65 research outputs found

    Detection of gravitational-wave bursts with chirplet-like template families

    Full text link
    Gravitational Wave (GW) burst detection algorithms typically rely on the hypothesis that the burst signal is "locally stationary", that is it changes slowly with frequency. Under this assumption, the signal can be decomposed into a small number of wavelets with constant frequency. This justifies the use of a family of sine-Gaussian templates in the Omega pipeline, one of the algorithms used in LIGO-Virgo burst searches. However there are plausible scenarios where the burst frequency evolves rapidly, such as in the merger phase of a binary black hole and/or neutron star coalescence. In those cases, the local stationarity of sine-Gaussians induces performance losses, due to the mismatch between the template and the actual signal. We propose an extension of the Omega pipeline based on chirplet-like templates. Chirplets incorporate an additional parameter, the chirp rate, to control the frequency variation. In this paper, we show that the Omega pipeline can easily be extended to include a chirplet template bank. We illustrate the method on a simulated data set, with a family of phenomenological binary black-hole coalescence waveforms embedded into Gaussian LIGO/Virgo-like noise. Chirplet-like templates result in an enhancement of the measured signal-to-noise ratio.Comment: 8 pages, 6 figures. Submitted to Class. Quantum Grav. Special issue: Proceedings of GWDAW-14, Rome (Italy), 2010; fixed several minor issue

    A rare and fatal complication of ear syringing: Rupture of pseudoaneurysm at petrous internal carotid artery

    Get PDF
    Ear syringing is a common procedure done for cleaning wax from the ear canal. Rupture of the pseudoaneurysm at the petrous part of the internal carotid artery (ICA) due to ear syringing is an extremely rare incidence in clinical practice. Sudden and profuse bleeding from the ear is the clinical presentation in case of ruptured pseudoaneurysm of ICA at the petrous part. Presence of the cholesteatoma at the middle ear cleft may be an etiology causing rupture of the pseudoaneurysm at the petrous part of the ICA, but the forceful ear syringing is an uncommon cause for the rupture of pseudoaneurysm. Radiological imaging is an important tool for the diagnosis. Endovascular technique is often used for the treatment of pseudoaneurysm of the ICA. Here, we are reporting an uncommon complication of forceful ear syringing making rupture of the pseudoaneurysm of petrous ICA leading to fatal spontaneous and profuse bleeding from the ear

    Performance of a Chirplet-based analysis for gravitational waves from binary black hole mergers

    Full text link
    The gravitational wave (GW) signature of a binary black hole (BBH) coalescence is characterized by rapid frequency evolution in the late inspiral and merger phases. For a system with total mass larger than 100 M_sun, ground based GW detectors are sensitive to the merger phase, and the in-band whitened waveform is a short-duration transient lasting about 10-30 ms. For a symmetric mass system with total mass between 10 and 100 M_sun, the detector is sensitive instead to the inspiral phase and the in-band signal has a longer duration, between 30 ms - 3 s. Omega is a search algorithm for GW bursts that, with the assumption of locally stationary frequency evolution, uses sine-Gaussian wavelets as a template bank to decompose interferometer strain data. The local stationarity of sine-Gaussians induces a performance loss for the detection of lower mass BBH signatures, due to the mismatch between template and signal. We present the performance of a modified version of the Omega algorithm, Chirplet Omega, which allows a linear variation of frequency, to target BBH coalescences. The use of Chirplet-like templates enhances the measured signal-to-noise ratio due to less mismatch between template and data, and increases the detectability of lower mass BBH coalescences. We present the results of a performance study of Chirplet Omega in colored Gaussian noise at initial LIGO sensitivity.Comment: 7 pages, 12 figures. Proceedings of Amaldi-9, Cardiff (UK), 201

    Sensitivity Comparison of Searches for Binary Black Hole Coalescences with Ground-based Gravitational-Wave Detectors

    Get PDF
    Searches for gravitational-wave transients from binary black hole coalescences typically rely on one of two approaches: matched filtering with templates and morphology-independent excess power searches. Multiple algorithmic implementations in the analysis of data from the first generation of ground-based gravitational wave interferometers have used different strategies for the suppression of non-Gaussian noise transients, and targeted different regions of the binary black hole parameter space. In this paper we compare the sensitivity of three such algorithms: matched filtering with full coalescence templates, matched filtering with ringdown templates and a morphology-independent excess power search. The comparison is performed at a fixed false alarm rate and relies on Monte-carlo simulations of binary black hole coalescences for spinning, non-precessing systems with total mass 25-350 solar mass, which covers the parameter space of stellar mass and intermediate mass black hole binaries. We find that in the mass range of 25 -100 solar mass the sensitive distance of the search, marginalized over source parameters, is best with matched filtering to full waveform templates, to within 10 percent at a false alarm rate of 3 events per year. In the mass range of 100-350 solar mass, the same comparison favors the morphology-independent excess power search to within 20 percent. The dependence on mass and spin is also explored.Comment: 11 pages, 2 tables, 25 figure

    Radiological significance of isolated ethmoid sinus infections in asymptomatic patients of recurrent acute rhinosinusitis

    Get PDF
    Background: Recurrent acute rhinosinusitis (RARS) being a low form chronic rhinosinusitis (CRS), is relatively under diagnosed many times because of lack of awareness regarding pattern of the disease presentation. Aim of the study is to evaluate the radiological significance of isolated ethmoid sinusitis in patients of RARS during the asymptomatic interval in between acute episodes of rhinosinusitis.Methods: Total 124 patients with history suggestive of RARS who had undergone computed tomography study of brain during April 2015 to October 2016 for indications other than sinonasal diseases, were evaluated for isolated ethmoid sinusitis in the department of Radiology. Patients having any inflammatory or expansile sinonasal masses were excluded.Results: Of total 124 patients of RARS aged from 18 to 70 years (mean age of 38.6 years), the study population included only seventy-two (58%) patients having isolated ethmoid sinus infections, were classified in to mild unilateral group I (46%) cases with grade I or II sinus infections and relatively severe bilateral group II (54%) cases having grade III or IV infections. Infective process involving two to three ethmoid cells each on either side is the most common variety encountered in 39% cases. Prevalence of infective process was fairly equal among all age groups. Statistical correlation between the severity of RARS in patients having group II variety of isolated ethmoid sinus infections was found highly significant.Conclusions: Isolated ethmoid sinus infections are commonly encountered CT findings in adult RARS patients while they are asymptomatic from acute episodes of rhinosinusitis

    Radiological significance of the sinonasal anatomical variants in recurrent acute rhinosinusitis patients

    Get PDF
    Background: Recurrent acute rhinosinusitis (RARS), a low form chronic rhinosinusitis is frequently under evaluated. The significance of sinonasal anatomical variants of osteomeatal complex (OMC) and spheno-ethmoidal (SE) recess regions in patients of RARS is assessed.Methods: Retrospective analysis of coronal sinonasal computed tomography images of 120 RARS patients presented with sinonasal anatomical variants during November 2013 to October 2016 was carried out. Patients with acute and expansile sinonasal lesions are excluded.Results: Sinonasal anatomical variants in the regions of OMC and SE recess are responsible for obstruction of normal mucociliary drainage of corresponding paranasal sinuses in presence of inflammation predisposing to RARS. Anatomical variants of nasal septum were, deviated nasal septum (DNS) in 86 (72%) and septal spur in 58 (48%) patients. Anatomical variants in OMC region were, pneumatized middle turbinate (concha bullosa) in 50 (48%), paradoxical middle turbinate in 38 (28%), giant ethmoid bulla in 35 (32%), agger nasi cell in 29 (38%), Haller cell in 23 (15%), pneumatised uncinate process in 20 (18%), medialized uncinate process in 18 (22%) and septated maxillary sinus in 5 (4%) patients. Anatomical variants in SE recess were superior concha bullosa in 14 (12%) and septal bullosa in 11 (9%) patients.Conclusions: OMC pattern of recurrent rhinosinusitis is often prevalent in patients of RARS due to abundance of anatomical variants in the OMC region. DNS or ethmoid bulla when gets associated with concha bullosa increased the incidence of RARS. Present analysis would help surgeons to evaluate RARS patients for selective endoscopic sinus surgery

    Alcohol as a Risk Factor for Type 2 Diabetes: A systematic review and meta-analysis

    Get PDF
    OBJECTIVE - To clarify the dose-response relationship between alcohol consumption and type 2 diabetes.RESEARCH DESIGN AND METHODS - A systematic computer-assisted and hand search was conducted to identify relevant articles with longitudinal design and quantitative measurement of alcohol consumption. Adjustment was made for the sick-quitter effect. We used fractional polynomials in a meta-regression to determine the dose-response relationships by sex and end point using lifetime abstainers as the reference group.RESULTS - The search revealed 20 cohort studies that met our inclusion criteria. A U-shaped relationship was found for both sexes. Compared with lifetime abstainers, the relative risk (RR) for type 2 diabetes among men was most protective when consuming 22 g/day alcohol (RR 0.87 [95% CI 0.76-1.00]) and became deleterious at just over 60 g/day alcohol (1.01 [0.71-1.44]). Among women, consumption of 24 g/day alcohol was most protective (0.60 [0.52-0.69]) and became deleterious at about 50 g/day alcohol (1.02 [0.83-1.26]).CONCLUSIONS - Our analysis confirms previous research findings that moderate alcohol consumption is protective for type 2 diabetes in men and women

    A Proposed Search for the Detection of Gravitational Waves from Eccentric Binary Black Holes

    Full text link
    Most of compact binary systems are expected to circularize before the frequency of emitted gravitational waves (GWs) enters the sensitivity band of the ground based interferometric detectors. However, several mechanisms have been proposed for the formation of binary systems, which retain eccentricity throughout their lifetimes. Since no matched-filtering algorithm has been developed to extract continuous GW signals from compact binaries on orbits with low to moderate values of eccentricity, and available algorithms to detect binaries on quasi-circular orbits are sub-optimal to recover these events, in this paper we propose a search method for detection of gravitational waves produced from the coalescences of eccentric binary black holes (eBBH). We study the search sensitivity and the false alarm rates on a segment of data from the second joint science run of LIGO and Virgo detectors, and discuss the implications of the eccentric binary search for the advanced GW detectors

    Globulin seed storage protein based genotyping and Study of genetic diversity in core accessions of mungbean under drought stress

    Get PDF
    Globulin seed storage protein profiles of 19 mungbean genotypes including two wild forms of Vigna radiata var. sublobata(TCR 20 and TCR 213) and two standard  checks(T 2-1 and LGG 460) were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Thirteen genotypes could be clearly identified based on genotype-specific seed protein fingerprints. The combined dendrogram showed six genetic clusters within 68% phenon level. The clustering based on the combined clustering analysis revealed discrimination of all test genotypes even immediately beyond 88% phenon level, whereas individual clustering analysis based on protein and agro-morphological level failed to do so. Nipania munga, TCR 213, T 2-1, LGG 460, TCR 20 and Banapur local B were identified to be highly divergent genotypes. TCR 20 appears to have more genetic proximity to the mungbean genotypes than TCR 213. T 2-1, LGG 460 and TCR 20 are potentially high yielding. These may serve as valuable materials for recombination breeding in mungbean
    • 

    corecore