Owing to its massive, dense core, Terzan 5 has the richest population of millisecond pulsars known among Galactic globular clusters. Here we report new deep \(2-8\,\)GHz radio continuum observations ...of Terzan\,5 obtained with the Karl G. Jansky Very Large Array. We have identified a total of 24 sources within the cluster half-light radius, including 17 within the core radius. 19 are associated with previously studied millisecond pulsars and X-ray binaries. Three of the new radio sources have steep radio spectra and are located within the cluster core, as expected for millisecond pulsars. These three sources have hard X-ray photon indices (\(\Gamma=1.3-1.5\)) and highly variable X-ray emission, suggesting they are binary millisecond pulsars belonging to the spider class. For the most X-ray luminous of these sources, the redback spider classification is confirmed by its X-ray light curve, which shows an orbital period of 12.32 hr and double peaked structure around X-ray maximum. The likely discovery of bright binary millisecond pulsars in a well-studied cluster like Terzan 5 highlights how deep radio continuum imaging can complement pulsar search and timing observations in finding probable eclipsing systems. The other new radio source in the core has a flat radio spectrum and is X-ray faint (\(L_X \approx 2\times 10^{31}\) erg s\(^{-1}\)) with a photon index \(\Gamma=2.1\pm0.5\), consistent with the properties expected for a quiescent stellar-mass black hole X-ray binary.
A human factors experiment was conducted to assess whether a reduction in noise at the ear would cause an improvement in speech intelligibility, an improvement in cognitive performance, and/or a ...reduction in subjective mental workload. Modified Rhyme Test (MRT) stimuli were used to determine intelligibility and specific tests within the Complex Cognitive Assessment Battery (CCAB) were used to assess cognitive performance. The tests chosen from the CCAB were: Tower Puzzle, Logical Relations, and Numbers and Words. These tests were chosen because of the specific set of cognitive functions that they measure which corresponded to command and control tasks.
Participants performed the MRT and CCAB tests simultaneously in a 114 dBA noise environment at two speech levels, 83 dB (linear) and 96 dB (linear), using two communication microphones, Gentex Model 1453 and a prototype communication microphone developed by Adaptive Technologies Inc. (ATI). The noise used in the experiment was from a recording made inside a US Army Bradley Fighting Vehicle. Subjective mental workload was assessed using the NASA-TLX and Modified Cooper-Harper (MCH) immediately after the experiment.
Results indicated that the communication microphone developed by ATI reduced the noise level at the ear better than the current Gentex microphone. However, the Gentex microphone produced significantly higher speech intelligibility scores at the 96 dB speech level. Cognitive performance scores significantly improved with increasing speech level for both communication microphones, with the ATI microphone having the advantage at 83 dB and the Gentex at 96 dB. The results also indicated that the main effects of speech level and communication microphone did not have an effect on subjective mental workload. A correlation analysis revealed that there was a positive relationship between the two workload measurement tools, indicating that either scale may be used to assess mental workload. Therefore, it was concluded that the MCH could have been used instead of the NASA-TLX, since the overall workload score was of interest.
Ph. D.
We model the intermediate-mass black hole HLX-1, using the Hubble Space Telescope, XMM-Newton and Swift. We quantify the relative contributions of a bluer component, function of X-ray irradiation, ...and a redder component, constant and likely coming from an old stellar population. We estimate a black hole mass of about (2^{+2}_{-1}) x 10^4 M_{sun}, a spin parameter a/M ~ 0.9 for moderately face-on view, and a peak outburst luminosity of about 0.3 times the Eddington luminosity. We discuss the discrepancy between the characteristic sizes inferred from the short X-ray timescale (R ~ a few 10^{11} cm) and from the optical emitter (R sqrtcos theta ~ 2.2 x 10^{13} cm). One possibility is that the optical emitter is a circumbinary disk; however, we disfavour this scenario because it would require a very small donor star. A more plausible scenario is that the disk is large but only the inner annuli are involved in the X-ray outburst. We propose that the recurrent outbursts are caused by an accretion-rate oscillation driven by wind instability in the inner disk. We argue that the system has a long-term-average accretion rate of a few percent Eddington, just below the upper limit of the low/hard state; a wind-driven oscillation can trigger transitions to the high/soft state, with a recurrence period of ~1 year (much longer than the binary period, which we estimate as ~10 days). The oscillation that dominated the system in the last decade is now damped such that the accretion rate no longer reaches the level required to trigger a transition. Finally, we highlight similarities between disk winds in HLX-1 and in the Galactic black hole V404 Cyg.
A human factors experiment was conducted to assess whether a reduction in noise at the ear would cause an improvement in speech intelligibility, an improvement in cognitive performance, and/or a ...reduction in subjective mental workload. Modified Rhyme Test (MRT) stimuli were used to determine intelligibility and specific tests within the Complex Cognitive Assessment Battery (CCAB) were used to assess cognitive performance. The tests chosen from the CCAB were: Tower Puzzle, Logical Relations, and Numbers and Words. These tests were chosen because of the specific set of cognitive functions that they measure which corresponded to command and control tasks. Participants performed the MRT and CCAB tests simultaneously in a 114 dBA noise environment at two speech levels, 83 dB (linear) and 96 dB (linear), using two communication microphones, Gentex Model 1453 and a prototype communication microphone developed by Adaptive Technologies Inc. (ATI). The noise used in the experiment was from a recording made inside a US Army Bradley Fighting Vehicle. Subjective mental workload was assessed using the NASA-TLX and Modified Cooper-Harper (MCH) immediately after the experiment. Results indicated that the communication microphone developed by ATI reduced the noise level at the ear better than the current Gentex microphone. However, the Gentex microphone produced significantly higher speech intelligibility scores at the 96 dB speech level. Cognitive performance scores significantly improved with increasing speech level for both communication microphones, with the ATI microphone having the advantage at 83 dB and the Gentex at 96 dB. The results also indicated that the main effects of speech level and communication microphone did not have an effect on subjective mental workload. A correlation analysis revealed that there was a positive relationship between the two workload measurement tools, indicating that either scale may be used to assess mental workload. Therefore, it was concluded that the MCH could have been used instead of the NASA-TLX, since the overall workload score was of interest.
ABSTRACT
Some ultraluminous X-ray sources (ULXs) are surrounded by collisionally ionized bubbles, larger and more energetic than supernova remnants: they are evidence of the powerful outflows ...associated with super-Eddington X-ray sources. We illustrate the most recent addition to this class: a huge (350 pc × 220 pc in diameter) bubble around a ULX in NGC 5585. We modelled the X-ray properties of the ULX (a broadened-disc source with LX ≈ 2–4 × 1039 erg s−1) from Chandra and XMM–Newton, and identified its likely optical counterpart in Hubble Space Telescope images. We used the Large Binocular Telescope to study the optical emission from the ionized bubble. We show that the line emission spectrum is indicative of collisional ionization. We refine the method for inferring the shock velocity from the width of the optical lines. We derive an average shock velocity ≈125 km s−1, which corresponds to a dynamical age of ∼600 000 yr for the bubble, and an average mechanical power Pw ∼ 1040 erg s−1; thus, the mechanical power is a few times higher than the current photon luminosity. With Very Large Array observations, we discovered and resolved a powerful radio bubble with the same size as the optical bubble, and a 1.4-GHz luminosity ∼1035 erg s−1, at the upper end of the luminosity range for this type of source. We explain why ULX bubbles tend to become more radio luminous as they expand while radio supernova remnants tend to fade.
Patients with primary sclerosing cholangitis (PSC) commonly undergo ileal pouch-anal anastomosis (IPAA) for medically-refractory ulcerative colitis (UC) or colorectal dysplasia. Pouchitis develops ...more frequently in patients with PSC, potentially leading to increased morbidity. We aimed to assess clinical characteristics and treatment outcomes for pouchitis in patients with PSC compared to a matched, non-PSC cohort.
All patients with PSC who underwent IPAA and were diagnosed with pouchitis (PSC-pouchitis) were identified. A matched cohort composed of non-PSC patients who underwent IPAA for UC and subsequently developed pouchitis (UC-pouchitis) was developed. Relevant demographic, clinical, endoscopic, histologic, and treatment data were collected and compared between groups.
Of those with PSC-pouchitis (n=182), 53.9% and 46.1% underwent IPAA for medically-refractory disease and dysplasia, respectively, compared to 88.7% and 11.3% in the UC-pouchitis group (P < .001). Patients with PSC-pouchitis were more likely to develop chronic pouchitis (68.1% vs 34.1%; P < .001), have moderate-to-severe pouch inflammation (54.9% vs 32.4%; P < .001), and prepouch ileitis (34.1% vs 11.5%; P < .001) compared to UC-pouchitis. Of those with PSC-pouchitis, 50.6% and 17.6% developed chronic antibiotic-dependent or antibiotic-refractory pouchitis, respectively, compared to 25.8% and 7.7% with UC-pouchitis. There was no difference in treatment response between the two groups with use of thiopurines, anti-tumor necrosis factor agents, and newer biologics.
PSC-associated pouchitis presents with a unique clinical phenotype, characterized by increased risk of chronic pouchitis, moderate-to-severe pouch inflammation, prepouch ileitis, and less response to conventional antimicrobial therapy.
Historically, two-dimensional (2D) cell culture has been the preferred method of producing disease models in vitro. Recently, there has been a move away from 2D culture in favor of generating ...three-dimensional (3D) multicellular structures, which are thought to be more representative of the in vivo environment. This transition has brought with it an influx of technologies capable of producing these structures in various ways. However, it is becoming evident that many of these technologies do not perform well in automated in vitro drug discovery units. We believe that this is a result of their incompatibility with high-throughput screening (HTS). In this study, we review a number of technologies, which are currently available for producing in vitro 3D disease models. We assess their amenability with high-content screening and HTS and highlight our own work in attempting to address many of the practical problems that are hampering the successful deployment of 3D cell systems in mainstream research.
•Lumacaftor/ivacaftor did not improve exercise tolerance compared to placebo.•Safety results were consistent with the known lumacaftor/ivacaftor safety profile.•Future exercise tolerance studies may ...benefit from lessons learned from this study.
The impact of lumacaftor/ivacaftor on exercise tolerance in people with cystic fibrosis (CF) has not been thoroughly studied.
We conducted a multisite Phase 4 trial comparing the impact of lumacaftor/ivacaftor on exercise tolerance with that of placebo in participants ≥ 12 years of age with CF homozygous for F508del-CFTR. The primary endpoint was relative change from baseline in maximum oxygen consumption (VO2max) during cardiopulmonary exercise testing (CPET) at Week 24. The key secondary endpoint was relative change from baseline in exercise duration during CPET at Week 24. Other secondary endpoints included changes in other indices of exercise tolerance and changes in CF assessments; safety and tolerability were assessed as an endpoint.
Seventy participants were randomized to receive lumacaftor/ivacaftor (n = 34) or placebo (n = 36). The least-squares mean difference for lumacaftor/ivacaftor versus placebo in relative change in VO2max from baseline at Week 24 was −3.2% (95% CI: −9.2, 2.9; P=0.3021); the least-squares mean difference in relative change from baseline in exercise duration at Week 24 was −3.2% (95% CI: −8.0, 1.6). Safety results were consistent with the known lumacaftor/ivacaftor safety profile.
Definitive conclusions regarding the impact of lumacaftor/ivacaftor on exercise tolerance cannot be drawn from these results; however, multicenter studies using CPETs can be reliably performed with multiple time points and conventional methods, provided that calibration can be achieved. Future studies of exercise tolerance may benefit from lessons learned from this study. NCT02875366.
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