Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

The Kepler Mission has discovered thousands of planets with radii $<4\ R_\oplus$, paving the way for the first statistical studies of the dynamics, formation, and evolution of these sub-Neptunes and super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern is therefore how to map the measured radii to mass estimates in this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters. We analyze how the results depend on the radius range of the sample, and on how the masses were measured. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that$M/M_\oplus=2.7(R/R_\oplus)^{1.3}$, a scatter in mass of$1.9\ M_\oplus$, and a mass constraint to physically plausible densities, is the "best-fit" probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes ($R_{pl}<4\ R_\oplus$). More broadly, this work provides a framework for further analyses of the M-R relation and its probable dependencies on period and stellar properties.Comment: 14 pages, 5 figures, 2 tables. Accepted to the Astrophysical Journal on April 28, 2016. Select posterior samples and code to use them to compute the posterior predictive mass distribution are available at https://github.com/dawolfgang/MRrelatio

An Examination of the Reading First Program at a Southeastern Virginia Elementary School and the Impact on K–2 Student Reading Achievement

Reading First was a federal initiative aimed at improving reading instruction and implementing programs and strategies grounded in scientifically-based reading research. The legislation was predicated on research findings that high-quality reading instruction and intervention in the primary grades significantly reduces the numbers of students who experience difficulties in later grades. This study examined the Reading First program at an elementary school in southeastern Virginia from 2006-2008. Specifically, the researcher investigated the impact of the independent variable, the tier three model of intervention on K-2 student reading achievement. Quantitative data was garnered from 792 K-2 student participants attending the research site. Using a regression discontinuity design, the study evaluated the significance of the multi-tiered intervention model on student reading achievement using a pre-test/post-test program group strategy (Trochin, 1982; Stanley, 1991; Shadish, Cook, & Campbell, 2002). The Phonological Awareness Literacy Screenings (PALS), K PALS and PALS 1-3, served as the study\u27s dependent measures examining differences in pre-post student scores to determine statistical significance in literacy growth among the population sample (Invernizzi, Meier, & Juel, 2003). Using PALS benchmark ranges established by the local division, 2006-2008 K-2 students were identified as tier 1, meeting benchmark standards, tier 2, strategic, or tier 3, intensive. The researcher evaluated the mean differences between groups using an Analysis of Variance (ANOVA). Additional independent variables analyzed included pre-k experience, student tier classification, grade level, and year. Statistical significance existed between pre-test/post-test scores among the 2006-2007 and 2007-2008 tier 1 student subgroups in Grade 1. No significant relationship was found among year 1 or year 2 tier 1 student subgroups in Kindergarten or Grade 2. Results of one-way analyses of variance showed statistical significance between pre-test/post-test scores among tier 2 student subgroups in Kindergarten, Grade 1, and Grade 2. Statistical significance existed between pre-test/post-test scores among the 2006-2007 and 2007-2008 tier 3 student subgroups in Kindergarten. No significant relationship was found among year 1 or year 2 tier 3 student subgroups in Grade 1 or Grade 2

Mortality after fluid bolus in children with shock due to sepsis or severe infection: a systematic review and meta-analysis.

Sepsis is one of the leading causes of childhood mortality, yet controversy surrounds the current treatment approach. We conducted a systematic review to assess the evidence base for fluid resuscitation in the treatment of children with shock due to sepsis or severe infection

Vitamin and Mineral Supplement Use by Older Adults with Complex Medication Needs; Potential for Adverse Drug-Nutrient Interactions

Objective: Vitamin and mineral supplements have been increasingly available for decades. The increase in availability of supplements and their use in combination with prescription drugs suggests that the risk of an adverse drug-nutrient interaction has drastically increased. This is especially concerning in populations with greater medication use. The purpose of this study was to assess vitamin and mineral supplement use in older adults with complex medication use to identify supplement use, overuse, and use from multiple sources. A secondary outcome of this study was to assess the potential for adverse drug-nutrient interactions in medically complex patients. Methods: A retrospective chart review was completed on 229 medically-complex patients 50 years of age and older who had new assessments of medications completed between January 2014 and January 19th, 2017 at the University of Saskatchewan Medication Assessment Centre. Results: Data indicate that 76.9% (n = 176) of patients (mean: 69 years) reported using ≥ 1 vitamin and/or mineral supplement daily. Total product count (oral prescriptions, over-the-counter (OTC) products, dietary supplements) ranged from 1-45 per day, with a mean 9.8 and median of 9. The tolerable upper intake level (UL) for nutrients was exceeded by 39.7% (n = 70) of reported supplement users (n = 176). One case exceeded the UL for 6 different nutrients, from supplemental intake alone. Of reported supplement users, 43.2% consumed supplemental nutrients from more than one source, which was significantly associated (p < 0.001) with supplemental nutrient intake at or above the UL. Conclusions: Vitamin and mineral supplement use in conjunction with prescription drugs and OTC products was observed in this population, with reported intake of many supplemental nutrients that exceeded the UL

The Eccentricity Distribution of Short-Period Planet Candidates Detected by Kepler in Occultation

We characterize the eccentricity distribution of a sample of ~50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is $\sigma=0.081 \pm^{0.014}_{0.003}$. We find that a two-component Gaussian mixture model for $e \cos \omega$ and $e \sin \omega$ provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that $\sim90\%$ of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion ($\sim0.01$), and $\sim10\%$ come from a population with a larger dispersion ($\sim0.22$). Finally, we investigate how the eccentricity distribution correlates with selected planet and host star parameters. We find evidence that suggests systems around higher metallicity stars and planet candidates with smaller radii come from a more complex eccentricity distribution.Comment: Accepted for publication in Ap

A Search for Planets Transiting the M Dwarf Debris Disk Host, AU Microscopii

We present high cadence, high precision multi-band photometry of the young, M1Ve, debris disk star, AU Microscopii. The data were obtained in three continuum filters spanning a wavelength range from 4500\AA to 6600\AA, plus H$\alpha$, over 28 nights in 2005. The lightcurves show intrinsic stellar variability due to starspots with an amplitude in the blue band of 0.051 magnitudes and a period of 4.847 days. In addition, three large flares were detected in the data which all occur near the minimum brightness of the star. We remove the intrinsic stellar variability and combine the lightcurves of all the filters in order to search for transits by possible planetary companions orbiting in the plane of the nearly edge-on debris disk. The combined final lightcurve has a sampling of 0.35 minutes and a standard deviation of 6.8 millimags (mmag). We performed Monte Carlo simulations by adding fake transits to the observed lightcurve and find with 95% significance that there are no Jupiter mass planets orbiting in the plane of the debris disk on circular orbits with periods, P $\le 5$ days. In addition, there are no young Neptune-like planets (with radii 2.5$\times$ smaller than the young Jupiter) on circular orbits with periods, P $\le 3$ days.Comment: accepted to MNRA

Phosphorus Availability Regulates TORC1 Signaling via LST8 in Chlamydomonas

Target of rapamycin complex 1 (TORC1) is a central regulator of cell growth. It balances anabolic and catabolic processes in response to nutrients, growth factors, and energy availability. Nitrogen- and carbon-containing metabolites have been shown to activate TORC1 in yeast, animals, and plants. Here, we show that phosphorus (P) regulates TORC1 signaling in the model green alga Chlamydomonas (Chlamydomonas reinhardtii) via LST8, a conserved TORC1 subunit that interacts with the kinase domain of TOR. P starvation results in a sharp decrease in LST8 abundance and downregulation of TORC1 activity. A hypomorphic lst8 mutation resulted in decreased LST8 abundance, and it both reduced TORC1 signaling and altered the cellular response to P starvation. Additionally, we found that LST8 levels and TORC1 activity were not properly regulated in a mutant defective in the transcription factor PSR1, which is the major mediator of P deprivation responses in Chlamydomonas. Unlike wild-type cells, the psr1 mutant failed to downregulate LST8 abundance and TORC1 activity when under P limitation. These results identify PSR1 as an upstream regulator of TORC1 and demonstrate that TORC1 is a key component in P signaling in Chlamydomonas.España Ministerio de Economía y Competitividad (grants BFU2015-68216-P and PGC2018-099048- B-100 to J.L.C. and grant BIO2015-74432-JIN to M.E.P.-P.)National Science Foundation (CAREER award MCB-1552522 to L.M.H. and grant MCB-1616820 to J.G.U.)European Commission (grant number 750996

The other side of the coin: harm due to the non-use of health-related data

ABSTRACT Objectives It is widely acknowledged that breaches and misuses of health-related data can have serious implications and consequently they often carry penalties. However, harm due to the omission of health data usage, or data non use, is a subject that lacks attention. A better understanding of this other side of the coin is required before it can be addressed effectively. Approach This article uses an international case study approach to explore why data non use is difficult to ascertain, the sources and types of health-related data non-use, its implications for citizens and society and some of the reasons it occurs. It does this by focussing on issues with clinical care records, research data and governance frameworks and associated examples of non-use. Results The non-use of health-related data is a complex issue with multiple sources and reasons contributing to it. Instances of data non-use can be associated with harm, but taken together they describe a trail of data non-use, and this may complicate and compound its impacts. Actual evidence of data non-use is sparse and harm due to data non use is difficult to prove. But although it can be nebulous, it is a real problem with largely unquantifiable consequences. There is ample indirect evidence that health data non-use is implicated in the deaths of many thousands of people and potentially £billions in financial burdens to societies. Conclusion The most effective initiatives to address specific contexts of data non-use will be those that are cognisant of the multiple aspects to this complex issue, in order to move towards socially responsible reuse of data becoming the norm to save lives and resources

Get on Your Feet and Up To Speed: Ways to Start-Up or Scale-Up an OER Initiative

How can you get started with or “scale-up” OER practices at your institution? And how will the library fit in? Two or three years ago, “OER Librarian” wasn’t even a title, but in a relatively short time librarians at all 24 campuses of the City University of New York (CUNY) have taken on a multitude of different roles to support OER initiatives. Each campus has come on board with its own timeline and developed its own structure and workflows to accomplish this work, in alignment with campus culture. While many have taken positions in support of individual faculty OER developers and become fierce advocates for open initiatives, the full range of how librarians contribute plays out very differently on each campus. At the same time, librarians collaborate across the campuses via an OER committee/working group overseen by the CUNY Office of Library Services, uniquely positioning us to observe and discuss best practices as well as the varying models of OER support. Join us for a panel featuring individual case studies and a facilitated conversation among CUNY OER librarians about developing, evolving, and scaling up OER initiatives at community colleges, four-year colleges, and graduate research institutions. We will explore questions such as: Which entity on campus is in the driver’s seat? How does intra-campus collaboration play out? What are the labor implications of these new initiatives for librarians and other faculty? Where do definitions of OER, ZTC (zero-textbook cost), and open pedagogy intersect and overlap