274 research outputs found
Development of an Inventory for Evaluating Sheltered Workshops in the State of Washington
The purposes of this investigation were two-fold: First, to provide workshop personnel with an effective, but time-saving instrument which may be used as an evaluative guide for individual sheltered workshops; second, to provide interested persons with an instrument which will point out basic requirements for a successful workshop
A Class of Eccentric Binaries with Dynamic Tidal Distortions Discovered with Kepler
We have discovered a class of eccentric binary systems within the Kepler data
archive that have dynamic tidal distortions and tidally-induced pulsations.
Each has a uniquely shaped light curve that is characterized by periodic
brightening or variability at time scales of 4-20 days, frequently accompanied
by shorter period oscillations. We can explain the dominant features of the
entire class with orbitally-varying tidal forces that occur in close, eccentric
binary systems. The large variety of light curve shapes arises from viewing
systems at different angles. This hypothesis is supported by spectroscopic
radial velocity measurements for five systems, each showing evidence of being
in an eccentric binary system. Prior to the discovery of these 17 new systems,
only four stars, where KOI-54 is the best example, were known to have evidence
of these dynamic tides and tidally-induced oscillations. We perform preliminary
fits to the light curves and radial velocity data, present the overall
properties of this class and discuss the work required to accurately model
these systems.Comment: 13 pages, submitted to Ap
Recommended from our members
Measuring the quality of inpatient specialist consultation in the intensive care unit: Nursing and family experiences of communication
Rationale: Critically ill patients in the intensive care unit (ICU) often require the care of specialist physicians for clinical or procedural expertise. The current state of communication between specialist physicians and families and nurses has not been explored. Objectives: To document the receipt of communication by nurses and family members regarding consultations performed on their patient or loved one, and to quantify how this impacts their overall perceptions of the quality of specialty care. Methods: Prospective survey of 60 adult family members and 90 nurses of 189 ICU patients who received a specialist consultation between March and October of 2015 in a single academic medical center in the United States. Surveys measured the prevalence of direct communication—defined as communication conducted in person, via telephone, or via text-page in which the specialist team gathered information about the patient from the nurse/family member and/or shared recommendations for care—and perceived quality of care. Results: In about two-thirds of family surveys (40/60) and one-half of nurse surveys (75/160), respondents had no direct communication with the specialist team that performed the consultation. Compared to nurses who had no direct communication with the specialists, those who did were 1.5 times more likely to rate the consultation as “excellent” (RR 1.48, 95% CI 1.2–1.8, p Conclusions: Most ICU families and nurses have no interaction with specialist providers. Nurses’ frequent exclusion from conversations about specialty care may pose safety risks and increase the likelihood of mixed messages for patients and families, most of whom desire some interaction with specialists. Future research is needed to identify effective mechanisms for information sharing that keep nurses and families aware of consultation requests, delivery, and outcomes without increasing the risk of mixed messages.</p
Terrestrial Planet Occurrence Rates for the Kepler GK Dwarf Sample
We measure planet occurrence rates using the planet candidates discovered by
the Q1-Q16 Kepler pipeline search. This study examines planet occurrence rates
for the Kepler GK dwarf target sample for planet radii, 0.75<Rp<2.5 Rearth, and
orbital periods, 50<Porb<300 days, with an emphasis on a thorough exploration
and identification of the most important sources of systematic uncertainties.
Integrating over this parameter space, we measure an occurrence rate of F=0.77
planets per star, with an allowed range of 0.3<F<1.9. The allowed range takes
into account both statistical and systematic uncertainties, and values of F
beyond the allowed range are significantly in disagreement with our analysis.
We generally find higher planet occurrence rates and a steeper increase in
planet occurrence rates towards small planets than previous studies of the
Kepler GK dwarf sample. Through extrapolation, we find that the one year
orbital period terrestrial planet occurrence rate, zeta_1=0.1, with an allowed
range of 0.01<zeta_1<2, where zeta_1 is defined as the number of planets per
star within 20% of the Rp and Porb of Earth. For G dwarf hosts, the zeta_1
parameter space is a subset of the larger eta_earth parameter space, thus
zeta_1 places a lower limit on eta_earth for G dwarf hosts. From our analysis,
we identify the leading sources of systematics impacting Kepler occurrence rate
determinations as: reliability of the planet candidate sample, planet radii,
pipeline completeness, and stellar parameters.Comment: 19 Pages, 17 Figures, Submitted ApJ. Python source to support Kepler
pipeline completeness estimates available at
http://github.com/christopherburke/KeplerPORTs
Cataclysmic Variables from SDSS II. The Second Year
The first full year of operation following the commissioning year of the
Sloan Digital Sky Survey has revealed a wide variety of newly discovered
cataclysmic variables. We show the SDSS spectra of forty-two cataclysmic
variables observed in 2002, of which thirty-five are new classifications, four
are known dwarf novae (CT Hya, RZ Leo, T Leo and BZ UMa), one is a known CV
identified from a previous quasar survey (Aqr1) and two are known ROSAT or
FIRST discovered CVs (RX J09445+0357, FIRST J102347.6+003841). The SDSS
positions, colors and spectra of all forty-two systems are presented. In
addition, the results of follow-up studies of several of these objects identify
the orbital periods, velocity curves and polarization that provide the system
geometry and accretion properties. While most of the SDSS discovered systems
are faint (>18th mag) with low accretion rates (as implied from their spectral
characteristics), there are also a few bright objects which may have escaped
previous surveys due to changes in the mass transfer rate.Comment: Accepted for publication in The Astronomical Journal, Vol. 126, Sep.
2003, 44 pages, 25 figures (now with adjacent captions), AASTeX v5.
Two Rare Magnetic Cataclysmic Variables with Extreme Cyclotron Features Identified in the Sloan Digital Sky Survey
Two newly identified magnetic cataclysmic variables discovered in the Sloan
Digital Sky Survey (SDSS), SDSSJ155331.12+551614.5 and SDSSJ132411.57+032050.5,
have spectra showing highly prominent, narrow, strongly polarized cyclotron
humps with amplitudes that vary on orbital periods of 4.39 and 2.6 hrs,
respectively. In the former, the spacing of the humps indicates the 3rd and 4th
harmonics in a magnetic field of ~60 MG. The narrowness of the cyclotron
features and the lack of strong emission lines imply very low temperature
plasmas and very low accretion rates, so that the accreting area is heated by
particle collisions rather than accretion shocks. The detection of rare systems
like these exemplifies the ability of the SDSS to find the lowest accretion
rate close binaries.Comment: Accepted for publication in the Astrophysical Journal, vol. 583,
February 1, 2003; slight revisions and additions in response to referee's
comments; 17 pages, 6 figures, AASTeX v4.
Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog with Measured Completeness and Reliability Based on Data Release 25
We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4 yr of Kepler time series photometry (Data Release 25, Q1–Q17). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it was able to separate TCEs caused by noise from those caused by low signal-to-noise transits. We discuss the Robovetter and the metrics it uses to sort TCEs. For orbital periods less than 100 days the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates between 200 and 500 days around FGK-dwarf stars, the Robovetter is 76.7% complete and the catalog is 50.5% reliable. The KOI catalog, the transit fits, and all of the simulated data used to characterize this catalog are available at the NASA Exoplanet Archive
Planetary Candidates Observed by Kepler IV: Planet Sample From Q1-Q8 (22 Months)
We provide updates to the Kepler planet candidate sample based upon nearly
two years of high-precision photometry (i.e., Q1-Q8). From an initial list of
nearly 13,400 Threshold Crossing Events (TCEs), 480 new host stars are
identified from their flux time series as consistent with hosting transiting
planets. Potential transit signals are subjected to further analysis using the
pixel-level data, which allows background eclipsing binaries to be identified
through small image position shifts during transit. We also re-evaluate Kepler
Objects of Interest (KOI) 1-1609, which were identified early in the mission,
using substantially more data to test for background false positives and to
find additional multiple systems. Combining the new and previous KOI samples,
we provide updated parameters for 2,738 Kepler planet candidates distributed
across 2,017 host stars. From the combined Kepler planet candidates, 472 are
new from the Q1-Q8 data examined in this study. The new Kepler planet
candidates represent ~40% of the sample with Rp~1 Rearth and represent ~40% of
the low equilibrium temperature (Teq<300 K) sample. We review the known biases
in the current sample of Kepler planet candidates relevant to evaluating planet
population statistics with the current Kepler planet candidate sample.Comment: 12 pages, 8 figures, Accepted ApJ Supplemen
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