814 research outputs found

    Preference and Nutrition of Quail Breeder 16, Common Agricultural Feeds, and a Mix of Native Seeds as Northern Bobwhite Food

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    Agricultural feeds are commonly dispersed along roads or in openings as an attractant or dietary supplement for northern bobwhites (Colinus virginianus). Quail Breeder 16e is a pelletized ration specifically developed by Lyssy & Eckel Feeds for breeding bobwhites to maximize nutritive content of diets. Captive bobwhites were used to examine relative preference of the pellets, sorghum, corn, soybean, and a mix of seeds of 8 native plant species. Protein, fat, acid detergent fiber, gross energy, and mineral content of the feeds were measured and we examined changes in body mass of bobwhites fed exclusive diets of each of the five feeds. A Latin rectangle experimental design with single and multiple-offer treatments was used to compare feed preference. Sorghum was most highly preferred in both the single and multiple offering experiments. Soybeans and the pelletized ration were least preferred. The native seed mix and corn were intermediate in preference. Nutritionally, soybeans had the highest protein (40%), highest fat (19%), and highest gross energy (21 kJ/g). Bobwhites fed exclusive diets of the native seed mix exhibited the greatest increase in body mass (40%), and birds fed the sorghum diet had the greatest decrease in body mass ( 8%). Providing supplements (pelletized rations and agricultural feeds) should not take precedence over managing bobwhite habitat to produce a variety of native grasses and forbs when improving bobwhite nutrition is a management objective

    A novel MC1R allele for black coat colour reveals the Polynesian ancestry and hybridization patterns of Hawaiian feral pigs

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    Pigs (Sus scrofa) have played an important cultural role in Hawaii since Polynesians first introduced them in approximately AD 1200. Additional varieties of pigs were introduced following Captain Cook’s arrival in Hawaii in 1778 and it has been suggested that the current pig population may descend primarily, or even exclusively, from European pigs. Although populations of feral pigs today are an important source of recreational hunting on all of the major islands, they also negatively impact native plants and animals. As a result, understanding the origins of these feral pig populations has significant ramifications for discussions concerning conservation management, identity and cultural continuity on the islands. Here, we analysed a neutral mitochondrial marker and a functional nuclear coat colour marker in 57 feral Hawaiian pigs. Through the identification of a new mutation in the MC1R gene that results in black coloration, we demonstrate that Hawaiian feral pigs are mostly the descendants of those originally introduced during Polynesian settlement, though there is evidence for some admixture. As such, extant Hawaiian pigs represent a unique historical lineage that is not exclusively descended from feral pigs of European originPeer reviewe

    A Compressed Sensing Approach to 3D Weak Lensing

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    (Abridged) Weak gravitational lensing is an ideal probe of the dark universe. In recent years, several linear methods have been developed to reconstruct the density distribution in the Universe in three dimensions, making use of photometric redshift information to determine the radial distribution of lensed sources. In this paper, we aim to address three key issues seen in these methods; namely, the bias in the redshifts of detected objects, the line of sight smearing seen in reconstructions, and the damping of the amplitude of the reconstruction relative to the underlying density. We consider the problem under the framework of compressed sensing (CS). Under the assumption that the data are sparse in an appropriate dictionary, we construct a robust estimator and employ state-of-the-art convex optimisation methods to reconstruct the density contrast. For simplicity in implementation, and as a proof of concept of our method, we reduce the problem to one-dimension, considering the reconstruction along each line of sight independently. Despite the loss of information this implies, we demonstrate that our method is able to accurately reproduce cluster haloes up to a redshift of z=1, deeper than state-of-the-art linear methods. We directly compare our method with these linear methods, and demonstrate minimal radial smearing and redshift bias in our reconstructions, as well as a reduced damping of the reconstruction amplitude as compared to the linear methods. In addition, the CS framework allows us to consider an underdetermined inverse problem, thereby allowing us to reconstruct the density contrast at finer resolution than the input data.Comment: Submitted to A&A (6 July 2011

    Mass segregation in young compact star clusters in the Large Magellanic Cloud: I. Data and Luminosity Functions

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    We have undertaken a detailed analysis of HST/WFPC2 and STIS imaging observations, and of supplementary wide-field ground-based observations obtained with the NTT of two young ~10-25 Myr) compact star clusters in the LMC, NGC 1805 and NGC 1818. The ultimate goal of our work is to improve our understanding of the degree of primordial mass segregation in star clusters. This is crucial for the interpretation of observational luminosity functions (LFs) in terms of the initial mass function (IMF), and for constraining the universality of the IMF. We present evidence for strong luminosity segregation in both clusters. The LF slopes steepen with cluster radius; in both NGC 1805 and NGC 1818 the LF slopes reach a stable level well beyond the clusters' core or half-light radii. In addition, the brightest cluster stars are strongly concentrated within the inner ~4 R_hl. The global cluster LF, although strongly nonlinear, is fairly well approximated by the core or half-light LF; the (annular) LFs at these radii are dominated by the segregated high-luminosity stars, however. We present tentative evidence for the presence of an excess number of bright stars surrounding NGC 1818, for which we argue that they are most likely massive stars that have been collisionally ejected from the cluster core. We therefore suggest that the cores of massive young stars clusters undergo significant dynamical evolution, even on time-scales as short as ~25 Myr.Comment: 19 pages, incl. 10 embedded postscript figures, MNRAS, resubmitted (referee's comments included

    ACR guidance document on MR safe practices: 2013

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    Because there are many potential risks in the MR environment and reports of adverse incidents involving patients, equipment and personnel, the need for a guidance document on MR safe practices emerged. Initially published in 2002, the ACR MR Safe Practices Guidelines established de facto industry standards for safe and responsible practices in clinical and research MR environments. As the MR industry changes the document is reviewed, modified and updated. The most recent version will reflect these changes. J. Magn. Reson. Imaging 2013;37:501–530. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96674/1/24011_ftp.pd

    Measurement of the Spectral Shape of the beta-decay of 137Xe to the Ground State of 137Cs in EXO-200 and Comparison with Theory

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    We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden non-unique β\beta-decay transition ^{137}\textrm{Xe}(7/2^-)\to\,^{137}\textrm{Cs}(7/2^+). The experimental data were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultra-low background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal-to-background ratio of more than 99-to-1 in the energy range from 1075 to 4175 keV. In addition to providing a rare and accurate measurement of the first-forbidden non-unique β\beta-decay shape, this work constitutes a novel test of the calculated electron spectral shapes in the context of the reactor antineutrino anomaly and spectral bump.Comment: Version as accepted by PR

    Universal Rights and Wrongs

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    This paper argues for the important role of customers as a source of competitive advantage and firm growth, an issue which has been largely neglected in the resource-based view of the firm. It conceptualizes Penrose’s (1959) notion of an ‘inside track’ and illustrates how in-depth knowledge about established customers combines with joint problem-solving activities and the rapid assimilation of new and previously unexploited skills and resources. It is suggested that the inside track represents a distinct and perhaps underestimated way of generating rents and securing long-term growth. This also implies that the sources of sustainable competitive advantage in important respects can be sought in idiosyncratic interfirm relationships rather than within the firm itself

    Work-Unit Absenteeism: Effects of Satisfaction, Commitment, Labor Market Conditions, and Time

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    Prior research is limited in explaining absenteeism at the unit level and over time. We developed and tested a model of unit-level absenteeism using five waves of data collected over six years from 115 work units in a large state agency. Unit-level job satisfaction, organizational commitment, and local unemployment were modeled as time-varying predictors of absenteeism. Shared satisfaction and commitment interacted in predicting absenteeism but were not related to the rate of change in absenteeism over time. Unit-level satisfaction and commitment were more strongly related to absenteeism when units were located in areas with plentiful job alternatives
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