4,588 research outputs found

    The Power of Posner: A Study of Prestige and Influence in the Federal Judiciary

    Get PDF
    Some judges have a disproportionate influence over the American judiciary; existing research has shown Judge Richard Posner is one of those judges. Our goal was to identify and determine how Judge Posner’s influence has changed over time. To measure and track his influence, we collected and compared citation and invocation data from three distinct time frames. While these measurements are imperfect, they can help illustrate the level of influence and prestige Judge Posner enjoys. The existing literature led us to expect Judge Posner’s early citation rates to be low. After several years on the bench, the citation rates for each opinion should rise dramatically. By contrast, Judge Posner’s citation rates are exceptionally high from the outset while more recent opinions actually have lower citation rates

    Emergence of a Dynamic Super-Structural Order Integrating Antiferroelectric and Antiferrodistortive Competing Instabilities in EuTiO3

    Full text link
    Microscopic structural instabilities of EuTiO3 single crystal were investigated by synchrotron x-ray diffraction. Antiferrodistortive (AFD) oxygen octahedral rotational order was observed alongside Ti derived antiferroelectric (AFE) distortions. The competition between the two instabilities is reconciled through a cooperatively modulated structure allowing both to coexist. The electric and magnetic field effect on the modulated AFD order shows that the origin of large magnetoelectric coupling is based upon the dynamic equilibrium between the AFD - antiferromagnetic interactions versus the electric polarization - ferromagnetic interactions

    Analysis of Observed Contamination Through SAGE III's First Year on Orbit

    Get PDF
    SAGE III is a payload on the International Space Station that conducts measurements of ozone and other atmospheric constituents through the use of a moderate resolution spectrometer with an operating wavelength range of 290 nm to 1550 nm. Because of the optically sensitive nature of the payload, a suite of eight Thermoelectric Quartz Crystal Microbalances (TQCMs) were included to monitor the operating environment. During the rst year of operation, the SAGE III TQCMs were instrumental in detecting several periods of higher contamination and localizing their sources. A clear window made from quartz crystal covers the instrument assembly's aperture. Under nominal operating conditions, this window is only open during science gathering activities. However, if the rates of contamination accumulation are detected to be above the background rate, the window will be kept closed during science gathering to protect the optically sensitive instrument mirror. An analysis of the signal transmissions through the window for the wavelengths of 290 nm to 1550 nm has been conducted to determine any possible degradation of the window and potential in uence on science data collected to date, and established a baseline for future analysis

    Spectral classification of photometrically selected AGB candidates in NGC 6822

    Get PDF
    © 2014 ESO. Reproduced with permission from Astronomy & Astrophysics. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.Context. The ratio of C- and M-type asymptotic giant branch (AGB) stars is commonly used to estimate the metallicity of extragalactic populations. Sources in the AGB population must therefore be accurately classified as either C- or M-type. Spectroscopic data are presented for candidate C- and M-type AGB stars, previously classified using JHK photometry, in the Local Group dwarf galaxy NGC 6822. Aims. This paper aims to evaluate the success of the JHK classification criteria used in order to determine the level of error associated with this method, and to refine the criteria for future studies. The success rate of a second independent method of source classification, the CN–TiO method, is also examined. We also review the validity of the 4 kpc radial limit imposed in our previous work. Methods. Spectra of 323 sources, distributed across an area of 2 deg2, were taken using the AAOmega multi-fibre spectrograph on the Anglo-Australian Telescope and have been classified using an automated classification system and spectral standards from the literature. Nearly half (135) of these sources were selected in common with a photometric catalogue that relied on the CN–TiO method. Results. Within this sample we were able to classify 158 sources, including 82 C-type giants and one anomalous M-type giant, all members of NGC 6822, and 75 foreground K- and M-type dwarf sources. All but three of the giant sources are located within 3 kpc of the galactic centre. Using this spectroscopic sample, new JHK photometric criteria for the isolation and classification of C- and M-type AGB stars have been derived. The error rate in the CN–TiO method, arising from stars incorrectly classified as C-type, has been estimated to be ~7%. Conclusions. Based on the new JHK classification criteria, revised estimates of the global C/M ratio, 0.95 ± 0.04, and iron abundance, −1.38 ± 0.06 dex, are presented for NGC 6822.Peer reviewe

    Corn and Soybean Potassium Uptake, Removal with Harvest, and Recycling to the Soil

    Get PDF
    Research has been conducted at the ISU Northeast Research Farm for many years to study potassium (K) fertilization rates and placement methods on corn and soybean grain yield, K uptake, and soil-test K values. However, no research has investigated K recycling to the soil from maturing plants and crop residue until the next crop is planted. Because all plant K is soluble in water, the amount and the timing of the K recycled to the soil should have a significant early impact on soil-test K values, and should explain a great deal of usually very high soil-test K temporal variability. Therefore, plots of several field K trials at this farm were used to investigate these issues

    The Rotation of the halo of NGC 6822 from the radial velocities of carbon stars

    Get PDF
    © The Authors 2016. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Using spectra taken with the AAOmega spectrograph, we measure the radial velocities of over 100 stars, many of which are intermediate age carbon stars, in the direction of the dwarf irregular galaxy NGC 6822. Kinematic analysis suggests that the carbon stars in the sample are associated with NGC 6822, and estimates of its radial velocity and galactic rotation are made from a star-by-star analysis of its carbon star population. We calculate a heliocentric radial velocity for NGC 6822 of −51±3 kms-1 and show that the population rotates with a mean rotation speed of 11.2±2.1 kms-1 at a mean distance of 1.1 kpc from the galactic centre, about a rotation axis with a position angle of 26 ∘ ±13 ∘ , as projected on the sky. This is close to the rotation axis of the HI gas disk and suggests that NGC 6822 is not a polar ring galaxy, but is dynamically closer to a late type galaxy. However, the rotation axis is not aligned with the minor axis of the AGB isodensity profiles and this remains a mystery.Peer reviewe

    Nutrient uptake by corn and soybean, removal, and recycling with crop residue

    Get PDF
    The prevailing phosphorus (P) and potassium (K) management system in Iowa and the Midwest is based on soil testing, response-based fertilizer application for low-testing soils, and removal-based fertilizer application to maintain desirable soil-test P (STP) and soil-test K (STK) values. Several issues are important for an effective implementation of this management concept. These include use of appropriate soil-test methods and field calibrations to determine optimum soil-test levels and fertilization rates, knowledge of fertilization and cropping impacts on soil-test values over time, and reliable estimates of P and K removal with harvest. In Iowa, continued research during the last two decades has provided calibrations for various soil-test methods for P and K, which have been used for existing soil-test interpretations in Iowa State University (ISU) Extension publication PM 1688. This publication also suggests to use estimates of P and K removal to maintain optimum STP and STK values, assuming there is a good relationship between P and K removal and STP or STK trends over time. Research during the last two decades has shown large temporal variability of yield and both STK and STP but very large for STK. Therefore, better study of the relationship between P or K removal and STP or STK in the short term and long term should be useful to improve the effectiveness of P and K management for crop production and to maintain acceptable water quality in Iowa

    Southern Ocean Overturning Compensation in an Eddy-Resolving Climate Simulation

    Get PDF
    The Southern Ocean’s Antarctic Circumpolar Current (ACC) and meridional overturning circulation (MOC) response to increasing zonal wind stress is, for the first time, analyzed in a high-resolution (0.1° ocean and 0.25° atmosphere), fully coupled global climate simulation using the Community Earth System Model. Results from a 20-yr wind perturbation experiment, where the Southern Hemisphere zonal wind stress is increased by 50% south of 30°S, show only marginal changes in the mean ACC transport through Drake Passage—an increase of 6% [136–144 Sverdrups (Sv; 1 Sv ≡ 10^6 m^3 s^(−1))] in the perturbation experiment compared with the control. However, the upper and lower circulation cells of the MOC do change. The lower cell is more affected than the upper cell with a maximum increase of 64% versus 39%, respectively. Changes in the MOC are directly linked to changes in water mass transformation from shifting surface isopycnals and sea ice melt, giving rise to changes in surface buoyancy forcing. The increase in transport of the lower cell leads to upwelling of warm and salty Circumpolar Deep Water and subsequent melting of sea ice surrounding Antarctica. The MOC is commonly supposed to be the sum of two opposing components: a wind- and transient-eddy overturning cell. Here, the transient-eddy overturning is virtually unchanged and consistent with a large-scale cancellation of localized regions of both enhancement and suppression of eddy kinetic energy along the mean path of the ACC. However, decomposing the time-mean overturning into a time- and zonal-mean component and a standing-eddy component reveals partial compensation between wind-driven and standing-eddy components of the circulation

    Identification of polymorphic genes for use in assemblage B genotyping assays through comparative genomics of multiple assemblage B Giardia duodenalis isolates

    Get PDF
    Giardia duodenalis assemblage B is potentially a zoonotic parasite. The characterisation and investigation of isolates has been hampered by greater genetic diversity of assemblage B, limiting the application and utility of current genotyping loci. Since whole genome sequencing is the optimal high-throughput method for gene identification, the present study sequenced assemblage B isolate BAH15c1 and compared the sequence to the draft GS references to identify polymorphic genes for potential use in genotyping assays. The majority of the genome sequence was conserved between the two isolates, producing 508 contigs of 10.4 Mb with 4968 genes. Seventy polymorphic genes for potential use in genotyping assays were identified ranging in variation from elongation factor 1 α, which was the most conserved, through to triose phosphate isomerase, which was the most variable
    • …
    corecore