The Next Great Exoplanet Hunt

What strange new worlds will our next-generation telescopes find?Comment: Published in American Scientist: Volume 103, Number 3, Pages 196 to 203 (http://www.americanscientist.org/issues/feature/2015/3/the-next-great-exoplanet-hunt). Error concerning liquid helium correcte

Evidence for the Tidal Destruction of Hot Jupiters by Subgiant Stars

Tidal transfer of angular momentum is expected to cause hot Jupiters to spiral into their host stars. Although the timescale for orbital decay is very uncertain, it should be faster for systems with larger and more evolved stars. Indeed, it is well established that hot Jupiters are found less frequently around subgiant stars than around main-sequence stars. However, the interpretation of this finding has been ambiguous, because the subgiants are also thought to be more massive than the F- and G-type stars that dominate the main-sequence sample. Consequently it has been unclear whether the absence of hot Jupiters is due to tidal destruction, or inhibited formation of those planets around massive stars. Here we show that the Galactic space motions of the planet-hosting subgiant stars demand that on average they be similar in mass to the planet-hosting main-sequence F- and G-type stars. Therefore the two samples are likely to differ only in age, and provide a glimpse of the same exoplanet population both before and after tidal evolution. As a result, the lack of hot Jupiters orbiting subgiants is clear evidence for their tidal destruction. Questions remain, though, about the interpretation of other reported differences between the planet populations around subgiants and main-sequence stars, such as their period and eccentricity distributions and overall occurrence rates.Comment: 12 pages and 6 figures in emulateapj format; accepted for publication in Ap

Due Diligence and Legal Obligations of Employment Screening in Healthcare Organizations

Few career fields are as dynamic as healthcare. Even non-clinical employees and volunteer staff may encounter risks or assume responsibilities unforeseeable in other career fields. Clinical workers in particular must respond to life and death workplace challenges with competence and compassion. Employee reliability is the single most important health system input. Reliability begins with thorough employment background screening. As they minimize risks from “bad hires,” background investigations must also comply with federal, state, and local laws as well as industry standards and best practices. Although predicting the likelihood of future malfeasance by any single employee is impossible, effective backgrounding enhances quality of care, decreases risks, and lowers costs. Managing the vetting process with competence requires a solid working knowledge of all lawful steps needed to ensure full, due-diligence compliant background investigations. If a screening process is transparent and impartial with fair group outcomes, due diligence is satisfied

The Opportunity to Dream: How an Early Learning Network Implemented the Liberatory Design Process

This resource is a case study created in partnership with the Friday Institute's PEER team, entitled "The Opportunity to Dream". The study focuses on the impact of the TIP Early Learning Network's third cohort and their use of the Liberatory Design process in promoting equity and opportunity for underrepresented groups. The study highlights the positive outcomes and benefits resulting from the implementation of the Liberatory Design process, specifically in the work of Edgecombe and Wake's prototypes. The case study serves as a valuable reference for those interested in understanding the impact of using the Liberatory Design process as part of the TIP Early Learning Network

Medical Volunteers During Pandemics, Disasters, and Other Emergencies: Management Best Practices

How best to utilize volunteers[1] during medical emergencies is an essential part of hospital compliance planning. Onboarding recruited and spontaneous volunteers during crisis situations require careful consideration of multiple legal issues. Volunteer planning becomes more complex if volunteers move across state lines because applicable tort immunity statutes,[2] compensation limits,[3]and workers compensation regimes vary significantly from one jurisdiction to another. Effective planning for volunteers requires these and other issues to be addressed well in advance of actual emergencies. Although predicting the scope or severity of any future crisis is impossible, the provided checklist of management best practices should facilitate enhanced care, decreased risk, and lowered costs. [1] Mark A. Hager & Jeffrey L. Brudney, Balancing Act: The Challenges and Benefits of Volunteers, The Urban Inst. (Dec. 2004), https://www.nationalservice.gov/pdf/Balancing_Act.pdf [https://perma.cc/A6M8-DM53]. [2] In Virginia, nonprofits are immune from suits by beneficiaries alleging negligence absent a finding of corporate negligence or failure to exercise ordinary care in the selection of employees or volunteers. Va. Code Ann. § 44-146.23 (2009). Wyoming limits charitable immunity only if a nonprofit provides services without charge Wyo. Stat. Ann. § 1-1-125 (2017). [3] Colorado limits judgments against non-profits to the extent of existing insurance coverage. Colo. Rev. Stat. § 7-123-105 (2004). Massachusetts has a cap of $20,000 for torts committed while engaged in acts to directly accomplish the charitable purposes of the organization. Mass. Gen. Laws ch. 231, § 85K (2012). South Carolina limits awards to$250,000 in actions for injury or death caused by the tort of an agent, servant, employee, or officer of charitable organizations. S.C. Code Ann. § 33-56-180 (2000). Texas operational tort liability is $500,000 per person and$1,000,000 per event but does not extend to hospitals. Tex. Civ. Prac. & Rem. § 84.006 (1987)

NEPC Review: Our Next Assignment: Where Americans Stand on Public K-12 Education (Public Agenda, November 2018)

Public Agenda compiled public opinion surveys to show where the American public stands on education issues. Their report notes the importance of gauging current public understanding of education in the nation, particularly given the three major policy changes in the past 10 years: Race to the Top, the Common Core State Standards, and the Every Student Succeeds Act. While this publication makes a unique contribution in its gathering of many surveys into a single report and its inclusion of interviews with employers, the lack of clarity in its methods makes many of its conclusions questionable. The report is inconsistent in how it addresses disaggregated data and respondents from different demographic groups (e.g., race, class, political affiliation), resulting in an inability to generalize to the population or to any subgroup. Therefore, the conclusions are cursory and incomplete, requiring further study and research.</p

Absence of a metallicity effect for ultra-short-period planets

Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2 Earth radii. It has been proposed that USP planets are the solid cores of hot Jupiters that lost their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We test this hypothesis by asking whether USP planets are associated with metal-rich stars, as has long been observed for hot Jupiters. We find the metallicity distributions of USP-planet and hot-Jupiter hosts to be significantly different ($p = 3\times 10^{-4}$), based on Keck spectroscopy of Kepler stars. Evidently, the sample of USP planets is not dominated by the evaporated cores of hot Jupiters. The metallicity distribution of stars with USP planets is indistinguishable from that of stars with short-period planets with sizes between 2--4~$R_\oplus$. Thus it remains possible that the USP planets are the solid cores of formerly gaseous planets smaller than Neptune.Comment: AJ, in pres

Evidence of Possible Spin-Orbit Misalignment Along the Line of Sight in Transiting Exoplanet Systems

Of the 26 transiting exoplanet systems with measurements of the Rossiter-McLaughlin (RM) effect, eight have now been found to be significantly spin-orbit misaligned in the plane of the sky. Unfortunately, the RM effect only measures the angle between the orbit of a transiting exoplanet and the spin of its host star projected in the plane of sky, leaving unconstrained the compliment misalignment angle between the orbit of the planet and the spin of its host star along the line of sight. I use a simple model of stellar rotation benchmarked with observational data to statistically identify ten exoplanet systems from a sample of 75 for which there is likely a significant degree of misalignment along the line of sight between the orbit of the planet and the spin of its host star. I find that HAT-P-7, HAT-P-14, HAT-P-16, HD 17156, Kepler-5, Kepler-7, TrES-4, WASP-1, WASP-12, and WASP-14 are likely spin-orbit misaligned along the line of sight. All ten systems have host stellar masses M_star in the range 1.2 M_sun <= M_star <= 1.5 M_sun, and the probability of this occurrence by chance is less than one in ten thousand. In addition, the planets in the candidate misaligned systems are preferentially massive and eccentric. The coupled distribution of misalignment from the RM effect and from this anaylsis suggests that transiting exoplanets are more likely to be spin-orbit aligned than expected given predictions for a transiting planet population produced entirely by planet-planet scattering or Kozai cycles and tidal friction. For that reason, there are likely two populations of close-in exoplanet systems: a population of aligned systems and a population of apparently misaligned systems in which the processes that lead to misalignment or to the survival of misaligned systems operate more efficiently in systems with massive stars and planets. (abridged)Comment: 16 pages, 5 figures, and 2 tables in emulateapj format; submitted to ApJ in original form 24 December 2009, resubmitted in response to referee report 1 June 201