2,313 research outputs found

    Numerical Relativity Injection Infrastructure

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    This document describes the new Numerical Relativity (NR) injection infrastructure in the LIGO Algorithms Library (LAL), which henceforth allows for the usage of NR waveforms as a discrete waveform approximant in LAL. With this new interface, NR waveforms provided in the described format can directly be used as simulated GW signals ("injections") for data analyses, which include parameter estimation, searches, hardware injections etc. As opposed to the previous infrastructure, this new interface natively handles sub-dominant modes and waveforms from numerical simulations of precessing binary black holes, making them directly accessible to LIGO analyses. To correctly handle precessing simulations, the new NR injection infrastructure internally transforms the NR data into the coordinate frame convention used in LAL.Comment: 20 pages, 2 figures, technical repor

    The Association Between Core Science Course Timing and Completion of an Associate Degree Nursing Program

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    The aging population in the United States has led to an increased demand for registered nurses. Nursing program administrators must examine ways to increase nursing program completion, which will increase the supply registered nurses. The purpose of this study was to determine the associations among length of time between core science course completion and nursing program admission, on-time completion, and National Council Licensure Examination for Registered Nurses (NCLEX-RN) success for students at a southeastern community college. A convenience sample of 288 community students admitted to an associate degree level nursing (ADN) program between 2007 and 2012 was selected. The guiding research questions examined if the length of time from completion of core science courses, Anatomy and Physiology, and admission to a selective admission nursing program was associated with on-time completion as well as passing the NCLEX-RN examination on first attempt. Using Karen\u27s gatekeeping theory as the theoretical foundation, this nonexperimental, nonparametric, quantitative design tested for statistical significance. A Pearson chi square with phi coefficient was utilized for data analysis. The results indicated a statistically significant association between on-time completion and completion of core science courses (X2 (4, N = 288) = 19.730, p = .001, ɸ .262); however, passing the NCLEX-RN on the first attempt was not significant (X2 (4, n = 178) = 4.182, p = .382). The study contributes to positive social change by providing research-based findings on the association between core science course timing and program completion. This knowledge may impact course scheduling and increase the number of registered nurses, which will have a positive impact on meeting the healthcare needs of society

    Merging of Soap Bubbles and Why Surfactant Matters

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    The merging of two soap bubbles is a fundamental fluid mechanical process in foam formation. In the present experimental study the liquid films from two soap bubbles are brought together. Once the liquid layers initially separated by a gas sheet are bridged on a single spot the rapid merging of the two liquid films proceed. Thereby the connecting rim is rapidly accelerated into the separating gas layer. We show that due to the dimple formation the velocity is not uniform and the high acceleration causes initially a Rayleigh-Taylor instability of the liquid rim. At later times, the rim takes heals into a circular shape. However for sufficient high concentrations of the surfactant the unstable rim pinches off microbubbles resulting in a fractal dendritic structure after coalescence

    Heterogeneous cavitation from atomically smooth liquid-liquid interfaces

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    Pressure reduction in liquids may result in vaporization and bubble formation. This thermodynamic process is termed cavitation. It is commonly observed in hydraulic machinery, ship propellers, and even in medical therapy within the human body. While cavitation may be beneficial for the removal of malign tissue, yet in many cases it is unwanted due to its ability to erode nearly any material in close contact. Current understanding is that the origin of heterogeneous cavitation are nucleation sites where stable gas cavities reside, e.g., on contaminant particles, submerged surfaces or shell stabilized microscopic bubbles. Here, we present the finding of a so far unreported nucleation site, namely the atomically smooth interface between two immiscible liquids. The non-polar liquid of the two has a higher gas solubility and acts upon pressure reduction as a gas reservoir that accumulates at the interface. We describe experiments that clearly reveal the formation of cavitation on non-polar droplets in contact with water and elucidate the working mechanism that leads to the nucleation of gas pockets through simulations.Comment: This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in Nature Physics, and is available online at https://doi.org/10.1038/s41567-022-01764-

    Recombinant Proteins as Antigens in Serological Diagnosis of Brucellosis

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    Brucellosis is considered the major zoonosis in developing countries. In susceptible animal species, diagnosis of brucellosis remains a challenge due to the variety of clinical signs that it shares with a wide range of diseases. At present, isolation of Brucella is considered the gold standard for diagnosis of brucellosis; because of its low sensitivity and becoming potentially hazardous to laboratory technicians, serology is used for the detection of specific antibodies induced by infection. However, since traditional methods commonly show drawbacks and do not differentiate between vaccinated and naturally infected animals, it is necessary to search and test immunoreactive molecules for specific diagnosis of Brucella-infected cattle, thus significantly reducing the killing of suspected herds mainly due to vaccination. Advances in biotechnology have allowed exploring the use of recombinant proteins as antigens to avoid the risk involved in the use of viable Brucella strains. The benefit of using recombinant proteins, such as outer membrane proteins (OMP) and other non-lipopolysaccharide (non-LPS) molecules as antigens, for serological diagnosis is promising, but there are still many concerns about their application. The aim of the present work is to show advances in the use of recombinant antigens and discuss their advantages and potential use as markers for the serological diagnosis in brucellosis

    Distinguishing the nature of comparable-mass neutron star binary systems with multimessenger observations: GW170817 case study

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    The discovery of GW170817 with gravitational waves (GWs) and electromagnetic (EM) radiation is prompting new questions in strong-gravity astrophysics. Importantly, it remains unknown whether the progenitor of the merger comprised two neutron stars (NSs), or a NS and a black hole (BH). Using new numerical-relativity simulations and incorporating modeling uncertainties we produce novel GW and EM observables for NS-BH mergers with similar masses. A joint analysis of GW and EM measurements reveals that if GW170817 is a NS-BH merger, <40% of the binary parameters consistent with the GW data are compatible with EM observations.Comment: 8 page

    The SXS Collaboration catalog of binary black hole simulations

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    Accurate models of gravitational waves from merging black holes are necessary for detectors to observe as many events as possible while extracting the maximum science. Near the time of merger, the gravitational waves from merging black holes can be computed only using numerical relativity. In this paper, we present a major update of the Simulating eXtreme Spacetimes (SXS) Collaboration catalog of numerical simulations for merging black holes. The catalog contains 2018 distinct configurations (a factor of 11 increase compared to the 2013 SXS catalog), including 1426 spin-precessing configurations, with mass ratios between 1 and 10, and spin magnitudes up to 0.998. The median length of a waveform in the catalog is 39 cycles of the dominant =m=2\ell=m=2 gravitational-wave mode, with the shortest waveform containing 7.0 cycles and the longest 351.3 cycles. We discuss improvements such as correcting for moving centers of mass and extended coverage of the parameter space. We also present a thorough analysis of numerical errors, finding typical truncation errors corresponding to a waveform mismatch of 104\sim 10^{-4}. The simulations provide remnant masses and spins with uncertainties of 0.03% and 0.1% (90th90^{\text{th}} percentile), about an order of magnitude better than analytical models for remnant properties. The full catalog is publicly available at https://www.black-holes.org/waveforms .Comment: 33+18 pages, 13 figures, 4 tables, 2,018 binaries. Catalog metadata in ancillary JSON file. v2: Matches version accepted by CQG. Catalog available at https://www.black-holes.org/waveform

    Cancer Control Plannersʼ Perceptions and Use of Evidence-Based Programs

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    The Cancer Prevention and Control Research Network (CPCRN) surveyed 282 cancer control planners to inform its efforts to increase the use of evidence-based cancer control programs (EBPs; programs that have been scientifically tested and successfully changed behavior). Respondents included planners from organizations in state Comprehensive Cancer Control coalitions as well as other governmental and non-governmental organizations, and community-based coalitions. Respondents provided information about personal and organizational characteristics, their cancer control programs, their attitudes toward EBPs, and their awareness and use of Web-based resources for EBPs. Although findings showed strong preferences for cancer control programs that have been shown to work, less than half of respondents (48%) had ever used EBP resources. Regardless of whether they had used EBP resources, almost all respondents (97%) indicated that further training would help them and their organization adopt and adapt EBPs for use in their communities. The most frequently endorsed training needs were finding and securing additional resources (such as funding and technical assistance), followed by adapting EBPs for cultural appropriateness. The CPCRN consortium is using these findings to develop a Web-based interactive training and decision support tool that is responsive to the needs identified by the survey respondents
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