We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black ...hole pair yet found by more than 2 orders of magnitude. These results are based on recent multifrequency observations using the Very Long Baseline Array (VLBA), which reveal two compact, variable, flat-spectrum, active nuclei within the elliptical host galaxy of 0402+379. Multiepoch observations from the VLBA also provide constraints on the total mass and dynamics of the system. Low spectral resolution spectroscopy using the Hobby-Eberly Telescope indicates two velocity systems with a combined mass of the two black holes of 6 1.5 x 10 super(8) M sub(z). The two nuclei appear stationary, while the jets emanating from the weaker of the two nuclei appear to move out and terminate in bright hot spots. The discovery of this system has implications for the number of close binary black holes that might be sources of gravitational radiation. Green Bank Telescope observations at 22 GHz to search for water masers in this interesting system are also presented.
To determine the extent to which ethnic differences in BMI Z-scores and obesity rates could be explained by the differential distribution of demographic (e.g. age), familial (e.g. family income), ...area (e.g. area deprivation), parental (e.g. immigration status), and birth (e.g. gestational age) characteristics across ethnic groups.
We used data on 4-year-old children born in New Zealand who attended the B4 School Check between the fiscal years of 2010/2011 to 2015/2016, who were resident in the country when the 2013 census was completed (n = 253,260). We implemented an Oaxaca-Blinder decomposition to explain differences in BMI Z-score and obesity between Māori (n = 63,061) and European (n = 139,546) children, and Pacific (n = 21,527) and European children.
Overall, 15.2% of the children were obese and mean BMI Z-score was 0.66 (SD = 1.04). The Oaxaca-Blinder decomposition demonstrated that the difference in obesity rates between Māori and European children would halve if Māori children experienced the same familial and area level conditions as Europeans. If Pacific children had the same characteristics as European children, differences in obesity rates would reduce by approximately one third, but differences in mean BMI Z-scores would only reduce by 16.1%.
The differential distribution of familial, parental, area, and birth characteristics across ethnic groups explain a substantial percentage of the ethnic differences in obesity, especially for Māori compared to European children. However, marked disparities remain.
Summary
Background
Magnetic resonance imaging (MRI) is the gold standard for assessment of perianal fistulising Crohn's disease (CD). The Van Assche index is the most commonly used MRI fistula index.
...Aims
To assess the reliability of the Van Assche index, and to modify the instrument to improve reliability and create a novel index for fistulising CD.
Methods
A consensus process developed scoring conventions for existing Van Assche index component items and new items. Four experienced radiologists evaluated 50 MRI images in random order on three occasions. Reliability was assessed by estimates of intraclass correlation coefficients (ICCs). Common sources of disagreement were identified and recommendations made to minimise disagreement. A mixed effects model used a 100 mm visual anologue scale (VAS) for global severity as outcome and component items as predictors to create a modified Van Assche index.
Results
Intraclass correlation coefficients (95% confidence intervals) for intra‐rater reliability of the original and modified Van Assche indices and the VAS were 0.86 (0.81‐0.90), 0.90 (0.86‐0.93) and 0.86 (0.82‐0.89). Corresponding ICCs for inter‐rater reliability were 0.66 (0.52‐0.76), 0.67 (0.55‐0.75) and 0.58 (0.47‐0.66). Sources of disagreement included number, location, and extension of fistula tracts, and rectal wall involvement. A modified Van Assche index (range 0‐24) was created that included seven component items.
Conclusions
Although “almost perfect” intra‐rater reliability was observed for the assessment of MRI images for fistulising CD using the Van Assche index, inter‐rater reliability was considerably lower. Our modification of this index should result in a more optimal instrument.
Linked ContentThis article is linked to Lung and Ng paper. To view this article visit https://doi.org/10.1111/apt.14235.
The MiniBooNE-DM Collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8-GeV Booster proton beam in a dedicated run with 1.86×10^{20} protons delivered to a ...steel beam dump. The MiniBooNE detector, 490 m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous MiniBooNE scattering results were employed, and several constraining data sets were simultaneously analyzed to minimize systematic errors from neutrino flux and interaction rates. No excess of events over background was observed, leading to a 90% confidence limit on the dark matter cross section parameter, Y=ε^{2}α_{D}(m_{χ}/m_{V})^{4}≲10^{-8}, for α_{D}=0.5 and for dark matter masses of 0.01<m_{χ}<0.3 GeV in a vector portal model of dark matter. This is the best limit from a dedicated proton beam dump search in this mass and coupling range and extends below the mass range of direct dark matter searches. These results demonstrate a novel and powerful approach to dark matter searches with beam dump experiments.
We present new Chandra images of the X-ray emission from the core of the Perseus cluster of galaxies. The total observation time is now 1.4 Ms. New depressions in X-ray surface brightness are ...discovered to the north of NGC 1275, which we interpret as old rising bubbles. They imply that bubbles are long-lived and do not readily breakup when rising in the hot cluster atmosphere. The existence of a 300 kpc long NNW-SSW bubble axis means there cannot be significant transverse large-scale flows exceeding 100 km s−1. Interesting spatial correlations are seen along that axis in early deep radio maps. A semicircular cold front about 100 kpc west of the nucleus is seen. It separates an inner disturbed region dominated by the activity of the active nucleus of NGC 1275 from the outer region where a subcluster merger dominates.
We present multifrequency Very Long Baseline Array (VLBA) follow-up observations of VLBA Imaging and Polarimetry Survey sources identified as likely compact symmetric objects (CSOs) or supermassive ...binary black holes (SBBHs). We also present new spectroscopic redshifts for 11 sources observed with the Hobby–Eberly Telescope. While no new SBBHs can be confirmed from these observations, we have identified 24 CSOs in the sample, 15 of which are newly designated, and refuted 52 candidates leaving 33 unconfirmed candidates. This is the first large uniform sample of CSOs which can be used to elicit some of the general properties of these sources, including morphological evolution and environmental interaction. We have detected polarized emission from two of these CSOs the properties of which are consistent with active galactic nuclei unification schemes.
The purpose of our study was to determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on cardiac CT angiography (CTA) signal, noise, and image quality.
We evaluated 62 ...consecutive patients at three sites who underwent clinically indicated cardiac CTA using an ASIR-capable 64-MDCT scanner and a low-dose cardiac CTA technique. Studies were reconstructed using filtered back projection (FBP), ASIR-FBP composites using 20-80% ASIR, and 100% ASIR. The signal and noise were measured in the aortic root and each of the four coronary arteries. Two blinded readers graded image quality on a 5-point Likert scale and determined the proportion of interpretable segments. All segments were included for analysis regardless of size.
In comparison with FBP (0% ASIR), the use of 20%, 40%, 60%, 80%, and 100% ASIR resulted in reduced image noise between groups (-7%, -17%, -26%, -35%, and -43%, respectively; p < 0.001) without difference in signal (p = 0.60). There were significant differences between groups (0%, 20%, 40%, 60%, 80%, and 100% ASIR) in the Likert scores (1.5, 2.1, 3.7, 3.8, 2.0, and 1.1, respectively; p < 0.001) and proportion of interpretable segments (88.7%, 89.3%, 90.5%, 90.4%, 88.0%, and 87.3%, respectively; p < 0.001). Reconstruction using 40% and 60% ASIR had the highest Likert scores and largest proportion of interpretable segments. In comparison with FBP, each was associated with higher Likert scores and increased interpretable segments (p < 0.001 for all).
ASIR resulted in noise reduction and significantly impacted image quality. When using a low tube current technique, cardiac CTA reconstruction using 40% or 60% ASIR significantly improved image quality and the proportion of interpretable segments compared with FBP reconstruction.
Summary
Background
Prevalence of childhood obesity is high in developed countries, and there is a growing concern regarding increasing socio‐economic disparities.
Objectives
To assess trends in the ...prevalence of overweight, obesity and extreme obesity among New Zealand 4‐year olds, and whether these differ by socio‐economic and ethnic groupings.
Methods
A national screening programme, the B4 School Check, collected height and weight data for 75–92% of New Zealand 4‐year‐old children (n = 317 298) between July 2010 and June 2016. Children at, or above, the 85th, 95th and 99.7th percentile for age and sex adjusted body mass index (according to World Health Organization standards) were classified as overweight, obese and extremely obese, respectively. Prevalence rates across 6 years (2010/11 to 2015/16) were examined by sex, across quintiles of socio‐economic deprivation, and by ethnicity.
Results
The prevalence of overweight, obesity and extreme obesity decreased by 2.2 95% CI, 1.8–2.5, 2.0 1.8–2.2 and 0.6 0.4–0.6 percentage points, respectively, between 2010/2011 and 2015/2016. The downward trends in overweight, obesity and extreme obesity in the population persisted after adjustment for sex, ethnicity, deprivation and urban/rural residence. Downward trends were also observed across sex, ethnicity and deprivation groups.
Conclusions
The prevalence of obesity appears to be declining in 4‐year‐old children in New Zealand across all socio‐economic and ethnic groups.
Abstract
We observed the galaxy cluster CIZA J2242.8+5301 with the Sardinia Radio Telescope to provide new constraints on its spectral properties at high frequency. We conducted observations in three ...frequency bands centred at 1.4, 6.6 and 19 GHz, resulting in beam resolutions of 14, 2.9 and 1 arcmin, respectively. These single-dish data were also combined with archival interferometric observations at 1.4 and 1.7 GHz. From the combined images, we measured a flux density of S
1.4 GHz = (158.3 ± 9.6) mJy for the central radio halo and S
1.4 GHz = (126 ± 8) and (11.7 ± 0.7) mJy for the northern and the southern relics, respectively. After the spectral modelling of the discrete sources, we measured at 6.6 GHz S
6.6 GHz = (17.1 ± 1.2) and (0.6 ± 0.3) mJy for the northern and southern relics, respectively. Assuming simple diffusive shock acceleration, we interpret measurements of the northern relic with a continuous injection model represented by a broken power law. This yields an injection spectral index αinj = 0.7 ± 0.1 and a Mach number M = 3.3 ± 0.9, consistent with recent X-ray estimates. Unlike other studies of the same object, no significant steepening of the relic radio emission is seen in data up to 8.35 GHz. By fitting the southern relic spectrum with a simple power law (S
ν ∝ ν−α), we obtained a spectral index α ≈ 1.9 corresponding to a Mach number (M ≈ 1.8) in agreement with X-ray estimates. Finally, we evaluated the rotation measure of the northern relic at 6.6 GHz. These results provide new insights on the magnetic structure of the relic, but further observations are needed to clarify the nature of the observed Faraday rotation.
We present an analysis of the 2-10 keV X-ray emission associated with the active galactic nuclei (AGN) in brightest cluster galaxies (BCGs). Our sample consists of 32 BCGs that lie in highly X-ray ...luminous cluster of galaxies (
3\times 10^{44}\,{\rm erg}\,{\rm s}^{-1}\,$>
) in which AGN-jetted outflows are creating and sustaining clear X-ray cavities. Our sample covers the redshift range 0 < z < 0.6 and reveals strong evolution in the nuclear X-ray luminosities, such that the black holes in these systems have become on average at least 10 times fainter over the last 5 Gyr. Mindful of potential selection effects, we propose two possible scenarios to explain our results: (1) either that the AGN in BCGs with X-ray cavities are steadily becoming fainter, or more likely, (2) that the fraction of these BCGs with radiatively efficient nuclei is decreasing with time from roughly 60 per cent at z 0.6 to 30 per cent at z 0.1. Based on this strong evolution, we predict that a significant fraction of BCGs in z 1 clusters may host quasars at their centres, potentially complicating the search for such clusters at high redshift. In analogy with black hole binaries and based on the observed Eddington ratios of our sources, we further propose that the evolving AGN population in BCGs with X-ray cavities may be transiting from a canonical low/hard state, analogous to that of X-ray binaries, to a quiescent state over the last 5 Gyr.
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