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We present the results of a {\it James Webb Space Telescope} NIRCam investigation into the young massive star cluster (YMC) population in the luminous infrared galaxy VV 114. We identify 374 compact YMC candidates with a $S/N \geq 3$, 5, and 5 at F150W, F200W, and F356W respectively. A direct comparison with our {\it HST} cluster catalog reveals that $\sim 20\%$ of these sources are undetected at optical wavelengths. Based on {\it yggdrasil} stellar population models, we identify 17 YMC candidates in our {\it JWST} imaging alone with F150W-F200W and F200W-F356W colors suggesting they are all very young, dusty ($A_{V} = 5 - 15$), and massive ($10^{5.8} < M_{\odot} < 10^{6.1}$). The discovery of these `hidden' sources, many of which are found in the `overlap' region between the two nuclei, quadruples the number of $t < 3$ Myr clusters, and nearly doubles the number of $t < 6$ Myr clusters detected in VV 114. Now extending the cluster age distribution ($dN/d\tau \propto \tau^{\gamma}$) to the youngest ages, we find a slope of $\gamma = -1.30 \pm 0.39$ for $10^{6} < \tau (\mathrm{yr}) < 10^{7}$, which is consistent with the previously determined value from $10^{7} < \tau (\mathrm{yr}) < 10^{8.5}$, and confirms that VV 114 has a steep age distribution slope for all massive star clusters across the entire range of cluster ages observed. Finally, the consistency between our {\it JWST}- and {\it HST}-derived age distribution slopes indicates that the balance between cluster formation and destruction has not been significantly altered in VV 114 over the last 0.5 Gyr., Comment: 13 pages, 4 figures, 1 table, published in the Astrophysical Journal

Infective endocarditis affects patients of all socioeconomic status. We hypothesized that the Distressed Communities Index (DCI), a comprehensive assessment of socioeconomic status, would be associated with risk-adjusted mortality for patients with endocarditis. All patients with endocarditis (2001-2017) in a regional Society of Thoracic Surgeons database were analyzed. DCI scores range from 0 (no socioeconomic distress) to 100 (severe distress) and account for unemployment, poverty rate, median income, housing vacancies, education level, and business growth by zip code. The most distressed patients (top quartile, DCI75) were compared to all other patients. Hierarchical logistic regression modeled the association between DCI and mortality. A total of 2,075 patients were included (median age 55 years, 65.2% urgent/emergent cases, 42.7% self-pay). Major morbidity was 32.8% and operative mortality was 9.5%. Tricuspid/pulmonic valve endocarditis was present in 12.5% of cases, with significantly worse mean DCI compared to patients with left-sided endocarditis (median 55.3, IQR 20.3-77.6 vs 46.8, IQR 17.3-74.2, P = 0.016). High socioeconomic distress (DCI75) was associated with higher rates of major morbidity, operative mortality, increased length of stay, and higher total cost. After risk-adjustment, DCI was independently predictive of higher operative mortality for patients with endocarditis (OR 1.24 per DCI quartile increase, 95% CI 1.06-1.45, P0.001). Increasing DCI, an indicator of poor socioeconomic status, independently predicts increased risk-adjusted mortality and resource utilization for patients with endocarditis. Accounting for socioeconomic status allows for more accurate risk prediction and resource allocation for patients with endocarditis.

Staphylococcus aureus remains the most common cause of sternal surgical site infections (SSIs). Opinions on the postoperative implications of preoperative methicillin-resistant S aureus (MRSA) colonization currently differ. This study aimed to investigate whether MRSA carriage affects postoperative outcomes and safety of operation.A total of 1,774,811 cardiac surgical patients from 2009 to 2014 were identified from the National Inpatient Sample database. Among these patients, 5798 (0.33%) were MRSA carriers. Propensity-score matching was used to determine the effect of MRSA colonization on outcomes.MRSA carriers did not differ in age or sex from noncarriers, but they more often presented for urgent surgery (P .001). Among matched pairs, there was no difference in mortality (P = .76), stroke, SSIs, pneumonia, renal failure, cardiac complications, respiratory failure, or prolonged mechanical ventilation. MRSA infection (P.001), MRSA septicemia (P = 0.03), and blood transfusion (P = .003) occurred more often among MRSA carriers. There was no increase in cost (P = .12), but the hospital length of stay was longer (P = .005). Predictors of MRSA infection among carriers included age older than 85 years, rural hospital location, and diabetes. Carriers with endocarditis and drug abuse were at highest risk for MRSA infection.MRSA carriers undergoing cardiac surgery are not at higher risk for mortality or SSIs and can expect outcomes similar to those of noncarriers. Higher rates of postoperative MRSA infection and septicemia among carriers, although still very low, support the need for selective preoperative screening and prophylaxis when possible.

Readmissions cost an estimated $41 billion in the United States each year. To address this, a single institution recently developed a new risk model predictive of 30-day readmission after adult cardiac surgery. The purpose of this study is to validate and refine this new readmission risk model using a statewide database.A total of 19,964 patients were analyzed using a statewide Society of Thoracic Surgeons database (2014-2017). The aforementioned multivariate model was replicated (model 1): race, hospital length of stay, chronic lung disease, operation type, and renal failure. Model 2 also included discharge location. Thirty-day readmission risk scores and low-risk (0%-10%), moderate-risk (10%-13%), and high-risk (≥13%) categories were calculated.The overall 30-day readmission rate was 11.1% with both models 1 and 2 predicting readmission (odds ratio, 1.09; 95% confidence interval, 1.08-1.11 vs odds ratio, 1.10; 95% confidence interval, 1.08-1.11). Statistically significant differences were observed across all risk categories in discharge location and total cost. For models 1 and 2, 86% of low-risk patients were discharged to home vs 66.9% and 42.9% of patients in high-risk groups, respectively (P.001). The largest increases were observed with a hospice discharge location for both model 1 (from $37,930 to $89,285) and model 2 (from $37,930 to $89,230).Both risk models significantly predicted 30-day readmission in our multiinstitutional dataset, confirming the score is valid and a generalizable quality improvement tool. The addition of discharge location and total cost adds valuable information of the ongoing efforts to identify patients at high risk for readmission.

With a rising emphasis on public reporting, we hypothesized that select hospitals are becoming increasingly risk-averse by avoiding high-risk operations. Further, we evaluated the association between risk-averse practices, outcomes, and publicly reported quality measures.Clinical data from 78,417 patients undergoing cardiac surgery (2002-2016) from a regional consortium was paired with publicly available reimbursement and quality data. High-risk surgery was defined as predicted risk of mortality ≥5%. Hospital risk aversion was defined as a significant decrease in both high-risk volume and proportion, with cases stratified by hospital risk aversion status for univariate analysis.The rate of high-risk cases decreased from 17.9% in 2002 to 12.6% in 2016. Significant risk aversion was seen in 39% of hospitals, which had a 59% decrease in high-risk volume vs a 16% decrease at non-risk-averse hospitals. In the last 5 years, declining high-risk cases at risk-averse hospitals were driven by fewer cases from transfers (19.2% vs 28.1%, P.001) and the emergency department (17.6% vs 19.2%, P = .001). Only non-risk-averse hospitals had mortality rates lower than expected (risk-averse: 0.97 [95% confidence interval, 0.91-1.03], P = .30; non-risk-averse: 0.88 [95% confidence interval, 0.83-0.94], P = .001). There were no differences by risk aversion status in reported ratings or financial incentives (all P.05).Over 60% of hospitals continue to operate on high-risk patients, with concentration of care driven by transfer patterns. These non-risk-averse hospitals are high-performing with better-than-expected outcomes, particularly in high-risk cases. Transparency and objectivity in reporting are essential to ensure continued access for these high-risk patients.

Transfer from hospital to hospital for cardiac surgery represents a large portion of some clinical practices. Previous literature in other surgical fields has shown worse outcomes for transferred patients. We hypothesized that transferred patients would be higher risk and demonstrate worse outcomes than those admitted through the emergency department.All patients undergoing cardiac operations with a Society of Thoracic Surgeons Predicted Risk of Mortality were evaluated from a multicenter, statewide Society of Thoracic Surgeons database. Only patients requiring admission before surgery were included. Patients were stratified by admission through the emergency department or in transfer. Transfers were further stratified by the cardiothoracic surgery capabilities at the referring center.A total of 13,094 patients met the inclusion criteria of admission before surgery. This included 7582 (57.9%) transfers, of which 502 (6.6%) were referred from cardiac centers. Compared with emergency department admissions, transfers had increased hospital costs despite lower operative risk (Predicted Risk of Mortality 1.5% vs 1.6%, P .01) and equivalent postoperative morbidity (15.6% vs 15.3% P = .63). In risk-adjusted analysis, transfer status was not independently associated with worse outcomes. Patients transferred from centers that perform cardiac surgery are higher risk than general transfers (Predicted Risk of Mortality 2.5% vs 1.5, P .01), but specialized care results in excellent risk-adjusted outcomes (observed/expected: mortality 0.81; morbidity or mortality 0.90).Transfer patients have similar rates of postoperative complications but increased resource use compared with patients admitted through the emergency department. Patients transferred from centers that perform cardiac surgery represent a particularly high-risk subgroup.

We study the ionization and excitation structure of the interstellar medium in the late-stage gas-rich galaxy merger NGC 6240 using a suite of emission line maps at $\sim$25 pc resolution from the Hubble Space Telescope, Keck NIRC2 with Adaptive Optics, and ALMA. NGC 6240 hosts a superwind driven by intense star formation and/or one or both of two active nuclei; the outflows produce bubbles and filaments seen in shock tracers from warm molecular gas (H$_2$ 2.12$\mu$m) to optical ionized gas ([O III], [N II], [S II], [O I]) and hot plasma (Fe XXV). In the most distinct bubble, we see a clear shock front traced by high [O III]/H$\beta$ and [O III]/[O I]. Cool molecular gas (CO(2-1)) is only present near the base of the bubble, towards the nuclei launching the outflow. We interpret the lack of molecular gas outside the bubble to mean that the shock front is not responsible for dissociating molecular gas, and conclude that the molecular clouds are partly shielded and either entrained briefly in the outflow, or left undisturbed while the hot wind flows around them. Elsewhere in the galaxy, shock-excited H$_2$ extends at least $\sim$4 kpc from the nuclei, tracing molecular gas even warmer than that between the nuclei, where the two galaxies' interstellar media are colliding. A ridgeline of high [O III]/H$\beta$ emission along the eastern arm aligns with the south nucleus' stellar disk minor axis; optical integral field spectroscopy from WiFeS suggests this highly ionized gas is centered at systemic velocity and likely photoionized by direct line-of-sight to the south AGN., Comment: 27 pages, 18 figures; accepted for publication in ApJ

Annular enlargement (AE) is a critical technique to avoid patient-prosthesis mismatch and may help facilitate future valve-in-valve (ViV) transcatheter replacement. We hypothesized that the addition of annular enlargement would increase risk of morbidity and mortality and that the number of annular enlargement procedures is increasing to accommodate future ViV procedures.Patients undergoing aortic valve replacement ± coronary surgery (2012 to 2017) were extracted from a regional Society of Thoracic Surgeons database. Patients were stratified by annular enlargement and era, pre-ViV (2012 to 2014) vs ViV (2015 to 2017) for univariate analysis. Risk-adjusted outcomes were assessed by hierarchical regression modeling adjusting for predicted risk of mortality.Of 6045 patients, the 300 (5.0%) who received an annular enlargement were younger and more commonly female. Patients receiving an annular enlargement had higher complication rates including operative mortality (4.7% vs 2.5%, P = .024). After risk adjustment, AE was independently associated with increased mortality (odds ratio, 2.06, P = .016) and major morbidity (odds ratio, 1.41, P = .042). The rate of enlargement increased from 3.9% pre-ViV to 6.3% ViV (P .001). The use of ViV capable valves (bioprosthetic ≥23 mm) from 61% to 67% (P = .001), and more in AE patients (30% vs 11% non-AE). Alternatively, the rate of patient prosthesis mismatch declined from 23% to 16%.Increasing utilization of AE coincides with a decline in patient prosthesis mismatch and may facilitate future ViV transcatheter aortic valve replacement. However, AE was independently associated with increased morbidity and mortality. High variability in AE volume may be increasing risk and deserves further investigation.

Background The effects of socioeconomic factors other than insurance status and race on outcomes after cardiac operations are not well understood. We hypothesized that the Distressed Communities Index (DCI), a comprehensive socioeconomic ranking by zip code, would predict operative mortality after coronary artery bypass grafting (CABG). Methods All patients who underwent isolated CABG (2010 to 2017) in the Virginia Cardiac Services Quality Initiative database were analyzed. The DCI accounts for unemployment, education level, poverty rate, median income, business growth, and housing vacancies, with scores ranging from 0 (no distress) to 100 (severe distress). Patients were stratified by DCI quartiles (I: 0 to 24.9, II: 25 to 49.9, III: 50 to 74.9, IV: 75 to 100) and compared. Hierarchical linear regression modeled the association between the DCI and mortality. Results A total of 19,756 CABG patients were analyzed, with mean predicted risk of mortality of 2.0% ± 3.5%. Higher DCI scores were associated with increasing predicted risk of mortality. Overall operative mortality was 2.1% (n = 424) and increased with increasing DCI quartile (I: 1.6% [n = 95], II: 2.1% [n = 77], III: 2.4% [n = 114], IV: 2.6% [n = 138]; p = 0.0009). The observed-to-expected ratio for mortality increased as level of socioeconomic distress increased. After risk adjustment for The Society of Thoracic Surgeons predicted risk of mortality, year of surgical procedure, and hospital, the DCI remained predictive of operative mortality after CABG (odds ratio, 1.14 for each 25-point increase in DCI; 95% confidence interval 1.04 to 1.26; p = 0.007). Conclusions The DCI independently predicts risk-adjusted operative mortality after CABG. Socioeconomic status, although not part of traditional risk calculators, should be considered when building risk models, evaluating resource utilization, and comparing hospitals.

Although liver disease increases surgical risk, it is not considered in The Society for Thoracic Surgeons (STS) risk calculator. This study assessed the impact of Model for End-Stage Liver Disease (MELD) on outcomes after cardiac surgical procedures and the additional predictive value of MELD in the STS risk model.Deidentified records of 21,272 patients were extracted from a regional STS database. Inclusion criteria were any cardiac operation with a risk score available (2011-2016). Exclusion criteria included missing MELD (n = 2,895) or preoperative anticoagulation (n = 144). Patients were stratified into three categories, MELD9 (low), MELD 9 to 15 (moderate), and MELD15 (high). Univariate and multivariate logistic regression assessed risk-adjusted associations between MELD and operative outcomes.Increasing MELD scores were associated with greater comorbid disease, mitral operation, prior cardiac operation, and higher STS-predicted risk of mortality (1.1%, 2.3%, and 6.0% by MELD category; p0.0001). The operative mortality rate increased with increasing MELD score (1.6%, 3.9%, and 8.4%; p0.0001). By logistic regression MELD score was an independent predictor of operative mortality (odds ratio, 1.03 per MELD score point; p0.0001) as were the components total bilirubin (odds ratio, 1.22 per mg/dL; p = 0.002) and international normalized ratio (odds ratio, 1.40 per unit; p0.0001). Finally, MELD score was independently associated with STS major morbidity and the component complications renal failure and stroke.Increasing MELD score, international normalized ratio, and bilirubin all independently increase risk of operative mortality. Because high rates of missing data currently limit utilization of MELD, efforts to simplify and improve data collection would help improve future risk models.

Background: The Merit-Based Incentive Payment System adjusts clinician payments based on a performance score that includes cost measures. With the Centers for Medicare & Medicaid Services, we developed a novel cost measure that compared interventional cardiologists on a targeted set of costs related to elective percutaneous coronary intervention (PCI). We describe the measure and compare it to a hypothetical version including all expenditures post-PCI. Methods: Measure development was guided by 39 clinician experts. They identified services within 30 days of PCI that could be potentially affected by the interventional cardiologist. Expenditures for these PCI-related services were included as measure costs in a process termed service assignment. We used 1 year of Medicare claims to calculate clinician scores using the final measure that included only PCI-related costs (with service assignment) and a hypothetical version that included all costs post-PCI (without service assignment). We calculated reliability for both measures. This marker of precision breaks measure variance into signal (difference between clinicians) versus noise (difference between PCI episodes for a clinician). We also determined the change in clinician performance quintile between measures. Results: We identified 100 992 elective outpatient PCI episodes from May 2, 2016, to May 1, 2017. Total Medicare expenditures within 30 days of PCI averaged $13 234. After excluding costs unrelated to PCI, average cost was $10 966. For individual clinicians, mean reliability for the hypothetical measure without service assignment was 0.36. After service assignment, final measure reliability increased to 0.53. When evaluated as clinician groups, reliability increased from 0.43 to 0.73 following service assignment. Approximately 66% (2340 of 3527) of clinicians were reclassified into a different performance quintile after excluding unrelated costs. Conclusions: The elective outpatient PCI cost measure had increased precision and reclassified clinician performance relative to a hypothetical version that included total expenditures.

The primary goal of the Carnegie Chicago Hubble Program (CCHP) is to calibrate the zero-point of the Type Ia supernova (SN Ia) Hubble Diagram through the use of Population II standard candles. So far, the CCHP has measured direct distances to 11 SNe Ia, and here we increase that number to 15 with two new TRGB distances measured to NGC 5643 and NGC 1404, for a total of 20 SN Ia calibrators. We present resolved, point-source photometry from new Hubble Space Telescope (HST) imaging of these two galaxies in the F814W and F606W bandpasses. From each galaxy's stellar halo, we construct an F814W-band luminosity function in which we detect an unambiguous edge feature identified as the Tip of the Red Giant Branch (TRGB). For NGC 5643, we find $\mu_0 = 30.48\pm0.03(stat)\pm0.07(sys) $ mag, and for NGC 1404 we find $ \mu_0=31.36\pm 0.04(stat)\pm 0.05(sys)$ mag. From a preliminary consideration of the SNe Ia in these galaxies, we find increased confidence in the results presented in Paper VIII (Freedman et al. 2019). The high precision of our TRGB distances enables a significant measurement of the 3D displacement between the Fornax Cluster galaxies NGC 1404 and NGC 1316 (Fornax A) equal to $1.50^{+0.25}_{-0.39}$ Mpc, which we show is in agreement with independent literature constraints., Comment: 24 pages; 15 figures; submitted to ApJ (v2: references added; typos corrected; abstract shortened)

We present $HST$ narrow-band near-infrared imaging of Pa$\alpha$ and Pa$\beta$ emission of 48 local Luminous Infrared Galaxies (LIRGs) from the Great Observatories All-Sky LIRG Survey (GOALS). These data allow us to measure the properties of 810 spatially resolved star-forming regions (59 nuclei and 751 extra-nuclear clumps), and directly compare their properties to those found in both local and high-redshift star-forming galaxies. We find that in LIRGs, the star-forming clumps have radii ranging from $\sim90-900$ pc and star formation rates (SFRs) of $\sim1\times10^{-3}$ to 10 M$_\odot$yr$^{-1}$, with median values for extra-nuclear clumps of 170 pc and 0.03 M$_\odot$yr$^{-1}$. The detected star-forming clumps are young, with a median stellar age of $8.7$ Myrs, and a median stellar mass of $5\times10^{5}$ M$_\odot$. The SFRs span the range of those found in normal local star-forming galaxies to those found in high-redshift star-forming galaxies at $\rm{z}=1-3$. The luminosity function of the LIRG clumps has a flatter slope than found in lower-luminosity, star-forming galaxies, indicating a relative excess of luminous star-forming clumps. In order to predict the possible range of star-forming histories and gas fractions, we compare the star-forming clumps to those measured in the MassiveFIRE high-resolution cosmological simulation. The star-forming clumps in MassiveFIRE cover the same range of SFRs and sizes found in the local LIRGs and have total gas fractions that extend from 10 to 90%. If local LIRGs are similar to these simulated galaxies, we expect future observations with ALMA will find a large range of gas fractions, and corresponding star formation efficiencies, among the star-forming clumps in LIRGs.

The Tip of the Red Giant (TRGB) method provides one of the most accurate and precise means of measuring the distances to nearby galaxies. Here we present a VIJHK absolute calibration of the TRGB based on observations of TRGB stars in the Large Magellanic Cloud (LMC),grounded on detached eclipsing binaries (DEBs). This paper presents a more detailed description of the method first presented in Freedman et al. (2019) for measuring corrections for the total line-of-sight extinction and reddening to the LMC. In this method, we use a differential comparison of the red giant population in the LMC, first with red giants in the Local Group galaxy, IC 1613, and then with those in the Small Magellanic Cloud. As a consistency check, we derive an independent calibration of the TRGB sequence using the SMC alone, invoking its geometric distance also calibrated by DEBs. An additional consistency check comes from near-infrared observations of Galactic globular clusters covering a wide range of metallicities. In all cases we find excellent agreement in the zero-point calibration. We then examine the recent claims by Yuan et al. (2019), demonstrating that, in the case of the SMC, they corrected for extinction alone while neglecting the essential correction for reddening as well. In the case of IC 1613, we show that their analysis contains an incorrect treatment of (over-correction for) metallicity. Using our revised (and direct) measurement of the LMC TRGB extinction, we find a value of Ho = 69.6 +/-0.8 (+/-1.1% stat) +/- 1.7 (+/-2.4% sys) km/s/Mpc., Comment: 33 pages, 13 figures, accepted to the Astrophysical Journal February 4, 2020

A statewide database identified prolonged ventilation (PV) and acute renal failure (RF) as the biggest cost drivers after isolated coronary artery bypass grafting. Reducing these complications through regional collaboration should improve outcomes and lower health care costs.A total of 27,978 patients who underwent isolated coronary artery bypass grafting were divided into pre- and post-quality improvement initiative groups (early era: 2008 to 2011, n = 15,176; later era: 2012 to 2015, n = 12,802). Focused learning sessions on PV and postoperative RF were undertaken in the earlier era. Incidence of death, PV, and RF in the two groups was analyzed using one-way analysis of variance and Fisher exact tests.The Society of Thoracic Surgeons (STS) predicted risk of mortality and predicted risk of mortality/morbidity were significantly higher in the later era (p 0.01), as were STS predicted PV (10.1% vs 11.3%) and RF (3.4% vs 3.8%). Despite these increased risks, STS observed-to-expected ratios for mortality and mortality/morbidity fell. Observed rates for PV (10.5% vs 8.8%, p 0.01) and RF (3.6% vs 2.3%, p0.01) were associated with STS observed-to-expected ratios of PV (1.04 vs 0.78) and RF (1.03 vs 0.60). Adjusting for case volume in the two eras, 271 cases of PV and 170 of RF were avoided, with estimated cost savings of $10,212,637 and $8,519,630, respectively.A regional collaboration using a statewide STS and an all-payor database with focused quality improvement is a powerful tool for change. Despite rising risks for mortality and morbidity, outcomes for PV and RF improved and produced significant cost savings. Applying these efforts nationally can enormously affect patient care and health care costs.

Although tricuspid valve operations remain associated with high mortality (approximately 8% to 10%), no robust prediction models exist to support clinical decision making. We developed a preoperative clinical risk model with an easily calculable clinical risk score (CRS) to predict mortality and major morbidity after isolated tricuspid valve surgery.The Society of Thoracic Surgeons database records were evaluated for 2,050 isolated TV repair and replacement operations for any etiology performed at 50 hospitals (2002 to 2014) in a number of states. Parsimonious preoperative risk prediction models were developed using multiple-level mixed effects regression to estimate mortality and composite major morbidity risk. Model results were utilized to establish a novel CRS for patients undergoing tricuspid valve operations. Models were evaluated for discrimination and calibration.Operative mortality and composite major morbidity rates were 9% and 42%, respectively. Final regression models performed well (both p0.001; areas under the receiver-operating characteristics curve 0.74 and 0.76) and included preoperative factors: age, sex, stroke, hemodialysis, ejection fraction, lung disease, New York Heart Association class, reoperation, and urgent or emergency status (all p0.05). A simple CRS from 0 to 10+ was highly associated (p0.001) with incremental increases in predicted mortality and major morbidity. Predicted mortality risk ranged from 2% to 34% across CRS categories, and predicted major morbidity risk ranged from 13% to 71%.Mortality and major morbidity after isolated tricuspid valve surgery can be predicted using preoperative patient data from The Society of Thoracic Surgeons National Adult Cardiac Database. A simple clinical risk score predicts mortality and major morbidity after isolated tricuspid valve surgery. This score may facilitate perioperative counseling and identification of suitable patients for tricuspid valve surgery.

Background The technical expertise required for treatment of coronary and structural heart valve disease differs. Correlation between center-specific mortality rates after coronary artery bypass grafting (CABG) and valve operations has not been demonstrated. This study tested the hypothesis that risk-adjusted outcomes between coronary and valve procedures do not correlate within centers. Methods Records of patients undergoing isolated CABG, isolated aortic valve replacement (AVR), or isolated mitral valve replacement (MVR) procedures from 2008 to 2015 in a multi-institutional Society of Thoracic Surgeons (STS) database were used to generate observed-to-expected (O/E) ratios for morbidity and death. Ratios were based on the STS predicted risks of morbidity and death and were calculated by procedure for each institution. Linear regression models evaluated the relationship between institutional performance in CABG and valve operations. Results A total of 22,258 records from 18 institutions were analyzed: 17,026 CABG, 3,238 isolated AVR, and 1,994 MVR procedures. With respect to deaths, the correlation coefficients were weak; for AVR and CABG, it was 0.22 and was 0.26 for MVR and CABG. With respect to morbidity, a strong relationship was seen between the morbidity O/E ratios, with coefficients of 1.03 for AVR and 0.97 for MVR, suggesting a nearly 1:1 relationship between morbidities observed in an institution's CABG and valve operations. Conclusions Sites that perform CABG with low mortality rates may not have similarly low mortality rates with valve operations. Most striking, however, is the nearly identical O/E ratio for morbidity for CABG and valve operations at each center. These findings suggest postoperative care as a major determinant for morbidity after cardiac operation.

The Congress recently passed legislation to repeal the Sustainable Growth Rate Formula and replace it with the Medicare Access and Children Health Plan Reauthorization Act's Quality Payment Program. The Quality Payment Program is designed to move physician payment from a volume-based to a value-based methodology. There are two pathways of payment that diverge and are differentiated by managing risks or managing rewards. The Merit-based Incentive Payment System (MIPS) is a competitive payment system that is budget neutral and results in defined winners and losers with potential losses/gains in payments from 4% in 2019 to 9% in 2022. Characteristically, this is not dissimilar to the Sustainable Growth Rate Formula of days past but with quality measures applied. The second pathway is that toward Alternative Payment Models (APMs) that allow clinicians to participate in payment models that that provide rewards for higher-quality, lower-cost care with entry bonuses as high as 5%. The Virginia Cardiac Services Quality Initiative, a well-known regional quality collaborative, was awarded a federal grant as a Support and Alignment Network 2.0 in September 2016. As an awardee, the Virginia Cardiac Services Quality Initiative is offering, free of charge, educational support to clinicians to understand the Medicare Access and Children Health Plan Reauthorization Act, MIPS, and APMs. These support services will include on-site education, continual evaluation, and guided transformation of practices to move from MIPS, a very competitive and possibly very difficult system for Society of Thoracic Surgeons members, toward Advanced APMs, where they can self-direct their measurement and rewards, allowing success financially under the Medicare Access and Children Health Plan Reauthorization Act.

Objectives The Centers for Medicare and Medicaid Services plans to institute a 5-year trial of bundled payments for coronary artery bypass grafting through 90 days after discharge. To investigate the impact, we reviewed actual inpatient costs for patients undergoing bypass surgery relative to the target price. Methods A total of 13,276 Medicare patients with estimated cost data underwent isolated coronary artery bypass grafting from 2008 to 2015 in 18 hospitals over 8 Medicare-defined regions within the Commonwealth of Virginia. Actual 2015 inpatient costs were compared with estimated target prices for each year of the pilot, based on the previous 3 years and stratified by Diagnosis-Related Group. Results The mean 2015 cost per patient was $50,394 with high variation (range, $27,862-$74,169). On average, hospitals would receive a refund of $17,682 in year 1, but then owe Medicare increasing amounts up to $367,985 in year 5. If 2015 were the final year of the pilot, 13 of the 18 hospitals (72%) would have owed Medicare for cost overruns averaging $614,270 (range, $67,404-$2,102,292). Costs were below the target price at 5 of 18 hospitals, and the Centers for Medicare and Medicaid Services would have paid them an extra $272,355 on average (range, $88,628-$567,429). Conclusions Hospitals will face immediate financial pressure due to average cost increases of 3.6% per year and an automatic reduction in payment. As regional pricing is phased in, hospitals can expect to owe Medicare increasing amounts. The net effect is shifting of financial risks to hospitals, which could restrict access to care for higher-risk patients.

The surgical management of acute type A aortic dissection is evolving, and many aortic centers of excellence are reporting superior outcomes. We hypothesize that similar trends exist in a multiinstitutional regional consortium.Records for 884 consecutive patients who underwent aortic operations (2003 to 2015) for acute type A aortic dissection were extracted from a regional The Society of Thoracic Surgeons database. Patients were stratified into three equal operative eras. Differences in outcomes and risk factors for morbidity and mortality were determined.Surgical procedures for type A aortic dissection are increasing in extent and complexity. Aortic root repair was performed in 16% of early era cases compared with 67% currently (p0.0001). Similarly, aortic arch repair increased from 27% to 37% cases (p0.0001). Cerebral perfusion is currently used in 85% of circulatory arrest cases, most frequently antegrade (57%). Total circulatory arrest times increased (29 minutes vs 31 minutes vs 36 minutes; p = 0.005), but times without cerebral perfusion were stable (12 minutes vs 6 minutes; p = 0.68). Although the operative mortality rate remained stable at 18.9% during the 3 operative eras, there were significant decreases in pneumonia and reoperations (p 0.05). Predictors of operative mortality and major morbidity are age (odds ratio [OR], 1.04; p0.0001), previous stroke (OR, 2.09; p = 0.03), and elevated creatinine (OR, 1.31; p = 0.01). Importantly, the extent of aortic operation did not increase risk for morbidity or mortality.Operative morbidity and mortality remain significant for type A aortic dissection, but lower than historical outcomes. The extent of aortic surgery has increased, resulting in adaptive cerebral protection changes in contemporary "real-world" practice.

BACKGROUND A unified definition of primary graft dysfunction (PGD) after heart transplantation was adopted in 2014, with moderate and severe PGD defined as a need for mechanical circulatory support. While risk factors for PGD are well identified, outcomes and resource utilization have not been well-studied. We examined the resource utilization and associated costs with PGD. METHODS All adult heart transplantations (2001-2016) from a statewide Society of Thoracic Surgery database were analyzed by dividing them into two groups-with PGD (requiring mechanical circulatory support) and without PGD. RESULTS Of the 718 heart transplants, 110 (15.3%) patients developed PGD. Prevalence of PGD for the study duration ranged from 3.7% to 22.7% with no significant trend. The most frequently used mechanical circulatory support device was intra-aortic balloon pump (88%), followed by extracorporeal membrane oxygenation (17%), and catheter-based circulatory support devices (3%). There were no significant differences in demographics or preoperative variables between the two groups. Resource utilization such as total intensive care unit hours, ventilation hours, reoperation for bleeding, blood product transfusions, and length of stay were significantly higher in the PGD group. Postoperative complications were also higher in PGD group including operative mortality (31.8% vs 3.8%, P

RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology have been made in recent years to increase their precision as distance indicators. We present multi-wavelength (optical $UBVR_cI_c$ and Gaia $G, BP, RP$; near-infrared $JHK_s$; mid-infrared $[3.6], [4.5]$) period-luminosity-metallicity (PLZ), period-Wesenheit-metallicity (PWZ) relations, calibrated using photometry obtained from The Carnegie RR Lyrae Program and parallaxes from the Gaia second data release for 55 Galactic field RR Lyrae stars. The metallicity slope, which has long been predicted by theoretical relations, can now be measured in all passbands. The scatter in the PLZ relations is on the order of 0.2 mag, and is still dominated by uncertainties in the parallaxes. As a consistency check of our PLZ relations, we also measure the distance modulus to the globular cluster M4, the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), and our results are in excellent agreement with estimates from previous studies., Accepted for publication in MNRAS, 15 pages, 14 figures

We determine the distances to the Type Ia Supernova host galaxies M66 (NGC 3627) and M96 (NGC 3368) of the Leo I Group using the Tip of the Red Giant Branch (TRGB) method. We target the stellar halos of these galaxies using the Hubble Space Telescope ACS/WFC in the F606W and F814W bandpasses. By pointing to the stellar halos we sample RGB stars predominantly of Population II, minimize host-galaxy reddening, and significantly reduce the effects of source crowding. Our absolute calibration of the I-band TRGB is based on a recent detached eclipsing binary distance to the Large Magellanic Cloud. With this geometric zero point in hand, we find for M66 and M96, respectively, true distance moduli $ {\mu}_0 = 30.23 \pm 0.04\text{ (stat)} \pm 0.06\text{ (sys)} $ mag and $ {\mu}_0 = 30.29 \pm 0.02\text{ (stat)} \pm 0.06\text{ (sys)} $ mag., Comment: Accepted to ApJ; 15 pages; 5 figures

Objectives Outcomes in cardiac surgery are benchmarked against national Society of Thoracic Surgeons (STS) data and include patients undergoing elective, urgent, emergent, and salvage operations. This practice relies on accurate risk adjustment to avoid risk-averse behavior. We hypothesize that the STS risk calculator does not adequately characterize the risk of salvage operations because of their heterogeneity and infrequent occurrence. Methods Data on all cardiac surgery patients with an STS predicted risk score (2002-2017) were extracted from a regional database of 19 cardiac surgery centers. Patients were stratified according to operative status for univariate analysis. Observed-to-expected (O:E) ratios for mortality and composite morbidity/mortality were calculated and compared among elective, urgent, emergent, and salvage patients. Results A total of 76,498 patients met inclusion criteria. The O:E mortality ratios for elective, urgent, and emergent cases were 0.96, 0.98, and 0.93, respectively (all P values > .05). However, mortality rate was significantly higher than expected for salvage patients (O:E ratio, 1.41; P = .04). Composite morbidity/mortality rate was lower than expected in elective (O:E ratio, 0.81; P = .0001) and urgent (O:E ratio, 0.93; P = .0001) cases but higher for emergent (O:E ratio, 1.13; P = .0006) and salvage (O:E ratio, 1.24; P = .01). O:E ratios for salvage mortality were highly variable among each of the 19 centers. Conclusions The current STS risk models do not adequately predict outcomes for salvage cardiac surgery patients. On the basis of these results, we recommend more detailed reporting of salvage outcomes to avoid risk aversion in these potentially life-saving operations.

We present a new and independent determination of the local value of the Hubble constant based on a calibration of the Tip of the Red Giant Branch (TRGB) applied to Type Ia supernovae (SNeIa). We find a value of Ho = 69.8 +/- 0.8 (+/-1.1\% stat) +/- 1.7 (+/-2.4\% sys) km/sec/Mpc. The TRGB method is both precise and accurate, and is parallel to, but independent of the Cepheid distance scale. Our value sits midway in the range defined by the current Hubble tension. It agrees at the 1.2-sigma level with that of the Planck 2018 estimate, and at the 1.7-sigma level with the SHoES measurement of Ho based on the Cepheid distance scale. The TRGB distances have been measured using deep Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging of galaxy halos. The zero point of the TRGB calibration is set with a distance modulus to the Large Magellanic Cloud of 18.477 +/- 0.004 (stat) +/-0.020 (sys) mag, based on measurement of 20 late-type detached eclipsing binary (DEB) stars, combined with an HST parallax calibration of a 3.6 micron Cepheid Leavitt law based on Spitzer observations. We anchor the TRGB distances to galaxies that extend our measurement into the Hubble flow using the recently completed Carnegie Supernova Project I sample containing about 100 well-observed SNeIa. There are several advantages of halo TRGB distance measurements relative to Cepheid variables: these include low halo reddening, minimal effects of crowding or blending of the photometry, only a shallow (calibrated) sensitivity to metallicity in the I-band, and no need for multiple epochs of observations or concerns of different slopes with period. In addition, the host masses of our TRGB host-galaxy sample are higher on average than the Cepheid sample, better matching the range of host-galaxy masses in the CSP distant sample, and reducing potential systematic effects in the SNeIa measurements., Comment: 60 pages, 20 figures, accepted for publication in the Astrophysical Journal

We present a systematic study of the diffuse ionized gas (DIG) in M83 and its effects on the measurement of metallicity gradients at varying resolution scales. Using spectrophotometric data cubes of M83 obtained at the 2.5m duPont telescope at Las Campanas Observatory as part of the TYPHOON program, we separate the HII regions from the DIG using the [SII]/H$\alpha$ ratio, HIIphot (HII finding algorithm) and the H$\alpha$ surface brightness. We find that the contribution to the overall H$\alpha$ luminosity is approximately equal for the HII and DIG regions. The data is then rebinned to simulate low-resolution observations at varying resolution scales from 41 pc up to 1005 pc. Metallicity gradients are measured using five different metallicity diagnostics at each resolution. We find that all metallicity diagnostics used are affected by the inclusion of DIG to varying degrees. We discuss the reasons of why the metallicity gradients are significantly affected by DIG using the HII dominance and emission line ratio radial profiles. We find that applying the [SII]/H$\alpha$ cut will provide a closer estimate of the true metallicity gradient up to a resolution of 1005 pc for all metallicity diagnostics used in this study., Comment: 26 pages, 12 figures + Appendix/Supplementary Material, accepted for publication by MNRAS

In the nearby galaxy NGC 4258, the well-modeled orbital motion of H$_2$O masers about its supermassive black hole provides the means to measure a precise geometric distance. As a result, NGC 4258 is one of a few "geometric anchors" available to calibrate the true luminosities of stellar distance indicators such as the Tip of the Red Giant Branch (TRGB) or the Cepheid Leavitt law. In this paper, we present a detailed study of the apparent magnitude of the TRGB within NGC 4258 using publicly-available HST observations optimally situated in the gas- and dust-free halo along the minor axis, spanning distances ranging from 8 to 22 kpc in projected galactocentric radius. We undertake a systematic evaluation of the uncertainties associated with measuring the TRGB in this galaxy, based on an analysis of 54 arcmin$^2$ of HST/ACS imaging. After quantifying these uncertainties, we measure the TRGB in NGC 4258 to be F814W$_0$ = 25.347 $\pm$ 0.014(stat) $\pm$ 0.042(sys) mag. Combined with a recent 1.5% megamaser distance to NGC 4258, we determine the absolute luminosity of the TRGB to be $M_{F814W}^{TRGB}$ = -4.050 $\pm$ 0.028(stat) $\pm$ 0.048(sys) mag. This new calibration agrees to better than 1% with an independent calibration presented in Freedman et al. (2019, 2020) that was based on detached eclipsing binaries (DEBs) located in the LMC., Comment: 31 pages, 19 figures, 4 tables, and 3 appendices, accepted for publication in ApJ

We compare mid-infrared 3.6 and 4.5 $\mu$m Warm Spitzer observations for Cepheids in the Milky Way and the Large and Small Magellanic Clouds. Using models, we explore in detail the effect of the CO rotation-vibration band-head at 4.6 $\mu$m on the mid-infrared photometry. We confirm the temperature sensitivity of the CO band-head at 4.6 $\mu$m and find no evidence for an effect at 3.6 $\mu$m. We compare the ([3.6]-[4.5]) period-colour relations in the MW, LMC, and SMC. The slopes of the period-colour relations for the three galaxies are in good agreement, but there is a trend in zero-point with metallicity, with the lowest metallicity Cepheids having redder mid-IR colours. Finally, we present a colour-[Fe/H] relation based on published spectroscopic metallicities. This empirical relation, calibrated to the metallicity system of Genovali et al. (2014), demonstrates that the ([3.6]-[4.5]) colour provides a reliable metallicity indicator for Cepheids, with a precision comparable to current spectroscopic determinations., Comment: Accepted for publication in MNRAS. 9 pages, 8 figures

Background The Placement of Aortic Transcatheter Valve (PARTNER) trial suggested an economic advantage for transcatheter aortic valve replacement (TAVR) for high-risk patients. The purpose of this study was to evaluate the cost effectiveness of TAVR in the "real world" by comparing TAVR with surgical aortic valve replacement (SAVR) in intermediate-risk and high-risk patients. Methods A multiinstitutional database of The Society of Thoracic Surgeons (STS) (2011 to 2013) linked with estimated cost data was evaluated for isolated TAVR and SAVR operations (n = 5,578). TAVR-treated patients (n = 340) were 1:1 propensity matched with SAVR-treated patients (n = 340). Patients undergoing SAVR were further stratified into intermediate-risk (SAVR-IR: predicted risk of mortality [PROM] 4% to 8%) and high-risk (SAVR-HR: PROM >8%) cohorts. Results Median STS PROM for TAVR was 6.32% compared with 6.30% for SAVR (SAVR-IR 4.6% and SAVR-HR 12.4%). A transfemoral TAVR approach was most common (61%). Mortality was higher for TAVR (10%) compared with SAVR (6%, p p p p p Conclusions TAVR was associated with greater total costs and mortality compared with SAVR in intermediate-risk and high-risk patients while conferring lower major morbidity and improved resource use. Increased cost of TAVR appears largely related to the cost of the valve. Until the price of TAVR valves decreases, these data suggest that TAVR may not provide the most cost-effective strategy, particularly for intermediate-risk patients.

The role of feedback in triggering or quenching star formation and hence driving galaxy evolution can be directly studied with high resolution integral field observations. The manifestation of feedback in shocks is particularly important to examine in galaxy mergers, where violent interactions of gas takes place in the interstellar medium during the course of the galactic collision. As part of our effort to systematically study the local population of luminous infrared galaxies within the Great Observatories All-Sky LIRG Survey, we undertook the Keck OSIRIS AO LIRG Analysis observing campaign to study the gas dynamics in the inner kiloparsec regions of these systems at spatial scales of a few 10s of parsecs. With high-resolution near-infrared adaptive optics-assisted integral-field observations taken with OSIRIS on the Keck Telescopes, we employ near-infrared diagnostics such as Brg and the ro-vibrationally excited H2 lines to quantify the nuclear star formation rate and identify feedback associated with shocked molecular gas seen in 21 nearby luminous infrared galaxies. Shocked molecular gas is preferentially found in the ultraluminous infrared systems, but may also be triggered at a lower luminosity, earlier merging stage. On circumnuclear scales, AGN have a strong effect on heating the surrounding molecular gas, though their coupling is not simply driven by AGN strength but rather is complicated by orientation, dust shielding, density, and other factors. We find that the nuclear star formation correlates with merger class and diminishing projected nuclear separations. These trends are largely consistent with the picture of merger-induced starbursts within the center of galaxy mergers., Accepted to ApJ; 31 pages (with 5 tables and 10 embedded figures) + figure set

The Carnegie-Chicago Hubble Program is undertaking a re-calibration of the extragalactic distance scale, using SNe Ia that are tied to Tip of the Red Giant Branch (TRGB) distances to local galaxies. We present here deep Hubble Space Telescope ACS/WFC imaging of the resolved stellar populations in the metal-poor halos of the SN Ia-host galaxies NGC 4424, NGC 4526, and NGC 4536. These three Virgo constellation galaxies are prime targets for calibrating the extragalactic distance scale given their relative proximity in the local universe and their low line-of-sight reddenings. Anchoring the TRGB zero-point to the geometric distance to the Large Magellanic Cloud via detached eclipsing binaries, we measure extinction-corrected distance moduli of 31.00 ± 0.03stat ± 0.06sys mag, 30.98 ± 0.03stat ± 0.06sys mag, and 30.99 ± 0.03stat ± 0.06sys mag for NGC 4424, NGC 4526, and NGC 4536, respectively, or 15.8 ± 0.2stat ± 0.4sys Mpc, 15.7 ± 0.2stat ± 0.4sys Mpc, and 15.8 ± 0.2stat ± 0.4sys Mpc. For these three galaxies, the distances are the first that are based on the TRGB, and for NGC 4424 and NGC 4526, they are the highest-precision distances published to date, each measured to 3%. Finally, we report good agreement between our TRGB distances and the available Cepheid distances for NGC 4424 and NGC 4536, demonstrating consistency between the distance scales currently derived from stars of Population I and II.

Acute kidney injury (AKI) occurs in 7% to 18% of hospitalized patients and complicates the course of 50% to 60% of those admitted to the intensive care unit, carrying both significant mortality and morbidity.[1][1] Even though many cases of AKI are reversible within days to weeks of occurrence, data

Postoperative atrial fibrillation (POAF) is a known risk factor for morbidity and mortality after cardiac surgery but has not been investigated in the left ventricular assist device (LVAD) population. We hypothesize that POAF will increase morbidity and resource utilization after LVAD placement.Records were extracted for all patients in a regional database who underwent continuous-flow LVAD placement (n = 1064, 2009-2017). Patients without a history of atrial fibrillation (n = 689) were stratified by POAF for univariate analysis. Multivariable regression models calculated the risk-adjusted association of arrhythmias on outcomes and resource utilization.The incidence of new-onset POAF was 17.6%, and patients who developed POAF were older and more likely to have moderate/severe mitral regurgitation, a history of stroke, and concomitant tricuspid surgery. After risk adjustment, POAF was not associated with operative mortality or stroke but was associated with major morbidity (odds ratio [OR] 2.5 P = .0004), prolonged ventilation (OR 2.7, P .0001), unplanned right ventricular assist device (OR 2.9, P = .01), and a trend toward renal failure (OR 2.0, P = .06). In addition, POAF was associated with greater risk-adjusted resource utilization, including discharge to a facility (OR 2.2, P = .007), an additional 4.9 postoperative days (P = .02), and 88 hours in the intensive care unit (P = .01).POAF was associated with increased major morbidity, possibly from worsening right heart failure leading to increased renal failure and unplanned right ventricular assist device placement. This led to patients with POAF having longer intensive care unit and hospital stays and more frequent discharges to a facility.

We report a luminous Type II supernova, ASASSN-15nx, with a peak luminosity of M_V=-20 mag, that is between typical core-collapse supernovae and super-luminous supernovae. The post-peak optical light curves show a long, linear decline with a steep slope of 2.5 mag/100 days (i.e., an exponential decline in flux), through the end of observations at phase ~260 days. In contrast, the light curves of hydrogen rich supernovae (SNe II-P/L) always show breaks in their light curves at phase ~100 days, before settling onto Co56 radioactive decay tails with a decline rate of about 1 mag/100 days. The spectra of ASASSN-15nx do not exhibit the narrow emission-line features characteristic of Type IIn SNe, which can have a wide variety of light-curve shapes usually attributed to strong interactions with a dense circumstellar medium (CSM). ASASSN-15nx has a number of spectroscopic peculiarities, including a relatively weak and triangularly-shaped H-alpha emission profile with no absorption component. The physical origin of these peculiarities is unclear, but the long and linear post-peak light curve without a break suggests a single dominant powering mechanism. Decay of a large amount of Ni56 (M_Ni56 = 1.6 +/- 0.2 M_sun) can power the light curve of ASASSN-15nx, and the steep light-curve slope requires substantial gamma-ray escape from the ejecta, which is possible given a low-mass hydrogen envelope for the progenitor. Another possibility is strong CSM interactions powering the light curve, but the CSM needs to be sculpted to produce the unique light-curve shape and to avoid producing SN IIn-like narrow emission lines., Accepted for publication in ApJ. Ancillary ASCII tables added: photsn.txt -- photometry; L.txt -- blackbody bolometric luminosity

We present a new empirical \(JHK\) absolute calibration of the tip of the red giant branch (TRGB) in the Large Magellanic Cloud (LMC). We use published data from the extensive \emph{Near-Infrared Synoptic Survey} containing 3.5 million stars, of which 65,000 are red giants that fall within one magnitude of the TRGB. Adopting the TRGB slopes from a companion study of the isolated dwarf galaxy IC\,1613 as well as an LMC distance modulus of \(\mu_0 = \)~18.49~mag from (geometric) detached eclipsing binaries, we derive absolute \(JHK\) zero-points for the near-infrared TRGB. For comparison with measurements in the bar alone, we apply the calibrated \(JHK\) TRGB to a 500 deg\textsuperscript{2} area of the 2MASS survey. The TRGB reveals the 3-dimensional structure of the LMC with a tilt in the direction perpendicular to the major axis of the bar, in agreement with previous studies., Comment: 14 pages, 8 figures, Accepted to ApJ

The Carnegie-Chicago Hubble Program seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB). Based on deep $Hubble$ $Space$ $Telescope$ ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax Cluster that is host to the supernova SN2012fr. We have measured its extinction-corrected TRGB magnitude to be F814W $= 27.34 \pm 0.03_{stat} \pm0.01_{sys}$ mag. In advance of future direct calibration by $Gaia$, we set a provisional TRGB luminosity via the Large Magellanic Cloud and find a true distance modulus $\mu_0 = 31.29 \pm 0.04_{stat}\pm0.05_{sys}$ mag or $D = 18.1 \pm 0.3_{stat} \pm0.4_{sys}$ Mpc. This high-fidelity measurement shows excellent agreement with recent Cepheid-based distances to NGC 1365 and suggests no significant difference in the distances derived from stars of Population I and II. We revisit the error budget for the $CCHP$ path to the Hubble Constant based on this analysis of one of our most distant hosts, finding a 2.5% measurement is feasible with our current sample., Comment: 18 pages, 9 figures, 2 tables, submitted to ApJ, typos corrected

The azimuthal variation of the HII region oxygen abundance in spiral galaxies is a key observable for understanding how quickly oxygen produced by massive stars can be dispersed within the surrounding interstellar medium. Observational constraints on the prevalence and magnitude of such azimuthal variations remain rare in the literature. Here, we report the discovery of pronounced azimuthal variations of HII region oxygen abundance in NGC 2997, a spiral galaxy at approximately 11.3 Mpc. Using 3D spectroscopic data from the TYPHOON Program, we study the HII region oxygen abundance at a physical resolution of 125 pc. Individual HII regions or complexes are identified in the 3D optical data and their strong emission line fluxes measured to constrain their oxygen abundances. We find 0.06 dex azimuthal variations in the oxygen abundance on top of a radial abundance gradient that is comparable to those seen in other star-forming disks. At a given radial distance, the oxygen abundances are highest in the spiral arms and lower in the inter-arm regions, similar to what has been reported in NGC 1365 using similar observations. We discuss whether the azimuthal variations could be recovered when the galaxy is observed at worse physical resolutions and lower signal-to-noise ratios., Comment: 13 pages, 17 figures, accepted to A&A

We detect widespread [CII]157.7um emission from the inner 5 kpc of the active galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The emission is found associated with warm H2, distributed along and beyond the end of southern jet, in a zone known to contain shock-excited optical filaments. It is also associated with soft X-ray hot-spots, which are the counterparts of the `anomalous radio arms' of NGC~4258, and a 1 kpc-long filament on the minor axis of the galaxy which contains young star clusters. Palomar-CWI H-alpha integral field spectroscopy shows that the filament exhibits non-circular motions within NGC 4258. Many of the [CII] profiles are very broad, with the highest line width, 455 km/s, observed at the position of the southern jet bow-shock. Abnormally high ratios of L([CII])/L(FIR) and L([CII])/L(PAH7.7um) are found along and beyond the southern jet and in the X-ray hotspots. These are the same regions that exhibit unusually large intrinsic [CII] line widths. This suggests that the [CII] traces warm molecular gas in shocks and turbulence associated with the jet. We estimate that as much as 40% (3.8 x 10^39 erg/s) of the total [CII] luminosity from the inner 5 kpc of NGC 4258 arises in shocks and turbulence (< 1% bolometric luminosity from the active nucleus), the rest being consistent with [CII] excitation associated with star formation. We propose that the highly-inclined jet is colliding with, and being deflected around, dense irregularities in a thick disk, leading to significant energy dissipation over a wide area of the galaxy., Accepted for Publication in the Astrophysical Journal Oct 29 2018

We present photometry of 30 Galactic RR Lyrae variables taken with HST WFC3/IR for the Carnegie-Chicago Hubble Program. These measurements form the base of the distance ladder measurements that comprise a pure Population II base to a measurement of Ho at an accuracy of 3%. These data are taken with the same instrument and filter (F160W) as our observations of RR Lyrae stars in external galaxies so as to to minimize sources of systematic error in our calibration of the extragalactic distance scale. We calculate mean magnitudes based on one to three measurements for each RR Lyrae star using star-by-star templates generated from densely time-sampled data at optical and mid-infrared wavelengths. We use four RR Lyrae stars from our sample with well-measured HST parallaxes to determine a zero point. This zero point will soon be improved with the large number of precise parallaxes to be provided by Gaia. We also provide preliminary calibration with the TGAS & Gaia DR2 data, and all three zero points are in agreement, to within their uncertainties., Accepted for publication in the Astrophysical Journal, 8 pages, 3 figures, 5 tables