Gravitational wave burst vetoes in the LIGO S2 and S3 data analyses

The LIGO detectors collected about 4 months of data in 2003-2004 during two science runs, S2 and S3. Several environmental and auxiliary channels that monitor the instruments' physical environment and overall interferometric operation were analyzed in order to establish the quality of the data as well as the presence of transients of non-astrophysical origin. This analysis allowed better understanding of the noise character of the instruments and the establishment of correlations between transients in these channels and the one recording the gravitational wave strain. In this way vetoes for spurious burst were identified. We present the methodology we followed in this analysis and the results from the S2 and S3 veto analysis within the context of the search for gravitational wave bursts.Comment: 9 pages, 4 figures, submitted to Classical and Quantum Gravity for the special issue of the GWDAW9 Proceeding

Signal Alignment Problems on Multi-element X-Ray Fluorescence Detectors

X-ray fluorescence (XRF) is a spectroscopic technique with applications in several fields, such as biology, food science and forensics. Often setups have multi-element detectors in order to improve the signal-to-noise ratio. The relative set of produced spectra have to be aligned to a reference spectrum, in a procedure that is referred to as energy calibration, which is necessary for the fitting. Automated methods fail and a manual procedure is typically employed instead. In this paper, we discuss the signal alignment problem of such systems and we illustrate the preliminary results of a new automated method for linear XRF spectra alignment, which potentially can be used also for other time-series like data

Plans for the LIGO-TAMA Joint Search for Gravitational Wave Bursts

We describe the plans for a joint search for unmodelled gravitational wave bursts being carried out by the LIGO and TAMA collaborations using data collected during February-April 2003. We take a conservative approach to detection, requiring candidate gravitational wave bursts to be seen in coincidence by all four interferometers. We focus on some of the complications of performing this coincidence analysis, in particular the effects of the different alignments and noise spectra of the interferometers.Comment: Proceedings of the 8th Gravitational Wave Data Analysis Workshop, Milwaukee, WI, USA. 10 pages, 3 figures, documentclass ``iopart'

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

Minimally Invasive Mitral Valve Surgery in Elderly Patients: Results from a Multicenter Study

Background: Minimally invasive mitral valve surgery (MIMVS) has been increasingly adopted worldwide as an alternative to conventional sternotomy, especially for young patients. The remarkable results gained by MIMVS have encouraged its application in more complex and fragile patients, such as the elderly, though results in this subgroup remain controversial. It is the aim of this study to assess the postoperative outcomes of patients older than 75 years old undergoing MIMVS, and to compare these results to those of younger patients. Methods: The data of all patients undergoing MIMVS between 2015 and 2022 were retrospectively collected at seven high-volume cardiac surgery centers. Patients were divided into two age-based groups: the young (&lt;65 years old) and the elderly (&gt;75 years old). A propensity score (PS) matching analysis obtained two comparable groups. Postoperative outcomes were assessed in both the unmatched and PS-matched populations. Results: Out of 1113 patients undergoing MIMVS, 524 were young and 279 were elderly. Elderly patients were more commonly affected by multiple comorbidities, with a higher EuroSCORE II (4.6 +/- 5.5% vs. 1.6 +/- 3.3%, p &lt; 0.001). There was no difference in postoperative mortality, though the elderly had a greater incidence of postoperative complications, such as re-exploration for bleeding, stroke, reintubation, and a need for hemodialysis and blood transfusions. After PS matching, 119 pairs of young and elderly patients with similar risk profiles (EuroSCORE II 2.5 +/- 4.7% vs. 2.7 +/- 3.2%, p = 0.7) were compared, and no differences in all postoperative outcomes were found. Conclusions: Adequately selected elderly patients can report hospital outcomes similar to young patients after MIMVS

Neutrino-astronomia con l'esperimento macro al Gran Sasso

Dottorato di ricerca in fisica. 8. ciclo. A.a. 1994-95. Tutore F. Ronga. Coordinatore M. TestaConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal