1,064 research outputs found

    Optically Thin Core Accretion: How Planets Get Their Gas in Nearly Gas-Free Disks

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    Models of core accretion assume that in the radiative zones of accreting gas envelopes, radiation diffuses. But super-Earths/sub-Neptunes (1-4RR_\oplus, 2-20MM_\oplus) point to formation conditions that are optically thin: their modest gas masses are accreted from short-lived and gas-poor nebulae reminiscent of the transparent cavities of transitional disks. Planetary atmospheres born in such environments can be optically thin to both incident starlight and internally generated thermal radiation. We construct time-dependent models of such atmospheres, showing that super-Earths/sub-Neptunes can accrete their \sim1%-by-mass gas envelopes, and super-puffs/sub-Saturns their \sim20%-by-mass envelopes, over a wide range of nebular depletion histories requiring no fine tuning. Although nascent atmospheres can exhibit stratospheric temperature inversions effected by atomic Fe and various oxides that absorb strongly at visible wavelengths, the rate of gas accretion remains controlled by the radiative-convective boundary (rcb) at much greater pressures. For dusty envelopes, the temperature at the rcb Trcb2500T_{\rm rcb} \simeq 2500 K is still set by H2{\rm H}_2 dissociation; for dust-depleted envelopes, TrcbT_{\rm rcb} tracks the temperature of the visible or thermal photosphere, whichever is deeper, out to at least \sim5 AU. The rate of envelope growth remains largely unchanged between the old radiative diffusion models and the new optically thin models, reinforcing how robustly super-Earths form as part of the endgame chapter in disk evolution.Comment: accepted to MNRAS, new section 4.2 connects our formation scenario of super-Earths to atmospheric mass los

    Atypical propylthiouracil-induced ANCA-positive vasculitis: report of a case with unusual clinical and histopathologic findings

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    The side effects of propylthiouracil, including cytopenia and vasculitis, are well established.  We present an interesting case in which cytopenia and cutaneous vasculopathy occurred concomitantly in a critically ill patient.  The patient was initially treated for suspected infection until dermatologic and rheumatologic workup revealed ANCA-positivity and vasculopathy on histopathology, most consistent with an atypical presentation of ANCA-positive vasculitis.  Upon initiation of immunosuppressive therapy, the patient’s condition rapidly improved emphasizing the importance of early recognition of this condition

    GUAN AND SHAMING AMONG CHINESE FAMILIES IN THE UNITED STATES: THE MODERATING EFFECTS OF PERCEIVED CULTURAL NORMATIVENESS

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    This study utilized a confluence of propositions within interpersonal acceptance-rejection theory, the developmental niche model, model of acculturation strategies, and the cultural normativeness hypothesis to examine links between shaming and training parenting strategies, and psychological and academic outcomes among children of Chinese immigrants living in the U.S. The sample consisted of 51 Chinese ninth and tenth grade children and their mothers residing in the Cleveland metropolitan area. Mothers and children were asked to complete the Parental Training Scale, Critical Comparison and Shaming Questionnaire (CCS), and also asked about their perception of the normativeness of these parenting practices in their community. Mothers also filled out the Kessler 10 Psychological Distress Scale, and children were asked to report on their end of year letter grades. The research questions explored included: (1) What was the prevalence of the use of guan and shaming among Chinese-American mothers and did they vary by generational status and socio-economic status? (2) What were the direct associations between maternal use of guan and shaming and Chinese American 9th and 10th grade children’s psychological distress and academic performance? and (3) Did children’s perceptions of the normativeness of the use of guan and shaming moderate the associations between the use of guan and shaming and children’s psychological distress and academic performance? Did mother’s perceptions of the normativeness of the use of guan and shaming moderate the associations between their use of guan and shaming and children’s psychological distress and academic performance? Data were analyzed using one-way analysis of variance (ANOVA) and multiple regression techniques. Results indicated that mothers in the study strongly endorsed guan parenting, but less so shaming parenting. Mothers’ reports of shaming was a significant predictor of children’s psychological distress, but not children’s academic performance. Children’s reports of guan and shaming were significant predictors of their academic performance, but not their psychological distress. Children’s perceived cultural normativeness moderated the relation between maternal use of shaming and children’s psychological distress such that the association between mothers’ reports of the use of shaming and children’s psychological distress was stronger for children perceiving low cultural normativeness of shaming than for those perceiving high cultural normativeness of shaming. Findings are discussed in terms of the prevalence of the two indigenous parenting practices in Chinese immigrant families and their associations with children’s social adjustment and academic outcomes

    Impact of multimorbidity count on all-cause mortality and glycaemic outcomes in people with type 2 diabetes: a systematic review protocol

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    Introduction: Type 2 diabetes (T2D) is a leading health priority worldwide. Multimorbidity (MM) is a term describing the co-occurrence of two or more chronic diseases or conditions. The majority of people living with T2D have MM. The relationship between MM and mortality and glycaemia in people with T2D is not clear. Methods and analysis: Medline, Embase, Cumulative Index of Nursing and Allied Health Complete, The Cochrane Library, and SCOPUS will be searched with a prespecified search strategy. The searches will be limited to quantitative empirical studies in English with no restriction on publication date. One reviewer will perform title screening and two review authors will independently screen the abstract and full texts using Covidence software, with disagreements adjudicated by a third reviewer. Data will be extracted using a using a Population, Exposure, Comparator and Outcomes framework. Two reviewers will independently extract data and undertake the risk of bias (quality) assessment. Disagreements will be resolved by consensus. A narrative synthesis of the results will be conducted and meta-analysis considered if appropriate. Quality appraisal will be undertaken using the Newcastle-Ottawa quality assessment scale and the quality of the cumulative evidence of the included studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. This protocol was prepared in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines to ensure the quality of our review. Ethics and dissemination: This review will synthesise the existing evidence about the impact of MM on mortality and glycaemic outcomes in people living with T2D and increase our understanding of this subject and will inform future practice and policy. Findings will be disseminated via conference presentations, social media and peer-reviewed publication

    Bringing "The Moth" to Light: A Planet-Sculpting Scenario for the HD 61005 Debris Disk

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    The HD 61005 debris disk ("The Moth") stands out from the growing collection of spatially resolved circumstellar disks by virtue of its unusual swept-back morphology, brightness asymmetries, and dust ring offset. Despite several suggestions for the physical mechanisms creating these features, no definitive answer has been found. In this work, we demonstrate the plausibility of a scenario in which the disk material is shaped dynamically by an eccentric, inclined planet. We present new Keck NIRC2 scattered-light angular differential imaging of the disk at 1.2-2.3 microns that further constrains its outer morphology (projected separations of 27-135 AU). We also present complementary Gemini Planet Imager 1.6 micron total intensity and polarized light detections that probe down to projected separations less than 10 AU. To test our planet-sculpting hypothesis, we employed secular perturbation theory to construct parent body and dust distributions that informed scattered-light models. We found that this method produced models with morphological and photometric features similar to those seen in the data, supporting the premise of a planet-perturbed disk. Briefly, our results indicate a disk parent body population with a semimajor axis of 40-52 AU and an interior planet with an eccentricity of at least 0.2. Many permutations of planet mass and semimajor axis are allowed, ranging from an Earth mass at 35 AU to a Jupiter mass at 5 AU.Comment: Accepted to AJ; added Figure 5 and minor text edit

    Association of Over-The-Counter Pharmaceutical Sales with Influenza-Like-Illnesses to Patient Volume in an Urgent Care Setting

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    We studied the association between OTC pharmaceutical sales and volume of patients with influenza-like-illnesses (ILI) at an urgent care center over one year. OTC pharmaceutical sales explain 36% of the variance in the patient volume, and each standard deviation increase is associated with 4.7 more patient visits to the urgent care center (p<0.0001). Cross-correlation function analysis demonstrated that OTC pharmaceutical sales are significantly associated with patient volume during non-flu season (p<0.0001), but only the sales of cough and cold (p<0.0001) and thermometer (p<0.0001) categories were significant during flu season with a lag of two and one days, respectively. Our study is the first study to demonstrate and measure the relationship between OTC pharmaceutical sales and urgent care center patient volume, and presents strong evidence that OTC sales predict urgent care center patient volume year round. © 2013 Liu et al

    Detection of Strong Millimeter Emission from the Circumstellar Dust Disk Around V1094 Sco: Cold and Massive Disk around a T Tauri Star in a Quiescent Accretion Phase?

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    We present the discovery of a cold massive dust disk around the T Tauri star V1094 Sco in the Lupus molecular cloud from the 1.1 millimeter continuum observations with AzTEC on ASTE. A compact (rr\lesssim320 AU) continuum emission coincides with the stellar position having a flux density of 272 mJy which is largest among T Tauri stars in Lupus. We also present the detection of molecular gas associated with the star in the five-point observations in 12^{12}CO J=3--2 and 13^{13}CO J=3--2. Since our 12^{12}CO and 13^{13}CO observations did not show any signature of a large-scale outflow or a massive envelope, the compact dust emission is likely to come from a disk around the star. The observed SED of V1094 Sco shows no distinct turnover from near infrared to millimeter wavelengths, which can be well described by a flattened disk for the dust component, and no clear dip feature around 10 \micron suggestive of absence of an inner hole in the disk. We fit a simple power-law disk model to the observed SED. The estimated disk mass ranges from 0.03 to \gtrsim0.12 M_\sun, which is one or two orders of magnitude larger than the median disk mass of T Tauri stars in Taurus.Comment: 18 pages, 4 figures, accepted for publication in Ap
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