5,441 research outputs found
The Spectral Energy Distribution of the High-Z Blazar Q0906+693
We describe further observations of QSO J0906+6930, a z=5.48 blazar likely to
be detected in gamma-rays. New radio and X-ray data place significant
constraints on any kpc-scale extension of the VLBA-detected jet. Improved
optical spectroscopy detects absorption from an intervening galaxy at z=1.849
and raise the possibility that this distant, bright source is lensed. We
combine the new data into an improved SED for the blazar core and comment on
the Compton keV-GeV flux component.Comment: 10pp, 3 figures, accpeted for publication in the Astronomical Journa
A multi-class approach for ranking graph nodes: models and experiments with incomplete data
After the phenomenal success of the PageRank algorithm, many researchers have
extended the PageRank approach to ranking graphs with richer structures beside
the simple linkage structure. In some scenarios we have to deal with
multi-parameters data where each node has additional features and there are
relationships between such features.
This paper stems from the need of a systematic approach when dealing with
multi-parameter data. We propose models and ranking algorithms which can be
used with little adjustments for a large variety of networks (bibliographic
data, patent data, twitter and social data, healthcare data). In this paper we
focus on several aspects which have not been addressed in the literature: (1)
we propose different models for ranking multi-parameters data and a class of
numerical algorithms for efficiently computing the ranking score of such
models, (2) by analyzing the stability and convergence properties of the
numerical schemes we tune a fast and stable technique for the ranking problem,
(3) we consider the issue of the robustness of our models when data are
incomplete. The comparison of the rank on the incomplete data with the rank on
the full structure shows that our models compute consistent rankings whose
correlation is up to 60% when just 10% of the links of the attributes are
maintained suggesting the suitability of our model also when the data are
incomplete
Magnesium and other biometals in oxidative medicine and redox biology
No abstract available
Fitting Pulsar Wind Tori. II. Error Analysis and Applications
We have applied the torus fitting procedure described in Ng & Romani (2004)
to PWNe observations in the Chandra data archive. This study provides
quantitative measurement of the PWN geometry and we characterize the
uncertainties in the fits, with statistical errors coming from the fit
uncertainties and systematic errors estimated by varying the assumed fitting
model. The symmetry axis of the PWN are generally well determined, and
highly model-independent. We often derive a robust value for the spin
inclination . We briefly discuss the utility of these results in
comparison with new radio and high energy pulse measurementsComment: 15 pages, 3 figures, ApJ in pres
Burnout among physicians
Burnout is a common syndrome seen in healthcare workers, particularly physicians who are exposed to a high level of stress at work; it includes emotional exhaustion, depersonalization, and low personal accomplishment. Burnout among physicians has garnered significant attention because of the negative impact it renders on patient care and medical personnel. Physicians who had high burnout levels reportedly committed more medical errors. Stress management programs that range from relaxation to cognitive-behavioral and patientcentered therapy have been found to be of utmost significance when it comes to preventing and treating burnout. However, evidence is insufficient to support that stress management programs can help reducing jobrelated stress beyond the intervention period, and similarly mindfulness-based stress reduction interventions efficiently reduce psychological distress and negative vibes, and encourage empathy while significantly enhancing physicians’ quality of life. On the other hand, a few small studies have suggested that Balint sessions can have a promising positive effect in preventing burnout; moreover exercises can reduce anxiety levels and exhaustion symptoms while improving the mental and physical well-being of healthcare workers. Occupational interventions in the work settings can also improve the emotional and work-induced exhaustion. Combining both individual and organizational interventions can have a good impact in reducing burnout scores among physicians; therefore, multidisciplinary actions that include changes in the work environmental factors along with stress management programs that teach people how to cope better with stressful events showed promising solutions to manage burnout. However, until now there have been no rigorous studies to prove this. More interventional research targeting medical students, residents, and practicing physicians are needed in order to improve psychological well-being, professional careers, as well as the quality of care provided to patients.Keywords: burnout; health care professionals; stress management; mindfulness-based stress reduction programs; physicians well-bein
First Astronomical Application of a Cryogenic TES Spectrophotometer
We report on the first astronomical observations with a photon counting pixel
detector that provides arrival time- (delta t = 100ns) and energy- (delta
E_gamma < 0.15eV) resolved measurements from the near IR through the near UV.
Our test observations were performed by coupling this Transition Edge Sensor
(TES) device to a 0.6m telescope; we have obtained the first simultaneous
optical near-IR phase-resolved spectra of the Crab pulsar. A varying infrared
turnover gives evidence of self-absorption in the pulsar plasma. The potential
of such detectors in imaging arrays from a space platform are briefly
described.Comment: 4 pages, 5 figure
Blazar Counterparts for 3EG Sources at -40 < decl. < 0: Pushing South Through the Bulge
Supplementing existing survey data with VLA observations, we have extended
ray counterpart identifications down to decl. = -40 using our
Figure of Merit approach. We find blazar counterparts for 70% of EGRET
sources above decl. = -40 away from the Galaxy. Spectroscopic
confirmation is in progress, and spectra for two dozen sources are
presented here. We find evidence that increased exposure in the bulge region
allowed EGRET to detect relatively faint blazars; a clear excess of non-blazar
objects in this region however argues for an additional (new) source class.Comment: ApJ accepte
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