965 research outputs found

    Measurement of the Absolute Differential Cross Section for np Elastic Scattering at 194 MeV

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    A tagged medium-energy neutron beam has been used in a precise measurement of the absolute differential cross section for np back-scattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with 1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.Comment: 22 pages, 21 figures, submitted for publication in Physical Review

    Measurement of the Absolute np Scattering Differential Cross Section at 194 MeV

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    We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np back-scattering to better than 2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle-dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial wave analyses (PWA). The present results are in good accord with the PWA, but deviate systematically from other recent measurements.Comment: 4 pages, 4 figure

    A Calibration of the K600 FPP from 120 to 200 MeV

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    A Coincidence Measurement of D_NN' for p+p Elastic Scattering at T_p = 200 MeV

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    Oral Long-Term Complications of Allogeneic Haematopoietic Stem Cell Transplantation

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    INTRODUCTION: Kinesin superfamily (KIF) genes encode motor proteins that have fundamental roles in brain functioning, development, survival and plasticity by regulating the transport of cargo along microtubules within axons, dendrites and synapses. Mouse knockout studies support these important functions in the nervous system. The role of KIF genes in intellectual disability (ID) has so far received limited attention, although previous studies have suggested that many ID genes impinge on synaptic function. METHODS: By applying next-generation sequencing (NGS) in ID patients, we identified likely pathogenic mutations in KIF4A and KIF5C. To further confirm the pathogenicity of these mutations, we performed functional studies at the level of synaptic function in primary rat hippocampal neurons. RESULTS AND CONCLUSIONS: Four males from a single family with a disruptive mutation in the X-linked KIF4A (c.1489-8_1490delins10; p.?- exon skipping) showed mild to moderate ID and epilepsy. A female patient with a de novo missense mutation in KIF5C (c.11465A>C; p.(Glu237Lys)) presented with severe ID, epilepsy, microcephaly and cortical malformation. Knock-down of Kif4a in rat primary hippocampal neurons altered the balance between excitatory and inhibitory synaptic transmission, whereas the mutation in Kif5c affected its protein function at excitatory synapses. Our results suggest that mutations in KIF4A and KIF5C cause ID by tipping the balance between excitatory and inhibitory synaptic excitability

    A Measurement of the Spin Transfer Observable D_NN' for p+p Elastic Scattering at T_p = 200MeV

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    This research was sponsored by the National Science Fooundation Grant NSF PHY-931478

    Relativistic MHD with Adaptive Mesh Refinement

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    This paper presents a new computer code to solve the general relativistic magnetohydrodynamics (GRMHD) equations using distributed parallel adaptive mesh refinement (AMR). The fluid equations are solved using a finite difference Convex ENO method (CENO) in 3+1 dimensions, and the AMR is Berger-Oliger. Hyperbolic divergence cleaning is used to control the B=0\nabla\cdot {\bf B}=0 constraint. We present results from three flat space tests, and examine the accretion of a fluid onto a Schwarzschild black hole, reproducing the Michel solution. The AMR simulations substantially improve performance while reproducing the resolution equivalent unigrid simulation results. Finally, we discuss strong scaling results for parallel unigrid and AMR runs.Comment: 24 pages, 14 figures, 3 table

    Amine functionalization of cholecyst-derived extracellular matrix with generation 1 PAMAM dendrimer

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    This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Biomacromolecules, copyright © American Chemical Society after peer review. To access the final edited and published work, see http://pubs.acs.org/doi/pdf/10.1021/bm701055k.A method to functionalize cholecyst-derived extracellular matrix (CEM) with free amine groups was established in an attempt to improve its potential for tethering of bioactive molecules. CEM was incorporated with Generation-1 polyamidoamine (G1 PAMAM) dendrimer by using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide and N-hydroxysuccinimide cross-linking system. The nature of incorporation of PAMAM dendrimer was evaluated using shrink temperature measurements, Fourier transform infrared (FTIR) assessment, ninhydrin assay, and swellability. The effects of PAMAM incorporation on mechanical and degradation properties of CEM were evaluated using a uniaxial mechanical test and collagenase degradation assay, respectively. Ninhydrin assay and FTIR assessment confirmed the presence of increasing free amine groups with increasing quantity of PAMAM in dendrimer-incorporated CEM (DENCEM) scaffolds. The amount of dendrimer used was found to be critical in controlling scaffold degradation, shrink temperature, and free amine content. Cell culture studies showed that fibroblasts seeded on DENCEM maintained their metabolic activity and ability to proliferate in vitro. In addition, fluorescence cell staining and scanning electron microscopy analysis of cell-seeded DENCEM showed preservation of normal fibroblast morphology and phenotype
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