4,191 research outputs found

    On the global warping of a thin self-gravitating near Keplerian gaseous disk with application to the disk in NGC 4258

    Full text link
    On the global warping of a thin self-gravitating near Keplerian gaseous disk with application to the disk in NGC 4258Comment: 36 pages (including 4 figures), Latex, to appear in Ap

    Treehoppers (Hemiptera: Aetalionidae and Membracidae) from Madre de Dios region, Peru

    Get PDF
    A list of treehoppers (Aetalionidae and Membracidae) is presented from Madre de Dios region at the southeastern Amazon basin in Peru. The treehopper specimens were collected as by-catch in a survey of the beetles in the Villa Carmen Biological Station and Los Amigos Biological Station. The list comprises 44 species, 31 genera, 16 tribes and 9 subfamilies. Ten genera are new records to Peru. The images of representative specimens of each identified species and genera are provided to facilitate the identification of the local treehopper fauna. Resumen: Se presenta una lista de los membrácidos (Aetalionidae y Membracidae) de la región Madre de Dios, en el sureste de la cuenca Amazónica, en Perú. La lista está basada en especímenes recolectados como captura fortuita en un inventario de escarabajos en las estaciones biológicas Villa Carmen y Los Amigos. La lista incluye 44 especies, 31 géneros, 16 tribus y 9 subfamilias. Diez géneros son nuevos registros para Perú. Se presentan las imágenes de especímenes representativos de cada especie y género para facilitar la identifición de la fauna local de los membrácidos

    Barriers Encountered by Syringe Exchange Clients in Vermont

    Get PDF
    Introduction and Aims. Vermont CARES is a nonprofit HIV prevention and advocacy organization which provides a needle exchange program for intravenous drug users. Services are focused on education, prevention, testing, and harm reduction. The Syringe Support Program (SSP) offers clients clean syringes to reduce intravenous transmission of disease. Although SSP are proven avenues for harm reduction, barriers prevent users from utilizing services. Clients are limited by social, economic, and personal obstacles de- scribed in similar populations across the country. This project seeks to identify the barriers Vermont CARES clients face in accessing the SSP, determine needs, and evaluate interest in additional services. Methods. Our team and Vermont CARES staff held a focus group with St. Johnsbury clients to discuss services and barriers. A 39 question paper survey was distributed to three Vermont CARES sites during October, 2017 by Vermont CARES. Participation was voluntary and uncompensated. Sixty-three clients completed the survey. Results and Discussion. Of the 63 respondents, 61.9% stated that lack of ade- quate income contributed most to their inability to meet basic needs. These same clients faced the most barriers to access with economic hardship precipitated by sub- stance abuse, disability, and family commitments. In assessing additional services, clients sought food pantries, hygiene kits, and dental clinics. 56.4% of respondents would use safe injection facilities if provided. Those without income to meet basic needs expressed most interest in safe injection facilities (p=0.022). With barriers recognized, our future aim is to track efficacy of new services in impacting care and quality of life.https://scholarworks.uvm.edu/comphp_gallery/1268/thumbnail.jp

    Efficacy of REACH Forgiveness across Cultures

    Get PDF
    Across cultures, most people agree that forgiveness is a virtue. However, culture may influence how willing one should be to forgive and how one might express forgiveness. At a university in the United States, we recruited both foreign-extraction students and domestic students (N = 102) to participate in a six-hour REACH Forgiveness intervention. We investigated the efficacy of the intervention overall as well as whether foreign-extraction and domestic students responded differently to treatment. Forgiveness was assessed using two measures—decisional forgiveness and emotional forgiveness. The six-hour REACH Forgiveness intervention improved participants’ ratings of emotional forgiveness, but not decisional forgiveness, regardless of their culture. Thus, the REACH Forgiveness intervention appears equally efficacious for participants from different cultural backgrounds when conducted in the United States with college students

    Critical Protoplanetary Core Masses in Protoplanetary Disks and the Formation of Short-Period Giant Planets

    Get PDF
    We study a solid protoplanetary core of 1-10 earth masses migrating through a disk. We suppose the core luminosity is generated as a result of planetesimal accretion and calculate the structure of the gaseous envelope assuming equilibrium. This is a good approximation when the core mass is less than the critical value, M_{crit}, above which rapid gas accretion begins. We model the structure of the protoplanetary nebula as an accretion disk with constant \alpha. We present analytic fits for the steady state relation between disk surface density and mass accretion rate as a function of radius r. We calculate M_{crit} as a function of r, gas accretion rate through the disk, and planetesimal accretion rate onto the core \dot{M}. For a fixed \dot{M}, M_{crit} increases inwards, and it decreases with \dot{M}. We find that \dot{M} onto cores migrating inwards in a time 10^3-10^5 yr at 1 AU is sufficient to prevent the attainment of M_{crit} during the migration process. Only at small radii where planetesimals no longer exist can M_{crit} be attained. At small radii, the runaway gas accretion phase may become longer than the disk lifetime if the core mass is too small. However, massive cores can be built-up through the merger of additional incoming cores on a timescale shorter than for in situ formation. Therefore, feeding zone depletion in the neighborhood of a fixed orbit may be avoided. Accordingly, we suggest that giant planets may begin to form early in the life of the protostellar disk at small radii, on a timescale that may be significantly shorter than for in situ formation. (abridged)Comment: 24 pages (including 9 figures), LaTeX, uses emulateapj.sty, to be published in ApJ, also available at http://www.ucolick.org/~ct/home.htm

    Electronic control of redox reactions inside Escherichia coli using a genetic module.

    Get PDF
    Microorganisms regulate the redox state of different biomolecules to precisely control biological processes. These processes can be modulated by electrochemically coupling intracellular biomolecules to an external electrode, but current approaches afford only limited control and specificity. Here we describe specific electrochemical control of the reduction of intracellular biomolecules in Escherichia coli through introduction of a heterologous electron transfer pathway. E. coli expressing cymAmtrCAB from Shewanella oneidensis MR-1 consumed electrons directly from a cathode when fumarate or nitrate, both intracellular electron acceptors, were present. The fumarate-triggered current consumption occurred only when fumarate reductase was present, indicating all the electrons passed through this enzyme. Moreover, CymAMtrCAB-expressing E. coli used current to stoichiometrically reduce nitrate. Thus, our work introduces a modular genetic tool to reduce a specific intracellular redox molecule with an electrode, opening the possibility of electronically controlling biological processes such as biosynthesis and growth in any microorganism
    corecore