39 research outputs found

    Orbital Architectures of Planet-Hosting Binaries:I. Forming Five Small Planets in the Truncated Disk of Kepler-444A

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    We present the first results from our Keck program investigating the orbital architectures of planet-hosting multiple star systems. Kepler-444 is a metal-poor triple star system that hosts five sub-Earth-sized planets orbiting the primary star (Kepler-444A), as well as a spatially unresolved pair of M dwarfs (Kepler-444BC) at a projected distance of 1.8" (66 AU). We combine our Keck/NIRC2 adaptive optics astrometry with multi-epoch Keck/HIRES RVs of all three stars to determine a precise orbit for the BC pair around A, given their empirically constrained masses. We measure minimal astrometric motion (1.0±0.61.0\pm0.6 mas yr1^{-1}, or 0.17±0.100.17\pm0.10 km s1^{-1}), but our RVs reveal significant orbital velocity (1.7±0.21.7\pm0.2 km s1^{-1}) and acceleration (7.8±0.57.8\pm0.5 m s1^{-1} yr1^{-1}). We determine a highly eccentric stellar orbit (e=0.864±0.023e=0.864\pm0.023) that brings the tight M dwarf pair within 5.01.0+0.95.0^{+0.9}_{-1.0} AU of the planetary system. We validate that the system is dynamically stable in its present configuration via n-body simulations. We find that the A-BC orbit and planetary orbits are likely aligned (98%) given that they both have edge-on orbits and misalignment induces precession of the planets out of transit. We conclude that the stars were likely on their current orbits during the epoch of planet formation, truncating the protoplanetary disk at \approx2 AU. This truncated disk would have been severely depleted of solid material from which to form the total \approx1.5 MEarthM_{\rm Earth} of planets. We thereby strongly constrain the efficiency of the conversion of dust into planets and suggest that the Kepler-444 system is consistent with models that explain the formation of more typical close-in Kepler planets in normal, not truncated, disks.Comment: accepted to Ap

    Identifying associations between diabetes and acute respiratory distress syndrome in patients with acute hypoxemic respiratory failure: an analysis of the LUNG SAFE database

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    Background: Diabetes mellitus is a common co-existing disease in the critically ill. Diabetes mellitus may reduce the risk of acute respiratory distress syndrome (ARDS), but data from previous studies are conflicting. The objective of this study was to evaluate associations between pre-existing diabetes mellitus and ARDS in critically ill patients with acute hypoxemic respiratory failure (AHRF). Methods: An ancillary analysis of a global, multi-centre prospective observational study (LUNG SAFE) was undertaken. LUNG SAFE evaluated all patients admitted to an intensive care unit (ICU) over a 4-week period, that required mechanical ventilation and met AHRF criteria. Patients who had their AHRF fully explained by cardiac failure were excluded. Important clinical characteristics were included in a stepwise selection approach (forward and backward selection combined with a significance level of 0.05) to identify a set of independent variables associated with having ARDS at any time, developing ARDS (defined as ARDS occurring after day 2 from meeting AHRF criteria) and with hospital mortality. Furthermore, propensity score analysis was undertaken to account for the differences in baseline characteristics between patients with and without diabetes mellitus, and the association between diabetes mellitus and outcomes of interest was assessed on matched samples. Results: Of the 4107 patients with AHRF included in this study, 3022 (73.6%) patients fulfilled ARDS criteria at admission or developed ARDS during their ICU stay. Diabetes mellitus was a pre-existing co-morbidity in 913 patients (22.2% of patients with AHRF). In multivariable analysis, there was no association between diabetes mellitus and having ARDS (OR 0.93 (0.78-1.11); p = 0.39), developing ARDS late (OR 0.79 (0.54-1.15); p = 0.22), or hospital mortality in patients with ARDS (1.15 (0.93-1.42); p = 0.19). In a matched sample of patients, there was no association between diabetes mellitus and outcomes of interest. Conclusions: In a large, global observational study of patients with AHRF, no association was found between diabetes mellitus and having ARDS, developing ARDS, or outcomes from ARDS. Trial registration: NCT02010073. Registered on 12 December 2013

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

    Novel Use of Glidescope Indirect Laryngoscopy for Insertion of a Minnesota Tube for Variceal Bleeding

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    BACKGROUND: With improvements in endoscopic and interventional radiologic therapies, insertion of gastroesophageal balloon tamponade catheters, commonly known as Sengstaken-Blakemore or Minnesota tubes, is a rarely performed procedure for esophageal or gastric variceal bleeding. In small hospitals or freestanding emergency departments, endoscopic or interventional radiology (IR) therapies might not be available, so patients with exsanguinating variceal bleeding must be stabilized or temporized for transport to larger hospitals. Occasionally, tamponade devices are necessary as a rescue therapy for failed endoscopic or IR therapies or can be used as definitive therapy in select cases. In addition to being rarely performed, there are multiple technical complications associated with blind insertion of tamponade catheters. DISCUSSION: We describe a novel use of indirect laryngoscopy using a Glidescope for assisting in placement of a Minnesota tube in 4 patients with exsanguinating esophageal bleeding. CONCLUSIONS: Insertion of a Minnesota tube for bleeding esophageal or gastric varices is an uncommon, technically challenging procedure that can be lifesaving, and is something emergency physicians, intensivists, and gastroenterologists should be capable of performing. Addition of indirect laryngoscopy may help to improve rapid, safe, and successful placement of these devices

    Novel Use of Glidescope Indirect Laryngoscopy for Insertion of a Minnesota Tube for Variceal Bleeding.

    No full text
    BACKGROUND: With improvements in endoscopic and interventional radiologic therapies, insertion of gastroesophageal balloon tamponade catheters, commonly known as Sengstaken-Blakemore or Minnesota tubes, is a rarely performed procedure for esophageal or gastric variceal bleeding. In small hospitals or freestanding emergency departments, endoscopic or interventional radiology (IR) therapies might not be available, so patients with exsanguinating variceal bleeding must be stabilized or temporized for transport to larger hospitals. Occasionally, tamponade devices are necessary as a rescue therapy for failed endoscopic or IR therapies or can be used as definitive therapy in select cases. In addition to being rarely performed, there are multiple technical complications associated with blind insertion of tamponade catheters. DISCUSSION: We describe a novel use of indirect laryngoscopy using a Glidescope for assisting in placement of a Minnesota tube in 4 patients with exsanguinating esophageal bleeding. CONCLUSIONS: Insertion of a Minnesota tube for bleeding esophageal or gastric varices is an uncommon, technically challenging procedure that can be lifesaving, and is something emergency physicians, intensivists, and gastroenterologists should be capable of performing. Addition of indirect laryngoscopy may help to improve rapid, safe, and successful placement of these devices

    Morphological variability of the tallow tree, Pentadesma butyracea Sabine (Clusiaceae), in Benin

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    The seeds of Pentadesma butyracea (butter tree) are exploited by rural populations in West Africa to produce butter used for consumption and as an ingredient in cosmetics and medicinal preparations. To improve our knowledge of this under-studied species, the morphological variation of the trees, fruits and seeds in 12 natural populations of Benin distributed over a gradient of climate aridity is described with 14 quantitative and 13 qualitative descriptors. Most traits, except seed shape categories, show significant differences among populations. Multivariate analyses distinguish two eco-geographical groups: trees located in the more humid southern part of the species distribution are taller and have larger fruits and seeds than trees located in the north. To disentangle the relative roles of genetic variation and phenotypic plasticity in shaping, further phenotypic studies should be performed in common garden experiments. © 2012 Springer Science+Business Media B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Immunocompromised patients with acute respiratory distress syndrome: Secondary analysis of the LUNG SAFE database

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    Background: The aim of this study was to describe data on epidemiology, ventilatory management, and outcome of acute respiratory distress syndrome (ARDS) in immunocompromised patients. Methods: We performed a post hoc analysis on the cohort of immunocompromised patients enrolled in the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) study. The LUNG SAFE study was an international, prospective study including hypoxemic patients in 459 ICUs from 50 countries across 5 continents. Results: Of 2813 patients with ARDS, 584 (20.8%) were immunocompromised, 38.9% of whom had an unspecified cause. Pneumonia, nonpulmonary sepsis, and noncardiogenic shock were their most common risk factors for ARDS. Hospital mortality was higher in immunocompromised than in immunocompetent patients (52.4% vs 36.2%; p &lt; 0.0001), despite similar severity of ARDS. Decisions regarding limiting life-sustaining measures were significantly more frequent in immunocompromised patients (27.1% vs 18.6%; p &lt; 0.0001). Use of noninvasive ventilation (NIV) as first-line treatment was higher in immunocompromised patients (20.9% vs 15.9%; p = 0.0048), and immunodeficiency remained independently associated with the use of NIV after adjustment for confounders. Forty-eight percent of the patients treated with NIV were intubated, and their mortality was not different from that of the patients invasively ventilated ab initio. Conclusions: Immunosuppression is frequent in patients with ARDS, and infections are the main risk factors for ARDS in these immunocompromised patients. Their management differs from that of immunocompetent patients, particularly the greater use of NIV as first-line ventilation strategy. Compared with immunocompetent subjects, they have higher mortality regardless of ARDS severity as well as a higher frequency of limitation of life-sustaining measures. Nonetheless, nearly half of these patients survive to hospital discharge. Trial registration: ClinicalTrials.gov, NCT02010073. Registered on 12 December 2013
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