1,299 research outputs found
Methods for multi-detector burst gravitational wave search
In this paper, a review of methods of data exchange and multi-detector analysis is given. Details of data exchange parameters will also be discussed. We focus on the coherent network search which turns out to be a fundamental step towards the overcoming of ambiguity in parameter estimation of a gravitational wave in the low signal-to-noise ratio regime
Laboratory investigation of the impact of air pollution on partial discharge inception voltage of insulators in a specific region
Studying the discharge characteristics of transmission line insulators in the presence of pollution, particularly when the contaminated layer is wet by rain, fog or condensation, is necessary for selecting the proper insulation. Therefore, identifying the major air pollutants as well as the most effective ones on the discharge performance of outdoor insulators is mandatory. A systematic approach has been proposed to evaluate the impact of dominant air pollutants of an area on partial discharge (P.D) inception voltage of specimen insulators. Based on the suggested method, determining the pollution constituents, defining the dominant pollutant of the area, finding the most commonly used insulators for medium and above distribution voltages within the geographical boundaries of the Central Province of Iran, as well as examining the effect of dominant air pollutant of the region on partial discharge inception voltage of designated insulators by laboratory measurements, are the necessary steps toward a comprehensive study of the subject
Enhancing the significance of gravitational wave bursts through signal classification
The quest to observe gravitational waves challenges our ability to
discriminate signals from detector noise. This issue is especially relevant for
transient gravitational waves searches with a robust eyes wide open approach,
the so called all- sky burst searches. Here we show how signal classification
methods inspired by broad astrophysical characteristics can be implemented in
all-sky burst searches preserving their generality. In our case study, we apply
a multivariate analyses based on artificial neural networks to classify waves
emitted in compact binary coalescences. We enhance by orders of magnitude the
significance of signals belonging to this broad astrophysical class against the
noise background. Alternatively, at a given level of mis-classification of
noise events, we can detect about 1/4 more of the total signal population. We
also show that a more general strategy of signal classification can actually be
performed, by testing the ability of artificial neural networks in
discriminating different signal classes. The possible impact on future
observations by the LIGO-Virgo network of detectors is discussed by analysing
recoloured noise from previous LIGO-Virgo data with coherent WaveBurst, one of
the flagship pipelines dedicated to all-sky searches for transient
gravitational waves
Prospects for intermediate mass black hole binary searches with advanced gravitational-wave detectors
We estimated the sensitivity of the upcoming advanced, ground-based
gravitational-wave observatories (the upgraded LIGO and Virgo and the KAGRA
interferometers) to coalescing intermediate mass black hole binaries (IMBHB).
We added waveforms modeling the gravitational radiation emitted by IMBHBs to
detectors' simulated data and searched for the injected signals with the
coherent WaveBurst algorithm. The tested binary's parameter space covers
non-spinning IMBHBs with source-frame total masses between 50 and 1050
and mass ratios between and 1. We found that
advanced detectors could be sensitive to these systems up to a range of a few
Gpc. A theoretical model was adopted to estimate the expected observation
rates, yielding up to a few tens of events per year. Thus, our results indicate
that advanced detectors will have a reasonable chance to collect the first
direct evidence for intermediate mass black holes and open a new, intriguing
channel for probing the Universe over cosmological scales.Comment: 9 pages, 4 figures, corrected the name of one author (previously
misspelled
Analysis of gut microbiota in rheumatoid arthritis patients. Disease-related dysbiosis and modifications induced by etanercept
A certain number of studies were carried out to address the question of how dysbiosis could affect the onset and development of rheumatoid arthritis (RA), but little is known about the reciprocal influence between microbiota composition and immunosuppressive drugs, and how this interaction may have an impact on the clinical outcome. The aim of this study was to characterize the intestinal microbiota in a groups of RA patients treatment-naïve, under methotrexate, and/or etanercept (ETN). Correlations between the gut microbiota composition and validated immunological and clinical parameters of disease activity were also evaluated. In the current study, a 16S analysis was employed to explore the gut microbiota of 42 patients affected by RA and 10 healthy controls. Disease activity score on 28 joints (DAS-28), erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti-cyclic citrullinated peptides, and dietary and smoking habits were assessed. The composition of the gut microbiota in RA patients free of therapy is characterized by several abnormalities compared to healthy controls. Gut dysbiosis in RA patients is associated with different serological and clinical parameters; in particular, the phylum of Euryarchaeota was directly correlated to DAS and emerged as an independent risk factor. Patients under treatment with ETN present a partial restoration of a beneficial microbiota. The results of our study confirm that gut dysbiosis is a hallmark of the disease, and shows, for the first time, that the anti-tumor necrosis factor alpha (TNF-α) ETN is able to modify microbial communities, at least partially restoring a beneficial microbiota
Feedback cooling of the normal modes of a massive electromechanical system to submillikelvin temperature
We apply a feedback cooling technique to simultaneously cool the three
electromechanical normal modes of the ton-scale resonant-bar gravitational wave
detector AURIGA. The measuring system is based on a dc Superconducting Quantum
Interference Device (SQUID) amplifier, and the feedback cooling is applied
electronically to the input circuit of the SQUID. Starting from a bath
temperature of 4.2 K, we achieve a minimum temperature of 0.17 mK for the
coolest normal mode. The same technique, implemented in a dedicated experiment
at subkelvin bath temperature and with a quantum limited SQUID, could allow to
approach the quantum ground state of a kilogram-scale mechanical resonator.Comment: 4 pages, 4 figure
TaqMan probe assays on different biological samples for the identification of three ambrosia beetle species, Xylosandrus compactus (Eichoff), X. crassiusculus (Motschulsky) and X. germanus (Blandford) (Coleoptera Curculionidae Scolytinae)
Molecular assays based on qPCR TaqMan Probes were developed to identify three species of the genus Xylosandrus, X.
compactus, X. crassiusculus and X. germanus (Coleoptera Curculionidae Scolytinae). These ambrosia beetles are xylophagous
species alien to Europe, causing damages to many ornamental and fruiting trees as well as shrubs. DNA extraction was
carried out from adults, larvae and biological samples derived from insect damages on infested plants. For X. compactus,
segments of galleries in thin infested twigs were cut and processed; in the case of X. crassiusculus, raw frass extruded from
exit holes was used, while DNA of X. germanus was extracted from small wood chips removed around insect exit holes. The
assays were inclusive for the target species and exclusive for all the non-target species tested. The LoD was 3.2 pg/μL for
the frass of X. crassiusculus and 0.016 ng/μL for the woody matrices of the other two species. Both repeatability and reproducibility
were estimated on adults and woody samples, showing very low values ranging between 0.00 and 4.11. Thus, the
proposed diagnostic assays resulted to be very efficient also on the woody matrices used for DNA extraction, demonstrating
the applicability of the protocol in the absence of dead specimens or living stages
Using INTERCheck® to Evaluate the Incidence of Adverse Events and Drug–Drug Interactions in Out- and Inpatients Exposed to Polypharmacy
Background: Polypharmacy exposes patients with comorbidities (particularly elderly patients) to an increased risk of drug-specific adverse events and drug–drug interactions. These adverse events could be avoided with the use of a computerized prescription support system in the primary care setting. The INTERCheck® software is a prescription support system developed with the aim of balancing the risks and benefits of polytherapy and examining drug–drug interactions. Objectives: This observational study used the INTERCheck® software to evaluate the incidence of adverse events and of drug–drug interactions in outpatients and inpatients receiving multiple medications. Methods: Patients were randomly enrolled from the outpatient department (n = 98) and internal medicine ward (n = 46) of S. Andrea Hospital of Rome. Polypharmacological treatment was analyzed using INTERCheck® software, and the prevalence of risk indicators and adverse events was compared between the two groups. Results: Polypharmacy (use of five or more drugs) applied to all except three cases among outpatients and one case among inpatients. A significant positive correlation was found between the number of medications and the INTERCheck® score (ρ = 0.67; p < 0.000001), and a significant negative correlation was found between the drug-related anticholinergic burden and cognitive impairment (r = − 0.30 p = 0.01). Based on the INTERCheck® analysis, inpatients had a higher score for class D (contraindicated drug combination should be avoided) than did outpatients (p = 0.01). The potential class D drug–drug interactions were associated with adverse events that caused hospitalization (χ2 = 7.428, p = 0.01). Conclusions: INTERCheck® analysis indicated that inpatients had a high risk of drug–drug interactions and a high percentage of related adverse drug events. Further prospective studies are necessary to evaluate whether the INTERCheck® software may help reduce polypharmacy-related adverse events when used in a primary care setting and thus potentially avoid related hospitalization and severe complications such as physical and cognitive decline
Networks of gravitational wave detectors and three figures of merit
This paper develops a general framework for studying the effectiveness of
networks of interferometric gravitational wave detectors and then uses it to
show that enlarging the existing LIGO-VIRGO network with one or more planned or
proposed detectors in Japan (LCGT), Australia, and India brings major benefits,
including much larger detection rate increases than previously thought... I
show that there is a universal probability distribution function (pdf) for
detected SNR values, which implies that the most likely SNR value of the first
detected event will be 1.26 times the search threshold. For binary systems, I
also derive the universal pdf for detected values of the orbital inclination,
taking into account the Malmquist bias; this implies that the number of
gamma-ray bursts associated with detected binary coalescences should be 3.4
times larger than expected from just the beaming fraction of the gamma burst.
Using network antenna patterns, I propose three figures of merit that
characterize the relative performance of different networks... Adding {\em any}
new site to the planned LIGO-VIRGO network can dramatically increase, by
factors of 2 to 4, the detected event rate by allowing coherent data analysis
to reduce the spurious instrumental coincident background. Moving one of the
LIGO detectors to Australia additionally improves direction-finding by a factor
of 4 or more. Adding LCGT to the original LIGO-VIRGO network not only improves
direction-finding but will further increase the detection rate over the
extra-site gain by factors of almost 2, partly by improving the network duty
cycle... Enlarged advanced networks could look forward to detecting three to
four hundred neutron star binary coalescences per year.Comment: 38 pages, 7 figures, 2 tables. Accepted for publication in Classical
and Quantum Gravit
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