Showing papers by "Christopher J. Russell published in 2019"
University of Manchester1, Arecibo Observatory2, Lafayette College3, National Radio Astronomy Observatory4, United States Naval Research Laboratory5, Swinburne University of Technology6, Goddard Space Flight Center7, West Virginia University8, ASTRON9, Curtin University10, Cornell University11, INAF12, Canadian Institute for Advanced Research13, Peking University14, Max Planck Society15, PSL Research University16, University of Orléans17, University of British Columbia18, Australia Telescope National Facility19, Paris Diderot University20, Hillsdale College21, University of East Anglia22, University of Maryland, College Park23, McGill University24, University of Birmingham25, University of Washington26, University of Wisconsin–Milwaukee27, Radboud University Nijmegen28, University of Toronto29, York University30, Hungarian Academy of Sciences31, University of Cagliari32, Commonwealth Scientific and Industrial Research Organisation33, University of Milan34, Oregon State University35, California Institute of Technology36, Vanderbilt University37, Chinese Academy of Sciences38, Monash University, Clayton campus39
TL;DR: In this article, the authors describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsars Timing array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes pulsar timing array, and find that the timing precisions of pulsars are generally improved compared to the previous data release.
Abstract: In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. We analyse and where possible combine high-precision timing data for 65 millisecond pulsars which are regularly observed by these groups. A basic noise analysis, including the processes which are both correlated and uncorrelated in time, provides noise models and timing ephemerides for the pulsars. We find that the timing precisions of pulsars are generally improved compared to the previous data release, mainly due to the addition of new data in the combination. The main purpose of this work is to create the most up-to-date IPTA data release. These data are publicly available for searches for low-frequency gravitational waves and other pulsar science.
289 citations
Swinburne University of Technology1, California Institute of Technology2, Australia Telescope National Facility3, Auckland University of Technology4, Curtin University5, West Virginia University6, Commonwealth Scientific and Industrial Research Organisation7, United States Naval Research Laboratory8, Chinese Academy of Sciences9, Monash University, Clayton campus10
TL;DR: The Parkes Pulsar Timing Array (PPTA) project monitors two dozen millisecond pulsars (MSPs) in order to undertake a variety of fundamental physics experiments using the Parkes 64m radio telescope.
Abstract: The Parkes Pulsar Timing Array (PPTA) project monitors two dozen millisecond pulsars (MSPs) in order to undertake a variety of fundamental physics experiments using the Parkes 64-m radio telescope. Since 2017 June, we have been undertaking commensal searches for fast radio bursts (FRBs) during the MSP observations. Here, we report the discovery of four FRBs (171209, 180309, 180311, and 180714). The detected events include an FRB with the highest signal-to-noise ratio ever detected at the Parkes Observatory, which exhibits unusual spectral properties. All four FRBs are highly polarized. We discuss the future of commensal searches for FRBs at Parkes.
43 citations
TL;DR: The scope of academic spam emails (ASEs) among career development grant awardees and the factors associated with the amount of time spent addressing them are investigated to find out whether there is an urgent need to mitigate this growing problem.
Abstract: Objective To investigate the scope of academic spam emails (ASEs) among career development grant awardees and the factors associated with the amount of time spent addressing them. Design A cross-sectional survey of career development grant investigators via an anonymous online survey was conducted. In addition to demographic and professional information, we asked investigators to report the number of ASEs received each day, how they determined whether these emails were spam and time they spent per day addressing them. We used bivariate analysis to assess factors associated with the amount of time spent on ASEs. Setting An online survey sent via email on three separate occasions between November and December 2016. Participants All National Institutes of Health career development awardees funded in the 2015 fiscal year. Main outcome measures Factors associated with the amount of time spent addressing ASEs. Results A total of 3492 surveys were emailed, of which 206 (5.9%) were returned as undeliverable and 96 (2.7%) reported an out-of-office message; our overall response rate was 22.3% (n=733). All respondents reported receiving ASEs, with the majority (54.4%) receiving between 1 and 10 per day and spending between 1 and 10 min each day evaluating them. The amount of time respondents reported spending on ASEs was associated with the number of peer-reviewed journal articles authored (p Conclusions ASEs are a common distraction for career development grantees that may impact faculty productivity. There is an urgent need to mitigate this growing problem.
26 citations
TL;DR: In this article, the authors reported the discovery of a new fast radio burst (FRB), FRB~010312, in archival data from a 1.4 GHz survey of the Magellanic Clouds using the multibeam receiver on the Parkes 64m-diameter radio telescope.
Abstract: We report the discovery of a new fast radio burst (FRB), FRB~010312, in archival data from a 1.4\,GHz survey of the Magellanic Clouds using the multibeam receiver on the Parkes 64\,m-diameter radio telescope. These data sets include the Lorimer burst (FRB~010724), which it pre-dates and which we also re-detect. The new burst has a much higher dispersion measure of 1187\,cm$^{-3}$pc. The burst is one of the broadest found to date, the second earliest FRB known, and the ninth FRB discovered with a dispersion measure larger than 1000\,cm$^{-3}\,$pc. Our discovery indicates that there are likely to be more burst events still to be found in the existing Parkes data archive.
22 citations
TL;DR: Early use of anti-influenza medications in children with tracheostomy hospitalized with influenza is associated with shorter LOS, but these children continue to receive antibiotics despite identification and treatment of their viral infections.
Abstract: BACKGROUND: Early administration of anti-influenza medications is recommended for all children hospitalized with influenza. We investigated whether early use of anti-influenza medications is associated with improved outcomes in children with tracheostomy hospitalized with influenza. METHODS: We performed a multicenter retrospective cohort study through the Pediatric Health Information System database for patients aged 30 days to 19 years who were discharged between October 1, 2007, and September 30, 2015 with diagnostic codes for both influenza and tracheostomy. Our primary predictor was receipt of anti-influenza medications on hospital day 0 or 1. We used propensity score matching to adjust for confounding by indication. Primary outcomes were length of stay (LOS) and 30-day all-cause revisit rate (emergency department visit or hospital admission). RESULTS: Of 1436 discharges screened, 899 met inclusion criteria. The median admission age was 5 years (interquartile range: 2–10). The majority had multiple complex chronic conditions (median 3; interquartile range: 3–4) and technology dependence, such as gastrostomy tube (73.6%). After matching 772 unique admissions by propensity score, LOS was shorter for the cohort receiving early anti-influenza medications (6.4 vs 7.5 days; P = .01) without increase in revisit rate (27.5% vs 24.1%; P = .28). More than 80% in both cohorts received empirical antibiotics, and the duration of antibiotic therapy was similar (5.0 vs 5.6 days; P = .11). CONCLUSIONS: Early use of anti-influenza medications in children with tracheostomy hospitalized with influenza is associated with shorter LOS, but these children continue to receive antibiotics despite identification and treatment of their viral infections.
10 citations
11 Mar 2019
TL;DR: A reliable and robust machine learning pipeline that autonomously classifies images of protein crystallisation droplets using CSIRO’s high-performance computing facilities achieves improved accuracies over existing implementations and delivers these results in real time.
Abstract: Many long-standing image processing problems in applied science domains are finding solutions through the application of deep learning approaches to image processing. Here we present one such application; the case of classifying images of protein crystallisation droplets. The Collaborative Crystallisation Centre in Melbourne, Australia is a medium throughput service facility that produces between five and twenty thousand images per day. This submission outlines a reliable and robust machine learning pipeline that autonomously classifies these images using CSIRO’s high-performance computing facilities. Our pipeline achieves improved accuracies over existing implementations and delivers these results in real time. We discuss the specific tools and techniques used to construct the pipeline, as well as the methodologies for testing and validating externally developed classification models.
6 citations
TL;DR: Because pre-trachotomy Pa growth on respiratory culture is associated with post-tracheotomy chronic Pa-positive respiratory cultures, future research should examine pre- tracheotomy Pa eradication or suppression protocols.
Abstract: Up to 90% of children develop Pseudomonas aeruginosa (Pa)-positive respiratory cultures after tracheotomy. To identify the factors associated with chronic Pa-positive respiratory cultures in the first 2 years after tracheotomy. We conducted a retrospective cohort study of 210 children ≤ 18 years old who underwent tracheotomy at a single freestanding children’s hospital that had two or more years of respiratory cultures post-tracheotomy available for analysis. We conducted multivariable logistic regression to test the association between demographic and clinical factors to our primary outcome of chronic Pa infection, defined as > 75% of respiratory cultures positive for Pa in the first 2 years after tracheotomy. Of the primarily male (61%), Hispanic (68%), and publicly insured (88%) cohort, 18% (n = 37) developed chronic Pa-positive respiratory cultures in the first 2 years. On multivariable logistic regression, pre-tracheotomy Pa-positive respiratory culture (aOR 11.3; 95% CI 4–1.5) and discharge on beta agonist (aOR 6.3; 95% CI 1.1–36.8) were independently associated with chronic Pa-positive respiratory cultures, while discharge on chronic mechanical ventilation was associated with decreased odds (aOR 0.3; 95% CI 0.1–0.7). On sensitivity analysis examining those without a pre-tracheotomy Pa-positive respiratory culture, discharge on MV continued to be associated with decreased odds of chronic Pa (aOR 0.1; 95% CI 0.02–0.4) and three other variables (male gender, chronic lung disease, and discharge on inhaled corticosteroids) were associated with increased odds of chronic Pa. Because pre-tracheotomy Pa growth on respiratory culture is associated with post-tracheotomy chronic Pa-positive respiratory cultures, future research should examine pre-tracheotomy Pa eradication or suppression protocols.
6 citations
TL;DR: Results demonstrated that nearly 1 in 3 emergency department visits and nearly one in 5 hospitalizations were associated with device complications, proportions that are higher than the 10% seen in previous studies.
Abstract: In the current issue of Hospital Pediatrics , Nackers et al1 retrospectively reviewed nearly 500 encounters in 98 children with medical complexity (CMC) to identify factors that predicted device-related complications. Results demonstrated that nearly 1 in 3 emergency department visits and nearly 1 in 5 hospitalizations were associated with device complications, proportions that are higher than the 10% seen in previous studies.2 Central venous catheters and feeding tubes (both primary gastrostomy tubes and nasoenteral tubes) accounted for 25% of all emergency department visits. Although certain device types were associated …