Geophysical measurements can reveal the structures and thermal states of icy ocean worlds. The interior density, temperature, sound speed, and electrical conductivity thus characterize their ...habitability. We explore the variability and correlation of these parameters using 1‐D internal structure models. We invoke thermodynamic consistency using available thermodynamics of aqueous MgSO4, NaCl (as seawater), and NH3; pure water ice phases I, II, III, V, and VI; silicates; and any metallic core that may be present. Model results suggest, for Europa, that combinations of geophysical parameters might be used to distinguish an oxidized ocean dominated by MgSO4 from a more reduced ocean dominated by NaCl. In contrast with Jupiter's icy ocean moons, Titan and Enceladus have low‐density rocky interiors, with minimal or no metallic core. The low‐density rocky core of Enceladus may comprise hydrated minerals or anhydrous minerals with high porosity. Cassini gravity data for Titan indicate a high tidal potential Love number (k2>0.6), which requires a dense internal ocean (ρocean>1,200 kg m−3) and icy lithosphere thinner than 100 km. In that case, Titan may have little or no high‐pressure ice, or a surprisingly deep water‐rock interface more than 500 km below the surface, covered only by ice VI. Ganymede's water‐rock interface is the deepest among known ocean worlds, at around 800 km. Its ocean may contain multiple phases of high‐pressure ice, which will become buoyant if the ocean is sufficiently salty. Callisto's interior structure may be intermediate to those of Titan and Europa, with a water‐rock interface 250 km below the surface covered by ice V but not ice VI.
Plain Language Summary
Seismometers, magnetometers, and other tools may be used in the future to glimpse the insides of ocean worlds‐moons of Jupiter and Saturn that have lots of liquid water under their icy surfaces. These measurements could reveal whether water and rock interact to produce chemical conditions that on Earth support life, how much life such chemical activity might support, and how long that activity has persisted through time. The pressures and temperatures in these extraterrestrial oceans differ from those in Earth's oceans, so only just now are the needed tools and data becoming available to predict what future measurements might reveal. In this work, we investigated the interior structures of icy ocean worlds based on available information—mainly NASA's Galileo and Cassini missions—and used chemical data to test what ocean and rock compositions are possible. Our calculations make predictions for Saturn's moons: Titan should not have an iron core, and its ocean may contain little or no high‐pressure ice. Fluids may flow through the whole of the rock core of Enceladus because Cassini gravity measurements seem to point to a porous interior. Geophysical investigations could test whether the ocean in Jupiter's moon Europa has a composition like Earth's or may instead by very acidic if water and rock have not interacted much. Our calculations predict that these two scenarios can create unique combinations of measurable properties that can be probed by future missions using seismology, magnetic field measurements, and other means.
Key Points
We examine possible ice thicknesses, mineralogy, and porosity in icy ocean worlds consistent with spacecraft and thermodynamic data
We identify available and needed thermodynamics of ices, oceans, silicates, and metals
We examine the influences of ocean composition and depth‐dependent ocean density on tidal dissipation
The SEIS (Seismic Experiment for Interior Structures) instrument on board the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of ...tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. The InSight noise model is a key tool for the InSight mission and SEIS instrument requirement setup. It will also be used for future operation planning. This paper presents the analyses made to build a model of the Martian seismic noise as measured by the SEIS seismometer, around the seismic bandwidth of the instrument (from 0.01 Hz to 1 Hz). It includes the instrument self-noise, but also the environment parameters that impact the measurements. We present the general approach for the model determination, the environment assumptions, and we analyze the major and minor contributors to the noise model.
Physician-rating websites are being increasingly used by patients to help guide physician choice. As such, an understanding of these websites and factors that influence ratings is valuable to ...physicians.
We sought to perform a comprehensive analysis of online urology ratings information, with a specific focus on the relationship between number of ratings or comments and overall physician rating.
We analyzed urologist ratings on the Healthgrades website. The data retrieval focused on physician and staff ratings information. Our analysis included descriptive statistics of physician and staff ratings and correlation analysis between physician or staff performance and overall physician rating. Finally, we performed a best-fit analysis to assess for an association between number of physician ratings and overall rating.
From a total of 9921 urology profiles analyzed, there were 99,959 ratings and 23,492 comments. Most ratings were either 5 ("excellent") (67.53%, 67,505/99,959) or 1 ("poor") (24.22%, 24,218/99,959). All physician and staff performance ratings demonstrated a positive and statistically significant correlation with overall physician rating (P<.001 for all analyses). Best-fit analysis demonstrated a negative relationship between number of ratings or comments and overall rating until physicians achieved 21 ratings or 6 comments. Thereafter, a positive relationship was seen.
In our study, a dichotomous rating distribution was seen with more than 90% of ratings being either excellent or poor. A negative relationship between number of ratings or comments and overall rating was initially seen, after which a positive relationship was demonstrated. Combined, these data suggest that physicians can benefit from understanding online ratings and that proactive steps to encourage patient rating submissions may help optimize overall rating.
Objectives
Prone positioning is widely used in mechanically ventilated patients with COVID-19; however, the specific clinical scenario in which the individual is most poised to benefit is not fully ...established. In patients with COVID-19 respiratory failure requiring mechanical ventilation, how effective is prone positioning in improving oxygenation and can that response be predicted?
Design
This is a retrospective observational study from two tertiary care centers including consecutive patients mechanically ventilated for COVID-19 from 3/1/2020 – 7/1/2021. The primary outcome is improvement in oxygenation as measured by PaO2/FiO2. We describe oxygenation before, during and after prone episodes with a focus on identifying patient, respiratory or ventilator variables that predict prone positioning success.
Setting
2 Tertiary Care Academic Hospitals
Patients
125 patients mechanically ventilated for COVID-19 respiratory failure.
Interventions
Prone positioning
Main Results
One hundred twenty-five patients underwent prone positioning a total of 309 times for a median duration of 23 hours IQR (14 – 49). On average, PaO2/FiO2 improved 19%: from 115 mm Hg (80 – 148) immediately before proning to 137 mm Hg (95 – 197) immediately after returning to the supine position. Prone episodes were more successful if the pre-prone PaO2/FiO2 was lower and if the patient was on inhaled epoprostenol (iEpo). For individuals with severe acute respiratory distress syndrome (ARDS) (PaO2/FiO2 < 100 prior to prone positioning) and on iEpo, the median improvement in PaO2/FiO2 was 27% in both instances.
Conclusions
Prone positioning in mechanically ventilated patients with COVID-19 is generally associated with sustained improvements in oxygenation, which is made more likely by the concomitant use of iEpo and is more impactful in those who are more severely hypoxemic prior to prone positioning.
The Marsquake catalogue from InSight, sols 0–478 Clinton, John F.; Ceylan, Savas; van Driel, Martin ...
Physics of the earth and planetary interiors,
January 2021, 2021-01-00, 2021-01, Letnik:
310
Journal Article
Recenzirano
Odprti dostop
The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission began collecting high quality seismic data on Mars in February 2019. This manuscript documents the ...seismicity observed by SEIS, InSight's seismometer, from this time until the end of March 2020. Within the InSight project, the Marsquake Service (MQS) is responsible for prompt review of all seismic data collected by InSight, detection of events that are likely to be of seismic origin, and curation and release of seismic catalogues. In the first year of data collection, MQS have identified 465 seismic events that we interpret to be from regional and teleseismic marsquakes. Seismic events are grouped into 2 different event families: the low frequency family is dominated by energy at long period below 1 s, and the high frequency family primarily include energy at and above 2.4 Hz. Event magnitudes, from Mars-specific scales, range from 1.3 to 3.7. A third class of events with very short duration but high frequency bursts have been observed 712 times. These are likely associated with a local source driven by thermal stresses. This paper describes the data collected so far in the mission and the procedures under which MQS operates; summarises the content of the current MQS seismic catalogue; and presents the key features of the events we have observed so far, using the largest events as examples.
•The Marsquake Service is providing updated catalogues of Martian seismicity as recorded on InSight.•465 distant marsquakes have been identified in the first 478 martian days (sol) since InSight landed.•This version of the catalogue includes an additional 712 events that may be due to local cracking from thermal forcing.
Introduction and hypothesis
The opioid epidemic is a recent focus of national initiatives to reduce opioid misuse and related addiction. As interstitial cystitis (IC) is a chronic pain state at risk ...for narcotic use, we sought to assess opioid prescription use in patients with IC.
Methods
Data were accessed from the Virginia All Payers Claims Database. We identified female patients diagnosed with IC from 2011 to 2016 using International Classification of Disease codes. A patient identifier was used to link diagnoses with outpatient prescription claims for opioids using generic product identifiers. We then analyzed opioid prescriptions within 30 days of a claim with a diagnosis of IC.
Results
A total of 6,884 patients with an IC diagnosis were identified. The median number of IC claims per patient was 2 (IQR 1 to 4). Mean patient age was 47.8. Twenty-eight percent of patients received at least 1 opioid prescription, with a median of 2 (IQR 1, 4) per patient. Among those receiving opioids, 185 (9.5%) had more than 10 opioid prescriptions, with a maximum of 129. The most common prescriptions were hydrocodone (
n
= 2,641, 32.3%), oxycodone (
n
= 2,545, 31.2%), and tramadol (
n
= 1,195, 14.6%). There was a decline in opioid prescriptions per month for IC, although the rate per IC diagnosis remained stable.
Conclusions
A significant number of patients with IC are treated with opioids. Although the overall number of opioid prescriptions associated with IC had declined, the prescription rate per IC diagnosis had not. As part of the national initiative to reduce opioid use, our data suggest that IC treatment strategies should be examined.
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