42 research outputs found
Calculation of molecular thermochemical data and their availability in databases
Thermodynamic properties of molecules can be obtained by experiment, by statistical mechanics in conjunction with electronic structure theory and by empirical rules like group additivity. The latter two methods are briefly re-viewed in this chapter. The overview of electronic structure methods is intended for readers less experienced in electronic structure theory and focuses on concepts without going into mathematical details. This is followed by a brief description of group additivity schemes; finally, an overview of databases listing reliable thermochemical data is given
A systematic review of tests of empathy in medicine
Abstract Background Empathy is frequently cited as an important attribute in physicians and some groups have expressed a desire to measure empathy either at selection for medical school or during medical (or postgraduate) training. In order to do this, a reliable and valid test of empathy is required. The purpose of this systematic review is to determine the reliability and validity of existing tests for the assessment of medical empathy. Methods A systematic review of research papers relating to the reliability and validity of tests of empathy in medical students and doctors. Journal databases (Medline, EMBASE, and PsycINFO) were searched for English-language articles relating to the assessment of empathy and related constructs in applicants to medical school, medical students, and doctors. Results From 1147 citations, we identified 50 relevant papers describing 36 different instruments of empathy measurement. As some papers assessed more than one instrument, there were 59 instrument assessments. 20 of these involved only medical students, 30 involved only practising clinicians, and three involved only medical school applicants. Four assessments involved both medical students and practising clinicians, and two studies involved both medical school applicants and students. Eight instruments demonstrated evidence of reliability, internal consistency, and validity. Of these, six were self-rated measures, one was a patient-rated measure, and one was an observer-rated measure. Conclusion A number of empathy measures available have been psychometrically assessed for research use among medical students and practising medical doctors. No empathy measures were found with sufficient evidence of predictive validity for use as selection measures for medical school. However, measures with a sufficient evidential base to support their use as tools for investigating the role of empathy in medical training and clinical care are available.</p
Design and characterization of the Large-aperture Experiment to Detect the Dark Age (LEDA) radiometer systems
The Large-Aperture Experiment to Detect the Dark Age (LEDA) was designed to
detect the predicted O(100)mK sky-averaged absorption of the Cosmic Microwave
Background by Hydrogen in the neutral pre- and intergalactic medium just after
the cosmological Dark Age. The spectral signature would be associated with
emergence of a diffuse Ly background from starlight during 'Cosmic
Dawn'. Recently, Bowman et al. (2018) have reported detection of this predicted
absorption feature, with an unexpectedly large amplitude of 530 mK, centered at
78 MHz. Verification of this result by an independent experiment, such as LEDA,
is pressing. In this paper, we detail design and characterization of the LEDA
radiometer systems, and a first-generation pipeline that instantiates a signal
path model. Sited at the Owens Valley Radio Observatory Long Wavelength Array,
LEDA systems include the station correlator, five well-separated redundant dual
polarization radiometers and backend electronics. The radiometers deliver a
30-85MHz band (16<z<34) and operate as part of the larger interferometric
array, for purposes ultimately of in situ calibration. Here, we report on the
LEDA system design, calibration approach, and progress in characterization as
of January 2016. The LEDA systems are currently being modified to improve
performance near 78 MHz in order to verify the purported absorption feature
