Hawking-Moss Tunneling with a Dirac-Born-Infeld Action

The Hawking-Moss tunneling rate for a field described by the Dirac-Born-Infeld action is calculated using a stochastic approach. We find that the effect of the non-trivial kinetic term is to enhance the tunneling rate, which can be exponentially significant. This result should be compared to the DBI enhancement found in the Coleman-de Luccia case.Comment: 4 pages, version accepted in Phys. Rev. D., additional references and example applicatio

The Clinical Outcomes of Percutaneous Coronary Intervention Performed Without Pre-Procedural Aspirin

ObjectivesThe purpose of this study was to examine the incidence and outcomes of percutaneous coronary intervention (PCI) performed in patients who had not received pre-procedural aspirin.BackgroundAspirin is an essential component of peri-PCI pharmacotherapy. Previous studies suggest that pre-procedural aspirin is not administered to a clinically significant number of patients undergoing PCI.MethodsWe evaluated the incidence of PCIs performed without pre-procedural aspirin use among patients undergoing PCI from January 2010 through December 2011 at 44 hospitals in Michigan. Propensity-matched multivariate analysis was used to adjust for the nonrandom use of aspirin.ResultsOur study population comprised 65,175 patients, of whom 4,640 (7.1%) did not receive aspirin within 24 h before undergoing PCI. Aspirin nonreceivers were more likely to have had previous gastrointestinal bleeding or to present with cardiogenic shock or after cardiac arrest. In the propensity-matched analysis, absence of aspirin before PCI was associated with a higher rate of death (3.9% vs. 2.8%; odds ratio: 1.89 [95% confidence interval: 1.32 to 2.71], p < 0.001) and stroke (0.5% vs. 0.1%; odds ratio: 4.24 [95% confidence interval: 1.49 to 12.11], p = 0.007) with no difference in need for transfusions. This association was consistent across multiple pre-specified subgroups.ConclusionsA significant number of patients do not receive aspirin before undergoing PCI. Lack of aspirin before PCI was associated with significantly increased in-hospital mortality and stroke. Our study results support the need for quality efforts focused on optimizing aspirin use before PCI

The Epidemiology and Outcomes of Percutaneous Coronary Intervention Before High‐Risk Noncardiac Surgery in Contemporary Practice: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) Registry

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139074/1/jah3534.pd

The vacuum bubbles in de Sitter background and black hole pair creation

We study the possible types of the nucleation of vacuum bubbles. We classify vacuum bubbles in de Sitter background and present some numerical solutions. The thin-wall approximation is employed to obtain the nucleation rate and the radius of vacuum bubbles. With careful analysis we confirm that Parke's formula is also applicable to the large true vacuum bubbles. The nucleation of the false vacuum bubble in de Sitter background is also evaluated. The tunneling process in the potential with degenerate vacua is analyzed as the limiting cases of the large true vacuum bubble and false vacuum bubble. Next, we consider the pair creation of black holes in the background of bubble solutions. We obtain static bubble wall solutions of junction equation with black hole pair. The masses of created black holes are uniquely determined by the cosmological constant and surface tension on the wall. Finally, we obtain the rate of pair creation of black holes.Comment: 3 figures, minor including errors and typos corrected, and refs. adde

Efficient ancestry and mutation simulation with msprime 1.0

Stochastic simulation is a key tool in population genetics, since the models involved are often analytically intractable and simulation is usually the only way of obtaining ground-truth data to evaluate inferences. Because of this, a large number of specialized simulation programs have been developed, each filling a particular niche, but with largely overlapping functionality and a substantial duplication of effort. Here, we introduce msprime version 1.0, which efficiently implements ancestry and mutation simulations based on the succinct tree sequence data structure and the tskit library. We summarize msprime’s many features, and show that its performance is excellent, often many times faster and more memory efficient than specialized alternatives. These high-performance features have been thoroughly tested and validated, and built using a collaborative, open source development model, which reduces duplication of effort and promotes software quality via community engagement

Expanding the stdpopsim species catalog, and lessons learned for realistic genome simulations

Simulation is a key tool in population genetics for both methods development and empirical research, but producing simulations that recapitulate the main features of genomic datasets remains a major obstacle. Today, more realistic simulations are possible thanks to large increases in the quantity and quality of available genetic data, and the sophistication of inference and simulation software. However, implementing these simulations still requires substantial time and specialized knowledge. These challenges are especially pronounced for simulating genomes for species that are not well-studied, since it is not always clear what information is required to produce simulations with a level of realism sufficient to confidently answer a given question. The community-developed framework stdpopsim seeks to lower this barrier by facilitating the simulation of complex population genetic models using up-to-date information. The initial version of stdpopsim focused on establishing this framework using six well-characterized model species (Adrion et al., 2020). Here, we report on major improvements made in the new release of stdpopsim (version 0.2), which includes a significant expansion of the species catalog and substantial additions to simulation capabilities. Features added to improve the realism of the simulated genomes include non-crossover recombination and provision of species-specific genomic annotations. Through community-driven efforts, we expanded the number of species in the catalog more than threefold and broadened coverage across the tree of life. During the process of expanding the catalog, we have identified common sticking points and developed the best practices for setting up genome-scale simulations. We describe the input data required for generating a realistic simulation, suggest good practices for obtaining the relevant information from the literature, and discuss common pitfalls and major considerations. These improvements to stdpopsim aim to further promote the use of realistic whole-genome population genetic simulations, especially in non-model organisms, making them available, transparent, and accessible to everyone

Barriers to Early Discharge after Elective Percutaneous Coronary Intervention (BED PCI): A Single-Center Study

Objective: To identify patient characteristics and procedural factors that may play a role in hindering same-day discharge (SDD) practices. Background: Multiple studies have shown the safety and cost effectiveness of SDD following elective percutaneous coronary intervention (PCI), but factors that hinder SDD practices have not been thoroughly studied. Material and Methods: A retrospective comparative analysis of elective PCI patients who had an overnight stay (OS) (n = 345) vs. SDD patients (n = 222) was conducted to identify significant differences between the two groups in baseline patient characteristics, procedural, and postprocedural factors. Results: Comparing OS to SDD patients, OS patients had a lower prevalence of radial access (20.29% vs. 39.64%, P < 0.0001); a higher incidence of suboptimal angiographic results (14.49% vs. 1.80%, P = 0.0027); CRCL values lower than 60 mL/min (26.38% vs. 15.32%, P = 0.0019); and greater femoral vascular site hemostasis with manual compression (69.09% vs. 36.57%, P = 0.0027). OS patients received larger sheath sizes (P = 0.0209), more bivalirudin (45.80% vs. 36.70%) and glycoprotein IIb/IIIa inhibitors (5.51% vs. 2.25%), but less heparin (51.30% vs. 53.21%). Chest pain (8.12% vs. 0.92%, P = 0.0042) and vascular access site concerns (20.58% vs. 0%, P = 0.0027) were more common among OS patients. Conclusions: Pre-, peri-, and post-procedural factors play a role in SDD eligibility. Understanding factors that limit as well as those that facilitate SDD may enable institutions to establish or enhance a SDD program

Risk of Acute Kidney Injury After Percutaneous Coronary Interventions Using Radial Versus Femoral Vascular Access Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium

Thrombosis and Hemostasi