnetar's emission and compare our results to other magnetars, high magnetic field pulsars, and fast radio bursts.Comment: 18 pages, 12 figures, Accepted for publication in ApJ on 2018 August 30. v2: Updated to match published versio

A Study of the 20 Day Superorbital Modulation in the High-Mass X-ray Binary IGR J16493-4348

We report on Nuclear Spectroscopic Telescope Array (NuSTAR), Neil Gehrels Swift Observatory (Swift) X-ray Telescope (XRT) and Swift Burst Alert Telescope (BAT) observations of IGR J16493-4348, a wind-fed Supergiant X-ray Binary (SGXB) showing significant superorbital variability. From a discrete Fourier transform of the BAT light curve, we refine its superorbital period to be 20.058 $\pm$ 0.007 days. The BAT dynamic power spectrum and a fractional root mean square analysis both show strong variations in the amplitude of the superorbital modulation, but no observed changes in the period were found. The superorbital modulation is significantly weaker between MJD 55,700 and MJD 56,300. The joint NuSTAR and XRT observations, which were performed near the minimum and maximum of one cycle of the 20 day superorbital modulation, show that the flux increases by more than a factor of two between superorbital minimum and maximum. We find no significant changes in the 3-50 keV pulse profiles between superorbital minimum and maximum, which suggests a similar accretion regime. Modeling the pulse-phase averaged spectra we find a possible Fe K$\alpha$ emission line at 6.4 keV at superorbital maximum. The feature is not significant at superorbital minimum. While we do not observe any significant differences between the pulse-phase averaged spectral continua apart from the overall flux change, we find that the hardness ratio near the broad main peak of the pulse profile increases from superorbital minimum to maximum. This suggests the spectral shape hardens with increasing luminosity. We discuss different mechanisms that might drive the observed superorbital modulation.Comment: 17 pages, 14 figures, 3 tables, accepted for publication in The Astrophysical Journal on 2019 May 1

Observations of Radio Magnetars with the Deep Space Network

The Deep Space Network (DSN) is a worldwide array of radio telescopes that supports NASA's interplanetary spacecraft missions. When the DSN antennas are not communicating with spacecraft, they provide a valuable resource for performing observations of radio magnetars, searches for new pulsars at the Galactic Center, and additional pulsar-related studies. We describe the DSN's capabilities for carrying out these types of observations. We also present results from observations of three radio magnetars, PSR J1745-2900, PSR J1622-4950, and XTE J1810-197, and the transitional magnetar candidate, PSR J1119-6127, using the DSN radio telescopes near Canberra, Australia.Comment: 14 pages, 8 figures, Accepted for publication in Advances in Astronomy on 2019 January 27 (Invited paper for a special issue on magnetars

Evaluation of lightweight wheelchairs using ANSI/RESNA testing standards

Lightweight wheelchairs are characterized by their low cost and limited range of adjustment. Our study evaluated three different folding lightweight wheelchair models using the American National Standards Institute/Rehabilitation Engineering Society of North America (ANSI/RESNA) standards to see whether quality had improved since the previous data were reported. On the basis of reports of increasing breakdown rates in the community, we hypothesized that the quality of these wheelchairs had declined. Seven of the nine wheelchairs tested failed to pass the multidrum test durability requirements. An average of 194,502 +/- 172,668 equivalent cycles was completed, which is similar to the previous test results and far below the 400,000 minimum required to pass the ANSI/ RESNA requirements. This was also significantly worse than the test results for aluminum ultralight folding wheelchairs. Overall, our results uncovered some disturbing issues with these wheelchairs and suggest that manufacturers should put more effort into this category to improve quality. To improve the durability of lightweight wheelchairs, we suggested that stronger regulations be developed that require wheelchairs to be tested by independent and certified test laboratories. We also proposed a wheelchair rating system based on the National Highway Transportation Safety Administration vehicle crash ratings to assist clinicians and end users when comparing the durability of different wheelchairs

Incoming Interns Perceived Preparedness for Core Entrustable Professional Activities

© 2019, International Association of Medical Science Educators. Introduction: The AAMC described 13 core entrustable professional activities (EPAs) for which every graduating medical student should perform proficiently on day 1 of residency. We studied how prepared starting interns felt in the core EPAs. Methods: Interns from a diverse health system were surveyed on how well medical school prepared them in the 13 core EPAs. Data were collected on type of medical school, participation in an acting/sub-internship (AI/SI), knowledge of EPAs, and participation in an EPA experience. Results: We collected 224 surveys out of 384 (58%) interns. 61.2% attended allopathic, 14.6% attended osteopathic, and 24.2% attended international schools. 67% had not heard of EPAs. 29% had an EPA experience of which 82% were required. 80% or more felt prepared in all EPAs except orders (60.7%) and handovers (73%). Allopathic interns were significantly more likely to have heard of EPAs and participated in an EPA experience than international. Allopathic interns felt more prepared than international in oral presentations and evidence-based medicine. Interns who participated in an EPA experience felt more prepared for oral presentation and evidence-based medicine. There were small but significant differences in feeling prepared in certain EPAs and types of AI/SI taken. Conclusion: The majority of interns entering residency have not heard of EPAs with fewer than 1/3 of interns participating in an EPA experience. International graduates were less likely to be aware or have experience with EPAs and report being less prepared in oral presentation and evidence-based medicine compared to allopathic graduates

Incorporation of an Interprofessional Palliative Care-Ethics Experience Into a Required Critical Care Acting Internship.

Introduction: The literature documents inadequate palliative medicine training in undergraduate and graduate medical education. As the population lives longer, many people will experience multiple chronic illnesses and the associated symptom burden. All physicians involved in clinical care of patients need to be equipped with the knowledge, attitudes, and skills necessary to provide palliative care, yet most physicians do not feel adequately prepared. We designed a curriculum to provide a meaningful palliative care-ethics (PCE) clinical experience to prepare senior medical students for future practice regardless of specialty choice. Methods: The Zucker School of Medicine at Hofstra/Northwell integrated a PCE experience into the required 4-week acting internship in critical care (AICC). Students met weekly with an interprofessional faculty member and presented clinical cases focusing on communication and/or bioethical challenges. Faculty facilitators ensured that the presentations integrated discussion of communication skills. During the final session, students shared written reflections. Students were invited to complete a satisfaction survey postrotation and 1 year after graduation. Results: The curriculum was evaluated positively by the graduating classes of 2015 ( Discussion: It is feasible to incorporate an interprofessional PCE experience into a required AICC. Students indicated a better understanding of palliative care and, at 1 year postgraduation, reported feeling comfortable caring for patients with serious illness

Observations of Radio Magnetars with the Deep Space Network

The Deep Space Network (DSN) is a worldwide array of radio telescopes which supports NASA’s interplanetary spacecraft missions. When the DSN antennas are not communicating with spacecraft, they provide a valuable resource for performing observations of radio magnetars, searches for new pulsars at the Galactic Center, and additional pulsar-related studies. We describe the DSN’s capabilities for carrying out these types of observations. We also present results from observations of three radio magnetars, PSR J1745–2900, PSR J1622–4950, and XTE J1810–197, and the transitional magnetar candidate, PSR J1119–6127, using the DSN radio telescopes near Canberra, Australia

Amniotic Fluid Glucose Concentration: A Marker for Infection in Preterm Labor and Preterm Premature Rupture of Membranes

Amniotic fluid Gram stain and culture have been utilized as laboratory tests of microbial invasion of the amniotic cavity. The Gram stain of amniotic fluid has a low sensitivity in the detection of clinical infection or microbial invasion of the amniotic cavity, and amniotic fluid culture results are not immediately available for management decisions. Glucose concentration is used to diagnose infection in other sites such as cerebrospinal fluid