Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ...ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect the data quality and decrease the efficiency of the data analysis pipelines looking for astrophysical signals from continuous waves as well as the transient events. In this work, we develop a scheme to subtract one such bilinear noise from the gravitational wave strain data and demonstrate it at the GEO 600 observatory. We estimate the coupling by making use of narrow-band signal injections that are already in place for noise projection purposes and construct a coherent bilinear signal by a two-stage system identification process. We improve upon the existing filter design techniques by employing a Bayesian adaptive directed search strategy that optimizes across the several key parameters that affect the accuracy of the estimated model. The scheme takes into account the possible nonstationarities in the coupling by periodically updating the involved filter coefficients. The resulting postoffline subtraction leads to a suppression of modulation sidebands around the calibration lines along with a broadband reduction of the midfrequency noise floor. The observed increase in the astrophysical range and a reduction in the occurrence of nonastrophysical transients suggest that the above method is a viable data cleaning technique for current and future generation gravitational wave observatories.
Modulated differential wavefront sensing (MDWS) is an alignment control scheme in the regime of beams with strong higher order transversal modes (HOMs). It is based on the differential wavefront ...sensing (DWS) technique. MDWS represents a significant upgrade over conventional techniques used in the presence of high HOM content as it allows for higher control bandwidths while eliminating the need of auxiliary alignment modulations, that otherwise cause loss of applied squeezing. The output port of gravitational wave (GW) interferometers (IFO) is one such place where a lot of HOMs are present. These are filtered out by a cavity called the output mode cleaner (OMC), whose alignment gets challenging due to the presence of HOMs. In this paper, we present the first demonstration of the MDWS scheme for aligning the fundamental mode from the IFO to the OMC at the gravitational wave detector-GEO 600.
The physical mechanisms responsible for pulsar timing glitches are thought to excite quasi-normal mode oscillations in their parent neutron star that couple to gravitational wave emission. In August ...2006, a timing glitch was observed in the radio emission of PSR B0833-45, the Vela pulsar. At the time of the glitch, the two co-located Hanford gravitational wave detectors of the Laser Interferometer Gravitational-wave observatory (LIGO) were operational and taking data as part of the fifth LIGO science run (S5). We present the first direct search for the gravitational wave emission associated with oscillations of the fundamental quadrupole mode excited by a pulsar timing glitch. No gravitational wave detection candidate was found. We place Bayesian 90% confidence upper limits of 6.3e-21 to 1.4e-20 on the peak intrinsic strain amplitude of gravitational wave ring-down signals, depending on which spherical harmonic mode is excited. The corresponding range of energy upper limits is 5.0e44 to 1.3e45 erg.
The probiotic medicinal product TSO (
Trichuris suis
ova) is administered to patients with active ulcerative colitis in an ongoing clinical phase IIb trial where the typical co-medications are ...steroids (prednisolone or budesonide) and antibiotics (e.g., phenoxymethylpenicillin). The present pre-clinical study evaluates the effects of these co-medications on the biological activity of TSO in Göttingen Minipigs. This translationally relevant pre-clinical model allows administration of TSO with and without oral steroids or antibiotics in a manner similar to the administration to patients, followed by quantification of the biological activity of TSO. The biological activity of TSO was not affected by oral steroids but was reduced by oral antibiotics. Fecal calprotectin, the common marker of intestinal inflammation in patients with UC, did not differ between groups.
Abstract Background and Aims To demonstrate that administration of 7500 Trichuris suis ova TSO every second week over 24 weeks would reduce the intestinal inflammation in moderate ulcerative colitis. ...Methods A single-centre, randomised, double-blinded, placebo-controlled, phase 2b clinical trial of 7500 Trichuris suis ova every 2 weeks for 24 weeks compared with placebo in moderate activity of ulcerative colitis Mayo score 6–10 were performed. Primary outcome: clinical remission; secondary outcomes: clinical response at 24 weeks, complete corticosteroid-free clinical remission, endoscopic remission, symptomatic remission at 12 and 24 weeks, and partial Mayo score over time. Results In all, 119 patients were randomised to Trichuris suis ova n = 60 or placebo n = 59. At Week 24, clinical remission was achieved in 30% of Trichuris suis ova-treated vs 34% of placebo-treated (risk ratio RR = 0.89; 95% confidence interval CI: 0.52–1.50; p = 0.80, intention to treat). No difference was found in clinical response in any of the clinical response subgroups. However, in patients who did not need treatment with corticosteroids during the trial, a temporary effect of TSO was seen in the analysis of symptomatic remission at Week 12 p = 0.01 and the partial Mayo score at Week 14 and Week 18 p < 0.05 and p = 0.02. Conclusions Compared with placebo, Trichuris suis ova administration was not superior in achieving clinical remission at Week 24 in ulcerative colitis or in achieving clinical Mayo score reduction, complete corticosteroid-free clinical remission, or endoscopic remission. However, Trichuris suis ova treatment induced symptomatic temporary remission at Week 12.
Using bottom-mounted, high-frequency, inverted echo sounders (the Tracor acoustic profiling system) to examine acoustic backscattering every 2 min in 50-cm range bins above the seabed, we recorded ...strong, remarkably regular, nightly migrations of organisms from$\leq\!\!0.5\>m$above the seabed to the upper pelagic layers over a period of 6 d in July-August 1995. Population migration speeds on ascent versus descent$(mean\>\pm\>1\>SD)$were not significantly different when estimated from the mode (or leading/trailing edge) of the population and were$0.59 \pm 0.24\> cm\>s^{-1}$in ascent ($0.96 \pm 0.25\>cm\>s^{-1}$leading edge) and$0.67 \pm 0.13\>cm\>s^{-1}$on descent ($0.78 \pm 0.14\>cm\>s^{-1}$trailing edge). The SD in start times of the ascent over the six nights was only 3 min, and that in the times of the completion of the descent was 7 min. Emergence began after and reentry was completed before downwelling irradiance at photosynthetically active wavelengths 1 m above bottom reached$0.5 \times 10^{-6}\>\mu mol\>quanta\>cm^{-2}\>s^{-1}$. Migrators increased column scattering strength at 265 kHz by a factor of 14. Emergence-trap samples and nighttime plankton tows suggested that the migrating population was dominated by mysids, mostly Neomysis kadiakensis. Our acoustic results suggest that emergence is much more prevalent and important in coastal and estuarine environments than trapping and net sampling can reveal and hence that this important component of benthic-pelagic coupling requires additional attention both in measurements and in theoretical treatments.
The Laser Interferometer Gravitational Wave Observatory (LIGO) is a network of three detectors built to detect local perturbations in the space-time metric from astrophysical sources. These ...detectors, two in Hanford, WA and one in Livingston, LA, are power-recycled Fabry-Perot Michelson interferometers. In their fifth science run (S5), between November 2005 and October 2007, these detectors accumulated one year of triple coincident data while operating at their designed sensitivity. In this paper, we describe the calibration of the instruments in the S5 data set, including measurement techniques and uncertainty estimation.
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