3,028 research outputs found

    Testing Diagnostics of Nuclear Activity and Star Formation in Galaxies at z>1

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    We present some of the first science data with the new Keck/MOSFIRE instrument to test the effectiveness of different AGN/SF diagnostics at z~1.5. MOSFIRE spectra were obtained in three H-band multi-slit masks in the GOODS-S field, resulting in two hour exposures of 36 emission-line galaxies. We compare X-ray data with the traditional emission-line ratio diagnostics and the alternative mass-excitation and color-excitation diagrams, combining new MOSFIRE infrared data with previous HST/WFC3 infrared spectra (from the 3D-HST survey) and multiwavelength photometry. We demonstrate that a high [OIII]/Hb ratio is insufficient as an AGN indicator at z>1. For the four X-ray detected galaxies, the classic diagnostics ([OIII]/Hb vs. [NII]/Ha and [SII]/Ha) remain consistent with X-ray AGN/SF classification. The X-ray data also suggest that "composite" galaxies (with intermediate AGN/SF classification) host bona-fide AGNs. Nearly 2/3 of the z~1.5 emission-line galaxies have nuclear activity detected by either X-rays or the classic diagnostics. Compared to the X-ray and line ratio classifications, the mass-excitation method remains effective at z>1, but we show that the color-excitation method requires a new calibration to successfully identify AGNs at these redshifts.Comment: 7 pages, 4 figures. Accepted to ApJ Letter

    Dynamic changes in methadone utilisation for opioid use disorder treatment: a retrospective observational study during the COVID-19 pandemic

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    Objectives: Opioid use disorder (OUD) is a major public health concern in the USA, resulting in high rates of overdose and other negative outcomes. Methadone, an OUD treatment, has been shown to be effective in reducing the risk of overdose and improving overall health and quality of life. This study analysed the distribution of methadone for the treatment of OUD across the USA over the past decade and through the COVID-19 pandemic. Design: Retrospective observational study using secondary data analysis of the Drug Enforcement Administration and Medicaid Databases. Setting: USA. Participants: Patients who were dispensed methadone at US opioid treatment programmes (OTPs). Primary and secondary outcome measures: The primary outcomes were the overall pattern in methadone distribution and the number of OTPs in the USA per year. The secondary outcome was Medicaid prescriptions for methadone. Results: Methadone distribution for OUD has expanded significantly over the past decade, with an average state increase of +96.96% from 2010 to 2020. There was a significant increase in overall distribution of methadone to OTP from 2010 to 2020 (+61.00%, p\u3c0.001) and from 2015 to 2020 (+26.22%, p\u3c0.001). However, the distribution to OTPs did not significantly change from 2019 to 2021 (-5.15%, p=0.491). There was considerable state-level variation in methadone prescribing to Medicaid patients with four states having no prescriptions. Conclusions: There have been dynamic changes in methadone distribution for OUD. Furthermore, pronounced variation in methadone distribution among states was observed, with some states having no OTPs or Medicaid coverage. New policies are urgently needed to increase access to methadone treatment, address the opioid epidemic in the USA and reduce overdose deaths

    Pyxis: A ground-based demonstrator for formation-flying optical interferometry

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    In the past few years, there has been a resurgence in studies towards space-based optical/infrared interferometry, particularly with the vision to use the technique to discover and characterise temperate Earth-like exoplanets around solar analogues. One of the key technological leaps needed to make such a mission feasible is demonstrating that formation flying precision at the level needed for interferometry is possible. Here, we present Pyxis\textit{Pyxis}, a ground-based demonstrator for a future small satellite mission with the aim to demonstrate the precision metrology needed for space-based interferometry. We describe the science potential of such a ground-based instrument, and detail the various subsystems: three six-axis robots, a multi-stage metrology system, an integrated optics beam combiner and the control systems required for the necessary precision and stability. We end by looking towards the next stage of Pyxis\textit{Pyxis}: a collection of small satellites in Earth orbit.Comment: 27 Pages, 14 Figures, submitted to JATI

    SUMOylation of DISC1: a potential role in neural progenitor proliferation in the developing cortex

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    DISC1 is a multifunctional, intracellular scaffold protein. At the cellular level, DISC1 plays a pivotal role in neural progenitor proliferation, migration, and synaptic maturation. Perturbation of the biological pathways involving DISC1 is known to lead to behavioral changes in rodents, which supports a clinical report of a Scottish pedigree in which the majority of family members with disruption of the DISC1 gene manifest depression, schizophrenia, and related mental conditions. The discrepancy between modest evidence in genetics and strong biological support for the role of DISC1 in mental conditions suggests a working hypothesis that regulation of DISC1 at the protein level, such as posttranslational modification, may play a role in the pathology of mental conditions. In this study, we report on the SUMOylation of DISC1. This posttranslational modification occurs on lysine residues where the small ubiquitin-related modifier (SUMO) and its homologs are conjugated to a large number of cellular proteins, which in turn regulates their subcellular distribution and protein stability. By using in silico, biochemical, and cell-biological approaches, we now demonstrate that human DISC1 is SUMOylated at one specific lysine 643 (K643). We also show that this residue is crucial for proper neural progenitor proliferation in the developing cortex

    A 25-Year Analysis of the American College of Gastroenterology Research Grant Program: Factors Associated With Publication and Advancement in Academics

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    The American College of Gastroenterology (ACG) has awarded research grants for 25 years. We assessed the characteristics of grant recipients, their current academic status, and the likelihood of publication resulting from the grant

    RCandy: an R package for visualizing homologous recombinations in bacterial genomes

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    SUMMARY: Homologous recombination is an important evolutionary process in bacteria and other prokaryotes, which increases genomic sequence diversity and can facilitate adaptation. Several methods and tools have been developed to detect genomic regions recently affected by recombination. Exploration and visualization of such recombination events can reveal valuable biological insights, but it remains challenging. Here, we present RCandy, a platform-independent R package for rapid, simple and flexible visualization of recombination events in bacterial genomes. AVAILABILITY AND IMPLEMENTATION: RCandy is an R package freely available for use under the MIT license. It is platform-independent and has been tested on Windows, Linux and MacOSX. The source code comes together with a detailed vignette available on GitHub at https://github.com/ChrispinChaguza/RCandy. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online

    An Expanded Stratigraphic Record of the Devonian-Carboniferous Boundary Hangenberg Biogeochemical Event from Southeast Iowa (U.S.A.)

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    The Devonian-Carboniferous boundary in the type area of the Mississippian subsystem (tri-state area of Iowa, Illinois, and Missouri) has been historically difficult to identify. Many of the localities contain similar lithologies and stratigraphic successions, but chronostratigraphic correlation of seemingly identical lithologies can vary greatly in this interval and frequently this has led to miscorrelation. In particular, the similar lithofacies that comprise the McCraney Formation and Louisiana Formation have been a source of stratigraphic confusion for over 100 years. To investigate the Devonian-Carboniferous boundary interval in the Mississippian type area we selected two localities in southeastern Iowa, the H-28 core from Lee County outside of Keokuk, Iowa, and the Starr’s Cave outcrop located near Burlington, Iowa. In total, 62 conodont samples and 299 carbonate carbon isotope samples were processed for this study and recorded the Hangenberg positive carbon isotope excursion and 25 conodont species, including a diverse assemblage of siphonodellids. The Hangenberg excursion is recorded in over 20 m of strata in southeast Iowa, making this one of the thickest stratigraphic records of this important biogeochemical event yet recovered, and helps to define more clearly the position of the base of the Carboniferous System in the region. These results show that the “McCraney” Fm. at the Starr’s Cave outcrop and the coeval carbonate unit in the H-28 core are both the Louisiana Formation, and calls into question the use of the name McCraney throughout the State of Iowa

    Report on the “Trait-based approaches to ocean life” scoping workshop, October 5-8, 2015

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    "Trait-based Approaches to Ocean Life” Scoping Workshop, October 5-8, 2015, Waterville Valley, NH, USAFrom the introduction: Marine ecosystems are rich and biodiverse, often populated by thousands of competing and interacting species with a vast range of behaviors, forms, and life histories. This great ecological complexity presents a formidable challenge to understanding how marine ecosystems are structured and controlled, but also how they respond to natural and anthropogenic changes. The trait-based approach to ocean life is emerging as a novel framework for understanding the complexity, structure, and dynamics of marine ecosystems, but also their broader significance. Rather than considering species individually, organisms are characterized by essential traits that capture key aspects of diversity. Trait distributions in the ocean emerge through evolution and natural selection, and are mediated by the environment, biological interactions, anthropogenic drivers, and organism behavior. Because trait variations within and across communities lead to variation in the rates of crucial ecosystem functions such as carbon export, this mechanistic approach sheds light on how variability in the environment, including climate change, impacts marine ecosystems, biogeochemical cycles, and associated feedbacks to climate and society.Funding from the National Science Foundation and National Aeronautics and Space Administration), the Simons Foundation, and the Gordon and Betty Moore Foundation
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