501 research outputs found

    Universal mean moment rate profiles of earthquake ruptures

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    Earthquake phenomenology exhibits a number of power law distributions including the Gutenberg-Richter frequency-size statistics and the Omori law for aftershock decay rates. In search for a basic model that renders correct predictions on long spatio-temporal scales, we discuss results associated with a heterogeneous fault with long range stress-transfer interactions. To better understand earthquake dynamics we focus on faults with Gutenberg-Richter like earthquake statistics and develop two universal scaling functions as a stronger test of the theory against observations than mere scaling exponents that have large error bars. Universal shape profiles contain crucial information on the underlying dynamics in a variety of systems. As in magnetic systems, we find that our analysis for earthquakes provides a good overall agreement between theory and observations, but with a potential discrepancy in one particular universal scaling function for moment-rates. The results reveal interesting connections between the physics of vastly different systems with avalanche noise.Comment: 13 pages, 5 figure

    Sleep Apnea and Fetal Growth Restriction (SAFER) study: Protocol for a pragmatic randomised clinical trial of positive airway pressure as an antenatal therapy for fetal growth restriction in maternal obstructive sleep apnoea

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    INTRODUCTION: Fetal growth restriction (FGR) is a major contributor to fetal and neonatal morbidity and mortality with intrauterine, neonatal and lifelong complications. This study explores maternal obstructive sleep apnoea (OSA) as a potentially modifiable risk factor for FGR. We hypothesise that, in pregnancies complicated by FGR, treating mothers who have OSA using positive airway pressure (PAP) will improve birth weight and neonatal outcomes. METHODS AND ANALYSIS: The Sleep Apnea and Fetal Growth Restriction study is a prospective, block-randomised, single-blinded, multicentre, pragmatic controlled trial. We enrol pregnant women aged 18-50, between 22 and 31 weeks of gestation, with established FGR based on second trimester ultrasound, who do not have other prespecified known causes of FGR (such as congenital anomalies or intrauterine infection). In stage 1, participants are screened by questionnaire for OSA risk. If OSA risk is identified, participants proceed to stage 2, where they undergo home sleep apnoea testing. Participants are determined to have OSA if they have an apnoea-hypopnoea index (AHI) ≄5 (if the oxygen desaturation index (ODI) is also ≄5) or if they have an AHI ≄10 (even if the ODI is \u3c5). These participants proceed to stage 3, where they are randomised to nightly treatment with PAP or no PAP (standard care control), which is maintained until delivery. The primary outcome is unadjusted birth weight; secondary outcomes include fetal growth velocity on ultrasound, enrolment-to-delivery interval, gestational age at delivery, birth weight corrected for gestational age, stillbirth, Apgar score, rate of admission to higher levels of care (neonatal intensive care unit or special care nursery) and length of neonatal stay. These outcomes are compared between PAP and control using intention-to-treat analysis. ETHICS AND DISSEMINATION: This study has been approved by the Institutional Review Boards at Washington University in St Louis, Missouri; Hadassah Hebrew University Medical Center, Jerusalem; and the University of Rochester, New York. Recruitment began in Washington University in November 2019 but stopped from March to November 2020 due to COVID-19. Recruitment began in Hadassah Hebrew University in March 2021, and in the University of Rochester in May 2021. Dissemination plans include presentations at scientific conferences and scientific publications. TRIAL REGISTRATION NUMBER: NCT04084990

    Utility of the ACC/AHA Lesion Classification to Predict Outcomes After Contemporary DES Treatment:Individual Patient Data Pooled Analysis From 7 Randomized Trials

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    BACKGROUND: Use of the modified American College of Cardiology (ACC)/American Heart Association (AHA) lesion classification as a prognostic tool to predict short‐ and long‐term clinical outcomes after percutaneous coronary intervention in the modern drug‐eluting stent era is uncertain. METHODS AND RESULTS: Patient‐level data from 7 prospective, randomized trials were pooled. Clinical outcomes of patients undergoing single lesion percutaneous coronary intervention with second‐generation drug‐eluting stent were analyzed according to modified ACC/AHA lesion class. The primary end point was target lesion failure (TLF: composite of cardiac death, target vessel myocardial infarction, or ischemia‐driven target lesion revascularization). Clinical outcomes to 5 years were compared between patients treated for noncomplex (class A/B1) versus complex (class B2/C) lesions. Eight thousand five hundred sixteen patients (age 63.1±10.8 years, 70.5% male) were analyzed. Lesions were classified as A, B1, B2, and C in 7.9%, 28.5%, 33.7%, and 30.0% of cases, respectively. Target lesion failure was higher in patients undergoing percutaneous coronary intervention of complex versus noncomplex lesions at 30 days (2.0% versus 1.1%, P=0.004), at 1 year (4.6% versus 3.0%, P=0.0005), and at 5 years (12.4% versus 9.2%, P=0.0001). By multivariable analysis, treatment of ACC/AHA class B2/C lesions was significantly associated with higher rate of 5‐year target lesion failure (adjusted hazard ratio, 1.39 [95% CI, 1.17–1.64], P=0.0001) driven by significantly higher rates of target vessel myocardial infarction and ischemia‐driven target lesion revascularization. CONCLUSIONS: In this pooled large‐scale analysis, treating complex compared with noncomplex lesions according to the modified ACC/AHA classification with second‐generation drug‐eluting stent was associated with worse 5‐year clinical outcomes. This historical classification system may be useful in the contemporary era for predicting early and late outcomes following percutaneous coronary intervention

    Aftershocks driven by afterslip and fluid pressure sweeping through a fault‐fracture mesh

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    A variety of physical mechanisms are thought to be responsible for the triggering and spatiotemporal evolution of aftershocks. Here we analyze a vigorous aftershock sequence and postseismic geodetic strain that occurred in the Yuha Desert following the 2010 Mw 7.2 El Mayor‐Cucapah earthquake. About 155,000 detected aftershocks occurred in a network of orthogonal faults and exhibit features of two distinct mechanisms for aftershock triggering. The earliest aftershocks were likely driven by afterslip that spread away from the main shock with the logarithm of time. A later pulse of aftershocks swept again across the Yuha Desert with square root time dependence and swarm‐like behavior; together with local geological evidence for hydrothermalism, these features suggest that the events were driven by fluid diffusion. The observations illustrate how multiple driving mechanisms and the underlying fault structure jointly control the evolution of an aftershock sequence

    Percutaneous Coronary Interventions Using a Ridaforolimus-Eluting Stent in Patients at High Bleeding Risk.

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    BACKGROUND: Patients treated with percutaneous coronary intervention are often considered to be at a high bleeding risk (HBR). Drug-eluting stents have been shown to be superior to bare-metal stents in patients with HBR, even when patients were given abbreviated periods of dual antiplatelet therapy (DAPT). Short DAPT has not been evaluated with the EluNIR ridaforolimus-eluting stent. The aim of this study was to evaluate the safety and efficacy of a shortened period of DAPT following implantation of the ridaforolimus-eluting stent in patients with HBR. METHODS AND RESULTS: This was a prospective, multicenter, binational, single-arm, open-label trial. Patients were defined as HBR according to the LEADERS-FREE (Prospective Randomized Comparison of the BioFreedom Biolimus A9 Drug-Coated Stent versus the Gazelle Bare-Metal Stent in Patients at High Bleeding Risk) trial criteria. After percutaneous coronary intervention, DAPT was given for 1 month to patients presenting with stable angina. In patients presenting with an acute coronary syndrome, DAPT was given for 1 to 3 months, at the investigator's discretion. The primary end point was a composite of cardiac death, myocardial infarction, or stent thrombosis up to 1 year (Academic Research Consortium definite and probable). Three hundred fifteen patients undergoing percutaneous coronary intervention were enrolled, and 56.4% presented with acute coronary syndrome; 33.7% were receiving oral anticoagulation. At 1 year, the primary end point occurred in 15 patients (4.9%), meeting the prespecified performance goal of 14.1% (P<0.0001). Stent thrombosis (Academic Research Consortium definite and probable) occurred in 2 patients (0.6%). Bleeding Academic Research Consortium type 3 and 5 bleeding occurred in 6 patients (1.9%). CONCLUSIONS: We observed favorable results in patients with HBR who underwent percutaneous coronary intervention with a ridaforolimus-eluting stent and received shortened DAPT, including a low rate of ischemic events and low rate of stent thrombosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03877848

    Outcome of paraosseous extra-medullary disease in newly diagnosed multiple myeloma patients treated with new drugs

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    Extramedullary disease is relatively frequent in multiple myeloma, but our knowledge on the subject is limited and mainly relies on small case series or single center experiences. Little is known regarding the role of new drugs in this setting. We performed a meta-analysis of eight trials focused on the description of extramedullary disease characteristics, clinical outcome, and response to new drugs. A total of 2,332 newly diagnosed myeloma patients have been included; 267 (11.4%) had extramedullary disease, defined as paraosseous in 243 (10.4%), extramedullary plasmocytoma in 12 (0.5%), and not classified in 12 (0.5%) patients. Median progression-free survival was 25.3 months and 25.2 in extramedullary disease and non-extramedullary disease patients, respectively. In multivariate analysis the presence of extramedullary disease did not impact on progression-free survival (hazard ratio 1.15, P=0.06), while other known prognostic factors retained their significance. Patients treated with immunomodulatory drugs, mainly lenalidomide, or proteasome inhibitors had similar progression-free survival and progression-free survival-2 regardless of extramedullary disease presence. Median overall survival was 63.5 months and 79.9 months (P=0.01) in extramedullary and non-extramedullary disease patients, respectively, and in multivariate analysis the presence of extramedullary disease was associated with a reduced overall survival (hazard ratio 1.41, P&lt;0.001), in line with other prognostic factors. With the limits of the use of low sensitivity imaging techniques, that lead to an underestimation of extramedullary disease, we conclude that in patients treated with new drugs the detrimental effect of extramedullary disease at diagnosis is limited, that lenalidomide is effective as are proteasome inhibitors, and that these patients tend to acquire a more aggressive disease in later stages. (EUDRACT2005-004714-32, NCT01063179 NCT00551928, NCT01091831, NCT01093196, NCT01190787, NCT01346787, NCT01857115)

    Ultrasensitivity of the Bacillus subtilis sporulation decision

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    Starving Bacillus subtilis cells execute a gene expression program resulting in the formation of stress-resistant spores. Sporulation master regulator, Spo0A, is activated by a phosphorelay and controls the expression of a multitude of genes, including the forespore- specific sigma factor σF and the mother cell-specific sigma factor σE. Identification of the system-level mechanism of the sporulation decision is hindered by a lack of direct control over Spo0A activity. This limitation can be overcome by using a synthetic system in which Spo0A activation is controlled by inducing expression of phosphorelay kinase KinA. This induction results in a switch-like increase in the number of sporulating cells at a threshold of KinA. Using a combination of mathematical modeling and single-cell microscopy, we investigate the origin and physiological significance of this ultrasensitive threshold. The results indicate that the phosphorelay is unable to achieve a sufficiently fast and ultrasensitive response via its positive feedback architecture, suggesting that the sporulation decision is made downstream. In contrast, activation of σF in the forespore and of σE in the mother cell compartments occurs via a cascade of coherent feed-forward loops, and thereby can produce fast and ultrasensitive responses as a result of KinA induction. Unlike σF activation, σE activation in the mother cell compartment only occurs above the KinA threshold, resulting in completion of sporulation. Thus, ultrasensitive σE activation explains the KinA threshold for sporulation induction. We therefore infer that under uncertain conditions, cells initiate sporulation but postpone making the sporulation decision to average stochastic fluctuations and to achieve a robust population response
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