27,240 research outputs found

    New host records of chewing lice (Mallophaga) on birds in Florida 2

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    This is a continuation of Holt (2004). Methods and sources of specimens are as reported in that paper. Representatives of all records below are deposited in the Florida State Collection of Arthropods and/or the author's collection

    New host records of chewing lice (Mallophaga) on birds in Florida 3

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    Here, I report some new county and Florida host records as well as two new U.S. host records for avian lice. County records for avian lice are less significant than the host records themselves. Considering that most avian lice are host specific, the county records should resemble the area the host would most likely be encountered. The main source of material for this publication has been the Marathon Wildlife Rehabilitation Center in Marathon, Monroe County, Florida, with Kelly Grinter as the official curator and keeper. The center takes in about 90 different species of birds per year. The following is a list of the avian lice species, hosts, and localities with collection dates. All of the following specimens were collected by the author, Kelly Grinter, or Leslie Straub. Representatives of all records below are deposited in the Florida State Collection of Arthropods and/or the author’s collection

    New county records of chewing lice (Mallophaga) on birds in Florida

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    County records for avian lice are less significant than the host records themselves. Considering that most avian lice are host specific, the county records should resemble the area the host would most likely be encountered. Nonetheless, the list cited in Forrester and Spalding (2003) contains few and spotty county records. The main source of material for this publication has been the Marathon Wildlife Rehabilitation Center in Marathon, Monroe Co., Florida. The center takes in specimens of about 90 species of birds per year. The following is a list of the avian lice species, hosts, and localities with collection dates. All specimens were collected by Kelly Grinter, Leslie Straub, or the author. Representative specimens are deposited in the Florida State Collection of Arthropods and/or the author\u27s collection

    Three-body forces and proton-rich nuclei

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    We present the first study of three-nucleon (3N) forces for proton-rich nuclei along the N=8 and N=20 isotones. Our results for the ground-state energies and proton separation energies are in very good agreement with experiment where available, and with the empirical isobaric multiplet mass equation. We predict the spectra for all N=8 and N=20 isotones to the proton dripline, which agree well with experiment for 18Ne, 19Na, 20Mg and 42Ti. In all other cases, we provide first predictions based on nuclear forces. Our results are also very promising for studying isospin symmetry breaking in medium-mass nuclei based on chiral effective field theory.Comment: 5 pages, 4 figures, minor changes, published versio

    Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes

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    We study excited-state properties of neutron-rich calcium isotopes based on chiral two- and three-nucleon interactions. We first discuss the details of our many-body framework, investigate convergence properties, and for two-nucleon interactions benchmark against coupled-cluster calculations. We then focus on the spectroscopy of 47-56Ca, finding that with both 3N forces and an extended pfg9/2 valence space, we obtain a good level of agreement with experiment. We also study electromagnetic transitions and find that experimental data are well described by our calculations. In addition, we provide predictions for unexplored properties of neutron-rich calcium isotopes.Comment: 15 pages, 22 figures, published versio

    Neutrinoless double-beta decay matrix elements in large shell-model spaces with the generator-coordinate method

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    We use the generator-coordinate method with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-beta decay of 48^{48}Ca, 76^{76}Ge, and 82^{82}Se. We work in one major shell for the first isotope, in the f5/2pg9/2f_{5/2}pg_{9/2} space for the second and third, and finally in two major shells for all three. Our coordinates include not only the usual axial deformation parameter β\beta, but also the triaxiality angle γ\gamma and neutron-proton pairing amplitudes. In the smaller model spaces our matrix elements agree well with those of full shell-model diagonalization, suggesting that our Hamiltonian-based GCM captures most of the important valence-space correlations. In two major shells, where exact diagonalization is not currently possible, our matrix elements are only slightly different from those in a single shell.Comment: 8 pages, 7 figure

    Nuclear forces and their impact on neutron-rich nuclei and neutron-rich matter

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    We review the impact of nuclear forces on matter at neutron-rich extremes. Recent results have shown that neutron-rich nuclei become increasingly sensitive to three-nucleon forces, which are at the forefront of theoretical developments based on effective field theories of quantum chromodynamics. This includes the formation of shell structure, the spectroscopy of exotic nuclei, and the location of the neutron dripline. Nuclear forces also constrain the properties of neutron-rich matter, including the neutron skin, the symmetry energy, and the structure of neutron stars. We first review our understanding of three-nucleon forces and show how chiral effective field theory makes unique predictions for many-body forces. Then, we survey results with three-nucleon forces in neutron-rich oxygen and calcium isotopes and neutron-rich matter, which have been explored with a range of many-body methods. Three-nucleon forces therefore provide an exciting link between theoretical, experimental and observational nuclear physics frontiers.Comment: 28 pages, 13 figures, 1 tabl

    Prediction and analysis of long-term variability of temperature and salinity in the Irish Sea

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    The variability of temperature and salinity in the Irish Sea over the 40 year period 1960 - 1999 is investigated using a free-running fine-resolution local area model. The skill of the model to represent observed temperature and salinity variability is assessed using conductivity-temperature-depth survey data ( 3397 profiles) and a long time series of measurements from Cypris station (southwest of Isle of Man). This clearly demonstrates that the model can reproduce the observed seasonal and longer-term cycles in temperature, with mean and RMS errors of - 0.01 degrees C and 0.78 degrees C. Particularly apparent is the long-term warming trend at Cypris station and throughout the model domain. Model estimates of salinity are less accurate and are generally too saline (mean and RMS errors are 0.79 and 0.98 practical salinity units). Inaccuracies are likely to arise from boundary conditions and forcing (riverine and surface). However, while absolute values are not particularly well represented, the model reproduces many of the trends in the salinity variability observed at Cypris station, suggesting that the dominant physical processes in the Irish Sea, with timescales up to similar to 3 years, are well represented. The model is also used to investigate the variability in temperature stratification. While stratification is confined to approximately the same geographical area in each year of the simulation, there is significant variability in the timing of the onset and breakdown of stratification and in the peak surface to bed temperature difference. Together, these results suggest that a local area model with limited boundary conditions may be sufficiently accurate for climatic investigation of some (locally forced) parameter
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