2,596 research outputs found

    Industry Specialization and Auditor Quality in US Markets

    Get PDF
    This study investigates the relation between audit quality, auditor industry market share, and audit fees. Prior literature has asserted that audit providers with high market shares can be designated as industry specialists and that the fee premiums that sometimes attach to these auditors is evidence of a quality differentiated audit product. Using data from the U.S. audit market for the fiscal year 2003 we extend this literature by investigating the relationships among audit fee premiums, auditor market shares, and two dimensions of audit quality: external reporting and economies of scope in providing joint audit and non-audit services. We find little evidence to support the conjecture that high market share auditors provide increased audit quality. Further, we find that most auditors with high market shares do not seem to charge a fee premium. To the contrary, we report that the high market share fee premiums found in pooled (across industry) tests are primarily attributable to a small set of industries in which the high market share (specialist) auditor has a dominant position. This leads us to conclude that the available evidence is more supportive of the hypothesis that high-market share firms are extracting rents than the hypothesis that these auditors are providing a quality differentiated product

    Morphology and processing of aligned carbon nanotube carbon matrix nanocomposites

    Get PDF
    Intrinsic and scale-dependent properties of carbon nanotubes (CNTs) have led aligned CNT architectures to emerge as promising candidates for next-generation multifunctional applications. Enhanced operating regimes motivate the study of CNT-based aligned nanofiber carbon matrix nanocomposites (CNT A-CMNCs). However, in order to tailor the material properties of CNT A-CMNCs, porosity control of the carbon matrix is required. Such control is usually achieved via multiple liquid precursor infusions and pyrolyzations. Here we report a model that allows the quantitative prediction of the CNT A-CMNC density and matrix porosity as a function of number of processing steps. The experimental results indicate that the matrix porosity of A-CMNCs comprised of ∼1% aligned CNTs decreased from ∼61% to ∼55% after a second polymer infusion and pyrolyzation. The model predicts that diminishing returns for porosity reduction will occur after 4 processing steps (matrix porosity of ∼51%), and that >10 processing steps are required for matrix porosity <50%. Using this model, prediction of the processing necessary for the fabrication of liquid precursor derived A-CMNC architectures, with possible application to other nanowire/nanofiber systems, is enabled for a variety of high value applications.National Science Foundation (U.S.) (Grant CMMI-1130437

    GMODWeb: a web framework for the generic model organism database

    Get PDF
    ABSTRACT: The Generic Model Organism Database (GMOD) initiative provides species-agnostic data models and software tools for representing curated model organism data. Here we describe GMODWeb, a GMOD project designed to speed the development of Model Organism Database (MOD) websites. Sites created with GMODWeb provide integration with other GMOD tools and allow users to browse and search through a variety of data types. GMODWeb was built using the open source Turnkey web framework and is available from http://turnkey.sourceforge.net

    Trapping Records of Fruit Fly Pest Species (Diptera: Tephritidae) on Oahu (Hawaiian Islands): Analysis of Spatial Population Trends

    Get PDF
    Fruit fly monitoring traps with male lures (cue-lure, methyl eugenol, trimedlure, latilure) and food lure (torula yeast and BioLure) were maintained on the island of Oahu for three years (2006–2008) at 40 sites, characterized as rural or residential, with or without agriculture or feral forest in proximity. The 1.7 million flies collected belonged to species already known to be established in Hawaii (Bactrocera cucurbitae, B. dorsalis, B. latifrons, and Ceratitis capitata); no new invasive species were trapped, though the remotely possible presence of sibling species nearly identical to B. dorsalis can’t be ruled out. B. cucurbitae was predominant in leeward western Oahu and most abundant, in both rural and residential areas, wherever agriculture was practiced nearby. B. dorsalis was trapped in highest numbers in the windward northeastern portion of Oahu, and the presence of adjacent forest increased captures in both residential and rural environments. C. capitata was trapped in very large numbers at a coffee farm in Waialua and was rare at all other sites

    Process-morphology scaling relations quantify self-organization in capillary densified nanofiber arrays

    Get PDF
    Capillary-mediated densification is an inexpensive and versatile approach to tune the application-specific properties and packing morphology of bulk nanofiber (NF) arrays, such as aligned carbon nanotubes. While NF length governs elasto-capillary self-assembly, the geometry of cellular patterns formed by capillary densified NFs cannot be precisely predicted by existing theories. This originates from the recently quantified orders of magnitude lower than expected NF array effective axial elastic modulus (E), and here we show via parametric experimentation and modeling that E determines the width, area, and wall thickness of the resulting cellular pattern. Both experiments and models show that further tuning of the cellular pattern is possible by altering the NF-substrate adhesion strength, which could enable the broad use of this facile approach to predictably pattern NF arrays for high value applications.United States. National Aeronautics and Space Administration (Grant NNX17AJ32G
    corecore