897 research outputs found

    Copycatting: Fiscal Policies of States and Their Neighbors

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    This paper formalizes and tests the notion that state governments' expenditures depend on the spending of similarly situated states. We find that even after allowing for fixed state effects, year effects, and common random effects between neighbors, as state government's level of per capita expenditure is positively and significantly affected by the expenditure levels of its neighbors. Ceteris paribus, a one dollar increase in a state's neighbors' expenditures increases its own expenditure by over 70 cents.

    The Open Navigation Surface Project

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    Many hydrographic and oceanographic agencies have moved or are moving towards gridded bathymetric products. However, there is no accepted format to allow these grids to be exchanged while maintaining data and metadata integrity. This paper describes the Open Navigation Surface (ONS) Project, which aims to fill this gap. The ONS Project is an open-source software project designed to provide a freely available, portable source-code library to encapsulate gridded bathymetric surfaces with associated uncertainty values. The data file format is called a Bathymetric Attributed Grid (BAG). The BAG is developed and maintained by the ONS Working Group (ONSWG), and the source code is available via the ONS websit

    Ariel - Volume 2 Number 6

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    Editors Richard J. Bonanno Robin A. Edwards Associate Editors Steven Ager Stephen Flynn Shep Dickman Tom Williams Lay-out Editor Eugenia Miller Contributing Editors Michael J. Blecker W. Cherry Light James J. Nocon Lynne Porter Editors Emeritus Delvyn C. Case, Jr. Paul M. Fernhof

    Bioluminescence of Colonial Radiolaria in the Western Sargasso Sea

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    Colonial radiolaria (Protozoa: Spumellarida) were a conspicuous feature in surface waters of the Sargasso Sea during the April (1985) Biowatt cruise. The abundance of colonies at the sea surface at one station was estimated to be 23 colonies · m−2. Bioluminescence by colonial radiolaria, representing at least six taxa, was readily evoked by mechanical stimuli and measured by fast spectroscopy and photon-counting techniques. Light emission was deep blue in color (peak emissions between 443 and 456 nm) and spectral distributions were broad (average half bandwidth of 80 nm). Single flashes were 1–2 s in duration at ≈23 °C, with species-dependent kinetics which were not attributed to differences in colony morphology, since colonies similar in appearance could belong to different species (even families) and display different flash kinetics. Although the presence of dinoflagellate symbionts was confirmed by the presence of dinoflagellate marker pigments in the colonies, luminescence in the radiolaria examined most likely did not originate from symbiotic dinoflagellates because of (1) differences in the emission spectra, (2) unresponsiveness to low pH stimulation, (3) differences in flash kinetics and photon emission of light emission, and (4) lack of light inhibition. The quantal content of single flashes averaged 1 × 109 photons flash−1, and colonies were capable of prolonged light emission. The mean value of bioluminescence potential based on measurements of total mechanically stimulated bioluminescence was 1.2 × 1011 photons · colony−1. It is estimated that colonial radiolaria are capable of producing ≈2.8 × 1012 photons · m−2 of sea surface. However, this represented only 0.5% of in situ measured bioluminescence potential

    CASTER - a concept for a Black Hole Finder Probe based on the use of new scintillator technologies

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    The primary scientific mission of the Black Hole Finder Probe (BHFP), part of the NASA Beyond Einstein program, is to survey the local Universe for black holes over a wide range of mass and accretion rate. One approach to such a survey is a hard X-ray coded-aperture imaging mission operating in the 10--600 keV energy band, a spectral range that is considered to be especially useful in the detection of black hole sources. The development of new inorganic scintillator materials provides improved performance (for example, with regards to energy resolution and timing) that is well suited to the BHFP science requirements. Detection planes formed with these materials coupled with a new generation of readout devices represent a major advancement in the performance capabilities of scintillator-based gamma cameras. Here, we discuss the Coded Aperture Survey Telescope for Energetic Radiation (CASTER), a concept that represents a BHFP based on the use of the latest scintillator technology.Comment: 12 pages; conference paper presented at the SPIE conference "UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XIV." To be published in SPIE Conference Proceedings, vol. 589

    Three years of Fermi GBM Earth Occultation Monitoring: Observations of Hard X-ray/Soft Gamma-Ray Sources

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    The Gamma ray Burst Monitor (GBM) on board Fermi has been providing continuous data to the astronomical community since 2008 August 12. In this paper we present the results of the analysis of the first three years of these continuous data using the Earth occultation technique to monitor a catalog of 209 sources. From this catalog, we detect 99 sources, including 40 low-mass X-ray binary/neutron star systems, 31 high-mass X-ray binary neutron star systems, 12 black hole binaries, 12 active galaxies, 2 other sources, plus the Crab Nebula, and the Sun. Nine of these sources are detected in the 100-300 keV band, including seven black-hole binaries, the active galaxy Cen A, and the Crab. The Crab and Cyg X-1 are also detected in the 300-500 keV band. GBM provides complementary data to other sky-monitors below 100 keV and is the only all-sky monitor above 100 keV. Up-to-date light curves for all of the catalog sources can be found at http://heastro.phys.lsu.edu/gbm/.Comment: 24 pages, 12 figures, accepted for publication in ApJ

    CASTER: a scintillator-based black hole finder probe

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    The primary scientific mission of the Black Hole Finder Probe (BHFP), part of the NASA Beyond Einstein program, is to survey the local Universe for black holes over a wide range of mass and accretion rate. One approach to such a survey is a hard X-ray coded-aperture imaging mission operating in the 10-600 keV energy band, a spectral range that is considered to be especially useful in the detection of black hole sources. The development of new inorganic scintillator materials provides improved performance (for example, with regards to energy resolution and timing) that is well suited to the BHFP science requirements. Detection planes formed with these materials coupled with a new generation of readout devices represent a major advancement in the performance capabilities of scintillator-based gamma cameras. Here, we discuss the Coded Aperture Survey Telescope for Energetic Radiation (CASTER), a concept that represents a BHFP based on the use of the latest scintillator technology

    The Open Navigation Surface Project

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    Many hydrographic and oceanographic agencies have moved or are moving towards gridded bathymetric products. However, there is no accepted format to allow these grids to be exchanged while maintaining data and metadata integrity. This paper describes the Open Navigation Surface (ONS) Project, which aims to fill this gap. The ONS Project is an open-source software project designed to provide a freely available, portable source-code library to encapsulate gridded bathymetric surfaces with associated uncertainty values. The data file format is called a Bathymetric Attributed Grid (BAG). The BAG is developed and maintained by the ONS Working Group (ONSWG), and the source code is available via the ONS website.Muchas agencies hidrogrâficas y oceanogrâficas se han orientado o se estân orientando hacia los productos batimétricos cuadriculados. Sin embargo, no existe un formato aceptado para que estas cuadricuias sean intercambiadas manteniendo la integridad de los datos y los meta datos. Este articulo describe el Proyecto « Superficie de Navegaciôn Abierta » (ONS) cuyo objeto es cubrir este vacio. El proyecto ONS es un proyecto de software de fuente abierta disehado para proveer una biblioteca portâtil de côdigo fuente de libre disponibilidad para encapsular superficies batimétricas cuadriculadas con sus valores de incertidumbre asociados. El formato de archivo de datos es llamado Cuadricula Batimétrica Tributada (BAG). El BAG es desarrollado y mantenido por el Grupo de Trabajo ONS (ONSWG), y el côdigo fuente es disponible a través de sitio web de ONS.De nombreuses agences hydrographiques et océanographiques se sont orientées ou s ’orientent actuellement vers les produits bathymétriques quadrillés. Toutefois, il n'existe pas de format accepté qui permette à ces quadrillages d'être échangés tout en conservant l’intégrité des données et des métadonnées. Le présent article décrit le projet ONS (Open Navigation Surface) qui vise à combler cette lacune. Le projet ONS est un projet de logiciel libre conçu pour fournir une bibliothèque portable de code source à libre disponibilité devant encapsuler des surfaces bathymétriques maillées avec des valeurs d'incertitude associées. Le format du fichier des données est appelé Carroyage bathymétrique attribué (BAG). Le BAG est développé est tenu à jour par le groupe de travail ONS et le code source est disponible sur le site Web ONS

    An integrated approach to identify new anti-filarial leads to treat river blindness, a neglected tropical disease

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    Filarial worms cause multiple debilitating diseases in millions of people worldwide, including river blindness. Currently available drugs reduce transmission by killing larvae (microfilariae), but there are no effective cures targeting the adult parasites (macrofilaricides) which survive and reproduce in the host for very long periods. To identify effective macrofilaricides, we carried out phenotypic screening of a library of 2121 approved drugs for clinical use against adul
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