We present SN2018kzr, the fastest declining supernova-like transient, second only to the kilonova, AT2017gfo. SN2018kzr is characterized by a peak magnitude of Mr = −17.98, a peak bolometric ...luminosity of ∼1.4 × 1043 erg s−1, and a rapid decline rate of 0.48 0.03 mag day−1 in the r band. The bolometric luminosity evolves too quickly to be explained by pure 56Ni heating, necessitating the inclusion of an alternative powering source. Incorporating the spin-down of a magnetized neutron star adequately describes the lightcurve and we estimate a small ejecta mass of Mej = 0.10 0.05 M . Our spectral modeling suggests the ejecta is composed of intermediate mass elements including O, Si, and Mg and trace amounts of Fe-peak elements, which disfavors a binary neutron star merger. We discuss three explosion scenarios for SN2018kzr, given the low ejecta mass, intermediate mass element composition, and high likelihood of additional powering-the core collapse of an ultra-stripped progenitor, the accretion induced collapse (AIC) of a white dwarf, and the merger of a white dwarf and neutron star. The requirement for an alternative input energy source favors either the AIC with magnetar powering or a white dwarf-neutron star merger with energy from disk wind shocks.
Abstract
We present DELIGHT, or Deep Learning Identification of Galaxy Hosts of Transients, a new algorithm designed to automatically and in real time identify the host galaxies of extragalactic ...transients. The proposed algorithm receives as input compact, multiresolution images centered at the position of a transient candidate and outputs two-dimensional offset vectors that connect the transient with the center of its predicted host. The multiresolution input consists of a set of images with the same number of pixels, but with progressively larger pixel sizes and fields of view. A sample of 16,791 galaxies visually identified by the Automatic Learning for the Rapid Classification of Events broker team was used to train a convolutional neural network regression model. We show that this method is able to correctly identify both relatively large (10″ <
r
< 60″) and small (
r
≤ 10″) apparent size host galaxies using much less information (32 kB) than with a large, single-resolution image (920 kB). The proposed method has fewer catastrophic errors in recovering the position and is more complete and has less contamination (<0.86%) recovering the crossmatched redshift than other state-of-the-art methods. The more efficient representation provided by multiresolution input images could allow for the identification of transient host galaxies in real time, if adopted in alert streams from new generation of large -etendue telescopes such as the Vera C. Rubin Observatory.
Abstract
We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining Type Ia supernova (SN Ia) in NGC 1784 (
D
≈ 31 Mpc), from <1 to 180 days ...after explosion. The high-cadence observations of SN 2022xkq, a photometrically transitional and spectroscopically 91bg-like SN Ia, cover the first days and weeks following explosion, which are critical to distinguishing between explosion scenarios. The early light curve of SN 2022xkq has a red early color and exhibits a flux excess that is more prominent in redder bands; this is the first time such a feature has been seen in a transitional/91bg-like SN Ia. We also present 92 optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a long-lived C
i
1.0693
μ
m feature that persists until 5 days post-maximum. We also detect C
ii
λ
6580 in the pre-maximum optical spectra. These lines are evidence for unburnt carbon that is difficult to reconcile with the double detonation of a sub-Chandrasekhar mass white dwarf. No existing explosion model can fully explain the photometric and spectroscopic data set of SN 2022xkq, but the considerable breadth of the observations is ideal for furthering our understanding of the processes that produce faint SNe Ia.
We present DELIGHT, or Deep Learning Identification of Galaxy Hosts of Transients, a new algorithm designed to automatically and in real-time identify the host galaxies of extragalactic transients. ...The proposed algorithm receives as input compact, multi-resolution images centered at the position of a transient candidate and outputs two-dimensional offset vectors that connect the transient with the center of its predicted host. The multi-resolution input consists of a set of images with the same number of pixels, but with progressively larger pixel sizes and fields of view. A sample of \nSample galaxies visually identified by the ALeRCE broker team was used to train a convolutional neural network regression model. We show that this method is able to correctly identify both relatively large (\(10\arcsec < r < 60\arcsec\)) and small (\(r \le 10\arcsec\)) apparent size host galaxies using much less information (32 kB) than with a large, single-resolution image (920 kB). The proposed method has fewer catastrophic errors in recovering the position and is more complete and has less contamination (\(< 0.86\%\)) recovering the cross-matched redshift than other state-of-the-art methods. The more efficient representation provided by multi-resolution input images could allow for the identification of transient host galaxies in real-time, if adopted in alert streams from new generation of large etendue telescopes such as the Vera C. Rubin Observatory.
IntroductionA reduction in platelet count in critically ill patients is a marker of severity of the clinical condition. However, whether this association holds true in acute kidney injury (AKI) is ...unknown. We analyzed the association between platelet reduction in patients with AKI and major adverse kidney events (MAKE).MethodsIn this retrospective cohort, we included AKI patients at the Hospital Civil of Guadalajara, in Jalisco, Mexico. Patients were divided according to whether their platelet count fell >21% during the first 10 days. Our objectives were to analyze the associations between a platelet reduction >21% and MAKE at 10 days (MAKE10) or at 30-90 days (MAKE30-90) and death.ResultsFrom 2017 to 2023, 400 AKI patients were included, 134 of whom had a > 21% reduction in platelet count. The mean age was 54 years, 60% were male, and 44% had sepsis. The mean baseline platelet count was 194 x 103 cells/µL, and 65% of the KDIGO3 patients met these criteria. Those who underwent hemodialysis (HD) had lower platelet counts. After multiple adjustments, a platelet reduction >21% was associated with MAKE10 (OR 4.2, CI 2.1-8.5) but not with MAKE30-90. The mortality risk increased 3-fold (OR 2.9, CI 1.1-7.7, p = 0.02) with a greater decrease in the platelets (<90 x 103 cells/µL). As the platelets decreased, the incidence of MAKE was more likely to increase. These associations lost significance when accounting for starting HD.ConclusionIn our retrospective cohort of patients with AKI, a > 21% reduction in platelet count was associated with MAKE. Our results are useful for generating hypotheses and motivating us to continue studying this association with a more robust design.
Fatigue has been characterized as a post COVID-19 condition known to persist months after SARS-CoV-2 infection. COVID-19 has been reported to be associated with impaired cognitive function, including ...disorders in attention, memory, information processing, and executive functions. The objective of this study was to determine if post-COVID fatigue, manifested as tiredness while performing low-intensity physical activity, has a detrimental effect on neuropsychological performance, to achieve this, we randomly selected 20 participants with post-COVID fatigue and 20 SARS-CoV-2 negative age-matched controls from a database of 360 residents of Tijuana, Baja California in a cross-sectional study design. All 40 participants responded to a health survey, along with a neuropsychological assessment test via telephone call. Statistical analysis was performed using a multiple linear regression model including the following independent variables: study condition (post-COVID fatigue or negative control), sex, age, years of education, hypertension, asthma, administration of supplemental oxygen during COVID-19 recovery, and the hour at which the evaluation started. Significant regression analysis was obtained for all global parameters of the assessment, including BANFE-2 score (p = 0.021, R
Adj. = 0.263), NEUROPSI score (p = 0.008, R
Adj. = 0.319), and total errors (p = 0.021, R
Adj. = 0.263), with significant regression coefficients for study condition on two global parameters, BANFE-2 score (p = 0.028, β = - 0.371) and NEUROPSI score (p = 0.010, β = -0.428). These findings suggest that the presence of post-COVID fatigue is a factor associated with a decrease in neuropsychological performance.
Aims
Patients with heart failure and mildly reduced or preserved ejection fraction have limited therapeutic options. The ALT‐FLOW Early Feasibility Study evaluated safety, haemodynamics and outcomes ...for the APTURE transcatheter shunt system, a novel left atrium to coronary sinus shunt in these patients.
Methods and results
Safety and shunt implantation success was evaluated for all 116 enrolled patients. An analysis population of implanted patients with a left ventricular ejection fraction (LVEF) >40% (n = 95) was chosen to assess efficacy via paired comparison between baseline and follow‐up haemodynamic (3 and 6 months), and echocardiographic, clinical and functional outcomes (6 months and 1 year). Health status and quality of life outcomes were assessed using the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ‐OSS). The primary safety endpoint, major adverse cardiac, cerebral, and renal events, and reintervention through 30 days, occurred in 3/116 patients (2.6%). All implanted shunts were patent at 1 year. In patients with LVEF >40%, the mean (95% confidence interval) reduction in exercise pulmonary capillary wedge pressure (PCWP) at 20 W was −5.7 (−8.6, −2.9) mmHg at 6 months (p < 0.001). At baseline, 8% had New York Heart Association class I–II status and improved to 68% at 1 year (p < 0.001). KCCQ‐OSS at baseline was 39 (35, 43) and improved at 6 months and 1 year by 25 (20–30) and 27 (22–32) points, respectively (both p < 0.0001). No adverse changes in haemodynamic and echocardiographic indices of right heart function were observed at 1 year. Overall, the reduction in PCWP at 20 W and improvement in KCCQ‐OSS in multiple subgroups were consistent with those observed for the entire population.
Conclusions
In patients with heart failure and LVEF >40%, the APTURE shunt demonstrated an acceptable safety profile with significant sustained improvements in haemodynamic and patient‐centred outcomes, underscoring the need for further evaluation of the APTURE shunt in a randomized trial.
(A) The nitinol APTURE shunt as it sits in intended location creates a 7 mm aperture connecting the left atrium and coronary sinus. The red arrows depict direction of blood flow from the left atrium to the coronary sinus and to the right atrium. (B) Paired outcomes versus baseline for New York Heart Association (NYHA) functional class at 6 months and 1 year. (C) Observed group mean with 95% confidence intervals (CI) for patients who are matched for availability of pulmonary capillary wedge pressure (PCWP) at 20 W exercise and Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ‐OSS) at each time point. (D) Concordance between paired changes from baseline in PCWP at 20 W versus paired changes from baseline in KCCQ‐OSS among completely matched patients. The proportion of concordance was 74% with a Spearman correlation of −0.26 (p = 0.07). Each dot represents one patient (green for concordance and red for non‐concordance).
retention is the most common adverse event of the small bowel capsule endoscopy procedure. Patency capsule (Medtronic, Dublin, Ireland) and magnetic resonance enterography are two diagnostic methods ...that can prevent small bowel capsule endoscopy retention. The aim of this study was to evaluate the predictive value of these two diagnostic methods.
a prospective, comparative and observational study was performed in patients with established Crohn's disease. All patients had undergone magnetic resonance enterography and patency capsule procedures. If the patency capsule was not retained, the patient underwent a small bowel capsule endoscopy; otherwise, double balloon enteroscopy was performed to locate the stenosis. Magnetic resonance enterography predictive criteria for retention were analyzed in all cases. Sensitivity, specificity, positive predictive value and negative predictive value of the patency capsule and magnetic resonance enterography compared to small bowel capsule endoscopy or double balloon enteroscopy were calculated.
forty patients were included (24 female, 55 ± 13 years old). Retention criteria with capsule endoscopy or double balloon enteroscopy were found in six patients, agreeing in five cases with patency capsule and in three cases with magnetic resonance enterography. Sensitivity, specificity, positive predictive value, negative predictive value and Kappa coefficient for predicting retention with the patency capsule were 83 %, 100 %, 100 % and 97 %, respectively, and 50 %, 91 %, 50 % and 91 %, respectively, with magnetic resonance enterography.
patency capsule has a higher sensitivity and positive predictive value than magnetic resonance enterography for preventing small bowel capsule endoscopy retention in Crohn's disease patients.
The arid Coquimbo region of Chile has experienced a significant economic growth in recent decades, fueled in large part by water-intensive activities such as mining and agriculture. Under this ...context, a monthly and annual trend analysis of precipitation, streamflow, and piezometric levels was carried out. Thus, 43 pluviometric stations, 11 fluviometric stations, and 11 wells were selected. These stations were evaluated for their temporal trends using the Mann–Kendall test. Results revealed a significant decrease in river flows, with negative and significant trends concentrated in the mean and maximum flows, both at annual and monthly levels. Likewise, positive trends were found in the depth to water table on wells, with significant trends in 81.8% of the monthly cases, and in 72.7% of the annual cases. While also decreasing over the same period, rainfall trends exhibit high variability and lacked significance. Although the amounts of precipitation have decreased, this does not seem to be the main factor responsible for the scarcity of water in the region, but rather an excessive consumption of this resource. This is endorsed by the increase in GDP (Gross Domestic Product), which is explained by activities that consume water (mining and agriculture). Similarly, an increase in the granting of underground water rights was verified, which speaks of the high demands for the resource. However, future modeling is advised to better understand the regional hydrology of the area and quantify the anthropic effects on water resources more precisely.
Abstract A compact source, G0.02467–0.0727, was detected in Atacama Large Millimeter/submillimeter Array 3 mm observations in continuum and very broad line emission. The continuum emission has a ...spectral index α ≈ 3.3, suggesting that the emission is from dust. The line emission is detected in several transitions of CS, SO, and SO 2 and exhibits a line width FWHM ≈ 160 km s −1 . The line profile appears Gaussian. The emission is weakly spatially resolved, coming from an area on the sky ≲1″ in diameter (≲10 4 au at the distance of the Galactic center, GC). The centroid velocity is v LSR ≈ 40–50 km s −1 , which is consistent with a location in the GC. With multiple SO lines detected, and assuming local thermodynamic equilibrium (LTE) conditions, the gas temperature is T LTE = 13 K, which is colder than seen in typical GC clouds, though we cannot rule out low-density, subthermally excited, warmer gas. Despite the high velocity dispersion, no emission is observed from SiO, suggesting that there are no strong (≳10 km s −1 ) shocks in the molecular gas. There are no detections at other wavelengths, including X-ray, infrared, and radio. We consider several explanations for the millimeter ultra-broad-line object (MUBLO), including protostellar outflow, explosive outflow, a collapsing cloud, an evolved star, a stellar merger, a high-velocity compact cloud, an intermediate-mass black hole, and a background galaxy. Most of these conceptual models are either inconsistent with the data or do not fully explain them. The MUBLO is, at present, an observationally unique object.
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