Kepler-68: Three Planets, One With a Density Between That of Earth and Ice Giants

NASA's Kepler Mission has revealed two transiting planets orbiting Kepler-68. Follow-up Doppler measurements have established the mass of the innermost planet and revealed a third jovian-mass planet orbiting beyond the two transiting planets. Kepler-68b, in a 5.4 day orbit has mass 8.3 +/- 2.3 Earth, radius 2.31 +/- 0.07 Earth radii, and a density of 3.32 +/- 0.92 (cgs), giving Kepler-68b a density intermediate between that of the ice giants and Earth. Kepler-68c is Earth-sized with a radius of 0.953 Earth and transits on a 9.6 day orbit; validation of Kepler-68c posed unique challenges. Kepler-68d has an orbital period of 580 +/- 15 days and minimum mass of Msin(i) = 0.947 Jupiter. Power spectra of the Kepler photometry at 1-minute cadence exhibit a rich and strong set of asteroseismic pulsation modes enabling detailed analysis of the stellar interior. Spectroscopy of the star coupled with asteroseismic modeling of the multiple pulsation modes yield precise measurements of stellar properties, notably Teff = 5793 +/- 74 K, M = 1.079 +/- 0.051 Msun, R = 1.243 +/- 0.019 Rsun, and density 0.7903 +/- 0.0054 (cgs), all measured with fractional uncertainties of only a few percent. Models of Kepler-68b suggest it is likely composed of rock and water, or has a H and He envelope to yield its density of about 3 (cgs).Comment: 32 pages, 13 figures, Accepted to Ap

Stellar Spin-Orbit Misalignment in a Multiplanet System

Stars hosting hot Jupiters are often observed to have high obliquities, whereas stars with multiple co-planar planets have been seen to have low obliquities. This has been interpreted as evidence that hot-Jupiter formation is linked to dynamical disruption, as opposed to planet migration through a protoplanetary disk. We used asteroseismology to measure a large obliquity for Kepler-56, a red giant star hosting two transiting co-planar planets. These observations show that spin-orbit misalignments are not confined to hot-Jupiter systems. Misalignments in a broader class of systems had been predicted as a consequence of torques from wide-orbiting companions, and indeed radial-velocity measurements revealed a third companion in a wide orbit in the Kepler-56 system.Comment: Accepted for publication in Science, published online on October 17 2013; PDF includes main article and supplementary materials (65 pages, 27 figures, 7 tables); v2: small correction to author lis

Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology

We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14, Kepler-23 and Kepler-25) and increase the total number of Kepler host stars with asteroseismic solutions to 77. A comparison with stellar properties in the planet-candidate catalog by Batalha et al. shows that radii for subgiants and giants obtained from spectroscopic follow-up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement. We furthermore apply asteroseismology to confirm that a large majority of cool main-sequence hosts are indeed dwarfs and not misclassified giants. Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant-planet/brown-dwarf/stellar regime to a sub-Jupiter size, or vice versa. A comparison of stellar densities from asteroseismology with densities derived from transit models in Batalha et al. assuming circular orbits shows significant disagreement for more than half of the sample due to systematics in the modeled impact parameters, or due to planet candidates which may be in eccentric orbits. Finally, we investigate tentative correlations between host-star masses and planet candidate radii, orbital periods, and multiplicity, but caution that these results may be influenced by the small sample size and detection biases.Comment: 19 pages, 10 figures, 4 tables; accepted for publication in ApJ; machine-readable versions of tables 1-3 are available as ancillary files or in the source code; v2: minor changes to match published versio

Inside-Out Corporate Governance

Until late in the twentieth century, internal corporate governance—that is, decision making by the principal constituencies of the firm—was clearly distinct from outside oversight by regulators, auditors and credit rating agencies, and markets. With the 1980s takeover wave and hedge funds’ and equity funds’ more recent involvement in corporate governance, the distinction between inside and outside governance has eroded. The tools of inside governance are now routinely employed by governance outsiders, intertwining the two traditional modes of governance. We argue in this Article that the shift has created a new governance paradigm, which we call inside-out corporate governance. Using the inside-out model as our lens, and drawing on comparisons to Italian and E.U. governance, we explore three areas of corporate governance that have been pervasively restructured by the Dodd-Frank Act and subsequent regulation: proxy access, credit rating agencies, and derivatives. We begin, in Part I, with proxy access, arguing that the new scheme for minority shareholder access excludes the very outsiders it ostensibly integrates into corporate governance. In Part II, which focuses on auditing and credit rating agencies, we argue that the inside-out relationship—in which the corporation itself chooses its gatekeeper—is deeply problematic but cannot be “cured.” The most realistic strategy is to create more flexibility in the audit relationship, and diminish the importance of credit ratings. Part III analyzes the new derivatives regulation. Here, we argue that Congress’s effort to sharply separate the inside and outside uses of derivatives is incoherent from a corporate governance perspective. We conclude by briefly speculating about the future implications of inside-out governance

Inside-Out Corporate Governance

Until late in the twentieth century, internal corporate governance—that is, decision making by the principal constituencies of the firm—was clearly distinct from outside oversight by regulators, auditors and credit rating agencies, and markets. With the 1980s takeover wave and hedge funds’ and equity funds’ more recent involvement in corporate governance, the distinction between inside and outside governance has eroded. The tools of inside governance are now routinely employed by governance outsiders, intertwining the two traditional modes of governance. We argue in this Article that the shift has created a new governance paradigm, which we call inside-out corporate governance. Using the inside-out model as our lens, and drawing on comparisons to Italian and E.U. governance, we explore three areas of corporate governance that have been pervasively restructured by the Dodd-Frank Act and subsequent regulation: proxy access, credit rating agencies, and derivatives. We begin, in Part I, with proxy access, arguing that the new scheme for minority shareholder access excludes the very outsiders it ostensibly integrates into corporate governance. In Part II, which focuses on auditing and credit rating agencies, we argue that the inside-out relationship—in which the corporation itself chooses its gatekeeper—is deeply problematic but cannot be “cured.” The most realistic strategy is to create more flexibility in the audit relationship, and diminish the importance of credit ratings. Part III analyzes the new derivatives regulation. Here, we argue that Congress’s effort to sharply separate the inside and outside uses of derivatives is incoherent from a corporate governance perspective. We conclude by briefly speculating about the future implications of inside-out governance

Preliminary study of illumination levels in university and elementary classrooms in Campina Grande, Brazil

The purpose of our study was to provide preliminary data on light levels used in university and elementary school classrooms in Campina Grande, Brazil with the aim of providing Brazilian politicians and educators with data to support continued educational initiatives in northeast Brazil. The data were gathered at the Universidade Federal de Campina Grande (UFCG) and compared with a sample of classrooms at Oklahoma State University (OSU) in Stillwater Oklahoma. The results indicated that many seats within UFCG classrooms met or exceeded minimum standards but significant numbers did not. Moreover, compared to classrooms at OSU, UFCG classrooms are not as highly illuminated and the Brazilian elementary classrooms examined did not meet minimum illumination standards.Peer reviewedPsychologyZoolog

Price survey comparison of alcoholic beverages with the five basic food groups in Paraiba, Brazil

The study of alcohol abuse is relatively new in Brazil. Government estimates suggest that 11.2% of the Brazilian population is alcohol dependent. Problems associated with alcohol dependence include domestic violence, increased risk of traffic accidents, poor self-esteem and weak academic performance. A factor known to correlate with alcohol abuse in 12-17 year olds is to have the money necessary to purchase alcoholic beverages. No data is available, however, on the price of alcoholic beverages. The objective of the present study was to provide data on price and to compare the price of alcoholic beverages to basic food items in the Brazilian diet. We also had interest in studying a population in the northeast region of Brazil. This region is the poorest in Brazil, has the highest percentage of alcohol dependency and is seldom the focus of research on dependency. We report that the prices of many alcoholic beverages are less than the price of basic food items. Prices of alcoholic beverages including beer, wine and spirits were compared to the prices of select food items as represented in the Food Pyramid. Food items were selected from the categories of Grain, Dairy, Fruit, Meat and Vegetable. Data was gathered from 32 supermarkets in 8 cities in the northeast state of Paraiba. The price of alcohol is generally less expensive than most basic food group items, especially brands of cachaca (a spirit distilled from sugar cane) and beer. Data on price should be considered in any alcohol dependency program in Brazil.Peer reviewedPsycholog

Ectodermal Influx and Cell Hypertrophy Provide Early Growth for All Murine Mammary Rudiments, and Are Differentially Regulated among Them by Gli3

Mammary gland development starts in utero with one or several pairs of mammary rudiments (MRs) budding from the surface ectodermal component of the mammalian embryonic skin. Mice develop five pairs, numbered MR1 to MR5 from pectoral to inguinal position. We have previously shown that Gli3Xt-J/Xt-J mutant embryos, which lack the transcription factor Gli3, do not form MR3 and MR5. We show here that two days after the MRs emerge, Gli3Xt-J/Xt-J MR1 is 20% smaller, and Gli3Xt-J/Xt-J MR2 and MR4 are 50% smaller than their wild type (wt) counterparts. Moreover, while wt MRs sink into the underlying dermis, Gli3Xt-J/Xt-J MR4 and MR2 protrude outwardly, to different extents. To understand why each of these five pairs of functionally identical organs has its own, distinct response to the absence of Gli3, we determined which cellular mechanisms regulate growth of the individual MRs, and whether and how Gli3 regulates these mechanisms. We found a 5.5 to 10.7-fold lower cell proliferation rate in wt MRs compared to their adjacent surface ectoderm, indicating that MRs do not emerge or grow via locally enhanced cell proliferation. Cell-tracing experiments showed that surface ectodermal cells are recruited toward the positions where MRs emerge, and contribute to MR growth during at least two days. During the second day of MR development, peripheral cells within the MRs undergo hypertrophy, which also contributes to MR growth. Limited apoptotic cell death counterbalances MR growth. The relative contribution of each of these processes varies among the five MRs. Furthermore, each of these processes is impaired in the absence of Gli3, but to different extents in each MR. This differential involvement of Gli3 explains the variation in phenotype among Gli3Xt-J/Xt-J MRs, and may help to understand the variation in numbers and positions of mammary glands among mammals

Water Contamination Reduces the Tolerance of Coral Larvae to Thermal Stress

Coral reefs are highly susceptible to climate change, with elevated sea surface temperatures (SST) posing one of the main threats to coral survival. Successful recruitment of new colonies is important for the recovery of degraded reefs following mortality events. Coral larvae require relatively uncontaminated substratum on which to metamorphose into sessile polyps, and the increasing pollution of coastal waters therefore constitutes an additional threat to reef resilience. Here we develop and analyse a model of larval metamorphosis success for two common coral species to quantify the interactive effects of water pollution (copper contamination) and SST. We identify thresholds of temperature and pollution that prevent larval metamorphosis, and evaluate synergistic interactions between these stressors. Our analyses show that halving the concentration of Cu can protect corals from the negative effects of a 2–3°C increase in SST. These results demonstrate that effective mitigation of local impacts can reduce negative effects of global stressors