658 research outputs found

    The Line Emission Region in III Zw 2: Kinematics and Variability

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    We have studied the Ly-al, Hbeta, Halpha and Mg II2798 line profiles of the Seyfert 1 galaxy III Zw 2. The shapes of these broad emission lines show evidence of a multicomponent origin and also features which may be identified as the peaks due to a rotating disk. We have proposed a two-component Broad Line Region (BLR) model consisting of an inner Keplerian relativistic disk and an outer structure surrounding the disk. The results of the fitting of the four Broad Emission Lines (BELs) here considered, are highly consistent in both the inner and outer component parameters. Adopting a mass of approx. 2 E8 sollar masses for the central object we found that the outer radius of the disk is approximately equal for the four considered lines (approx 0.01 pc). However, the inner radius of the disk is not the same: 0.0018 pc for Ly-alpha, 0.0027 pc for Mg II, and 0.0038 pc for the Balmer lines. This as well as the relatively broad component present in the blue wings of the narrow [OIII] lines indicate stratification in the emission-line region. Using long-term Hbeta observations (1972-1990, 1998) we found a flux variation of the BEL with respect to the [OIII] lines.Comment: ApJ, accepted, 22 pages, 10 figure

    Impaired dendritic cell proinflammatory cytokine production in psoriatic arthritis

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    Item does not contain fulltextOBJECTIVE: The pathogenesis of psoriatic arthritis (PsA) remains poorly understood. The underlying chronic inflammatory immune response is thought to be triggered by unknown environmental factors potentially arising from a defective immune function. We undertook this study to determine whether an impaired acute inflammatory response by dendritic cells (DCs) might compromise the clearance of bacteria and predispose to chronic inflammation. METHODS: We determined cytokine production by DCs from healthy controls and from patients with rheumatoid arthritis, PsA, and psoriasis in response to Mycobacterium tuberculosis, Mycobacterium avium paratuberculosis, and a range of other bacteria and Toll-like receptor (TLR) ligands. Phenotypic differences involved in cellular responses against (myco)bacteria were determined by quantitative polymerase chain reaction and flow cytometry. RESULTS: The secretion of proinflammatory cytokines by PsA DCs was impaired upon in vitro challenge with mycobacteria and TLR-2 ligands. This impairment was associated with elevated serum levels of C-reactive protein. The expression of TLR-2 and other receptors known to mediate mycobacterial recognition was unaltered. In contrast, the intracellular TLR inhibitors suppressor of cytokine signaling 3 and A20 were more highly expressed in DCs from PsA patients. PsA DCs further demonstrated up-regulated levels of ATG16L1, NADPH oxidase 2, and LL37, which are molecules implicated in the immune response against intracellular bacteria. CONCLUSION: Our findings indicate that DCs from PsA patients have a disordered immune response toward some species of (myco)bacteria. This might predispose to impaired immune responses to, and in turn impaired clearance of, these bacteria, setting the stage for the chronic inflammation of joints, entheses, skin, and the gut

    LCrowdV: Generating Labeled Videos for Simulation-based Crowd Behavior Learning

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    We present a novel procedural framework to generate an arbitrary number of labeled crowd videos (LCrowdV). The resulting crowd video datasets are used to design accurate algorithms or training models for crowded scene understanding. Our overall approach is composed of two components: a procedural simulation framework for generating crowd movements and behaviors, and a procedural rendering framework to generate different videos or images. Each video or image is automatically labeled based on the environment, number of pedestrians, density, behavior, flow, lighting conditions, viewpoint, noise, etc. Furthermore, we can increase the realism by combining synthetically-generated behaviors with real-world background videos. We demonstrate the benefits of LCrowdV over prior lableled crowd datasets by improving the accuracy of pedestrian detection and crowd behavior classification algorithms. LCrowdV would be released on the WWW

    Ensuring HLA-matched platelet support requires an ethnic diverse donor population

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    BACKGROUND: Patients refractory for platelet transfusions benefit from human leukocyte antigen (HLA)-matched platelet transfusions. Differences in ethnic background of patients and donors could hamper the availability of sufficient numbers of HLA-matched donors for all patients. We evaluated our HLA-matched donor program and explored the role of ethnic background of patients related to the number of available donors. METHODS: We performed a cohort study among consecutive patients who received HLA-matched platelet concentrates in the Netherlands between 1994 and 2017. The number of available matched donors was determined per patient. Haplotypes were constructed from genotypes with computer software (PyPop). Based on haplotypes, HaploStats, an algorithm from the National Marrow Donor Program, was used to assess the most likely ethnic background for patients with 5 or fewer and 30 or more donors. RESULTS: HLA typing was available for 19,478 donors in September 2017. A total of 1206 patients received 12,350 HLA-matched transfusions. A median of 83 (interquartile range, 18-266) donors were available per patient. For 95 (10.3%) patients, 5 or fewer donors were available. These patients were more likely to have an African American background, whereas patients with 30 or more donors were more often from Caucasian origin, compared with Caucasian origin for patients with 30 donors. CONCLUSION: Adequate transfusion support could be guaranteed for most but not all refractory patients. More non-Caucasian donors are required to ensure the availability of HLA-matched donors for all patients in the Netherlands

    Measurement of the conductance of a hydrogen molecule

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    Recent years have shown steady progress in research towards molecular electronics [1,2], where molecules have been investigated as switches [3-5], diodes [6], and electronic mixers [7]. In much of the previous work a Scanning Tunnelling Microscope was employed to address an individual molecule. As this arrangement does not provide long-term stability, more recently metal-molecule-metal links have been made using break junction devices [8-10]. However, it has been difficult to establish unambiguously that a single molecule forms the contact [11]. Here, we show that a single H2 molecule can form a stable bridge between Pt electrodes. In contrast to results for other organic molecules, the bridge has a nearly perfect conductance of one quantum unit, carried by a single channel. The H2-bridge provides a simple test system and a fundamental step towards understanding transport properties of single-molecule devices.Comment: 6 pages, 4 figure

    Analysis of 182 cerebral palsy transcriptomes points to dysregulation of trophic signalling pathways and overlap with autism

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    Cerebral palsy (CP) is the most common motor disability of childhood. It is characterised by permanent, non-progressive but not unchanging problems with movement, posture and motor function, with a highly heterogeneous clinical spectrum and frequent neurodevelopmental comorbidities. The aetiology of CP is poorly understood, despite recent reports of a genetic contribution in some cases. Here we demonstrate transcriptional dysregulation of trophic signalling pathways in patient-derived cell lines from an unselected cohort of 182 CP-affected individuals using both differential expression analysis and weighted gene co-expression network analysis (WGCNA). We also show that genes differentially expressed in CP, as well as network modules significantly correlated with CP status, are enriched for genes associated with ASD. Combining transcriptome and whole exome sequencing (WES) data for this CP cohort likely resolves an additional 5% of cases separated to the 14% we have previously reported as resolved by WES. Collectively, these results support a convergent molecular abnormality in CP and ASD.Clare L. van Eyk, Mark A. Corbett, Alison Gardner, Bregje W. van Bon, Jessica L. Broadbent, Kelly Harper, Alastair H. MacLennan and Jozef Gec

    SRAO CO Observation of 11 Supernova Remnants in l = 70 to 190 deg

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    We present the results of 12CO J = 1-0 line observations of eleven Galactic supernova remnants (SNRs) obtained using the Seoul Radio Astronomy Observatory (SRAO) 6-m radio telescope. The observation was made as a part of the SRAO CO survey of SNRs between l = 70 and 190 deg, which is intended to identify SNRs interacting with molecular clouds. The mapping areas for the individual SNRs are determined to cover their full extent in the radio continuum. We used halfbeam grid spacing (60") for 9 SNRs and full-beam grid spacing (120") for the rest. We detected CO emission towards most of the remnants. In six SNRs, molecular clouds showed a good spatial relation with their radio morphology, although no direct evidence for the interaction was detected. Two SNRs are particularly interesting: G85.4+0.7, where there is a filamentary molecular cloud along the radio shell, and 3C434.1, where a large molecular cloud appears to block the western half of the remnant. We briefly summarize the results obtained for individual SNRs.Comment: Accepted for publication in Astrophysics & Space Science. 12 pages, 12 figures, and 3 table
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