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A 2-Question Summative Score Correlates with the Maslach Burnout Inventory
Introduction: There is a high prevalence of burnout among emergency medicine (EM) residents. The Maslach Burnout Inventory - Human Services Survey (MBI-HSS) is a widely used tool to measure burnout. The objective of this study was to compare the MBI-HSS and a two-question tool to determine burnout in the EM resident population.Methods: Based on data from the 2017 National Emergency Medicine Resident Wellness Survey study, we determined the correlation between two single-item questions with their respective MBI subscales and the full MBI-HSS. We then compared a 2-Question Summative Score to the full MBI-HSS with respect to primary, more restrictive, and more inclusive definitions of burnout previously reported in the literature.Results: Of 1,522 residents who completed the survey 37.0% reported “I feel burned out from my work,” and 47.1% reported “I have become more callous toward people since I took this job” once a week or more (each item >3 on a scale of 0-6). A 2-Question Summative Score totaling >3 correlated most closely with the primary definition of burnout (Spearman’s rho 0.65 [95% confidence interval 0.62-0.68]). Using the summative score, 77.7% of residents were identified as burned out, compared to 76.1% using the full MBI-HSS, with a sensitivity and specificity of 93.6% and 73.0%, respectively.Conclusion: An abbreviated 2-Question Summative Score correlates well with the full MBI-HSS tool in assessing EM resident physician burnout and could be considered a rapid screening tool to identify at-risk residents experiencing burnout
The environment and distribution of emitting electrons as a function of source activity in Markarian 421
For the high-frequency peaked BL Lac object Mrk 421 we study the variation of
the spectral energy distribution (SED) as a function of source activity, from
quiescent to active. We use a fully automatized chi-squared minimization
procedure, instead of the "eyeball" procedure more commonly used in the
literature, to model nine SED datasets with a one-zone Synchrotron-Self-Compton
(SSC) model and examine how the model parameters vary with source activity. The
latter issue can finally be addressed now, because simultaneous broad-band SEDs
(spanning from optical to VHE photon energies) have finally become available.
Our results suggest that in Mrk 421 the magnetic field decreases with source
activity, whereas the electron spectrum's break energy and the Doppler factor
increase -- the other SSC parameters turn out to be uncorrelated with source
activity. In the SSC framework these results are interpreted in a picture where
the synchrotron power and peak frequency remain constant with varying source
activity, through a combination of decreasing magnetic field and increasing
number density of electrons below the break energy: since this leads to an
increased electron-photon scattering efficiency, the resulting Compton power
increases, and so does the total (= synchrotron plus Compton) emission.Comment: Accepted for publication in Astrophysical Journal; 23 pages, 3
figures, 2 table
The new model of fitting the spectral energy distributions of Mkn 421 and Mkn 501
The spectral energy distribution (SED) of TeV blazars has a double-humped
shape that is usually interpreted as Synchrotron Self Compton (SSC) model. The
one zone SSC model is used broadly but cannot fit the high energy tail of SED
very well. It need bulk Lorentz factor which is conflict with the observation.
Furthermore one zone SSC model can not explain the entire spectrum. In the
paper, we propose a new model that the high energy emission is produced by the
accelerated protons in the blob with a small size and high magnetic field, the
low energy radiation comes from the electrons in the expanded blob. Because the
high and low energy photons are not produced at the same time, the requirement
of large Doppler factor from pair production is relaxed. We present the fitting
results of the SEDs for Mkn 501 during April 1997 and Mkn 421 during March 2001
respectively.Comment: 5 pages, 1 figures, 1table. accepted for publication in Sciences in
China --
X-ray Time Lags in TeV Blazars
We use Monte Carlo/Fokker-Planck simulations to study the X-ray time lags.
Our results show that soft lags will be observed as long as the decay of the
flare is dominated by radiative cooling, even when acceleration and cooling
timescales are similar. Hard lags can be produced in presence of a competitive
achromatic particle energy loss mechanism if the acceleration process operates
on a timescale such that particles are slowly moved towards higher energy while
the flare evolves. In this type of scenario, the {\gamma} -ray/X-ray quadratic
relation is also reproduced.Comment: 4 pages, 6 figures, Proceeding of `Multiwavelength Variability of
Blazars', Guangzhou, Chin
ANN-based energy reconstruction procedure for TACTIC gamma-ray telescope and its comparison with other conventional methods
The energy estimation procedures employed by different groups, for
determining the energy of the primary -ray using a single atmospheric
Cherenkov imaging telescope, include methods like polynomial fitting in SIZE
and DISTANCE, general least square fitting and look-up table based
interpolation. A novel energy reconstruction procedure, based on the
utilization of Artificial Neural Network (ANN), has been developed for the
TACTIC atmospheric Cherenkov imaging telescope. The procedure uses a 3:30:1 ANN
configuration with resilient backpropagation algorithm to estimate the energy
of a -ray like event on the basis of its image SIZE, DISTANCE and
zenith angle. The new ANN-based energy reconstruction method, apart from
yielding an energy resolution of 26%, which is comparable to that of
other single imaging telescopes, has the added advantage that it considers
zenith angle dependence as well. Details of the ANN-based energy estimation
procedure along with its comparative performance with other conventional energy
reconstruction methods are presented in the paper and the results indicate that
amongst all the methods considered in this work, ANN method yields the best
results. The performance of the ANN-based energy reconstruction has also been
validated by determining the energy spectrum of the Crab Nebula in the energy
range 1-16 TeV, as measured by the TACTIC telescope.Comment: 23pages, 9 figures Accepted for publication in NIM
A Monte Carlo study of leading order scaling corrections of phi^4 theory on a three dimensional lattice
We present a Monte Carlo study of the one-component model on the
cubic lattice in three dimensions. Leading order scaling corrections are
studied using the finite size scaling method. We compute the corrections to
scaling exponent with high precision. We determine the value of the
coupling at which leading order corrections to scaling vanish. Using
this result we obtain estimates for critical exponents that are more precise
than those obtained with field theoretic methods.Comment: 20 pages, two figures; numbers cited from ref. 23 corrected, few
typos correcte
Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002
In April-May 2003, the blazar 1ES 1959+650 showed an increased level of X-ray
activity. This prompted a multiwavelength observation campaign with the Whipple
10 m gamma-ray telescope, the Rossi X-ray Timing Explorer, the Bordeaux Optical
Observatory, and the University of Michigan Radio Astrophysical Observatory. We
present the multiwavelength data taken from May 2, 2003 to June 7, 2003 and
compare the source characteristics with those measured during observations
taken during the years 2000 and 2002. The X-ray observations gave a data set
with high signal-to-noise light curves and energy spectra; however, the
gamma-ray observations did not reveal a major TeV gamma-ray flare. Furthermore,
we find that the radio and optical fluxes do not show statistically significant
deviations from those measured during the 2002 flaring periods. While the X-ray
flux and X-ray photon index appear correlated during subsequent observations,
the apparent correlation evolved significantly between the years 2000, 2002,
and 2003. We discuss the implications of this finding for the mechanism that
causes the flaring activity.Comment: 17 pages, 6 figures, 2 table
Synoptic studies of seventeen blazars detected in very high-energy gamma-rays
Since 2002, the number of detected blazars at gamma-ray energies above 100
GeV has more than doubled. I study 17 blazars currently known to emit E>100 GeV
gamma rays. Their intrinsic energy spectra are reconstructed by removing
extragalactic background light attenuation effects. Luminosity and spectral
slope in the E>100 GeV region are then compared and correlated among each
other, with X-ray, optical and radio data, and with the estimated black hole
(BH) masses of the respective host galaxies.
According to expectations from synchrotron self-Compton emission models, a
correlation on the 3.6-sigma significance level between gamma-ray and X-ray
fluxes is found, while correlations between gamma-ray and optical/radio fluxes
are less pronounced. Further, a general hardening of the E>100 GeV spectra with
increasing gamma-ray luminosity is observed. This goes in line with a
correlation of the gamma-ray luminosity and the synchrotron peak frequency,
which is also seen. Tests for possible selection effects reveal a hardening of
the spectra with increasing redshift. The gamma-ray emission might depend on
the mass of the central BH. The studied blazars show no correlation of the BH
masses with the spectral index and the luminosity in the E>100 GeV region.
Also temporal properties of the X-ray and E>100 GeV gamma-ray flux are
considered. No general trends are found, except that the blazars with the most
massive BHs do not show particularly high duty cycles. In general, VHE flare
time-scales are not found to scale with the BH mass.
As a specific application of the luminosity study, a constraint for the still
undetermined redshift of the blazar PG 1553+113 is discussed.Comment: 17 pages, 18 figures, MNRAS in press. Abstract extended; minor
modifications in sect. 3, 5.5; Fig. 7c corrected; references update
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