Thermal imaging of dust hiding the black hole in NGC 1068.

In the widely accepted 'unified model'1 solution of the classification puzzle of active galactic nuclei, the orientation of a dusty accretion torus around the central black hole dominates their appearance. In 'type-1' systems, the bright nucleus is visible at the centre of a face-on torus. In 'type-2' systems the thick, nearly edge-on torus hides the central engine. Later studies suggested evolutionary effects2 and added dusty clumps and polar winds3 but left the basic picture intact. However, recent high-resolution images4 of the archetypal type-2 galaxy NGC 10685,6, suggested a more radical revision. The images displayed a ring-like emission feature that was proposed to be hot dust surrounding the black hole at the radius where the radiation from the central engine evaporates the dust. That ring is too thin and too far tilted from edge-on to hide the central engine, and ad hoc foreground extinction is needed to explain the type-2 classification. These images quickly generated reinterpretations of the dichotomy between types 1 and 27,8. Here we present new multi-band mid-infrared images of NGC 1068 that detail the dust temperature distribution and reaffirm the original model. Combined with radio data (J.F.G. and C.M.V.I., manuscript in preparation), our maps locate the central engine that is below the previously reported ring and obscured by a thick, nearly edge-on disk, as predicted by the unified model. We also identify emission from polar flows and absorbing dust that is mineralogically distinct from that towards the Milky Way centre.

A multicenter evaluation of a point of care CRP Test.

BACKGROUND: Point-of-care (POC) C-reactive protein (CRP) testing in the primary healthcare setting is a cost-effective approach for reducing antibiotic prescriptions, but has yet to be widely adopted. METHODS: Analytical performance of the cobas CRP Test on the cobas b 101 system was evaluated at three POC sites and one reference laboratory. Within-run (repeatability), within-laboratory (intermediate precision), and between-laboratory precision (reproducibility) were assessed. Method comparison (reference test: CRPNX reagent [cobas c 501 module]) and matrix/lot-to-lot comparison experiments were conducted using prospectively collected blood samples from 217 adults (apparently healthy or with clinically relevant conditions). Usability and reliability were assessed by questionnaire and error reporting. RESULTS: Coefficients of variation (CV) for repeatability and intermediate precision ranged from 1.7%-4.0% and 1.9%-4.5%, respectively, for human serum pools containing CRP 4.7-350.7 mg/L; repeatability in clinical samples ranged from 1.6%-5.9% (3.3-360.3 mg/L). CVs for reproducibility ranged from 2.5%-4.0% (4.7-344.3 mg/L). CRP concentrations were comparable for capillary whole blood, serum, Li-heparin whole blood/plasma, K2 and K3 EDTA whole blood/plasma (Pearson's r ≥ 0.996), and among three CRP Test lots (r ≥ 0.993). Clinically relevant CRP concentrations measured with the CRP Test showed good agreement with those measured by CRPNX reagent (serum, weighted Deming regression y = 0.97× + 0.11; Pearson's r ≥ 0.996). The overall mean usability score was 4.18/5 and the error rate across 9378 tests was 1.00%. CONCLUSIONS: The cobas CRP Test on the cobas b 101 system demonstrates robust analytic performance when used by healthcare professionals in the POC setting.