| 1. |
- Evans, P. A., et al.
(författare)
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Swift Follow-up Observations of Candidate Gravitational-wave Transient Events
- 2012
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Ingår i: The Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 203:2
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Tidskriftsartikel (refereegranskat)abstract
- We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors (within less than 10 minutes) and their candidate sky locations were observed by the Swift observatory (within 12 hr). Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them is consistent with background and the other one was a test, part of a "blind injection challenge." With this work we demonstrate the feasibility of rapid follow-ups of GW transients and establish the sensitivity improvement joint electromagnetic and GW observations could bring. This is a first step toward an electromagnetic follow-up program in the regime of routine detections with the advanced GW instruments expected within this decade. In that regime, multi-wavelength observations will play a significant role in completing the astrophysical identification of GW sources. We present the methods and results from this first combined analysis and discuss its implications in terms of sensitivity for the present and future instruments.
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| 2. |
- Abadie, J., et al.
(författare)
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Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts
- 2012
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 539
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Tidskriftsartikel (refereegranskat)abstract
- Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec. 17, 2009 to Jan. 8, 2010 and Sep. 2 to Oct. 20, 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results. For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with similar to 50% or better probability with a few pointings of wide-field telescopes.
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| 3. |
- Andreasson, A., et al.
(författare)
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Fosfomycin versus Ciprofloxacin as transrectal prostatebiopsy antibiotic prophylaxis an open randomized controlled multicenter drug trial
- 2023
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Ingår i: European Urology. - : Elsevier. - 0302-2838 .- 1873-7560. ; 83:Suppl. 1, s. S180-S180
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction & Objectives: Antibiotic prophylaxis are administered as a routine to decrease the risk for septic complications following transrectal prostate biopsy. Fosfomycin administered 1 h or more prior to biopsy has equal or better infectious complication rates as compared to Ciprofloxacin in both prospective and retrospective studies from countries with high rates of antibiotic resistance. The aim of this study was to investigate if Fosfomycin administered immediately prior to prostate biopsy was as effective as Ciprofloxacin in Sweden, a country with low rates of antibiotic resistance.Materials & Methods: A randomized, controlled, open, multicenter, non-inferiority-study including men of all ages undergoing transrectal prostate biopsy was performed in the urology departments of three Swedish hospitals. The total number of patients were planned for 3448, divided into low and high infection risk groups. The low-risk group was randomized to either one dose of Fosfomycin 3g or Ciprofloxacin 750mg before biopsy. The high-risk group was randomized to either two doses of Fosfomycin 3g prior to biopsy and one more 24 h after biopsy or Ciprofloxacin 500mg once prior to biopsy and then twice daily for three days. The drugs were administered orally. All patients had a rectal swab for culture before and after biopsy. The endpoint was hospitalisation due to urinary tract infection within 14 days from biopsy, follow-up was performed with a phone interview.Results: The safety board prematurely interrupted the study after 42 included patients due to an unusual high number of hospitalisations. Four out of 20 patients (20%), three in the low-risk group and one in the high-risk group, had been hospitalised due to urosepsis in the Fosfomycin group. One further patient described fever symptoms but did not seek health care. No patient in the Ciprofloxacin group (n=21) described symptoms of infection from the urinary tract. One patient was lost to follow-up. A one-sided binomial test showed a p-value of <0.001. Two of the four hospitalised patients had a positive blood culture for Pseudomonas Aeruginosa and one had a positive rectal swab culture for Pseudomonas species both before and after biopsy.Conclusions: The study does not support the use of Fosfomycin administered immediately prior to prostate biopsy. The results may have been affected by the unexpected high number of Pseudomonas infections, a bacteria where Fosfomycin often lack effect. If Fosfomycin is to be used it should be with caution if Pseudomonas has been seen in earlier cultures
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