540 research outputs found
The value of using probabilities of gene origin to measure genetic variability in a population
The Joint Council on Thoracic Surgery Education (JCTSE) “Educate the Educators” Faculty Development Course: Analysis of the First 5 Years
BACKGROUND: Since 2010, the Joint Council on Thoracic Surgery Education, Inc (JCTSE) has sponsored an annual "Educate the Educators" (EtE) course. The goal is to provide United States academic cardiothoracic surgeons (CTS) the fundamentals of teaching skills, educational curriculum development, and using education for academic advancement. This report describes the course development and evaluation along with attendee's self-assessment of skills through the first 5 years of the program.
METHODS: The content of this 2½-day course was based on needs assessment surveys of CTS and residents attending annual meetings in 2009. From 2010 to 2014, EtE was offered to all CTS at training programs approved by the Accreditation Council for Graduate Medical Education. Course content was evaluated by using end-of-course evaluation forms. A 5-point Likert scale (1 = poor, 5 = excellent) was used to obtain composite assessment mean scores for the 5 years on course variables, session presentations, and self-assessments.
RESULTS: With 963 known academic CTS in the United States, 156 (16.3%) have attended, representing 70 of 72 training programs (97%), and 1 international surgeon attended. There were also 7 program coordinators. Ratings of core course contents ranged from 4.4 to 4.8, accompanied with highly complementary comments. Through self-assessment, skills and knowledge in all content areas statistically improved significantly. The effect of the course was evaluated with a follow-up survey in which responders rated the program 4.3 on the usefulness of the information for their career and 3.9 for educational productivity.
CONCLUSIONS: The EtE program offers an excellent opportunity for academic CTS to enhance their teaching skills, develop educational activities, and prepare for academic promotion. With its unique networking and mentorship environment, the EtE program is an important resource in the evolution of cardiothoracic surgical training in the United States
Prehistory of Transit Searches
Nowadays the more powerful method to detect extrasolar planets is the transit
method. We review the planet transits which were anticipated, searched, and the
first ones which were observed all through history. Indeed transits of planets
in front of their star were first investigated and studied in the solar system.
The first observations of sunspots were sometimes mistaken for transits of
unknown planets. The first scientific observation and study of a transit in the
solar system was the observation of Mercury transit by Pierre Gassendi in 1631.
Because observations of Venus transits could give a way to determine the
distance Sun-Earth, transits of Venus were overwhelmingly observed. Some
objects which actually do not exist were searched by their hypothetical
transits on the Sun, as some examples a Venus satellite and an infra-mercurial
planet. We evoke the possibly first use of the hypothesis of an exoplanet
transit to explain some periodic variations of the luminosity of a star, namely
the star Algol, during the eighteen century. Then we review the predictions of
detection of exoplanets by their transits, those predictions being sometimes
ancient, and made by astronomers as well as popular science writers. However,
these very interesting predictions were never published in peer-reviewed
journals specialized in astronomical discoveries and results. A possible
transit of the planet beta Pic b was observed in 1981. Shall we see another
transit expected for the same planet during 2018? Today, some studies of
transits which are connected to hypothetical extraterrestrial civilisations are
published in astronomical refereed journals. Some studies which would be
classified not long ago as science fiction are now considered as scientific
ones.Comment: Submiited to Handbook of Exoplanets (Springer
Protease-Activated Receptor 2 Deficiency Reduces Cardiac Ischemia/Reperfusion Injury
Protease-activated receptor-2 (PAR-2) signaling enhances inflammation in different diseases. The effect of PAR-2 deficiency in cardiac ischemia/reperfusion (I/R) injury is unknown. We investigated the effect of PAR-2 deficiency on I/R injury-induced infarct size, inflammation, heart remodeling and cardiac function
Transit Timing and Duration Variations for the Discovery and Characterization of Exoplanets
Transiting exoplanets in multi-planet systems have non-Keplerian orbits which
can cause the times and durations of transits to vary. The theory and
observations of transit timing variations (TTV) and transit duration variations
(TDV) are reviewed. Since the last review, the Kepler spacecraft has detected
several hundred perturbed planets. In a few cases, these data have been used to
discover additional planets, similar to the historical discovery of Neptune in
our own Solar System. However, the more impactful aspect of TTV and TDV studies
has been characterization of planetary systems in which multiple planets
transit. After addressing the equations of motion and parameter scalings, the
main dynamical mechanisms for TTV and TDV are described, with citations to the
observational literature for real examples. We describe parameter constraints,
particularly the origin of the mass/eccentricity degeneracy and how it is
overcome by the high-frequency component of the signal. On the observational
side, derivation of timing precision and introduction to the timing diagram are
given. Science results are reviewed, with an emphasis on mass measurements of
transiting sub-Neptunes and super-Earths, from which bulk compositions may be
inferred.Comment: Revised version. Invited review submitted to 'Handbook of
Exoplanets,' Exoplanet Discovery Methods section, Springer Reference Works,
Juan Antonio Belmonte and Hans Deeg, Eds. TeX and figures may be found at
https://github.com/ericagol/TTV_revie
Planetary Dynamics and Habitable Planet Formation In Binary Star Systems
Whether binaries can harbor potentially habitable planets depends on several
factors including the physical properties and the orbital characteristics of
the binary system. While the former determines the location of the habitable
zone (HZ), the latter affects the dynamics of the material from which
terrestrial planets are formed (i.e., planetesimals and planetary embryos), and
drives the final architecture of the planets assembly. In order for a habitable
planet to form in a binary star system, these two factors have to work in
harmony. That is, the orbital dynamics of the two stars and their interactions
with the planet-forming material have to allow terrestrial planet formation in
the habitable zone, and ensure that the orbit of a potentially habitable planet
will be stable for long times. We have organized this chapter with the same
order in mind. We begin by presenting a general discussion on the motion of
planets in binary stars and their stability. We then discuss the stability of
terrestrial planets, and the formation of potentially habitable planets in a
binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in
Binary Star Systems (Ed. N. Haghighipour, Springer publishing company
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