Absolute dimensions of the unevolved B-type eclipsing binary GG Orionis

We present photometric observations in B and V as well as spectroscopic observations of the detached, eccentric 6.6-day double-lined eclipsing binary GG Ori, a member of the Orion OB1 association. Absolute dimensions of the components, which are virtually identical, are determined to high accuracy (better than 1% in the masses and better than 2% in the radii) for the purpose of testing various aspects of theoretical modeling. We obtain M(A) = 2.342 +/- 0.016 solar masses and R(A) = 1.852 +/- 0.025 solar radii for the primary, and M(B) = 2.338 +/- 0.017 solar masses and R(B) = 1.830 +/- 0.025 solar radii for the secondary. The effective temperature of both stars is 9950 +/- 200 K, corresponding to a spectral type of B9.5. GG Ori is very close to the ZAMS, and comparison with current stellar evolution models gives ages of 65-82 Myr or 7.7 Myr depending on whether the system is considered to be burning hydrogen on the main sequence or still in the final stages of pre-main sequence contraction. We have detected apsidal motion in the binary at a rate of dw/dt = 0.00061 +/- 0.00025 degrees per cycle, corresponding to an apsidal period of U = 10700 +/- 4500 yr. A substantial fraction of this (approximately 70%) is due to the contribution from General Relativity.Comment: To appear in The Astronomical Journal, December 200

SphinX: The Solar Photometer in X-Rays

Solar Photometer in X-rays (SphinX) was a spectrophotometer developed to observe the Sun in soft X-rays. The instrument observed in the energy range ≈ 1 - 15 keV with resolution ≈ 0.4 keV. SphinX was flown on the Russian CORONAS-PHOTON satellite placed inside the TESIS EUV and X telescope assembly. The spacecraft launch took place on 30 January 2009 at 13:30 UT at the Plesetsk Cosmodrome in Russia. The SphinX experiment mission began a couple of weeks later on 20 February 2009 when the first telemetry dumps were received. The mission ended nine months later on 29 November 2009 when data transmission was terminated. SphinX provided an excellent set of observations during very low solar activity. This was indeed the period in which solar activity dropped to the lowest level observed in X-rays ever. The SphinX instrument design, construction, and operation principle are described. Information on SphinX data repositories, dissemination methods, format, and calibration is given together with general recommendations for data users. Scientific research areas in which SphinX data find application are reviewed

Anesthesia Workload Nationally During Regular Workdays and Weekends

BACKGROUND: We analyze data from the American Society of Anesthesiologist's (ASA) Anesthesia Quality Institute (AQI) to report the U.S. anesthesia workload by time of day and day of the week. We consider the extent to which first case starts, rather than durations of workdays and weekend cases, influence the number of anesthesia providers nationally. METHODS: The ASA AQI data were from all the U.S. anesthesia groups that submitted cases to the National Anesthesia Clinical Outcomes Registry (NACOR) for all 12 months of 2013. For each of the n = 2,075,188 cases, we identified the local date and time of the start of anesthesia care, duration of anesthesia care, and the local time zone. Anesthesia workload was measured as the time from the start to the end of continuous anesthesia care. Data are reported as mean SEM with 95% confidence intervals (CIs). RESULTS: Half (53.0% +/- 0.6%) of the ASA AQI-reported weekly anesthesia workload was completed by 1:00 pm, local time, on regular workdays. The busiest 8-hour interval was from 7:30 am to 3:30 pm and accounted for 70.3% +/- 0.7% of anesthetic minutes. Although most facilities completed the majority of their weekly anesthesia workload in the mornings of regular workdays (P < 0.0001; 62.3%; CI, 58.6%-66.1%), just 24.4% of the University and large community hospitals did so (P = 0.0008 relative to half; CI, 13.8%-38.4%). CONCLUSIONS: The results are inconsistent with widespread use of surgical facilities (i.e., anesthesia providers) in mornings only, especially at University and large community hospitals. The observed national work hours match with what would be expected if most anesthesiologists work at least 8 hours on regular workdays. Opportunity for greater use of the capital (building and equipment) probably would involve the use of additional anesthesia providers representing a second shift or use of weekends

Diversity and Similarity of Anesthesia Procedures in the United States During and Among Regular Work Hours, Evenings, and Weekends

BACKGROUND: Anesthesiologists providing care during off hours (ie, weekends or holidays, or cases started during the evening or late afternoon) are more likely to care for patients at greater risk of sustaining major adverse events than when they work during regular hours (eg, Monday through Friday, from 7:00 am to 2:59 pm). We consider the logical inconsistency of using subspecialty teams during regular hours but not during weekends or evenings. METHODS: We analyzed data from the Anesthesia Quality Institute's National Anesthesia Clinical Outcomes Registry (NACOR). Among the hospitals in the United States, we estimated the average number of common types of anesthesia procedures (ie, diversity measured as inverse of Herfindahl index), and the average difference in the number of common procedures between 2 off-hours periods (regular hours versus weekends, and regular hours versus evenings). We also used NACOR data to estimate the average similarity in the distributions of procedures between regular hours and weekends and between regular hours and evenings in US facilities. Results are reported as mean +/- standard error of the mean among 399 facilities nationwide with weekend cases. RESULTS: The distributions of common procedures were moderately similar (ie, not large, 2x the number of common procedures calculated by facility). CONCLUSIONS: The numbers of procedures commonly performed at most facilities are fewer in number than those that are commonly performed nationally. Thus, decisions on anesthesia specialization should be based on quantitative analysis of local data rather than national recommendations using pooled data. By facility, the number of different procedures that take place during regular hours and off hours (diversity) is essentially the same, but there is only moderate similarity in the procedures performed. Thus, at many facilities, anesthesiologists who work principally within a single specialty during regular work hours will likely not have substantial contemporary experience with many procedures performed during off hours