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We present a summary of the McDonald Observatory Planetary Search program. We first summarize results on the star ∊ Eridani, in which we combine McDonald Observatory data with data from CFHT, Lick, and ESO, to detect a planet in orbit around this very nearby star. We then concentrate on results from the first 4 years of the Texas Hyades survey using the HIRES spectrograph on Keck 1. The Hyades constitute a very homogeneous sample of stars, in which the major independent variable is the stellar mass. In this survey, we have achieved 3 m s−1 internal error on a sample of about 100 Hyades dwarfs. We discuss the rms radial velocity jitter of the sample stars, and its relationship to spectral type, stellar rotation, and chromospheric activity.
We present the results of five years of high precision radial velocity (RV) monitoring of the α Centauri system. Observations were performed with the ESO 1.4m CAT telescope and the Coudé Echelle Spectrometer (CES) on La Silla. From the achieved RV precision we establish the detection threshold for Jovian planets in orbit around α Centauri A & B. Together with the known dynamical limits for stable planetary orbits we can set strong constraints on the presence of giant planets in our neighbouring binary system.
Gilliland et al. (2000) have reported HST photometric observations of 34000 stars in the globular cluster 47 Tuc, showing an absence of close-in giant planets in that cluster relative to their frequency in the solar neighborhood. Here we describe the methods of time-series analysis that were used to search the 47 Tuc data for transits by giant extrasolar planets, and the means by which these methods were validated.
Several different high-precision radial-velocity programs are now underway at The University of Texas. This paper discusses the aspects of these programs that are related to the problem of detection of extrasolar planetary systems. This includes the McDonald Observatory Planetary Search program on the McDonald 2.7-m Harlan Smith Telescope, an accompanying program of high-resolution stellar line profile measurement, the European Southern Observatory planetary search program, the Keck Hyades survey, and the Hobby∙Eberly Telescope planet surveys. Here, we summarize each of these programs, and present recent results from each.
At McDonald Observatory we have been monitoring the relative radial velocities of a sample of K giants. The technique employed uses the telluric O2 lines near 6300 Å as a reference for measuring the stellar line shifts. We demonstrate that precisions of 10 m s−1 are possible with this technique. We present radial velocity data covering a 2 year time span for α Boo, α Tau, and β Gem. All of these stars show both long term variations (~ several hundred days) with a peak-to-peak amplitude of about 400 m s−1 and short term variations (~ few days) with a peak-to-peak amplitude of about 100 m s−1. The long term variations may be due to the rotational modulation of surface active regions whereas the short term variations may be indicative of pulsations.
We are developing a prototype instrument for McDonald Observatory designed to measure stellar radial velocity variations to a precision of a few meters per second. The instrument will be used to study low amplitude stellar oscillations, to search for binary stellar systems with large mass ratios, and possibly to search for extra-solar planetary systems. A fixed gap Fabry-Perot etalon, used in reflection, imposes a set of fixed reference absorption lines on the stellar spectrum before it enters the McDonald Observatory 2.7m coudé spectrograph. The spectrum, covering 1500 Å at 0.13 Å resolution, is recorded on a set of eight Reticon arrays, placed end-to-end. Doppler shifts of the stellar spectral lines with respect to the fixed Fabry-Perot orders are measured by cross-correlation techniques. Calibration methods have been developed to measure any long-term drifts within the system.
Hot Jupiters, i.e., Jupiter-mass planets with orbital semi major axes of <10 stellar radii, can interact strongly with their host stars. If the planet is moving supersonically through the stellar wind, a bow shock will form ahead of the planet where the planetary magnetosphere slams into the the stellar wind or where the planetary outflow and stellar wind meet. Here we present high resolution spectra of the hydrogen Balmer lines for a single transit of the hot Jupiter HD 189733 b. Transmission spectra of the Balmer lines show strong absorption ~70 minutes before the predicted optical transit, implying a significant column density of excited hydrogen orbiting ahead of the planet. We show that a simple geometric bow shock model is able to reproduce the important features of the absorption time series while simultaneously matching the line profile morphology. Our model suggests a large planetary magnetic field strength of ~28 G. Follow-up observations are needed to confirm the pre-transit signal and investigate any variability in the measurement.
To investigate the association between food insecurity and intimate partner violence in a population-based sample of heterosexual women.
Logistic regression was used to evaluate the association between three levels of food insecurity and intimate partner violence.
Data from 6 years of the California Women’s Health Survey.
Randomly selected women (n 16 562) aged 18 years and older from the State of California, USA.
We found: (i) that African-American women had a higher prevalence of food insecurity and were more likely to report severe intimate partner violence; (ii) a strong positive association between food insecurity and intimate partner violence; (iii) evidence of effect modification of the association between food insecurity and intimate partner violence by marital status; and (iv) higher odds of intimate partner violence among those reporting more severe food insecurity.
Food insecurity is an important risk indicator for intimate partner violence among women. Understanding the factors that put women, especially minority women, at greatest risk facilitates intervention development.
We present Doppler tomographic observations of the transiting planet Kepler-13b (aka KOI-13b), a highly inflated hot Jupiter orbiting the Teff=8500 K primary of a hierarchical triple stellar system. As the planet transits the rapidly rotating host star, it successively blocks regions of the stellar disk with different radial velocities, causing a “bump” in the stellar spectral line shape, which we resolve spectroscopically. The manner in which this perturbation moves across the stellar line during the transit gives information on the relative alignment between the stellar spin and planetary orbital angular momentum vectors. This is a powerful statistical probe of planetary migration processes, as the expected spin-orbit misalignment distributions from dynamically cold migration (disk interactions) and dynamically hot migration (planet-planet scattering, Kozai cycles) are significantly different: the former will lead to primarily aligned orbits; the latter to a wide distribution. Doppler tomography also promises to be a powerful technique for confirming transiting planet candidates around rapidly rotating stars like Kepler-13A, which are not amenable to radial velocity follow-up and thus are currently a poorly sampled region of parameter space.
Little is known about how hospital organizational and cultural factors associated with implementation of quality initiatives such as the Institute for Healthcare Improvement's (IHI) 100,000 Lives Campaign differ among levels of healthcare staff.
Evaluation of a mixed qualitative and quantitative methodology (“trilogic evaluation model”).
Six hospitals that joined the campaign before June 2006.
Three strata of staff (executive leadership, midlevel, and frontline) at each hospital.
Surveys were completed in 2008 by 135 hospital personnel (midlevel, 43.7%; frontline, 38.5%; executive, 17.8%) who also participated in 20 focus groups. Overall, 93% of participants were aware of the IHI campaign in their hospital and perceived that 58% (standard deviation, 22.7%) of improvements in quality at their hospital were a direct result of the campaign. There were significant differences between staff levels on the organizational culture (OC) items, with executive-level staff having higher scores than midlevel and frontline staff. All 20 focus groups perceived that the campaign interventions were sustainable and that data feedback, buy-in, hardwiring (into daily activities), and leadership support were essential to sustainability.
The trilogic model demonstrated that the 3 levels of staff had markedly different perceptions regarding the IHI campaign and OC. A framework in which frontline, midlevel, and leadership staff are simultaneously assessed may be a useful tool for future evaluations of OC and quality initiatives such as the IHI campaign.
The Andean Common Market, the most recent attempt at regional integration in Latin America, differs from the other Latin American efforts both in the factors that prompted its formation and in the support it had when it was established. More importantly, it differs in its terms and provisions, providing for a higher level of integration than any other Latin American effort. Several of its features—a common policy on foreign investment, regional planning and coordination in such fields as industry and agriculture, a quasi–supranational secretariat — make it an innovative approach to integration in Latin America. Numerous factors enhance the integrative potential of Andean integration. Among these are relatively favorable ratings on several of the neo–functional variables of regional integration. These indicators suggest that the effort may attain its objectives and perhaps even set an example to be followed by other economic groupings among Latin American countries. Still, projections about the future of the Andean Common Market must remain mixed. Some negative factors exist within the movement that could, if they triumph over the positive factors, lead to the same stagnation that now characterizes LAFTA and the CACM.
The Kepler Mission is a space-based mission whose primary goal is to determine the frequency of Earth-size and larger planets in the habitable zone of solar-like stars. The mission will monitor more than 100,000 stars for patterns of transits with a differential photometric precision of 20 ppm at V = 12 for a 6.5 hour transit. It will also provide asteroseismic results on several thousand dwarf stars. It is specifically designed to continuously observe a single field of view of greater than 100 square degrees for 3.5 or more years.
This paper provides a short overview of the mission, a brief history of the mission development, expected results, new investigations by the recently chosen Participating Scientists, and the plans for the Guest Observer and Astrophysical Data Programs.
Congenitally corrected transposition is a complex cardiac lesion that is often associated with ventricular septal defect, obstruction of the outflow tract of the morphologically left ventricle, and abnormalities of the morphologically tricuspid valve.1,2 Nomenclature for this lesion has been variable and confusing.1 In this review, we define, and hopefully clarify this terminology. The lesion is a combination of discordant union of the atrial chambers with the ventricles, and the ventricles with the arterial trunks.1,2 In rare circumstances, discordant atrioventricular connections can be associated with concordant ventriculo-arterial connections. This malformation has been called “isolated ventricular inversion”. The term is less than precise, and the descriptive approach using the phrase “discordant atrioventricular connections with concordant ventriculo-arterial connections” is preferred, as discussed below.
The infectious diseases community shares a wide consensus about the need for control of antimicrobial use. However, current practices toward this goal remain controversial. This “Reality Check” session assessed attendees of the 4th Decennial Conference regarding their knowledge and practices about control of antimicrobial use in hospitals.
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