Stationary solutions to the compressible Navier–Stokes system driven by stochastic forces

Breit D, Feireisl E, Hofmanová M, Maslowski B. Stationary solutions to the compressible Navier–Stokes system driven by stochastic forces. Probability Theory and Related Fields. 2019;174(3-4):981-1032

All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration < 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc^3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range 5 10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see also the public announcement at http://www.ligo.org/science/Publication-S6BurstAllSky

Effects of Once-Weekly Exenatide on Cardiovascular Outcomes in Type 2 Diabetes.

Abstract BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo. (Funded by Amylin Pharmaceuticals; EXSCEL ClinicalTrials.gov number, NCT01144338 .)

On the Role of Weak-Motion Earthquakes Recorded on Earth Dams

Seismic accelerations recorded on earth dams through permanent monitoring systems could be very useful to handle the seismic safety assessment of earth dams. First, they allow to characterize the seismic loads, which in conjunction with the static ones, might induce critical changes in those physical quantities controlling dam safety, i.e. stresses, strains, permanent displacements, pore water pressures, seepage flows. In this way, control and quantification of all loads affecting dam response in its whole lifetime are assured. Second, seismic recordings could be useful to characterize some important features of dam mechanical behavior at relatively none or low cost. Focusing on this latter objective, the paper examines the basic procedures that could be adopted to interpret the seismic signals acquired on a zoned earth dam equipped with a permanent seismic network consisting of five accelerometer stations placed both on rock outcrops at the specific site and on the main cross section of the embankment (top, bank, base). As the dam is placed in a quite seismically active zone of Southern Italy, five years of continuous monitoring have delivered dozens of records associated to weak earthquakes having different source-site distance, magnitude and frequency content. Interpretation of these signals has yielded important aspects on the dynamic behaviour of the sample dam at low strain levels, such as natural frequencies, signal amplification, spatial variability of the motion. The recordings of weak-motion earthquakes, which surely are more frequent than strong motion events during the dam lifetime, may be easily interpreted and could be extremely convenient in completing - at relatively low cost - the huge amount of information needed to carry out the crucial task of seismic safety assessment of dams, especially in case of existing earth dams that have been in operation for several years