Fomalhaut's Debris Disk and Planet: Constraining the Mass of Formalhaut B from Disk Morphology

Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M(sub pl) 101.5AU, and an orbital eccentricity e(sub pl) = 0.11 - 0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a approximately equals 133AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e approximately equals 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of approximately 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to approximately 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties are difficult to quantify. Even if the apsidal misalignment proves real, our calculated upper mass limit of 3 M(sub J) still holds. Parent bodies are evacuated from mean-motion resonances with Fom b; these empty resonances are akin to the Kirkwood gaps opened by Jupiter. The belt contains at least 3M(sub Earth) of solids that are grinding down to dust, their velocity dispersions stirred so strongly by Fom b that collisions are destructive. Such a large mass in solids is consistent with Fom b having formed in situ

Exercise, or exercise and diet for the management of polycystic ovary syndrome:a systematic review and meta-analysis

Background: Typically, management of PCOS focuses on lifestyle changes (exercise and diet), aiming to alleviate symptoms, and lower the associated risk of type 2 diabetes and cardiovascular disease. Our objective was to analyse evidence on the effectiveness of exercise in the management of PCOS, when compared to (i) usual care, (ii) diet alone, and (iii) exercise combined with diet, and also exercise combined with diet, compared to (i) control or usual care and (ii) diet alone. Methods: Relevant databases were searched (June 2017) with no time limit for trial inclusion. Eligible trials employed a randomised or quasi-randomised design to measure the chronic effects of exercise, or exercise and diet in women with PCOS. Results: Searches returned 2390 articles; of those, 27 papers from 18 trials were included. Results are presented as mean difference (MD) and 95% confidence intervals (95% CI). Compared with control, exercise had a statistical effect on change from baseline fasting insulin (MD - 2.44 μIU/mL, 95% CIs - 4.24 to - 0.64; very low-quality evidence), HOMA-IR (- 0.57, - 0.99 to - 0.14; very low-quality evidence), total cholesterol (- 5.88 mg/dL, - 9.92 to - 1.83; low-quality evidence), LDL cholesterol (- 7.39 mg/dL, - 9.83 to - 4.95; low-quality evidence), and triglycerides (- 4.78 mg/dL, - 7.52 to - 2.05; low-quality evidence). Exercise also improved VO 2 max (3.84 ml/kg/min, 2.87 to 4.81), waist circumference (- 2.62 cm, - 4.13 to - 1.11), and body fat percentage (- 1.39%, - 2.61 to - 0.18) when compared with usual care. No effect was found for change value systolic/diastolic blood pressure, fasting glucose, HDL cholesterol (all low-quality evidence), or waist-to-hip ratio. Many favourable change score findings were supported by post-intervention value analyses: fasting insulin (- 2.11 μIU/mL, - 3.49 to - 0.73), total cholesterol (- 6.66 mg/dL, - 11.14 to - 2.17), LDL cholesterol (- 6.91 mg/dL, - 12.02 to - 1.80), and VO 2 max (5.01 ml/kg/min, 3.48 to 6.54). Statistically lower BMI (- 1.02 kg/m 2 , - 1.81 to - 0.23) and resting heart rate (- 3.26 beats/min - 4.93 to - 1.59) were also revealed in post-intervention analysis. Subgroup analyses revealed the greatest improvements in overweight/obese participants, and more outcomes improved when interventions were supervised, aerobic in nature, or of a shorter duration. Based on limited data, we found no differences for any outcome between the effects of exercise and diet combined, and diet alone. It was not possible to compare exercise vs diet or exercise and diet combined vs diet. Conclusion: Statistically beneficial effects of exercise were found for a range of metabolic, anthropometric, and cardiorespiratory fitness-related outcomes. However, caution should be adopted when interpreting these findings since many outcomes present modest effects and wide CIs, and statistical effects in many analyses are sensitive to the addition/removal of individual trials. Future work should focus on rigorously designed, well-reported trials that make comparisons involving both exercise and diet

Unveiling Shrouded Oceans on Temperate sub-Neptunes via Transit Signatures of Solubility Equilibria versus Gas Thermochemistry

The recent discovery and initial characterization of sub-Neptune-sized exoplanets that receive stellar irradiance of approximately Earth's raised the prospect of finding habitable planets in the coming decade, because some of these temperate planets may support liquid-water oceans if they do not have massive H2/He envelopes and are thus not too hot at the bottom of the envelopes. For planets larger than Earth, and especially planets in the 1.7-3.5 R⊕ population, the mass of the H2/He envelope is typically not sufficiently constrained to assess the potential habitability. Here we show that the solubility equilibria versus thermochemistry of carbon and nitrogen gases typically results in observable discriminators between small H2 atmospheres versus massive ones, because the condition to form a liquid-water ocean and that to achieve the thermochemical equilibrium are mutually exclusive. The dominant carbon and nitrogen gases are typically CH4 and NH3 due to thermochemical recycling in a massive atmosphere of a temperate planet, and those in a small atmosphere overlying a liquid-water ocean are most likely CO2 and N2, followed by CO and CH4 produced photochemically. NH3 is depleted in the small atmosphere by dissolution into the liquid-water ocean. These gases lead to distinctive features in the planet's transmission spectrum, and a moderate number of transit observations with the James Webb Space Telescope should tell apart a small atmosphere versus a massive one on planets like K2-18 b. This framework thus points to a way to use near-term facilities to constrain the atmospheric mass and habitability of temperate sub-Neptune exoplanets

Geodynamics and Rate of Volcanism on Massive Earth-like Planets

We provide estimates of volcanism versus time for planets with Earth-like composition and masses from 0.25 to 25 times Earth, as a step toward predicting atmospheric mass on extrasolar rocky planets. Volcanism requires melting of the silicate mantle. We use a thermal evolution model, calibrated against Earth, in combination with standard melting models, to explore the dependence of convection-driven decompression mantle melting on planet mass. Here we show that (1) volcanism is likely to proceed on massive planets with plate tectonics over the main-sequence lifetime of the parent star; (2) crustal thickness (and melting rate normalized to planet mass) is weakly dependent on planet mass; (3) stagnant lid planets live fast (they have higher rates of melting than their plate tectonic counterparts early in their thermal evolution) but die young (melting shuts down after a few Gyr); (4) plate tectonics may not operate on high mass planets because of the production of buoyant crust which is difficult to subduct; and (5) melting is necessary but insufficient for efficient volcanic degassing - volatiles partition into the earliest, deepest melts, which may be denser than the residue and sink to the base of the mantle on young, massive planets. Magma must also crystallize at or near the surface, and the pressure of overlying volatiles must be fairly low, if volatiles are to reach the surface. If volcanism is detected in the Tau Ceti system, and tidal forcing can be shown to be weak, this would be evidence for plate tectonics.Comment: Revised version, accepted by Astrophysical Journa

Predictably confirmatory: The influence of stereotypes during decisional processing.

Stereotypes facilitate the processing of expectancy-consistent (vs expectancy-inconsistent) information, yet the underlying origin of this congruency effect remains unknown. As such, here we sought to identify the cognitive operations through which stereotypes influence decisional processing. In six experiments, participants responded to stimuli that were consistent or inconsistent with respect to prevailing gender stereotypes. To identify the processes underpinning task performance, responses were submitted to a hierarchical drift diffusion model (HDDM) analysis. A consistent pattern of results emerged. Whether manipulated at the level of occupational (Expts. 1, 3, and 5) or trait-based (Expts. 2, 4, and 6) expectancies, stereotypes facilitated task performance and influenced decisional processing via a combination of response and stimulus biases. Specifically, (1) stereotype-consistent stimuli were classified more rapidly than stereotype-inconsistent stimuli; (2) stereotypic responses were favoured over counter-stereotypic responses (i.e., starting-point shift towards stereotypic responses); (3) less evidence was required when responding to stereotypic than counter-stereotypic stimuli (i.e., narrower threshold separation for stereotypic stimuli); and (4) decisional evidence was accumulated more efficiently for stereotype-inconsistent than stereotype-consistent stimuli and when targets had a typical than atypical facial appearance. Collectively, these findings elucidate how stereotypes influence person construal

The Influence of Polycystic Ovary Syndrome (PCOS) and Other Related Factors upon Health-Related Quality of Life in Women of Reproductive Age: A Case-Control Study

This study aimed to assess the impact of a polycystic ovary syndrome (PCOS) diagnosis and other factors on health-related quality of life (HRQoL) in women of reproductive age. Online questionnaires were completed and study groups compared. Potential causal relationships were evaluated using path analysis. Analyses revealed that a PCOS diagnosis alongside BMI had the largest effect on HRQoL. Higher levels of physical activity (PA) were not associated with greater HRQoL, and PA was not directly affected by any other outcome. However, reduced self-esteem was identified as a key factor in the promotion of physical and mental health

Linking the oceans to public health : current efforts and future directions

© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License The definitive version was published in Environmental Health 7 (2008): S6, doi:10.1186/1476-069X-7-S2-S6.We review the major linkages between the oceans and public health, focusing on exposures and potential health effects due to anthropogenic and natural factors including: harmful algal blooms, microbes, and chemical pollutants in the oceans; consumption of seafood; and flooding events. We summarize briefly the current state of knowledge about public health effects and their economic consequences; and we discuss priorities for future research. We find that: • There are numerous connections between the oceans, human activities, and human health that result in both positive and negative exposures and health effects (risks and benefits); and the study of these connections comprises a new interdisciplinary area, "oceans and human health." • The state of present knowledge about the linkages between oceans and public health varies. Some risks, such as the acute health effects caused by toxins associated with shellfish poisoning and red tide, are relatively well understood. Other risks, such as those posed by chronic exposure to many anthropogenic chemicals, pathogens, and naturally occurring toxins in coastal waters, are less well quantified. Even where there is a good understanding of the mechanism for health effects, good epidemiological data are often lacking. Solid data on economic and social consequences of these linkages are also lacking in most cases. • The design of management measures to address these risks must take into account the complexities of human response to warnings and other guidance, and the economic tradeoffs among different risks and benefits. Future research in oceans and human health to address public health risks associated with marine pathogens and toxins, and with marine dimensions of global change, should include epidemiological, behavioral, and economic components to ensure that resulting management measures incorporate effective economic and risk/benefit tradeoffs.Funding was provided in part by the NSF-NIEHS Oceans Centers at Woods Hole, University of Hawaii, University of Miami, and University of Washington, and the NOAA Oceans and Human Health Initiative Centers of Excellent in Charleston, Seattle and Milwaukee, the National Center for Environmental Health (NCEH) of the Centers for Disease Control and Prevention (CDC), and the WHOI Marine Policy Center. Grant numbers are: NIEHS P50 ES012742 and NSF OCE-043072 (HLKP, RJG, PH); NSF OCE 0432368 and NIEHS P50 ES12736 (LEF); NIEHS P50 ES012762 and NSF OCE-0434087 (EMF, AT, LRY); NSF OCE04-32479 and NIEHS P50 ES012740 (BAW

Possible Disintegrating Short-Period Super-Mercury Orbiting KIC 12557548

We report here on the discovery of stellar occultations, observed with Kepler, that recur periodically at 15.685 hour intervals, but which vary in depth from a maximum of 1.3% to a minimum that can be less than 0.2%. The star that is apparently being occulted is KIC 12557548, a K dwarf with T_eff = 4400 K and V = 16. Because the eclipse depths are highly variable, they cannot be due solely to transits of a single planet with a fixed size. We discuss but dismiss a scenario involving a binary giant planet whose mutual orbit plane precesses, bringing one of the planets into and out of a grazing transit. We also briefly consider an eclipsing binary, that either orbits KIC 12557548 in a hierarchical triple configuration or is nearby on the sky, but we find such a scenario inadequate to reproduce the observations. We come down in favor of an explanation that involves macroscopic particles escaping the atmosphere of a slowly disintegrating planet not much larger than Mercury. The particles could take the form of micron-sized pyroxene or aluminum oxide dust grains. The planetary surface is hot enough to sublimate and create a high-Z atmosphere; this atmosphere may be loaded with dust via cloud condensation or explosive volcanism. Atmospheric gas escapes the planet via a Parker-type thermal wind, dragging dust grains with it. We infer a mass loss rate from the observations of order 1 M_E/Gyr, with a dust-to-gas ratio possibly of order unity. For our fiducial 0.1 M_E planet, the evaporation timescale may be ~0.2 Gyr. Smaller mass planets are disfavored because they evaporate still more quickly, as are larger mass planets because they have surface gravities too strong to sustain outflows with the requisite mass-loss rates. The occultation profile evinces an ingress-egress asymmetry that could reflect a comet-like dust tail trailing the planet; we present simulations of such a tail.Comment: 14 pages, 7 figures; submitted to ApJ, January 10, 2012; accepted March 21, 201

Endotoxin, cytokines and lipid peroxides in children with intussusception

Background: Intussusception is a relatively common paediatric surgical emergency. The aim of this study was to investigate selected in¯ammatory mediators in children with acute intussusception and to identify potentially useful plasma markers of clinical outcome. Methods: Clinical, radiographic, operative and pathological details were recorded prospectively of all children presenting to a single institution with a con®rmed diagnosis of acute intussusception during 1 year. Paired acute and convalescent venous blood samples were collected in a standard manner for blinded analysis of the following: malondialdehyde, C-reactive protein (CRP), interleukin (IL) 6, neopterin, tumour necrosis factor a, endotoxin, and immunoglobulin (Ig) G and IgM antiendotoxin core antibody (EndoCAb). Results: Thirty-two consecutive children (23 boys, nine girls) with a median age of 4 months were studied. Acute ileocolic intussusception was managed by air enema reduction (n = 19), operative reduction (n = 8) or surgical resection (n = 5). Peripheral blood cultures were sterile. Acute levels of plasma IL-6, neopterin and CRP were signi®cantly raised in comparison to both normal laboratory ranges and convalescent samples (P < 0´001). Using stepwise discriminant analysis, CRP was identi®ed as the best variable at distinguishing between the three treatment groups (P < 0´001). IgM EndoCAb concentrations were signi®cantly greater in the convalescent sera of all the patients (P < 0´001). Conclusion: Acute ileocolic intussusception in childhood is associated with endotoxinaemia and signi®cantly raised levels of circulating in¯ammatory cytokines. Plasma CRP at diagnosis showed a statistically signi®cant positive correlation with disease severity

Developing a Wellbeing Framework for Aboriginal and Torres Strait Islander Peoples Living with Chronic Disease (Wellbeing Study)

Addressing a need identified by Aboriginal and Torres Strait Islander peoples and their primary healthcare providers, this study developed a Wellbeing Framework for managing chronic disease in a manner that also supports wellbeing. Chronic care models that are currently in use usually focus upon the systems, resources and policies that are required to deliver care. The important roles of culture, spirituality, Country and family in maintaining health and wellbeing are notably absent from such models. Re-defining the way in which care is delivered to reflect Aboriginal and Torres Strait Islander peoples’ needs and values is essential for improving the accessibility and acceptability of primary healthcare services.The research reported in this paper is a project of the Australian Primary Health Care Research Institute which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research Evaluation and Development Strategy