49 research outputs found

    CHANG-ES IV: Radio continuum emission of 35 edge-on galaxies observed with the Karl G. Jansky Very Large Array in D-configuration, Data Release 1

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    We present the first part of the observations made for the Continuum Halos in Nearby Galaxies, an EVLA Survey (CHANG-ES) project. The aim of the CHANG-ES project is to study and characterize the nature of radio halos, their prevalence as well as their magnetic fields, and the cosmic rays illuminating these fields. This paper reports observations with the compact D configuration of the Karl G. Jansky Very Large Array (VLA) for the sample of 35 nearby edge-on galaxies of CHANG-ES. With the new wide bandwidth capabilities of the VLA, an unprecedented sensitivity was achieved for all polarization products. The beam resolution is an average of 9.6" and 36" with noise levels reaching approximately 6 and 30 microJy per beam for C- and L-bands, respectively (robust weighting). We present intensity maps in these two frequency bands (C and L), with different weightings, as well as spectral index maps, polarization maps, and new measurements of star formation rates (SFRs). The data products described herein are available to the public in the CHANG-ES data release available at www.queensu.ca/changes. We also present evidence of a trend among galaxies with larger halos having higher SFR surface density, and we show, for the first time, a radio continuum image of the median galaxy, taking advantage of the collective signal-to-noise ratio of 30 of our galaxies. This image shows clearly that a typical spiral galaxy is surrounded by a halo of magnetic fields and cosmic rays.Comment: 70 pages, of which 35 pages present the data of each galax

    Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- I: Introduction to the Survey

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    We introduce a new survey to map the radio continuum halos of a sample of 35 edge-on spiral galaxies at 1.5 GHz and 6 GHz in all polarization products. The survey is exploiting the new wide bandwidth capabilities of the Karl G. Jansky Very Large Array (i.e. the Expanded Very Large Array, or EVLA) in a variety of array configurations (B, C, and D) in order to compile the most comprehensive data set yet obtained for the study of radio halo properties. This is the first survey of radio halos to include all polarization products. In this first paper, we outline the scientific motivation of the survey, the specific science goals, and the expected improvements in noise levels and spatial coverage from the survey. Our goals include investigating the physical conditions and origin of halos, characterizing cosmic ray transport and wind speed, measuring Faraday rotation and mapping the magnetic field, probing the in-disk and extraplanar far-infrared - radio continuum relation, and reconciling non-thermal radio emission with high-energy gamma-ray models. The sample size allows us to search for correlations between radio halos and other properties, including environment, star formation rate, and the presence of AGNs. In a companion paper (Paper II) we outline the data reduction steps and present the first results of the survey for the galaxy, NGC 4631.Comment: 17 pages, 1 figure, accepted to the Astronomical Journal, Version 2 changes: added acknowledgement to NRA

    Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction

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    Angiotensin-converting enzyme 2 (ACE2) is the primary enzyme of the vasoprotective axis of the renin angiotensin system (RAS). We tested the hypothesis that loss of ACE2 would exacerbate diabetic retinopathy by promoting bone marrow dysfunction. ACE2-/y were crossed with Akita mice, a model of type 1 diabetes. When comparing the bone marrow of the ACE2-/y-Akita mice to that of Akita mice, we observed a reduction of both short-term and long-term repopulating hematopoietic stem cells, a shift of hematopoiesis towards myelopoiesis, and an impairment of lineage-c-kit+ hematopoietic stem/progenitor cell (HS/PC) migration and proliferation. Migratory and proliferative dysfunction of these cells was corrected by exposure to angiotensin-1–7 (Ang-1–7), the protective peptide generated by ACE2. Over the duration of diabetes examined, ACE2 deficiency led to progressive reduction in electrical responses assessed by electroretinography and to increases in neural infarcts observed by fundus photography. Compared to Akita mice, ACE2-/y-Akita at 9-months of diabetes showed an increased number of acellular capillaries indicative of more severe diabetic retinopathy. In diabetic and control human subjects, CD34+ cells, a key bone marrow HS/PC population, were assessed for changes in mRNA levels for MAS, the receptor for Ang-1–7. Levels were highest in CD34+ cells from diabetics without retinopathy. Higher serum Ang-1–7 levels predicted protection from development of retinopathy in diabetics. Treatment with Ang-1–7 or alamandine restored the impaired migration function of CD34+ cells from subjects with retinopathy. These data support that activation of the protective RAS within HS/PCs may represent a therapeutic strategy for prevention of diabetic retinopathy

    Inclusive fitness theory and eusociality

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    All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme Multimessenger Universe

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    The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity in the 200 keV to 10 GeV energy range with a wide field of view, good spectral resolution, and polarization sensitivity. Therefore, AMEGO is key in the study of multimessenger astrophysical objects that have unique signatures in the gamma-ray regime, such as neutron star mergers, supernovae, and flaring active galactic nuclei. The order-of-magnitude improvement compared to previous MeV missions also enables discoveries of a wide range of phenomena whose energy output peaks in the relatively unexplored medium-energy gamma-ray band

    Building a transdisciplinary expert consensus on the cognitive drivers of performance under pressure: An international multi-panel Delphi study

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    IntroductionThe ability to perform optimally under pressure is critical across many occupations, including the military, first responders, and competitive sport. Despite recognition that such performance depends on a range of cognitive factors, how common these factors are across performance domains remains unclear. The current study sought to integrate existing knowledge in the performance field in the form of a transdisciplinary expert consensus on the cognitive mechanisms that underlie performance under pressure.MethodsInternational experts were recruited from four performance domains [(i) Defense; (ii) Competitive Sport; (iii) Civilian High-stakes; and (iv) Performance Neuroscience]. Experts rated constructs from the Research Domain Criteria (RDoC) framework (and several expert-suggested constructs) across successive rounds, until all constructs reached consensus for inclusion or were eliminated. Finally, included constructs were ranked for their relative importance.ResultsSixty-eight experts completed the first Delphi round, with 94% of experts retained by the end of the Delphi process. The following 10 constructs reached consensus across all four panels (in order of overall ranking): (1) Attention; (2) Cognitive Control—Performance Monitoring; (3) Arousal and Regulatory Systems—Arousal; (4) Cognitive Control—Goal Selection, Updating, Representation, and Maintenance; (5) Cognitive Control—Response Selection and Inhibition/Suppression; (6) Working memory—Flexible Updating; (7) Working memory—Active Maintenance; (8) Perception and Understanding of Self—Self-knowledge; (9) Working memory—Interference Control, and (10) Expert-suggested—Shifting.DiscussionOur results identify a set of transdisciplinary neuroscience-informed constructs, validated through expert consensus. This expert consensus is critical to standardizing cognitive assessment and informing mechanism-targeted interventions in the broader field of human performance optimization
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