4,316 research outputs found

    The HI Chronicles of LITTLE THINGS BCDs II: The Origin of IC 10's HI Structure

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    In this paper we analyze Very Large Array (VLA) telescope and Green Bank Telescope (GBT) atomic hydrogen (HI) data for the LITTLE THINGS(1) blue compact dwarf galaxy IC 10. The VLA data allow us to study the detailed HI kinematics and morphology of IC 10 at high resolution while the GBT data allow us to search the surrounding area at high sensitivity for tenuous HI. IC 10's HI appears highly disturbed in both the VLA and GBT HI maps with a kinematically distinct northern HI extension, a kinematically distinct southern plume, and several spurs in the VLA data that do not follow the general kinematics of the main disk. We discuss three possible origins of its HI structure and kinematics in detail: a current interaction with a nearby companion, an advanced merger, and accretion of intergalactic medium. We find that IC 10 is most likely an advanced merger or a galaxy undergoing accretion. 1:Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey; https://science.nrao.edu/science/surveys/littlethingsComment: 36 pages, 17 figures, accepted for publication in The Astronomical Journa

    Patterns of Tobacco Product Use in the US Population using the Population Assessment of Tobacco and Health Study

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    The U.S. Centers for Disease Control and Prevention (CDC) reported that, in the United States, tobacco product use is the prominent cause of avoidable disease, disability, and death in the year 2017.While tobacco use has severe public health consequences, it has been difficult to fully understand the behaviors surrounding this preventable public health challenge. Introduced in 2011, the Population Assessment of Tobacco and Health (PATH) Studyā€™s purpose is to influence the Food and Drug Administration\u27s regulatory activities via the Family Smoking Prevention and Tobacco Control Act (TCA). The PATH study is a longitudinal cohort study examining tobacco use and behavior in adolescents and adults. The purpose of this dissertation is to examine use and behavior for tobacco products over time and examine both initiation and switching of products. In our analysis, we found that demographically, those who initiated or consistently used smokeless products over time were white and male while those who used traditional combustible products varied more in terms of racial makeup. With smokeless and traditional combustible products, most participants chose to use tobacco products with moderate nicotine levels, regardless of previous exposure in a prior study wave. There was very little evidence of product switching that resulted in increased tar/nicotine content differences among the population we studied. Younger participants were using electronic cigarettes in greater proportions than adults and as opposed to traditional combustible products. We also found that the rate of nicotine metabolism was not related to frequency of e-cigarette use or type of product. These results provide insight into ways in which prevention strategies can be targeted to groups that are more likely to initiate and stay using tobacco products

    Using Biologic Markers in Blood to Assess Exposure to Multiple Environmental Chemicals for Inner-City Children 3ā€“6 Years of Age

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    We assessed concurrent exposure to a mixture of > 50 environmental chemicals by measuring the chemicals or their metabolites in the blood of 43 ethnically diverse children (3ā€“6 years of age) from a socioeconomically disadvantaged neighborhood in Minneapolis. Over a 2-year period, additional samples were collected every 6ā€“12 months from as many children as possible. We analyzed blood samples for 11 volatile organic compounds (VOCs), 2 heavy metals (lead and mercury, 11 organochlorine (OC) pesticides or related compounds, and 30 polychlorinated biphenyl (PCB) congeners. The evidence suggests that numerous VOCs originated from common sources, as did many PCBs. Longitudinal measurements indicate that between-child variance was greater than within-child variance for two VOCs (benzene, toluene), for both heavy metals (Pb, Hg), for all detectable OC pesticides, and for 15 of the measured PCB congeners (74, 99, 101, 118, 138ā€“158, 146, 153, 156, 170, 178, 180, 187, 189, 194, 195). Despite the relatively small sample size, highest measured blood levels of 1,4-dichlorobenzene, styrene, m-/p-xylene, Pb, Hg, heptachlor epoxide, oxychlordane, dichlorodiphenyldichloroethene (p,pā€²-DDE), trans-nonachlor, and PCB congeners 74, 99, 105, 118, 138, 146, 153, 156, 170, and 180 were comparable with or higher than 95th percentile measurements of older children and adults from national surveys. Results demonstrate that cumulative exposures to multiple environmental carcinogens and neurotoxins can be comparatively high for children from a poor inner-city neighborhood

    Interventions for Infection and Inflammation-Induced Preterm Birth: a Preclinical Systematic Review

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    Spontaneous preterm births (<ā€‰37Ā weeks gestation) are frequently associated with infection. Current treatment options are limited but new therapeutic interventions are being developed in animal models. In this PROSPERO-registered preclinical systematic review, we aimed to summarise promising interventions for infection/inflammation-induced preterm birth. Following PRISMA guidance, we searched PubMed, EMBASE, and Web of Science using the themes: "animal models", "preterm birth", "inflammation", and "therapeutics". We included original quantitative, peer-reviewed, and controlled studies applying prenatal interventions to prevent infection/inflammation-induced preterm birth in animal models. We employed two risk of bias tools. Of 4020 identified studies, 23 studies (24 interventions) met our inclusion criteria. All studies used mouse models. Preterm birth was most commonly induced by lipopolysaccharide (18 studies) or Escherichia coli (4 studies). Models varied according to infectious agent serotype, dose, and route of delivery. Gestational length was significantly prolonged in 20/24 interventions (83%) and markers of maternal inflammation were reduced in 20/23 interventions (87%). Interventions targeting interleukin-1, interleukin-6, and toll-like receptors show particular therapeutic potential. However, due to the heterogeneity of the methodology of the included studies, meta-analysis was impossible. All studies were assigned an unclear risk of bias using the SYRCLE risk of bias tool. Interventions targeting inflammation demonstrate therapeutic potential for the prevention of preterm birth. However, better standardisation of preterm birth models, including the dose, serotype, timing of administration and pathogenicity of infectious agent, and outcome reporting is urgently required to improve the reproducibility of preclinical studies, allow meaningful comparison of intervention efficacy, and aid clinical translation

    Effects of Art Intervention on Pediatric Anxiety and Pain in the Medical Setting

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    Introduction: Hospitalization and illness can be a painful and stressful time for a child. There may be anxiety over procedures and inpatient stays disrupt normal routines. Previous research found that for pre-school aged children, having parents around, having the help of the hospital staff, and playing an active role in alleviating their fears were the most helpful in reducing anxiety. Another study found that visual creative expressions can be meaningful experiences for young adult cancer survivors. Additionally, there is abundant literature on formal art therapy and its favorable effects on children in the hospital, however, there are fewer studies investigating less standardized ā€œart interventionā€ in the same population. The purpose of our project was to assess whether art intervention reduces anxiety and pain in inpatient and outpatient pediatric patients.https://scholarworks.uvm.edu/comphp_gallery/1224/thumbnail.jp

    A Resolved Ring of Debris Dust around the Solar Analog HD 107146

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    We present resolved images of the dust continuum emission from the debris disk around the young (80-200 Myr) solar-type star HD 107146 with CARMA at Ī» = 1.3 mm and the CSO at Ī» = 350 Ī¼. Both images show that the dust emission extends over an approximately 10" diameter region. The high-resolution (3") CARMA image further reveals that the dust is distributed in a partial ring with significant decrease in a flux inward of 97 AU. Two prominent emission peaks appear within the ring separated by ~140Ā° in the position angle. The morphology of the dust emission is suggestive of dust captured into a mean motion resonance, which would imply the presence of a planet at an orbital radius of ~45-75 AU

    Dynamically Driven Evolution of the Interstellar Medium in M51

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    Massive star formation occurs in giant molecular clouds (GMCs); an understanding of the evolution of GMCs is a prerequisite to develop theories of star formation and galaxy evolution. We report the highest-fidelity observations of the grand-design spiral galaxy M51 in carbon monoxide (CO) emission, revealing the evolution of GMCs vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (giant molecular associations (GMAs)) are first assembled and then broken up as the gas flow through the spiral arms. The GMAs and their H_2 molecules are not fully dissociated into atomic gas as predicted in stellar feedback scenarios, but are fragmented into smaller GMCs upon leaving the spiral arms. The remnants of GMAs are detected as the chains of GMCs that emerge from the spiral arms into interarm regions. The kinematic shear within the spiral arms is sufficient to unbind the GMAs against self-gravity. We conclude that the evolution of GMCs is driven by large-scale galactic dynamicsā€”their coagulation into GMAs is due to spiral arm streaming motions upon entering the arms, followed by fragmentation due to shear as they leave the arms on the downstream side. In M51, the majority of the gas remains molecular from arm entry through the interarm region and into the next spiral arm passage
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