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BackgroundThe management of patients with initially mild acute ischemic stroke (AIS), defined by the National Institutes of Health Stroke Scale (NIHSS) scores 0–5, remains ambiguous despite advances in stroke treatment. The early identification of patients likely to deteriorate is critical in preventing lasting disability.AimsWe investigated the frequency and early predictors of poor functional outcomes in AIS patients with large-vessel occlusion (LVO) and initial mild deficits.MethodsWe performed a retrospective observational study of consecutive AIS patients admitted to a single comprehensive stroke center between 2018 and 2021. The inclusion criteria were a diagnosis of AIS, an arrival NIHSS score of 0–5, imaging-confirmed LVO, and arrival within 24 h of the last-known-well time. The primary outcome was the change in the discharge-modified Rankin Score (ΔmRS) from baseline, categorized as 0–1 (stable outcome) or >1 (poor outcome). Early neurological deterioration was defined as a mean NIHSS score increase of >1 in the first 24-h period. Univariate and multivariable regression analyses were performed. The mean daily NIHSS scores were compared between groups using an analysis of variance (ANOVA).ResultsOf 4,410 stroke admissions, 120 patients met the study inclusion criteria, with 71 (59.2%) patients having a ΔmRS of 0–1 and 49 (40.8%) patients having a ΔmRS of > 1. The mean arrival NIHSS score was similar between groups. However, the mean first-24-h NIHSS score was significantly higher in the poor outcome group vs. the stable outcome group (2.13 vs. 0.95, p < 0.001). A demographic-adjusted multivariable logistic regression revealed that a higher mean first-24-h NIHSS score was the sole early predictor of poor outcome (odds ratio [OR] of 1.65 and a 95% confidence interval [CI] of [1.18, 2.48]). The only association with early neurological deterioration was vertebral artery occlusion, with an OR of 0.35 and a 95% CI of [0.14, 0.81]. The trending mean daily NIHSS scores revealed that patients with poor outcomes deteriorate within 24 h, a significant difference from the stable group (p < 0.001).ConclusionPoor outcomes occurred in a significant proportion of LVO patients with initial mild deficits. The only association was early neurological deterioration. To prevent poor outcomes, rapid identification of any clinical deterioration should prompt consideration of thrombectomy.

The unprecedented medium-resolution ( R _λ ∼ 1500–3500) near- and mid-infrared (1–18 μ m) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12–20 M _Jup ) L–T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this data set utilizing a forward-modeling approach applying our Bayesian framework, ForMoSA . We explore five distinct atmospheric models to assess their performance in estimating key atmospheric parameters: T _eff , log( g ), [M/H], C/O, γ , f _sed , and R . Our findings reveal that each parameter’s estimate is significantly influenced by factors such as the wavelength range considered and the model chosen for the fit. This is attributed to systematic errors in the models and their challenges in accurately replicating the complex atmospheric structure of VHS 1256 b, notably the complexity of its clouds and dust distribution. To propagate the impact of these systematic uncertainties on our atmospheric property estimates, we introduce innovative fitting methodologies based on independent fits performed on different spectral windows. We finally derived a T _eff consistent with the spectral type of the target, considering its young age, which is confirmed by our estimate of log( g ). Despite the exceptional data quality, attaining robust estimates for chemical abundances [M/H] and C/O, often employed as indicators of formation history, remains challenging. Nevertheless, the pioneering case of JWST’s data for VHS 1256 b has paved the way for future acquisitions of substellar spectra that will be systematically analyzed to directly compare the properties of these objects and correct the systematics in the models.

Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μ m) VFN demonstrator mode was deployed on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory and presented earlier. In this Letter, we present the first VFN companion detections. Three targets, HIP 21543 Ab, HIP 94666 Ab, and HIP 50319 B, were detected with host–companion flux ratios between 70 and 430 at and within one diffraction beamwidth ( λ / D ). We complement the spectra from KPIC VFN with flux ratio and position measurements from the CHARA Array to validate the VFN results and provide a more complete characterization of the targets. This Letter reports the first direct detection of these three M dwarf companions, yielding their first spectra and flux ratios. Our observations provide measurements of bulk properties such as effective temperatures, radial velocities, and $v\sin i$ , and verify the accuracy of the published orbits. These detections corroborate earlier predictions of the KPIC VFN performance, demonstrating that the instrument mode is ready for science observations.

We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same data set to explore the random, static, and calibration errors of NIRISS AMI observables. We compare the observed noise properties and achievable contrast to theoretical predictions. We explore possible sources of calibration errors and show that differences in charge migration between the observations of HIP 65426 and point-spread function calibration stars can account for the achieved contrast curves. Lastly, we use self-calibration tests to demonstrate that with adequate calibration NIRISS F380M AMI can reach contrast levels of ∼9–10 mag at ≳ λ / D . These tests lead us to observation planning recommendations and strongly motivate future studies aimed at producing sophisticated calibration strategies taking these systematic effects into account. This will unlock the unprecedented capabilities of JWST/NIRISS AMI, with sensitivity to significantly colder, lower-mass exoplanets than lower-contrast ground-based AMI setups, at orbital separations inaccessible to JWST coronagraphy.

We present Super-RDI, a unique framework for the application of reference star differential imaging (RDI) to Keck/NIRC2 high-contrast imaging observations with the vortex coronagraph. Super-RDI combines frame selection and signal-to-noise ratio (S/N) optimization techniques with a large multiyear reference point-spread function (PSF) library to achieve optimal PSF subtraction at small angular separations. We compile an ∼7000 frame reference PSF library based on a set of 288 new Keck/NIRC2 $L^{\prime} $ sequences of 237 unique targets acquired between 2015 and 2019 as part of two planet-search programs designed for RDI, one focusing on nearby young M dwarfs and the other targeting members of the Taurus star-forming region. For our data set, synthetic companion injection-recovery tests reveal that frame selection with the mean-squared error metric combined with Karhunen–Loève Image-Processing-based PSF subtraction using 1000–3000 frames and ≲500 principal components yields the highest average S/N for injected synthetic companions. We uniformly reduce targets in the young M-star survey with both Super-RDI and angular differential imaging (ADI). For the typical parallactic angle rotation of our data set (∼10°), Super-RDI performs better than a widely used implementation of ADI-based PSF subtraction at separations ≲0.″4 (≈5 λ / D ), gaining an average of 0.25 mag in contrast at 0.″25 and 0.4 mag in contrast at 0.″15. This represents a performance improvement in separation space over RDI with single-night reference star observations (∼100 frame PSF libraries) applied to a similar Keck/NIRC2 data set in previous work. We recover two known brown dwarf companions and provide detection limits for 155 targets in the young M-star survey. Our results demonstrate that increasing the PSF library size with careful selection of reference frames can improve the performance of RDI with the Keck/NIRC2 vortex coronagraph in $L^{\prime} $ .

GQ Lup B is one of the few substellar companions with a detected cicumplanetary disk (CPD). Observations of the CPD suggest the presence of a cavity, possibly formed by an exosatellite. Using the Keck Planet Imager and Characterizer (KPIC), a high-contrast imaging suite that feeds a high-resolution spectrograph (1.9–2.5 µ m, R ∼35,000), we present the first dedicated radial velocity (RV) observations around a high-contrast, directly imaged substellar companion, GQ Lup B, to search for exosatellites. Over 11 epochs, we find a best and median RV error of 400–1000 m s ^−1 , most likely limited by systematic fringing in the spectra due to transmissive optics within KPIC. With this RV precision, KPIC is sensitive to exomoons 0.6%–2.8% the mass of GQ Lup B (∼30 M _Jup ) at separations between the Roche limit and 65 R _Jup , or the extent of the cavity inferred within the CPD detected around GQ Lup B. Using simulations of HISPEC, a high resolution infrared spectrograph planned to debut at W.M. Keck Observatory in 2026, we estimate future exomoon sensitivity to increase by over an order of magnitude, providing sensitivity to less massive satellites potentially formed within the CPD itself. Additionally, we run simulations to estimate the amount of material that different masses of satellites could clear in a CPD to create the observed cavity. We find satellite-to-planet mass ratios of q > 2 × 10 ^−4 can create observable cavities and report a maximum cavity size of ∼51 R _Jup carved from a satellite.

We used the Keck Planet Imager and Characterizer to obtain high-resolution ( R ∼ 35,000) K -band spectra of κ Andromedae b, a planetary-mass companion orbiting the B9V star, κ Andromedae A. We characterized its spin, radial velocity, and bulk atmospheric parameters through use of a forward-modeling framework to jointly fit planetary spectra and residual starlight speckles, obtaining likelihood-based posterior probabilities. We also detected H _2 O and CO in its atmosphere via cross correlation. We measured a $v\sin (i)$ value for κ Andromedae b of 38.42 ± 0.05 km s ^−1 , allowing us to extend our understanding of the population of close-in bound companions at higher rotation rates. This rotation rate is one of the highest spins relative to breakup velocity measured to date, at close to 50% of breakup velocity. We identify a radial velocity $-{17.35}_{-0.09}^{+0.05}$ km s ^−1 , which we use with existing astrometry and radial velocity measurements to update the orbital fit. We also measure an effective temperature of 1700 ± 100 K and a $\mathrm{log}(g)$ of 4.7 ± 0.5 cgs dex.

Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 M _Jup high-contrast companion on a 17 au orbit, using the fiber-fed high-resolution spectrograph KPIC ( ${ \mathcal R }$ ∼ 35,000) on the Keck II telescope. Our K -band observations led to detections of H _2 O and CO in the atmosphere of HIP 99770 b. We carried out free retrieval analyses using petitRADTRANS to measure its chemical abundances, including the metallicity and C/O ratio, projected rotation velocity ( $v\sin i$ ), and radial velocity (RV). We found that the companion’s atmosphere has C/O $=\,{0.55}_{-0.04}^{+0.06}$ and [M/H] $=\,{0.26}_{-0.23}^{+0.24}$ (1 σ confidence intervals), values consistent with those of the Sun and with a companion formation via gravitational instability or core accretion. The projected rotation velocity $v\sin (i)\lt 7.8$ km s ^−1 is small relative to other directly imaged companions with similar masses and ages. This may imply a nearly pole-on orientation or effective magnetic braking by a circumplanetary disk. In addition, we added the companion-to-primary relative RV measurement to the orbital fitting and obtained updated constraints on orbital parameters. Detailed characterization of super-Jovian companions within 20 au like HIP 99770 b is critical for understanding the formation histories of this population.

Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations of protoplanetary disks in the millimeter continuum have shown a variety of radial gaps, cavities, and spiral features. These substructures may be signposts for ongoing planet formation, and therefore these systems are promising targets for direct imaging planet searches in the near-infrared. To this end, we present results from a deep imaging survey in the $L^{\prime} $ band (3.8 μ m) with the Keck/NIRC2 vortex coronagraph to search for young planets in 43 disks with resolved features in the millimeter continuum or evidence for gaps/central cavities from their spectral energy distributions. Although we do not detect any new point sources, using the vortex coronagraph allows for high sensitivity to faint sources at small angular separations (down to ∼0.″1), allowing us to place strong upper limits on the masses of potential gas giant planets. We compare our mass sensitivities to the masses of planets derived using ALMA observations, and while we are sensitive to ∼1 M _Jup planets in the gaps in some of our systems, we are generally not sensitive to planets of the masses expected from the ALMA observations. In addition to placing upper limits on the masses of gas giant planets that could be interacting with the dust in the disks to form the observed millimeter substructures, we are also able to map the micron-sized dust as seen in scattered light for 8 of these systems. Our large sample of systems also allows us to investigate limits on planetary accretion rates and disk viscosities.

We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager and Characterizer (KPIC) high-resolution spectroscopy. HD 33632 Ab is a nearby benchmark brown dwarf companion at a separation of ∼20 au that straddles the L–T transition. Using a forward-modeling framework with on-axis host star spectra, which provides self-consistent substellar atmospheric and retrieval models for HD 33632 Ab, we derive a projected rotational velocity of 53 ± 3 km s ^−1 and carbon monoxide and water mass fractions of logCO = −2.3 ± 0.3 and logH _2 O = −2.7 ± 0.2, respectively. The inferred carbon-to-oxygen ratio (C/O = 0.58 ± 0.14), molecular abundances, and metallicity ([C/H] = 0.0 ± 0.2 dex) of HD 33632 Ab are consistent with its host star. Although detectable methane opacities are expected in L–T transition objects, we did not recover methane in our KPIC spectra, partly due to the high v sin i and to disequilibrium chemistry at the pressures to which we are sensitive. We parameterize the spin as the ratio of rotation to the breakup velocity, and compare HD 33632 Ab to a compilation of >200 very low-mass objects ( M ≲ 0.1 M _⊙ ) that have spin measurements in the literature. There appears to be no clear trend for the isolated low-mass field objects versus mass, but a tentative trend is identified for low-mass companions and directly imaged exoplanets, similar to previous findings. A larger sample of close-in gas giant exoplanets and brown dwarfs will critically examine our understanding of their formation and evolution through rotation and chemical abundance measurements.

We present the first on-sky segmented primary mirror closed-loop piston control using a Zernike wavefront sensor (ZWFS) installed on the Keck II telescope. Segment cophasing errors are a primary contributor to contrast limits on Keck and will be necessary to correct for the next generation of space missions and ground-based extremely large telescopes, which will all have segmented primary mirrors. The goal of the ZWFS installed on Keck is to monitor and correct primary mirror cophasing errors in parallel with science observations. The ZWFS is ideal for measuring phase discontinuities such as segment cophasing errors and is one of the most sensitive WFSs, but has limited dynamic range. The vector-ZWFS at Keck works on the adaptive-optics-corrected wavefront and consists of a metasurface focal plane mask that imposes two different phase shifts on the core of the point-spread function to two orthogonal light polarizations, producing two pupil images. This design extends the dynamic range compared with the scalar ZWFS. The primary mirror segment pistons were controlled in closed loop using the ZWFS, improving the Strehl ratio on the NIRC2 science camera by up to 10 percentage points. We analyze the performance of the closed-loop tests, the impact on NIRC2 science data, and discuss the ZWFS measurements.

The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high-resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities (RVs). Using PHOENIX stellar models, we find that the primary has a temperature of 3460 ± 50 K and a metallicity of 0.16 ± 0.04, while the secondary has a temperature of 2510 ± 50 K and a metallicity of ${0.13}_{-0.11}^{+0.12}$ . Recent work suggests this system is associated with the Hyades, giving it an older age than previous estimates. Both metallicities agree with current Hyades [Fe/H] measurements (0.11–0.21). Using stellar evolutionary models, we obtain significantly higher masses for the objects, 0.30 ± 0.15 M _⊙ and 0.08 ± 0.01 M _⊙ (84 ± 11 M _Jup ), respectively. Using the RVs and a new astrometry point from Keck/NIRC2, we find that the system is likely an edge-on, moderately eccentric ( ${0.41}_{-0.08}^{+0.27}$ ) configuration. We also estimate the C/O ratio of both objects using custom grid models, obtaining 0.42 ± 0.10 (primary) and 0.55 ± 0.10 (companion). From these results, we confirm that this system most likely went through a binary star formation process in the Hyades. The significant changes in this system's parameters since its discovery highlight the importance of high-resolution spectroscopy for both orbital and atmospheric characterization of directly imaged companions.

We present high-resolution K -band emission spectra of the quintessential hot Jupiter HD 189733 b from the Keck Planet Imager and Characterizer. Using a Bayesian retrieval framework, we fit the dayside pressure–temperature profile, orbital kinematics, mass-mixing ratios of H _2 O, CO, CH _4 , NH _3 , HCN, and H _2 S, and the ^13 CO/ ^12 CO ratio. We measure mass fractions of ${\mathrm{logH}}_{2}{\rm{O}}=-{2.0}_{-0.4}^{+0.4}$ and $\mathrm{logCO}=-{2.2}_{-0.5}^{+0.5}$ , and place upper limits on the remaining species. Notably, we find logCH _4 < −4.5 at 99% confidence, despite its anticipated presence at the equilibrium temperature of HD 189733 b assuming local thermal equilibrium. We make a tentative (∼3 σ ) detection of ^13 CO, and the retrieved posteriors suggest a ^12 C/ ^13 C ratio similar to or substantially less than the local interstellar value. The possible ^13 C enrichment would be consistent with accretion of fractionated material in ices or in the protoplanetary disk midplane. The retrieved abundances correspond to a substantially substellar atmospheric C/O = 0.3 ± 0.1, while the carbon and oxygen abundances are stellar to slightly superstellar, consistent with core-accretion models which predict an inverse correlation between C/O and metallicity. The specific combination of low C/O and high metallicity suggests significant accretion of solid material may have occurred late in the formation process of HD 189733 b.

The Management of Anticoagulation in the Periprocedural Period (MAPPP) app is a free tool providing up-to-date guidelines on the periprocedural management of patients on long-term anticoagulants. After validating its effectiveness in the post-procedural period, we aimed to study its overall cost-effectiveness. SF-12 surveys were sent to eligible patients, converted into SF-6D forms, and subsequently into quality-adjusted life years (QALYs) to calculate the incremental cost-effectiveness ratio (ICER). The number of 30-day readmissions was used to calculate hospitalization costs, utilizing publicly available data. From 1/1/2018 to 1/31/2019, 642 patients were screened for enrollment, with an overall response rate of 94% (164/175) among the consented and 49% (164/336) among all eligible patients. The average QALY score was 0.7134 (95% CI [0.6836, 0.7431]) for the patients whose treatment plan followed the MAPPP app recommendations (acceptance group) and 0.7104 (95% CI [0.6760, 0.7448]) for those who did not (rejection group), without statistically significant differences. The difference in ICER scores was −$429 866.67, with the negative sign demonstrating that acceptance was the dominant strategy. By utilizing QALYs and ICER scores we have shown that the acceptance of MAPPP app recommendations is the dominant strategy for the periprocedural management of patients on long-term anticoagulation.

We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 μ m, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 μ m. At a separation of ∼0.″82 (87 ${}_{-31}^{+108}$ au), HIP 65426b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first-ever direct detection of an exoplanet beyond 5 μ m. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5 σ contrast limits of ∼1 × 10 ^−5 and ∼2 × 10 ^−4 at 1″ for NIRCam at 4.4 μ m and MIRI at 11.3 μ m, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3 M _Jup beyond separations of ∼100 au. Together with existing ground-based near-infrared data, the JWST photometry are fit well by a BT-SETTL atmospheric model from 1 to 16 μ m, and they span ∼97% of HIP 65426b's luminous range. Independent of the choice of model atmosphere, we measure an empirical bolometric luminosity that is tightly constrained between $\mathrm{log}\left({L}_{\mathrm{bol}}/{L}_{\odot }\right)$ = −4.31 and −4.14, which in turn provides a robust mass constraint of 7.1 ± 1.2 M _Jup . In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterize the population of exoplanets amenable to high-contrast imaging in greater detail.

We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a

Background Treatment and prognosis of vertebrobasilar atherosclerotic disease differs depending on stroke mechanism, such as artery‐to‐artery embolism, branch atheromatous disease, and hemodynamic ischemia. Our aim was to investigate the relationship between infarction pattern and flow status using quantitative magnetic resonance angiography (QMRA), to determine the validity of using infarction patterns to infer stroke mechanism. Methods and Results This is a retrospective study of patients with ischemic stroke with intra‐ or extracranial vertebrobasilar atherosclerotic stenosis, who underwent magnetic resonance imaging of the brain, neurovascular imaging, and QMRA, between 2009 and 2021. Patients with cerebral infarction predating or following QMRA by ≥1 year, or QMRA studies performed for basilar thrombosis, vertebral dissection, or only postangioplasty/stenting, were excluded. Poststenotic flow (basilar and posterior cerebral arteries) was dichotomized as low‐flow or normal‐flow based on published criteria. Of 1211 consecutive patients who underwent QMRA noninvasive optimal analysis, 69 met inclusion. Mixed patterns were most common (46.4%), followed by perforator (23.2%), borderzone (14.5%), and territorial (15.9%). Patients with low‐flow had a significantly higher rate of borderzone+ patterns (borderzone alone or in mixed pattern) compared with patients with normal‐flow (77.4% low‐flow versus 39.5% normal‐flow, P=0.002). Borderzone+ patterns were associated with 61.5% probability of low‐flow state, while no borderzone (perforator/territorial) patterns were associated with 76.7% probability of normal‐flow state. Conclusions Borderzone infarction pattern (alone or mixed) was associated with low poststenotic posterior circulation flow by QMRA. However, borderzone pattern only moderately predicted low‐flow state, and may be an unreliable flow marker. Therefore, infarct topography may complement, but should not replace hemodynamic studies to establish flow status.

We present Keck Planet Imager and Characterizer (KPIC) high-resolution ( R ∼35,000) K -band thermal emission spectroscopy of the ultrahot Jupiter WASP-33b. The use of KPIC’s single-mode fibers greatly improves both blaze and line-spread stabilities relative to slit spectrographs, enhancing the cross-correlation detection strength. We retrieve the dayside emission spectrum with a nested-sampling pipeline, which fits for orbital parameters, the atmospheric pressure–temperature profile, and the molecular abundances. We strongly detect the thermally inverted dayside and measure mass-mixing ratios for CO ( ${\mathrm{logCO}}_{\mathrm{MMR}}=-{1.1}_{-0.6}^{+0.4}$ ), H _2 O ( ${\mathrm{logH}}_{2}{{\rm{O}}}_{\mathrm{MMR}}\,=-{4.1}_{-0.9}^{+0.7}$ ), and OH ( ${\mathrm{logOH}}_{\mathrm{MMR}}=-{2.1}_{-1.1}^{+0.5}$ ), suggesting near-complete dayside photodissociation of H _2 O. The retrieved abundances suggest a carbon- and possibly metal-enriched atmosphere, with a gas-phase C/O ratio of ${0.8}_{-0.2}^{+0.1}$ , consistent with the accretion of high-metallicity gas near the CO _2 snow line and post-disk migration or with accretion between the soot and H _2 O snow lines. We also find tentative evidence for ^12 CO/ ^13 CO ∼ 50, consistent with values expected in protoplanetary disks, as well as tentative evidence for a metal-enriched atmosphere (2–15 × solar). These observations demonstrate KPIC’s ability to characterize close-in planets and the utility of KPIC’s improved instrumental stability for cross-correlation techniques.

The HR 2562 system is a rare case where a brown dwarf companion resides in a cleared inner hole of a debris disk, offering invaluable opportunities to study the dynamical interaction between a substellar companion and a dusty disk. We present the first ALMA observation of the system as well as the continued Gemini Planet Imager monitoring of the companion’s orbit with six new epochs from 2016 to 2018. We update the orbital fit, and in combination with absolute astrometry from GAIA, place a 3 σ upper limit of 18.5 M _J on the companion’s mass. To interpret the ALMA observations, we used radiative transfer modeling to determine the disk properties. We find that the disk is well resolved and nearly edge-on. While the misalignment angle between the disk and the orbit is weakly constrained, due to the short orbital arc available, the data strongly support a (near) coplanar geometry for the system. Furthermore, we find that the models that describe the ALMA data best have inner radii that are close to the companion’s semimajor axis. Including a posteriori knowledge of the system’s SED further narrows the constraints on the disk’s inner radius and places it at a location that is in reasonable agreement with (possibly interior to) predictions from existing dynamical models of disk truncation by an interior substellar companion. HR 2562 has the potential over the next few years to become a new test bed for dynamical interaction between a debris disk and a substellar companion.

Orbital eccentricities directly trace the formation mechanisms and dynamical histories of substellar companions. Here, we study the effect of hyperpriors on the population-level eccentricity distributions inferred for the sample of directly imaged substellar companions (brown dwarfs and cold Jupiters) from hierarchical Bayesian modeling (HBM). We find that the choice of hyperprior can have a significant impact on the population-level eccentricity distribution inferred for imaged companions, an effect that becomes more important as the sample size and orbital coverage decrease to values that mirror the existing sample. We reanalyze the current observational sample of imaged giant planets in the 5–100 au range from Bowler et al. and find that the underlying eccentricity distribution implied by the imaged planet sample is broadly consistent with the eccentricity distribution for close-in exoplanets detected using radial velocities. Furthermore, our analysis supports the conclusion from that study that long-period giant planets and brown dwarf eccentricity distributions differ by showing that it is robust to the choice of hyperprior. We release our HBM and forward-modeling code in an open-source Python package, ePop! , and make it freely available to the community.

The detection of satellites around extrasolar planets, so called exomoons, remains a largely unexplored territory. In this work, we study the potential of detecting these elusive objects from radial velocity monitoring of self-luminous, directly imaged planets. This technique is now possible thanks to the development of dedicated instruments combining the power of high-resolution spectroscopy and high-contrast imaging. First, we demonstrate a sensitivity to satellites with a mass ratio of 1%–4% at separations similar to the Galilean moons from observations of a brown-dwarf companion (HR 7672 B; K _mag = 13; 0.″7 separation) with the Keck Planet Imager and Characterizer ( R ∼ 35,000 in the K band) at the W. M. Keck Observatory. Current instrumentation is therefore already sensitive to large unresolved satellites that could be forming from gravitational instability akin to binary star formation. Using end-to-end simulations, we then estimate that future instruments such as the Multi-Object Diffraction-limited High-resolution Infrared Spectrograph, planned for the Thirty Meter Telescope, should be sensitive to satellites with mass ratios of ∼10 ^−4 . Such small moons would likely form in a circumplanetary disk similar to the Jovian satellites in the solar system. Looking for the Rossiter–McLaughlin effect could also be an interesting pathway to detecting the smallest moons on short orbital periods. Future exomoon discoveries will allow precise mass measurements of the substellar companions that they orbit and provide key insight into the formation of exoplanets. They would also help constrain the population of habitable Earth-sized moons orbiting gas giants in the habitable zone of their stars.

Introduction: The purpose of this study was to illustrate the potential costs and health consequences of implementing advanced CT angiography and perfusion (CTAP) as the initial imaging in patients presenting with acute ischemic stroke (AIS) symptoms at a comprehensive stroke center (CSC).Methods: A decision-simulation model based on the American Heart Association's recommendations for AIS care pathways was developed to assess imaging strategies for a 5-year period from the institutional perspective. The following strategies were compared: (1) advanced CTAP imaging: NCCT + CTA + CT perfusion at the time of presentation; (2) standard-of-care: non-contrast CT (NCCT) at the time of presentation, with CT angiography (CTA) ± CT perfusion only in select patients (initial imaging to exclude hemorrhage and extensive ischemia) for mechanical thrombectomy (MT) evaluation. Model parameters were defined with evidence-based data. Cost-consequence and sensitivity analyses were performed. The modified Rankin Scale (mRS) at 90 days was used as the outcome measure.Results: The decision-simulation modeling revealed that adoption of the advanced CTAP imaging increased per-patient imaging costs by 1.19% ($9.28/$779.72), increased per-patient treatment costs by 33.25% ($729.96/$2,195.24), and decreased other per-patient acute care costs by 0.7% (–$114.12/$16,285.85). The large increase in treatment costs was caused by higher proportion of patients being treated. However, improved outcomes lowered the other per-patient acute care costs. Over the five-year period, advanced CTAP imaging led to 1.63% (66/4,040) more patients with good outcomes (90-day mRS 0-2), 2.23% (66/2,960) fewer patients with poor outcomes (90-day mRS 3-5), and no change in mortality (90-day mRS 6). Our CT equipment utilization analysis showed that the demand for CT equipment in terms of scanner time (minutes) was 24% lower in the advanced CTAP imaging strategy compared to the standard-of-care strategy. The number of EVT procedures performed at the CSC may increase by 50%.Conclusions: Our study reveals that adoption of advanced CTAP imaging at presentation increases the demand for treatment of acute ischemic stroke patients as more patients are diagnosed within the treatment time window compared to standard-of-care imaging. Advanced imaging also leads to more patients with good functional outcomes and fewer patients with dependent functional status.

Appropriate perioperative management of patients on chronic oral anticoagulation (OAC)—including warfarin and the direct oral anticoagulants—is a poorly defined yet important clinical issue with potentially severe consequences in the postoperative period. We sought to prospectively evaluate the effect of the Management of Anticoagulation in the Periprocedural Period (MAPPP) mobile app as a clinical decision tool in the management of patients on chronic OAC undergoing elective procedures or surgeries. Between January 1, 2018, and January 31, 2019, 642 patients treated in our health system were included. Eligible patients met the following criteria: age >18 years old, creatinine clearance ≥15 mL/min, and on chronic OAC with adequate information regarding baseline characteristics. Our study outcome was patient’s emergency department (ED) visits within 30 days postprocedure. The MAPPP app was integrated into the electronic health record (EHR), and the end user was free to accept or decline recommended evidence-based perioperative anticoagulation management guidance. Analysis revealed that acceptance was more common in younger patients ( P = .0137), patients on oral anticoagulants other than warfarin ( P < .0001), and patients undergoing increased bleeding risk procedures ( P = .0068). Acceptance of the MAPPP app recommendation was significantly associated with fewer ED visits (acceptance group: 4.0% vs rejection group: 8.3%, P = .0205). Logistic regression showed that intervention acceptance and female gender were significantly associated with fewer—while age ≥80 with more—30-day ED visits. Our findings indicate that newer technologies, such as the MAPPP app, integrated into clinical EHR workflow, can significantly augment evidence-based perioperative anticoagulation management and potentially result in a reduction of adverse outcomes.

The formation and evolution pathway for the directly imaged multiplanetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery. We perform a detailed atmospheric retrieval on HR 8799 c to infer the chemical abundances and abundance ratios using a combination of photometric data along with low- and high-resolution spectroscopic data ( R ∼ 20–35,000). We specifically retrieve [C/H], [O/H], and C/O and find them to be ${0.55}_{-0.39}^{+0.36}$ , ${0.47}_{-0.32}^{+0.31}$ , and ${0.67}_{-0.15}^{+0.12}$ at 68% confidence. The superstellar C and O abundances, yet a stellar C/O ratio, reveal a potential formation pathway for HR 8799 c. Planet c, and likely the other gas giant planets in the system, formed early on (likely within ∼1 Myr), followed by further atmospheric enrichment in C and O through the accretion of solids beyond the CO ice line. The enrichment either preceded or took place during the early phase of the inward migration to the current planet locations.

Electronic health records (EHRs) provide timely access to millions of patient data records while limiting errors associated with manual data extraction. To demonstrate these advantages of EHRs to public health practice, we examine the ability of a EHR calculated blood-pressure (BP) measure to replicate seasonal variation as reported by prior studies that used manual data extraction. Our sample included 609 primary-care practices in New York City. BP control among hypertensives was defined as systolic blood pressure of 140 or less and diastolic blood pressure of 90 or less (BP

Abstract Background Warfarin's adverse drug events are dangerous, common, and costly. While outpatient warfarin management tools exist, there is a dearth of guidance for inpatients. Objectives We sought to describe a health system's chronic warfarin quality metrics in older inpatients, defined by international normalized ratio (INR) control, explore associations between INR overshoots and clinical outcomes, and identify factors associated with overshoots. Patients/Methods Data on patients 65 years and older who were prescribed chronic warfarin and admitted during January 1, 2014, to June 30, 2016, were extracted through retrospective chart review. We defined overshoots as INRs 5 or greater after 48 hours of hospitalization. Logistic regression modeling was used to determine risks for overshoots and multivariate analysis for overshoots' association with length of stay (LOS), bleeding, and mortality. Results Of the 12,107 older inpatients on chronic warfarin, most were 75 years or older (75.7%), female (51.2%), and white (70.0%). While 1,333 (11.0%) of patients had overshoots during the admission, 449 (33.7%) of these reached overshoots after 48 hours. When stratified by overshoots versus no overshoots, LOS more than doubled (15.6 vs. 6.8 days) and the bleed rate was significantly higher (27.4 vs. 8.3%) in the overshoot group. While overall mortality was small (0.4%), the overshoot group's mortality was significantly higher (3.12 vs. 0.28%). Black race and weight were protective against overshoots; history of heart failure and antibiotic/amiodarone exposure were predictive of overshoots. Conclusion This is the largest study examining warfarin quality metrics for hospitalized adults, specifically older inpatients. Our model may serve as the basis for identifying high-risk warfarin patients to target interventions to reduce adverse drug events.

Introduction Studies showing sustained improvements in the delivery of clinical preventive services are limited. Fewer studies demonstrate sustained improvements among independent practices that are not affiliated with hospitals or integrated health systems. This study examines the continued improvement in clinical quality measures for a group of independent primary care practices using electronic health records (EHRs) and receiving technical support from a local public health agency. Methods We analyzed clinical quality measure performance data from a cohort of primary care practices that implemented an EHR at least 3 months before October 2009, the study baseline. We assessed trends for 4 key quality measures: antithrombotic therapy, blood pressure control, smoking cessation intervention, and hemoglobin A1c (HbA1c) testing based on monthly summary data transmitted by the practices. Results Of the 151 practices, 140 were small practices and 11 were community health centers; average time using an EHR was 13.7 months at baseline. From October 2009 through October 2011, average rates increased for antithrombotic therapy (from 58.4% to 74.8%), blood pressure control (from 55.3% to 64.1%), HbA1c testing (from 46.4% to 57.7%), and smoking cessation intervention (from 29.3% to 46.2%). All improvements were significant. Conclusion During 2 years, practices showed significant improvement in the delivery of several key clinical preventive services after implementing EHRs and receiving support services from a public health agency.