512 research outputs found

    Food insecurity and dietary intake among US youth, 2007–2010

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137588/1/ijpo12044.pd

    Quantum effective potential, electron transport and conformons in biopolymers

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    In the Kirchhoff model of a biopolymer, conformation dynamics can be described in terms of solitary waves, for certain special cross-section asymmetries. Applying this to the problem of electron transport, we show that the quantum effective potential arising due to the bends and twists of the polymer enables us to formalize and quantify the concept of a {\it conformon} that has been hypothesized in biology. Its connection to the soliton solution of the cubic nonlinear Schr\"{o}dinger equation emerges in a natural fashion.Comment: to appear in J. Phys.

    Social Workers' Attitudes Towards Public Accountability

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    The public demand for accountability of human services has been increasing in the United States. Despite the growing importance of public accountability as a special responsibility of social workers, little information is available in U.S. on how these pro fessionals react to the implementation of accountability programs. The survey reported in this paper was made to explore the attitudes of social workers in U.S. hospitals toward PSRO, a nationwide health care service review system. The paper presents a descriptive overview of significant aspects of American social workers' personal attitudes toward various issues of current concern about this accountability system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67090/2/10.1177_002087288402700307.pd

    Measurement of Spin Correlation Parameters ANN_{NN}, ASS_{SS}, and A_SL{SL} at 2.1 GeV in Proton-Proton Elastic Scattering

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    At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for ANN_{NN}, ASS_{SS}, and A_SL{SL} for c.m. scattering angles between 30o^o and 90o^o. Our data on ASS_{SS} -- the first measurement of this observable above 800 MeV -- clearly disagrees with predictions of available of pp scattering phase shift solutions while ANN_{NN} and A_SL{SL} are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced.Comment: 4 pages, 4 figure

    Implications of sperm banking for health-related quality of life up to 1 year after cancer diagnosis.

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    Sperm banking is recommended for all men diagnosed with cancer where treatment is associated with risk of long-term gonadatoxicity, to offer the opportunity of fatherhood and improved quality of life. However, uptake of sperm banking is lower than expected and little is known about why men refuse. Our aims were to determine: (i) demographic and medical variables associated with decisions about banking and (ii) differences in quality of life between bankers and non-bankers at diagnosis (Time 1 (T1)) and 1 year later (Time 2 (T2))

    GG-Strands

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    A GG-strand is a map g(t,s):R×RGg(t,{s}):\,\mathbb{R}\times\mathbb{R}\to G for a Lie group GG that follows from Hamilton's principle for a certain class of GG-invariant Lagrangians. The SO(3)-strand is the GG-strand version of the rigid body equation and it may be regarded physically as a continuous spin chain. Here, SO(3)KSO(3)_K-strand dynamics for ellipsoidal rotations is derived as an Euler-Poincar\'e system for a certain class of variations and recast as a Lie-Poisson system for coadjoint flow with the same Hamiltonian structure as for a perfect complex fluid. For a special Hamiltonian, the SO(3)KSO(3)_K-strand is mapped into a completely integrable generalization of the classical chiral model for the SO(3)-strand. Analogous results are obtained for the Sp(2)Sp(2)-strand. The Sp(2)Sp(2)-strand is the GG-strand version of the Sp(2)Sp(2) Bloch-Iserles ordinary differential equation, whose solutions exhibit dynamical sorting. Numerical solutions show nonlinear interactions of coherent wave-like solutions in both cases. Diff(R){\rm Diff}(\mathbb{R})-strand equations on the diffeomorphism group G=Diff(R)G={\rm Diff}(\mathbb{R}) are also introduced and shown to admit solutions with singular support (e.g., peakons).Comment: 35 pages, 5 figures, 3rd version. To appear in J Nonlin Sc

    Cross section of the ppK+Σ+npp\to K^+\Sigma^+n reaction close to threshold

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    We have measured inclusive data on K+K^+-meson production in pppp collisions at COSY J\"ulich close to the hyperon production threshold and determined the hyperon-nucleon invariant mass spectra. The spectra were decomposed into three parts: Λp\Lambda p, Σ0p\Sigma^0p and Σ+n\Sigma^+n. The cross section for the Σ+n\Sigma^+n channel was found to be much smaller than a previous measurement in that excess energy region. The data together with previous results at higher energies are compatible with a phase space dependence.Comment: accepted by Phys. lett. B some typos correcte

    High resolution study of the Lambda p final state interaction in the reaction p + p -> K+ + (Lambda p)

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    The reaction pp -> K+ + (Lambda p) was measured at Tp=1.953 GeV and Theta = 0 deg with a high missing mass resolution in order to study the Lambda p final state interaction. The large final state enhancement near the Lambda p threshold can be described using the standard Jost-function approach. The singlet and triplet scattering lengths and effective ranges are deduced by fitting simultaneously the Lambda p invariant mass spectrum and the total cross section data of the free Lambda p scattering.Comment: submitted to Physics Letters B, 10 pages, 3 figure

    A Precision Measurement of pp Elastic Scattering Cross Sections at Intermediate Energies

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    We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range 30θc.m.9030 \leq \theta_{c.m.} \leq 90 deg. Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Comment: 23 pages 29 figure
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