ABSTRACT We present the results of our extensive search using the Bayesian block method for long tails following short bursts from a magnetar, SGR J1550-5418, over all RXTE observations of the ...source. We identified four bursts with extended tails, most of which occurred during its 2009 burst active episode. The durations of tails range between ∼13 s and over 3 ks, which are much longer than the typical duration of bursts. We performed detailed spectral and temporal analyses of the burst tails. We find that the spectra of three tails show a thermal nature with a trend of cooling throughout the tail. We compare the results of our investigations with the properties of four other extended tails detected from SGR 1900+14 and SGR 1806-20 and suggest a scenario for the origin of the tail in the framework of the magnetar model.
We present multiwavelength observations of the afterglow of GRB 130427A, the brightest (in total fluence) gamma-ray burst (GRB) of the past 29 yr. Optical spectroscopy from Gemini-North reveals the ...redshift of the GRB to be z = 0.340, indicating that its unprecedented brightness is primarily the result of its relatively close proximity to Earth; the intrinsic luminosities of both the GRB and its afterglow are not extreme in comparison to other bright GRBs. We present a large suite of multiwavelength observations spanning from 300 s to 130 days after the burst and demonstrate that the afterglow shows relatively simple, smooth evolution at all frequencies, with no significant late-time flaring or rebrightening activity. The entire data set from 1 GHz to 10 GeV can be modeled as synchrotron emission from a combination of reverse and forward shocks in good agreement with the standard afterglow model, providing strong support to the applicability of the underlying theory and clarifying the nature of the GeV emission observed to last for minutes to hours following other very bright GRBs. A tenuous, wind-stratified circumburst density profile is required by the observations, suggesting a massive-star progenitor with a low mass-loss rate, perhaps due to low metallicity. GRBs similar in nature to GRB 130427A, inhabiting low-density media and exhibiting strong reverse shocks, are probably not uncommon but may have been difficult to recognize in the past owing to their relatively faint late-time radio emission; more such events should be found in abundance by the new generation of sensitive radio and millimeter instruments.
To analyse clinical severity/activity of rheumatoid arthritis (RA) according to smoking status.
The QUEST-RA multinational database reviews patients for Core Data Set measures including 28 swollen ...and tender joint count, physician global estimate, erythrocyte sedimentation rate (ESR), HAQ-function, pain, and patient global estimate, as well as DAS28, rheumatoid factor (RF), nodules, erosions and number of DMARDs were recorded. Smoking status was assessed by self-report as 'never smoked', 'currently smoking' and 'former smokers'. Patient groups with different smoking status were compared for demographic and RA measures.
Among the 7,307 patients with smoking data available, status as 'never smoked,' 'current smoker' and 'former smoker' were reported by 65%, 15% and 20%. Ever smokers were more likely to be RF-positive (OR 1.32;1.17-1.48, p<0.001). Rheumatoid nodules were more frequent in ever smokers (OR 1.41;1.24-1.59, p<0.001). The percentage of patients with erosive arthritis and extra-articular disease was similar in all smoking categories. Mean DAS28 was 4.4 (SD 1.6) in non-smokers vs. 4.0 (SD 1.6) in those who had ever smoked. However, when adjusted by age, sex, disease duration, and country gross domestic product, only ESR remained significantly different among Core Data Set measures (mean 31.7mm in non-smokers vs. 26.8mm in ever smoked category).
RA patients who had ever smoked were more likely to have RF and nodules, but values for other clinical status measures were similar in all smoking categories (never smoked, current smokers and former smokers).
The aim of this study was to understand practices regarding smoking cessation among rheumatologists for patients with inflammatory rheumatic diseases.
A survey was sent to the rheumatologists ...participating in the multinational Quantitative Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST-RA) group. The survey inquired about the clinical practice characteristics and practices regarding smoking cessation (proportion of smokers with inflammatory rheumatic diseases given smoking cessation advice, specific protocols and written advice material, availability of dedicated smoking cessation clinic).
Rheumatologists from 44 departments in 25 countries (16 European) completed the survey. The survey involved 395 rheumatologists, of whom 25 (6.3%) were smokers, and 199 nurses for patient education, of whom 44 (22.1%) were smokers. Eight departments (18.1 %) had a specific protocol for smoking cessation; 255 (64.5%) rheumatologists reported giving smoking cessation advice to all or almost all smokers with inflammatory diseases. In a regression model, early arthritis clinics (P = 0.01) and high gross domestic product countries (P = 0.001) were both independently associated with advice by the rheumatologist. Nurse gives advice to most patients in 11 of the 36 (30.5%) departments with nurses for patient education.
Advice for smoking cessation within rheumatology departments is not homogeneous. In half of the departments, most doctors give advice to quit smoking to all or almost all patients with inflammatory diseases. However, only one in five departments have a specific protocol for smoking cessation. Our data highlight the need to improve awareness of the importance of and better practice implementation of smoking cessation advice for inflammatory rheumatic disease patients.
Numerical modeling results indicate that mantle lithosphere rheology can influence the pressure‐temperature‐time (P‐T‐t) trajectories of continental crust subducted and exhumed during the onset of ...continental collision. Exhumation of ultrahigh‐pressure (~35 kbar)/high‐temperature (~750°C) metamorphic rocks is more prevalent in models with stronger continental mantle lithosphere (e.g., dry), whereas high‐pressure (~9–22 kbar)/low‐temperature (350°C–630°C) metamorphic rocks occur in models with weaker rheology (e.g., hydrated) for the same layer. In the latter case, the buried crustal rocks can remain encased in ablatively subducting mantle lithosphere, reach only moderate temperatures, and exhume by dripping/detachment of the lithospheric root. In this transition from subduction to a dripping style of “vertical tectonics,” burial and exhumation of crustal rocks are driven without imposed far‐field plate convergence. The model results are compared against thermobarometric P‐T estimates from major (ultra)high‐pressure metamorphic terranes. We propose that the exhumation of high‐pressure/low‐temperature metamorphic rocks in Tavşanlı and Afyon zones in western Anatolia may be caused by viscous dripping of mantle lithosphere suggesting a weaker continental mantle lithosphere, whereas (ultra)high‐pressure exhumation (e.g., Dabie Shan‐eastern China and Dora Maira‐western Alps) may be associated with plate‐like subduction. In the latter case, the slab is much stronger and deformation is localized to the subduction interface along which rocks are buried to >100 km depth before they are exhumed to the near surface.
Key Points
Mantle lithosphere rheology can control the burial and exhumation of crustal rocks
Viscous removal of a weaker continental mantle lithosphere may yield high‐pressure/low‐temperature exhumation
Ultrahigh‐pressure/high‐temperature metamorphic rocks may be prevalent in subduction of a stronger continental mantle lithosphere
ABSTRACT
Archival XMM–Newton, Chandra, and Hubble Space Telescope(HST) data have been used to study the X-ray and optical properties of two candidate ultraluminous X-ray sources in NGC 4536. In order ...to search for potential optical counterparts, relative astrometry between Chandra and HST was improved, and as a result, optical counterparts were detected for both X-ray sources. To complement our findings (based on the archival data), ground-based optical spectra of the counterparts were obtained with the 6-m BTA (Big Telescope Alt-azimuth) Telescope located at the Special Astrophysical Observatory. The calculated redshift (z = 0.4391 ± 0.0010) for one of the sources (X-3) indicates that the source is, in fact, a background active galactic nucleus. Two possible optical counterparts (s1 and s2) were found for X-2. Whether s1 is point-like or an extended source is unclear: If it is point-like and the emission is dominated by the donor, its spectral type indicates O–B star. The second source (s2) is point-like and is consistent with the colours and absolute magnitudes of a red supergiant.
Magnetars are strongly magnetized, isolated neutron stars
with magnetic fields up to around 10
gauss, luminosities of approximately 10
-10
ergs per second and rotation periods of about 0.3-12.0 s. ...Very energetic giant flares from galactic magnetars (peak luminosities of 10
-10
ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays
, and only one has been detected from outside our galaxy
. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed
, but their statistical significance has been questioned
. High-frequency QPOs have been seen only during the tail phase of the flare
. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare
in the direction of the NGC 253 galaxy
, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument
aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 10
to 40 × 10
electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.
We present a multi-wavelength study of GRB 081008, at redshift 1.967, by Swift, ROTSE-III, and Gamma-Ray Burst Optical/NearInfrared Detector. Compared to other Swift GRBs, GRB 081008 has a typical ...gamma-ray isotropic equivalent energy output ({approx}10{sup 53} erg) during the prompt phase, and displayed two temporally separated clusters of pulses. The early X-ray emission seen by the Swift X-Ray Telescope was dominated by the softening tail of the prompt emission, producing multiple flares during and after the Swift Burst Alert Telescope detections. Optical observations that started shortly after the first active phase of gamma-ray emission showed two consecutive peaks. We interpret the first optical peak as the onset of the afterglow associated with the early burst activities. A second optical peak, coincident with the later gamma-ray pulses, imposes a small modification to the otherwise smooth light curve and thus suggests a minimal contribution from a probable internal component. We suggest the early optical variability may be from continuous energy injection into the forward shock front by later shells producing the second epoch of burst activities. These early observations thus provide a potential probe for the transition from the prompt phase to the afterglow phase. The later light curve of GRB 081008 displays a smooth steepening in all optical bands and X-ray. The temporal break is consistent with being achromatic at the observed wavelengths. Our broad energy coverage shortly after the break constrains a spectral break within optical. However, the evolution of the break frequency is not observed. We discuss the plausible interpretations of this behavior.
The aim of this study was to determine the prevalence of diabetic peripheral neuropathy (DPN) and neuropathic pain in diabetic patients attending university outpatient clinics in Turkey. In this ...multicenter cross-sectional study, neurologic examinations and nerve conduction studies along with clinical diabetic neuropathy score, and Leeds Assessment of Neuropathic Symptoms and Signs pain scale were performed on 1,113 patients (46.2% male) from 14 centers. Prevalence of DPN determined only by clinical examination was 40.4% and increased to 62.2%, by combining nerve conduction studies with clinical examination. According to Leeds Assessment of Neuropathic Symptoms and Signs scores, neuropathic pain prevalence was 16.0% in those who reported pain. Poor glycemic control, retinopathy, microalbuminuria, hyperlipidemia, diabetic foot, and foot amputation were more commonly observed in patients with DPN. Clinical DPN affected 40.4% of diabetic patients, and neuropathic pain prevalence in diabetic patient population was 14.0%. Clinical examinations and nerve conduction studies are important components for early detection and accurate diagnosis of DPN and painful DPN.
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