Abstract
Superluminous supernovae (SLSNe) are a rare class of stellar explosions with luminosities ∼ 10–100 times greater than ordinary core-collapse supernovae. One popular model to explain the ...enhanced optical output of hydrogen-poor (Type I) SLSNe invokes energy injection from a rapidly spinning magnetar. A prediction in this case is that high-energy gamma-rays, generated in the wind nebula of the magnetar, could escape through the expanding supernova ejecta at late times (months or more after optical peak). This paper presents a search for gamma-ray emission in the broad energy band from 100 MeV to 30 TeV from two Type I SLSNe, SN2015bn, and SN2017egm, using observations from Fermi-LAT and VERITAS. Although no gamma-ray emission was detected from either source, the derived upper limits approach the putative magnetar’s spin-down luminosity. Prospects are explored for detecting very-high-energy (VHE; 100 GeV–100 TeV) emission from SLSNe-I with existing and planned facilities such as VERITAS and CTA.
Contralateral prophylactic mastectomy (CPM) rates in women with unilateral breast cancer are increasing despite controversy regarding survival advantage. Current scrutiny of the medical costs led us ...to evaluate the cost-effectiveness of CPM versus routine surveillance as an alternative contralateral breast cancer (CBC) risk management strategy.
Using a Markov model, we simulated patients with breast cancer from mastectomy to death. Model parameters were gathered from published literature or national databases. Base-case analysis focused on patients with average-risk breast cancer, 45 years of age at treatment. Outcomes were valued in quality-adjusted life-years (QALYs). Patients' age, risk level of breast cancer, and quality of life (QOL) were varied to assess their impact on results.
Mean costs of treatment for women age 45 years are comparable: $36,594 for the CPM and $35,182 for surveillance. CPM provides 21.22 mean QALYs compared with 20.93 for surveillance, resulting in an incremental cost-effectiveness ratio (ICER) of $4,869/QALY gained for CPM. To prevent one CBC, six CPMs would be needed. CPM is no longer cost-effective for patients older than 70 years (ICER $62,750/QALY). For BRCA-positive patients, CPM is clearly cost-effective, providing more QALYs while being less costly. In non-BRCA patients, cost-effectiveness of CPM is highly dependent on assumptions regarding QOL for CPM versus surveillance strategy.
CPM is cost-effective compared with surveillance for patients with breast cancer who are younger than 70 years. Results are sensitive to BRCA-positive status and assumptions of QOL differences between CPM and surveillance patients. This highlights the importance of tailoring treatment for individual patients.
Technology development and design decisions in wind energy are often based on results from simulations performed for individual wind turbines or entire wind plants. It is therefore critical to ensure ...that the models being used for research and industry applications in wind energy be thoroughly validated against measurements. A full-system validation of wind plant simulations must consider the atmospheric inflow, the response of the wind turbines, and their wakes. This task is complicated by the lack of freely available, quality-controlled, high-quality measurements. Here, such measurements are used to offer a validation exercise that can be used to assess the accuracy of models of any fidelity level. When it comes to real-world measurements, the dataset considered herein is simple in terms of terrain but exhibits pronounced diurnal cycles. Instead of a full-scale wind plant, we consider an individual research-scale, utility wind turbine instrumented for power and loads measurements. Three benchmarks are defined, with increasing levels of complexity: near neutral, slightly unstable, and very stable atmospheric stratification. Through comparisons between observations and simulations, the benchmarks provide complementary information about the model performance and its ability to reproduce mean and dynamic wake characteristics. This article describes the measurements and methodology used to define these benchmarks and provides the information required to perform simulations and conduct the model-measurement comparison. The objective is to provide a robust wake model validation exercise open to anyone, which will serve to minimize uncertainty in model validation practices related to varying methodologies across simulation tools and users.
Teleneonatology (TN) allows remote neonatologists to provide real-time audio-video telemedicine support to community hospitals when neonates require advanced resuscitation or critical care. ...Currently, there are no published economic evaluations of U.S. TN programs.
To evaluate the cost of TN from the perspective of the health care system.
We constructed a decision tree comparing TN to usual care for neonates born in hospitals without a neonatal intensive care unit (NICU) who require consultation. Our outcome of interest was total cost per patient, which included the incremental cost of a TN program, the cost of medical transport, and the cost of NICU or non-NICU hospitalization. We performed threshold sensitivity analyses where we varied each parameter to determine whether the base-case finding reverted.
For neonates requiring consultation after birth in a hospital without a NICU, TN was less costly ($16,878) than usual care ($28,047), representing a cost-savings of $11,168 per patient. Sensitivity analyses demonstrated that at least one of the following conditions would need to be met for TN to no longer be cost saving compared to usual care: transfer rate with usual care <12% (base-case = 82%), TN reducing the odds of transfer by <8% (base-case = 52%), or TN cost exceeding $12,989 per patient (base-case = $1,821 per patient).
Economic modeling from the health system perspective demonstrated that TN was cost saving compared to usual care for neonates requiring consultation following delivery in a non-NICU hospital. Understanding the cost savings associated with TN may influence organizational decisions regarding implementation, diffusion, and retention of these programs.
Abstract
We report on the search for very-high-energy gamma-ray emission from the regions around three nearby supersonic pulsars (PSR B0355+54, PSR J0357+3205, and PSR J1740+1000) that exhibit long ...X-ray tails. To date there is no clear detection of TeV emission from any pulsar tail that is prominent in X-ray or radio. We provide upper limits on the TeV flux, and luminosity, and also compare these limits with other pulsar wind nebulae detected in X-rays and the tail emission model predictions. We find that at least one of the three tails is likely to be detected in observations that are a factor of 2–3 more sensitive. The analysis presented here also has implications for deriving the properties of pulsar tails, for those pulsars whose tails could be detected in TeV.
The radio source 3C 264, hosted by the giant elliptical galaxy NGC 3862, was observed with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) between 2017 February and 2019 May. ...These deep observations resulted in the discovery of very high energy (VHE; E > 100 GeV) γ-ray emission from this active galaxy. An analysis of ∼57 hr of quality-selected live time yields a detection at the position of the source, corresponding to a statistical significance of 7.8 standard deviations above background. The observed VHE flux is variable on monthly timescales, with an elevated flux seen in 2018 observations. The VHE emission during this elevated state is well characterized by a power-law spectrum with a photon index Γ = 2.20 0.27 and flux F(>315 GeV) = ( cm−2 s−1, or approximately 0.7% of the Crab Nebula flux above the same threshold. 3C 264 (z = 0.0217) is the most distant radio galaxy detected at VHE, and the elevated state is thought to be similar to that of the famously outbursting jet in M87. Consequently, extensive contemporaneous multiwavelength data were acquired in 2018 at the time of the VHE high state. An analysis of these data, including Very Long Baseline Array, Very Large Array, Hubble Space Telescope, Chandra, and Swift observations in addition to the VERITAS data, is presented, along with a discussion of the resulting spectral energy distribution.
Abstract
HESS J0632+057 belongs to a rare subclass of binary systems that emit gamma rays above 100 GeV. It stands out for its distinctive high-energy light curve, which features a sharp “primary” ...peak and broader “secondary” peak. We present the results of contemporaneous observations by NuSTAR and VERITAS during the secondary peak between 2019 December and 2020 February, when the orbital phase (
ϕ
) is between 0.55 and 0.75. NuSTAR detected X-ray spectral evolution, while VERITAS detected TeV emission. We fit a leptonic wind-collision model to the multiwavelength spectra data obtained over the four NuSTAR and VERITAS observations, constraining the pulsar spin-down luminosity and the magnetization parameter at the shock. Despite long-term monitoring of the source from 2019 October to 2020 March, the MDM observatory did not detect significant variation in H
α
and H
β
line equivalent widths, an expected signature of Be-disk interaction with the pulsar. Furthermore, fitting folded Swift-XRT light-curve data with an intrabinary shock model constrained the orbital parameters, suggesting two orbital phases (at
ϕ
D
= 0.13 and 0.37), where the pulsar crosses the Be-disk, as well as phases for the periastron (
ϕ
0
= 0.30) and inferior conjunction (
ϕ
IFC
= 0.75). The broadband X-ray spectra with Swift-XRT and NuSTAR allowed us to measure a higher neutral hydrogen column density at one of the predicted disk-passing phases.
The growth of fingering patterns in dewetting nanofluids (colloidal solutions of thiol-passivated gold nanoparticles) has been followed in real time using contrast-enhanced video microscopy. The ...fingering instability on which we focus here arises from evaporatively driven nucleation and growth in a nanoscopically thin precursor solvent film behind the macroscopic contact line. We find that well-developed isotropic fingering structures only form for a narrow range of experimental parameters. Numerical simulations, based on a modification of the Monte Carlo approach introduced by Rabani et al. Nature (London) 426, 271 (2003)10.1038/nature02087, reproduce the patterns we observe experimentally.
To investigate opioid use and pain scores associated with incisional injection of liposomal bupivacaine compared with bupivacaine hydrochloride after laparotomy for gynecologic malignancies.
A ...retrospective cohort study was conducted to compare abdominal incision infiltration with liposomal bupivacaine with bupivacaine hydrochloride after modification of a pre-existing enhanced recovery pathway. Patients undergoing staging laparotomy or complex cytoreductive surgery under the updated pathway were compared with patients treated under the original pathway (historic controls). Endpoints included cumulative opioid use (primary outcome) in oral morphine equivalents and cumulative pain score.
In the complex cytoreductive cohort, median oral morphine equivalents were lower in the liposomal bupivacaine group through 24 hours (30 compared with 53.5 mg, P=.002), 48 hours (37.5 compared with 82.5 mg, P=.005), and the length of stay (62 compared with 100.5 mg, P=.006). Fewer liposomal bupivacaine patients required intravenous rescue opioids (28.9% compared with 55.6%, P<.001) or patient-controlled analgesia (4.1% compared with 33.3%, P<.001). Cumulative pain score was no different between groups through 48 hours (161 compared with 158, P=.69). Postoperative nausea and ileus were less frequent in patients receiving liposomal bupivacaine. Median hospital stay was 5 days in both groups. In the staging laparotomy cohort, cumulative opioids and cumulative pain score were no different between groups (through 48 hours: 162 compared with 161, P=.62; 38 compared with 38, P=.68, respectively). Intravenous rescue opioids (15.3% compared with 28.6%, P=.05) and patient-controlled analgesia (1.4% compared with 8.3%, P=.05) were used less frequently in the liposomal bupivacaine group. Median hospital stay was 4 days in both groups. Despite the higher cost of liposomal bupivacaine, total pharmacy costs did not differ between groups.
Abdominal incision infiltration with liposomal bupivacaine was associated with less opioid and patient-controlled analgesia use with no change in pain scores compared with bupivacaine hydrochloride after complex cytoreductive surgery for gynecologic malignancies. Improvements were also seen in patients undergoing staging laparotomy.
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