auto-multithresh: A General Purpose Automasking Algorithm Kepley, Amanda A.; Tsutsumi, Takahiro; Brogan, Crystal L. ...
Publications of the Astronomical Society of the Pacific,
02/2020, Letnik:
132, Številka:
1008
Journal Article
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Producing images from interferometer data requires accurate modeling of the sources in the field of view, which is typically done using the clean algorithm. Given the large number of degrees of ...freedom in interferometeric images, one constrains the possible model solutions for clean by masking regions that contain emission. Traditionally this process has largely been done by hand. This approach is not possible with today's large data volumes which require automated imaging pipelines. This paper describes an automated masking algorithm that operates within clean called auto-multithresh. This algorithm was developed and validated using a set of ∼1000 Atacama Large Millimeter/submillimeter Array (ALMA) images chosen to span a range of intrinsic morphology and data characteristics. It takes a top-down approach to producing masks: it uses the residual images to identify significant peaks and then expands the mask to include emission associated with these peaks down to lower signal-to-noise noise. The auto-multithresh algorithm has been implemented in CASA and has been used in production as part of the ALMA Imaging Pipeline starting with Cycle 5. It has been shown to be able to mask a wide range of emission ranging from simple point sources to complex extended emission with minimal tuning of the parameters based on the point-spread function of the data. Although the algorithm was developed for ALMA, it is general enough to have been used successfully with data from other interferometers with appropriate parameter tuning. Integrating the algorithm more deeply within the minor cycle could lead to future performance improvements.
We present EMPIRE, an IRAM 30 m large program that mapped λ = 3-4 mm dense gas tracers at ∼1-2 kpc resolution across the whole star-forming disk of nine nearby massive spiral galaxies. We describe ...the EMPIRE observing and reduction strategies and show new whole-galaxy maps of HCN(1−0), HCO+(1−0), HNC(1−0), and CO(1−0). We explore how the HCN-to-CO and IR-to-HCN ratios, observational proxies for the dense gas fraction and dense gas star formation efficiency, depend on host galaxy and local environment. We find that the fraction of dense gas correlates with stellar surface density, gas surface density, molecular-to-atomic gas ratio, and dynamical equilibrium pressure. In EMPIRE, the star formation rate per unit dense gas is anticorrelated with these same environmental parameters. Thus, although dense gas appears abundant in the central regions of many spiral galaxies, this gas appears relatively inefficient at forming stars. These results qualitatively agree with previous work on nearby galaxies and the Milky Way's Central Molecular Zone. To first order, EMPIRE demonstrates that the conditions in a galaxy disk set the gas density distribution and that the dense gas traced by HCN shows an environment-dependent relation to star formation. However, our results also show significant ( 0.2 dex) galaxy-to-galaxy variations. We suggest that gas structure below the scale of our observations and dynamical effects likely also play an important role.
We use new ALMA observations to investigate the connection between dense gas fraction, star formation rate (SFR), and local environment across the inner region of four local galaxies showing a wide ...range of molecular gas depletion times. We map HCN (1-0), HCO+ (1-0), CS (2-1), 13CO (1-0), and C18O (1-0) across the inner few kiloparsecs of each target. We combine these data with short-spacing information from the IRAM large program EMPIRE, archival CO maps, tracers of stellar structure and recent star formation, and recent HCN surveys by Bigiel et al. and Usero et al. We test the degree to which changes in the dense gas fraction drive changes in the SFR. (tracing the dense gas fraction) correlates strongly with ICO (tracing molecular gas surface density), stellar surface density, and dynamical equilibrium pressure, PDE. Therefore, becomes very low and HCN becomes very faint at large galactocentric radii, where ratios as low as become common. The apparent ability of dense gas to form stars, (where dense is traced by the HCN intensity and the star formation rate is traced by a combination of H and 24 m emission), also depends on environment. decreases in regions of high gas surface density, high stellar surface density, and high PDE. Statistically, these correlations between environment and both and are stronger than that between apparent dense gas fraction ( ) and the apparent molecular gas star formation efficiency . We show that these results are not specific to HCN.
ABSTRACT We present the first results from the EMPIRE survey, an IRAM large program that is mapping tracers of high-density molecular gas across the disks of nine nearby star-forming galaxies. Here, ...we present new maps of the 3 mm transitions of HCN, HCO+, and HNC across the whole disk of our pilot target, M51. As expected, dense gas correlates with tracers of recent star formation, filling the "luminosity gap" between Galactic cores and whole galaxies. In detail, we show that both the fraction of gas that is dense, f dense traced by HCN/CO, and the rate at which dense gas forms stars, SFE dense traced by IR/HCN, depend on environment in the galaxy. The sense of the dependence is that high-surface-density, high molecular gas fraction regions of the galaxy show high dense gas fractions and low dense gas star formation efficiencies. This agrees with recent results for individual pointings by Usero et al. but using unbiased whole-galaxy maps. It also agrees qualitatively with the behavior observed contrasting our own Solar Neighborhood with the central regions of the Milky Way. The sense of the trends can be explained if the dense gas fraction tracks interstellar pressure but star formation occurs only in regions of high density contrast.
Kepley and Streeter reflect on a 2016 report on behavioral health practitioners released by the U.S. Health Resources and Services Administration (HRSA), detailing the projected supply and demand of ...practitioners through 2025 at the national level. The report indicated significant shortages of psychiatrists, psychologists, social workers, school counselors, and marriage and family therapists. HRSA's Behavioral Health Workforce Education and Training (BHWET) program is designed to help those in need of high quality behavioral health care by supporting the training of new behavioral health providers, both professionals and paraprofessionals. The BHWET program supports the development and expansion of the behavioral health workforce serving individuals across their life span, from early childhood to the end of life.
Kinematics of the atomic ISM in M33 on 80 pc scales Koch, Eric W; Rosolowsky, Erik W; Lockman, Felix J ...
Monthly notices of the Royal Astronomical Society,
09/2018, Letnik:
479, Številka:
2
Journal Article
Inflammatory arthritis (e.g. rheumatoid arthritis; RA) is a complex disease driven by the interplay of multiple cellular lineages. Fullerene derivatives have previously been shown to have ...anti-inflammatory capabilities mediated, in part, by their ability to prevent inflammatory mediator release by mast cells (MC). Recognizing that MC can serve as a cellular link between autoantibodies, soluble mediators, and other effector populations in inflammatory arthritis, it was hypothesized that fullerene derivatives might be used to target this inflammatory disease. A panel of fullerene derivatives was tested for their ability to affect the function of human skin-derived MC as well as other lineages implicated in arthritis, synovial fibroblasts and osteoclasts. It is shown that certain fullerene derivatives blocked FcγR- and TNF-α-induced mediator release from MC; TNF-α-induced mediator release from RA synovial fibroblasts; and maturation of human osteoclasts. MC inhibition by fullerene derivatives was mediated through the reduction of mitochondrial membrane potential and FcγR-mediated increases in cellular reactive oxygen species and NF-κB activation. Based on these in vitro data, two fullerene derivatives (ALM and TGA) were selected for in vivo studies using K/BxN serum transfer arthritis in C57BL/6 mice and collagen-induced arthritis (CIA) in DBA/1 mice. Dye-conjugated fullerenes confirmed localization to affected joints in arthritic animals but not in healthy controls. In the K/BxN moldel, fullerenes attenuated arthritis, an effect accompanied by reduced histologic inflammation, cartilage/bone erosion, and serum levels of TNF-α. Fullerenes remained capable of attenuating K/BxN arthritis in mast cell-deficient mice Cre-Master mice, suggesting that lineages beyond the MC represent relevant targets in this system. These studies suggest that fullerene derivatives may hold promise both as an assessment tool and as anti-inflammatory therapy of arthritis.
To cite this article: Mathews JA, Ford J, Norton S, Kang D, Dellinger A, Gibb DR, Ford AQ, Massay H, Kepley CL, Scherle P, Keegan AD, Conrad DH. A potential new target for asthma therapy: A ...Disintegrin and Metalloprotease 10 (ADAM10) involvement in murine experimental asthma. Allergy 2011; 66: 1193–1200.
Background: Elevated levels of CD23, a natural regulator of IgE production, have been shown to decrease the signs of lung inflammation in mice. The aim of this study was to study the involvement of ADAM10, the primary CD23 sheddase, in experimental asthma.
Methods: ADAM10 was blocked either by using mice with a B‐cell‐specific deletion of the protease or pharmacologically by intranasal administration of selective ADAM10 inhibitors. Airway hypersensitivity (AHR) and bronchoaveolar lavage fluid (BALF) eosinophilia and select BALF cytokine/chemokine levels were then determined.
Results: Using an IgE and mast cell–dependent mouse model, B‐cell‐specific ADAM10−/− mice (C57B/6 background) exhibited decreased eosinophilia and AHR when compared with littermate (LM) controls. Treatment of C57B/6 mice with selective inhibitors of ADAM10 resulted in an even further decrease in BALF eosinophilia, as compared with the ADAM10−/− animals. Even in the Th2 selective strain, Balb/c, BALF eosinophilia was reduced from 60% to 23% respectively. In contrast, when an IgE/mast cell–independent model of lung inflammation was used, the B‐cell ADAM10−/− animals and ADAM10 inhibitor treated animals had lung inflammation levels that were similar to the controls.
Conclusions: These results thus show that ADAM10 is important in the progression of IgE‐dependent lung inflammation. The use of the inhibitor further suggested that ADAM10 was important for maintaining Th2 levels in the lung. These results thus suggest that decreasing ADAM10 activity could be beneficial in controlling asthma and possibly other IgE‐dependent diseases.
Abstract We report observations of the ground state transitions of 12 CO, 13 CO, C 18 O, HCN, and HCO + at 88–115 GHz in the inner region of the nearby galaxy IC 342. These data were obtained with ...the 16 pixel spectroscopic focal plane array Argus on the 100 m Robert C. Byrd Green Bank Telescope (GBT) at 6″–9″ resolution. In the nuclear bar region, the intensity distributions of 12 CO(1–0) and 13 CO(1–0) emission trace moderate densities, and differ from the dense gas distributions sampled in C 18 O(1–0), HCN(1–0), and HCO + (1–0). We observe a constant HCN(1–0)-to-HCO + (1–0) ratio of 1.2 ± 0.1 across the whole ∼1 kpc bar. This indicates that the HCN(1–0) and HCO + (1–0) lines have intermediate optical depth, and that the corresponding n H 2 of the gas producing the emission is of order 10 4.5−6 cm −3 . We show that HCO + (1–0) is thermalized and HCN(1–0) is close to thermalization. The very tight correlation between the HCN(1–0) and HCO + (1–0) intensities across the 1 kpc bar suggests that this ratio is more sensitive to the relative abundance of the two species than to the gas density. We confirm an angular offset (∼10″) between the spatial distribution of molecular gas and the star formation sites. Finally, we find a breakdown of the L IR – L HCN correlation at high spatial resolution due to the effect of incomplete sampling of star-forming regions by HCN emission in IC 342. The scatter of the L IR – L HCN relation decreases as the spatial scale increases from 10″ to 30″ (170–510 pc), and is comparable to the scatter of the global relation at a scale of 340 pc.
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